Patent Application
20190062528
This invention relates to compositions and medical devices comprising anti-microbial active particles, for inhibiting microbial growth. This invention further provides methods of making such compositions and medical devices.
The overwhelming diversity of bacteria in one individual's skin, gastro intestinal tract and oral cavity is well documented, demonstrating a complex ecosystem anatomically and dynamically in which poly-microbial biofilms are the norm.
Biofilms formed on tissues outside and inside the organism are the major cause of infectious diseases. For example in the oral cavity, biofilm formed on dental hard or soft tissue are the major cause of caries and periodontal disease (Sbordone L., Bortolaia C., Clin Oral Investig 2003; 7:181-8). Bacterial biofilm forms on both natural and artificial surfaces.
Special attention is paid in recent years to artificial surfaces contacting organisms, as these surfaces lack the epithelial shedding, a major natural mechanism to combat biofilms, thus biofilm accumulation is becoming a major source of medical problems that may result in life threatening complications. Two major factors influence the susceptibility of a surface to accumulate bacteria: surface roughness and the surface-free energy which is a property of the material used. Surface roughness has a higher influence on the adhesion of bacteria than surface-free energy. In this context, artificial restorative materials typically have a higher surface roughness than natural surfaces, and therefore are more prone to bacterial accumulation. Therefore, the development of new materials that diminishes biofilm formation is a critical topic.
The ultimate goal of the development of materials with antibiofilm properties is to improve health and reduce disease occurrence. None of the existing medical devices can guarantee immediate and comprehensive elimination of biofilm or prevention of secondary infection.
For example, in order to sustain the oral defense, dental materials with the following antibiofilm properties are sought after: (1) inhibition of initial binding of microorganisms (2) preventing biofilm growth, (3) affecting microbial metabolism in the biofilm, (4) killing biofilm bacteria, and (5) detaching biofilm (Busscher H J. Rinastiti M, Siswomihardjo W, van der Mei H C., J Dent Res, 2010; 89:657-65; Marsh P D. J Dent, 2010; 38).
Resin-based composites are complex dental materials that consist of a hydrophobic resin matrix and less hydrophobic filler particles, which implies that a resin-based composite surface is never a homogeneous interface but rather one that produces matrix-rich and filler-poor areas, as well as matrix-poor and filler-rich areas (lonescu A, Wutscher E, Brambilla E, Schneider-Feyrer S, Giessibl F J, Hahnel S.; Eur J Oral Sci 2012:120:458-65).
Biofilms on composites can cause surface deterioration. Polishing, as well as differences in the composition of the resin-based composite, may have an impact on biofilm formation on the resin-based composite surface (Ono M. et al., Dent Mater J, 2007; 26:613-22). Surface degradation of resin composites driven by polishing leads to increased roughness, changes in micro hardness, and filler particle exposure upon exposure to biofilms in vitro. Furthermore, biofilms on composites can cause surface deterioration.
There still remains a need for and it would be advantageous to have an extended variety of anti-microbial active composites, pharmaceutical compositions and medical devices which are cost-effective, non-toxic and easy to apply to contaminated surfaces.
In one embodiment, this invention is directed to a composition comprising anti-microbial particles, wherein the particles comprise:
(i) an inorganic or organic core; and
(ii) an anti-microbial active unit chemically bound to the core;
wherein the anti-microbial active unit is connected directly (via a bond) or indirectly (via a third linker) to the core;
wherein the anti-microbial active unit comprises an anti-microbial active group; and
wherein the number of the anti-microbial active groups per each anti-microbial active unit is between 1-200.
In one embodiment, this invention is directed to a medical device comprising anti-microbial particles, wherein the particles comprise:
(i) an inorganic or organic core; and
(ii) anti-microbial active unit chemically bound to the core;
wherein, the anti-microbial active unit is connected directly (via a bond) or indirectly (via a third linker) to the core;
wherein, the anti-microbial active unit comprises an anti-microbial active group; and wherein the number of the anti-microbial active groups per each anti-microbial active unit is between 1-200.
In another embodiment, the anti-microbially particle is represented by structure (1):
wherein
the core is an organic polymer or an inorganic material;
L1 is a first linker or a bond;
L2 is a second linker;
L3 is a third linker or a bond;
R1 and R1′ are each independently alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R2 and R2′ are each independently alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R3 and R3′ are each independently not present, hydrogen, alkyl, terpenoid moiety, cycloalkyl, aryl, heterocycle, a conjugated alkyl, alkenyl, alkynyl or any combination thereof; wherein if R3 or R3′ are not present, the nitrogen is not charged;
X1 and X2 is each independently a bond, alkylene, alkenylene, or alkynylene;
p defines the density of anti-microbial active unit per one sq nm (nm2) of the core surface, wherein said density is of between 0.01-20 anti-microbial units per one sq nm (nm2) of the core surface of the particle;
n1 is each independently an integer between 0 to 200;
n2 is each independently an integer between 0 to 200;
wherein n1+n2≥1; and
m is an integer between 1 to 200 and the repeating unit is the same or different.
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
against the Graham positive bacteria Staphylococcus aureus (S. aureus). The embedded particles were 186 nm in diameter on average and p=4, and the results are compared with the natural growth of S. aureus.
(SNP-Cial) against the Graham positive bacteria E. faecalis. The embedded particles were 186 nm in diameter on average and p=4, and the results are compared with the natural growth of E. faecalis.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the Figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the Figures to indicate corresponding or analogous elements.
In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that this invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure this invention.
In one embodiment, this invention is directed to a composition comprising anti-microbial particles, wherein the particles comprise:
(i) an inorganic or organic core; and
(ii) an anti-microbial active unit chemically bound to the core;
wherein the anti-microbial active unit is connected directly (via a bond) or indirectly (via a third linker) to the core;
wherein the anti-microbial active unit comprises an anti-microbial active group; and
wherein the number of the anti-microbial active groups per each anti-microbial active unit is between 1-200.
In one embodiment, this invention is directed to a composition comprising a polymeric material and anti-microbial particles, wherein the particles comprise:
(i) an inorganic or organic core; and
(ii) an anti-microbial active unit chemically bound to the core;
wherein the anti-microbial active unit is connected directly (via a bond) or indirectly (via a third linker) to the core;
wherein the anti-microbial active unit comprises comprising an anti-microbial active group; and
wherein the number of the anti-microbial active groups per each anti-microbial active unit is between 1-200.
In one embodiment, this invention is directed to a medical device comprising anti-microbial particles, wherein the particles comprise:
(i) an inorganic or organic core; and
(ii) anti-microbial active unit chemically bound to the core;
wherein, the anti-microbial active unit is connected directly (via a bond) or indirectly (via a third linker) to the core;
wherein, the anti-microbial active unit comprises an anti-microbial active group; and
wherein the number of the anti-microbial active groups per each anti-microbial active unit is between 1-200.
In some embodiments, the anti-microbial particles comprise (i) an inorganic or organic core; and (ii) an anti-microbial active part chemically bound to the core. In one embodiment, the anti-microbial active part comprises one monomeric unit. In one embodiment, the anti-microbial active part comprises more than one monomeric unit. In another embodiment, the anti-microbial active part with the more than one monomeric unit comprises more than one linker. In another embodiment, the anti-microbial active unit has between 2-200 monomeric units. In another embodiment, the anti-microbial active unit has between 2-5 monomeric units. In another embodiment, the anti-microbial active unit has between 5-10 monomeric units. In another embodiment, the anti-microbial active unit has between 10-20 monomeric units. In another embodiment, the anti-microbial active unit has between 20-50 monomeric units. In another embodiment, the anti-microbial active unit has between 50-100 monomeric units. In another embodiment, the anti-microbial active unit has between 100-200 monomeric units.
In one embodiment, the anti-microbial active unit comprises more than one monomeric unit. In another embodiment, the monomeric units are connected to each other via a first linker, a second linker or both. In another embodiment, each monomeric unit comprises an anti-microbial active group. In another embodiment, an anti-microbial active unit comprises at least one anti-microbial active group. In another embodiment, an anti-microbial active unit comprises at least two anti-microbial active groups. In another embodiment,
In some embodiment, the anti-microbial particles are presented by structure (1):
wherein
the core is an organic polymer or an inorganic material;
L1 is a first linker or a bond;
L2 is a second linker;
L3 is a third linker or a bond;
R1 and R1′ are each independently alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R2 and R2′ are each independently alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R3 and R3′ are each independently nothing/not present, hydrogen, alkyl, terpenoid moiety, cycloalkyl, aryl, heterocycle, a conjugated alkyl, alkenyl, alkynyl or any combination thereof;
wherein if R3 or R3′ are nothing/not present, the nitrogen is not charged;
X1 and X2 is each independently a bond, alkylene, alkenylene, or alkynylene;
p defines the density of anti-microbial active units per one sq nm (nm2) of the core surface, wherein said density is of between 0.01-20 anti-microbial units per one sq nm (nm2) of the core surface of the particle;
n1 is each independently an integer between 0 to 200;
n2 is each independently an integer between 0 to 200;
wherein n1+n≥1; and
m is an integer between 1 to 200 and the repeating unit is the same or different.
In some embodiments, the anti-microbial particles are represented by structure (2):
wherein
the core is an organic polymer or an inorganic material;
L1 is a first linker or a bond;
L2 is a second linker;
L3 is a third linker or a bond;
R1 and R1′ are each independently alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R2 and R2′ are each independently alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
X1 and X2 is each independently a bond, alkylene, alkenylene, or alkynylene;
p defines the density of anti-microbial active units per one sq nm (nm2) of the core surface, wherein said density is of between 0.01-20 anti-microbial units per one sq nm (nm2) of the core surface of the particle;
n1 is each independently an integer between 0 to 200;
n2 is each independently an integer between 0 to 200;
wherein n1+n2≥1;
m is an integer between 1 to 200 and the repeating unit is the same or different.
In another embodiment, the number of the anti-microbial active groups per each anti-microbial active part is at least two, i.e. n1+n2≥2 and m≥1. In another embodiment, the number of the anti-microbial active groups per each anti-microbial active part is one, i.e. n1+n2=1 and m=1.
In some embodiments, the anti-microbial particles are represented by structure (3):
wherein
the core is an organic polymer or an inorganic material;
L1 is a first linker or a bond;
L2 is a second linker;
L3 is a third linker or a bond;
R1 and R1′ are each independently alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R2 and R2′ are each independently alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
X1 and X2 is each independently a bond, alkylene, alkenylene, or alkynylene;
p defines the density of anti-microbial active units per one sq nm (nm2) of the core surface, wherein said density is of between 0.01-20 anti-microbial units per one sq nm (nm2) of the core surface of the particle;
n1 is each independently an integer between 0 to 200;
n2 is each independently an integer between 0 to 200;
wherein n1+n2≥1;
m is an integer between 1 to 200 and the repeating unit is the same or different.
In another embodiment, the number of the anti-microbial active groups per each anti-microbial active part is at least two, i.e. n1+n2≥2 and m≥1. In another embodiment, the number of the anti-microbial active groups per each anti-microbial active part is one, i.e. n1+n2=1 and m=1.
In another embodiment, the particles of structures (1) to (3) comprise one monomeric unit per one anti-microbial active unit. In another embodiment, the particles of structures (1) to (3) comprise more than one anti-microbial active group per one anti-microbial active unit.
In some embodiments, the anti-microbial particles are represented by structure (4):
wherein
the core is an organic polymer or an inorganic material;
L1 is a first linker or a bond;
L3 is a third linker or a bond;
R1 is alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R2 is alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R3 is nothing/not present, hydrogen, alkyl, terpenoid moiety, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof; wherein if R3 or R3′ are nothing/not present, the nitrogen is not charged;
X is a bond, alkyl, alkenyl, or alkynyl;
X′ is nothing or hydrogen; and
p defines the density of anti-microbial active units per one sq nm (nm2) of the core surface, wherein said density is of between 0.01-20 anti-microbial units per one sq nm (nm2) of the core surface of the particle;
wherein if L1 and X are bonds, then the nitrogen is part of the core;
wherein at least one of R1, R2, R3 is hydrophobic.
In some embodiments, the anti-microbial particles are represented by structure (5):
wherein
the core is an organic polymeric material or an inorganic material;
L1 is a first linker or a bond;
L3 is a third linker or a bond;
R1 is alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R2 is alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
X is a bond, alkyl, alkenyl or alkynyl;
X′ is nothing or hydrogen; and
p defines the density of anti-microbial active units per one sq nm (nm2) of the core surface, wherein said density is of between 0.01-20 anti-microbial units per one sq nm (nm2) of the core surface of the particle;
wherein if L1 and X are bonds, then the nitrogen is an integral part of the core;
wherein at least one of R1, R2 is hydrophobic.
In some embodiments, the anti-microbial particles are represented by structure (6):
wherein
the core is an organic polymeric material or an inorganic material;
L1 is a first linker or a bond;
L3 is a third linker or a bond;
R1 is alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R2 is alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
X is a bond, alkyl, alkenyl, or alkynyl;
X′ is nothing or hydrogen; and
p defines the density of anti-microbial active units per one sq nm (nm2) of the core surface, wherein said density is of between 0.01-20 anti-microbial units per one sq nm (nm2) of the core surface of the particle;
wherein if L1 and X are bonds, then the nitrogen is an integral part of the core;
wherein at least one of R1, R2 is hydrophobic.
Specific examples of anti-microbial particles of this invention include:
where n=1-200; “SNP” refers to the a silica core of the particles of this invention; and p defines the density of anti-microbial active units per one sq nm (nm2) of the core surface, wherein said density is of between 0.01-20 anti-microbial units per one sq nm (nm2) of the core surface of the particle. In another embodiment, n=1-3. In another embodiment, n=3-20. In another embodiment, n=20-50. In another embodiment, n=50-100. In another embodiment, n=100-200.
In some embodiments, the anti-microbial particles of structures (1) to (3) a hydrogen may or may not be present at the end of the anti-microbial active unit.
In some embodiments, the term “anti-microbial active group” and the term “monomeric anti-microbial active group” refer to the same and comprise a protonated tertiary amine, a tertiary amine or a quaternary ammonium, as represented by the following formulas:
wherein:
R1 is alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R2 is alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R3 is nothing, hydrogen, alkyl, terpenoid moiety, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof; wherein if R3 or R3′ are nothing, the nitrogen is not charged.
In another embodiment, at least one of R1, R2 or R3 is hydrophobic.
In another embodiment, the number of the anti-microbial active groups per each anti-microbial active unit is at least two, i.e. n1+n2≥2 and m≥1. In another embodiment, the number of the anti-microbial active groups per each anti-microbial active unit is one, i.e. n1+n2=1 and m=1.
In another embodiment, the particles of structures (4) to (6) comprise one monomeric unit per one anti-microbial active unit. In another embodiment, the particles of structures (1) to (3) comprise one or more than one anti-microbial active group per one anti-microbial active unit.
The anti-microbial active groups of this invention are chemically bound to the core at a surface density of at least one anti-microbial active group per 10 sq. nm of the core surface. In another embodiment at least 1 anti-microbial group per 1 sq nm of the core surface. In another embodiment between 0.001-300 anti-microbial groups per sq nm of the core surface. In another embodiment between 0.001-250 anti-microbial groups per sq nm of the core surface. In another embodiment between 0.001-200 anti-microbial groups per sq nm of the core surface. In another embodiment between 0.001-150 anti-microbial groups per sq nm of the core surface. In another embodiment between 0.001-100 anti-microbial groups per sq nm of the core surface. In another embodiment between 0.001-50 anti-microbial groups per sq nm of the core surface. In another embodiment between 0.001-20 anti-microbial groups per sq nm of the core surface. In another embodiment between 0.001-17 anti-microbial groups per sq nm of the core surface. In another embodiment between 0.001-15 anti-microbial groups per sq nm of the core surface. In another embodiment between 0.001-10 anti-microbial groups per sq nm of the core surface. In another embodiment between 0.001-4 anti-microbial groups per sq nm of the core surface. In another embodiment between 0.001-1 anti-microbial groups per sq nm of the core surface. In another embodiment between 50-100 anti-microbial groups per sq nm of the core surface. In another embodiment between 100-150 anti-microbial groups per sq nm of the core surface. In another embodiment between 150-200 anti-microbial groups per sq nm of the core surface. In another embodiment between 200-250 anti-microbial groups per sq nm of the core surface. In another embodiment between 250-300 anti-microbial groups per sq nm of the core surface. In another embodiment between 1-4 anti-microbial groups per sq nm of the core surface. In another embodiment between 1-6 anti-microbial groups per sq nm of the core surface. In another embodiment between 1-20 anti-microbial groups per sq nm of the core surface. In another embodiment between 1-10 anti-microbial groups per sq nm of the core surface. In another embodiment between 1-15 anti-microbial groups per sq nm of the core surface.
In some embodiments, the number of the anti-microbial active groups [(n1+n2)×m]per each anti-microbial active unit is between 1-200. In another embodiment, the number of the anti-microbial active groups per each anti-microbial active unit is between 1-150. In another embodiment, the number of the anti-microbial active groups per each anti-microbial active unit is between 1-100. In another embodiment, the number of the anti-microbial active groups per each anti-microbial active unit is between 1-50. In another embodiment, the number of the anti-microbial active groups per each anti-microbial active unit is between 1-30. In another embodiment, the number of the anti-microbial active groups per each anti-microbial active unit is between 1-20. In another embodiment, the number of the anti-microbial active groups per each anti-microbial active unit is between 1-10. In another embodiment, the number of the anti-microbial active groups per each anti-microbial active unit is between 50-100. In another embodiment, the number of the anti-microbial active groups per each anti-microbial active unit is between 100-150. In another embodiment, the number of the anti-microbial active unit per each anti-microbial active unit is between 150-200.
In some embodiments, the number of the monomeric units per each anti-microbial active unit is between 1-200. In another embodiment, the number of the monomeric units per each anti-microbial active unit is between 1-150. In another embodiment, the number of the monomeric units per each anti-microbial active unit is between 1-100. In another embodiment, the number of the monomeric units per each anti-microbial active unit is between 1-50. In another embodiment, the number of the monomeric units per each anti-microbial active unit is between 1-30. In another embodiment, the number of monomeric units per each anti-microbial active unit is between 1-20. In another embodiment, the number of the monomeric units per each anti-microbial active unit is between 1-10. In another embodiment, the number of the monomeric units per each anti-microbial active unit is between 50-100. In another embodiment, the number of the monomeric units per each anti-microbial active unit is between 100-150. In another embodiment, the number of the monomeric units per each anti-microbial active unit is between 150-200.
In another embodiment, the particle of structures (1) to (6) has an inorganic core. In another embodiment, the particle of structure (1) to (6) has an organic core. In another embodiment, the organic core is a polymeric organic core. In another embodiment, the core is inert. In one embodiment, the particles of this invention represented by structures (1)-(3) comprise an anti-microbial active group of —+N(R1)(R2)(R3), —+NH(R1)(R2), —N(R1)(R2)—+N(R1′)(R2′)(R3′), —+NH(R1′)(R2′) or —N(R1′)(R2′). In one embodiment R1 and/or R1′, R2 and/or R2′ and R3 and/or R3′ are the same or different and are independently alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof. In another embodiment, R1, R2 and R3 are independently an alkyl. In another embodiment, R1 and/or R1′, R2 and/or R2′ and R3 and/or R3′ are independently a terpenoid. In another embodiment, R1 and/or R1′, R2 and/or R2′ and R3 and/or R3′ are independently a cycloalkyl. In another embodiment, R1 and/or R1′, R2 and/or R2′ and R3 and/or R3′ are independently an aryl. In another embodiment, R1 and/or R1′, R2 and/or R2′ and R3 and/or R3′ are independently a heterocycle. In another embodiment, R1 and/or R1′, R2 and/or R2′ and R3 and/or R3′ are independently an alkenyl. In another embodiment, R1 and/or R1′, R2 and/or R2′ and R3 and/or R3′ are independently an alkynyl. In another embodiment, R3 is nothing. In another embodiment, R3 and/or R3′ is hydrogen. In another embodiment at least one of R1 and/or R1′, R2 and/or R2′ and R3 and/or R3′ is hydrophobic alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof. Each represents a separate embodiment of this invention.
In another embodiment R1 and R1′ are the same. In another embodiment R2 and R2′ are the same. In another embodiment R3 and R3′ are the same. In another embodiment R1 and R1′ are different. In another embodiment R2 and R2′ are different. In another embodiment R3 and R3′ are different.
As used herein, the term “alkyl” or “alkylene” refer to any linear- or branched-chain alkyl group containing up to about 24 carbons unless otherwise specified. In one embodiment, an alkyl includes C1-C3 carbons. In one embodiment, an alkyl includes C1-C4 carbons. In one embodiment, an alkyl includes C1-C5 carbons. In another embodiment, an alkyl includes C1-C6 carbons. In another embodiment, an alkyl includes C1-C8 carbons. In another embodiment, an alkyl includes C1-C10 carbons. In another embodiment, an alkyl includes C1-C12 carbons. In another embodiment, an alkyl includes C4-C8 carbons. In another embodiment, an alkyl includes C4-C10 carbons. In another embodiment, an alkyl include C4-C15 carbons. In another embodiment, an alkyl include C4-C24 carbons. In another embodiment, an alkyl includes C1-Cis carbons. In another embodiment, an alkyl includes C2-C18 carbons. In another embodiment, branched alkyl is an alkyl substituted by alkyl side chains of 1 to 5 carbons. In one embodiment, the alkyl group may be unsubstituted. In another embodiment, the alkyl group may be substituted by a halogen, haloalkyl, hydroxyl, alkoxy, carbonyl, amido, alkylamido, dialkylamido, cyano, nitro, CO2H, amino, alkylamino, dialkylamino, carboxyl, thio and/or thioalkyl. In another embodiment hydrophobic alkyl refers to an alkyl having at least four carbons. In another embodiment hydrophobic alkyl refers to a C4-C24 alkyl. In another embodiment hydrophobic alkyl refers to a C4-C8 alkyl. In another embodiment hydrophobic alkyl refers to a C4 alkyl. In another embodiment hydrophobic alkyl refers to a C5 alkyl. In another embodiment hydrophobic alkyl refers to a C6 alkyl. In another embodiment hydrophobic alkyl refers to a C7 alkyl. In another embodiment hydrophobic alkyl refers to a C8 alkyl.
As used herein, the term “aryl” refers to any aromatic ring that is directly bonded to another group and can be either substituted or unsubstituted. The aryl group can be a sole substituent, or the aryl group can be a component of a larger substituent, such as in an arylalkyl, arylamino, arylamido, etc. Exemplary aryl groups include, without limitation, phenyl, tolyl, xylyl, furanyl, naphthyl, pyridinyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, thiazolyl, oxazolyl, isooxazolyl, pyrazolyl, imidazolyl, thiophene-yl, pyrrolyl, phenylmethyl, phenylethyl, phenylamino, phenylamido, etc. Substitutions include but are not limited to: F, Cl, Br, I, C1-C5 linear or branched alkyl, C1-C5 linear or branched haloalkyl, C1-C5 linear or branched alkoxy, C1-C5 linear or branched haloalkoxy, CF3, CN, NO2, —CH2CN, NH2, NH-alkyl, N(alkyl)2, hydroxyl, —OC(O)CF3, —OCH2Ph, —NHCO-alkyl, COOH, —C(O)Ph, C(O)O-alkyl, C(O)H, or —C(O)NH2. In another embodiment hydrophobic aryl refers to aryl having at least six carbons.
The term “alkenyl” or “alkenylene” refer to a substance that includes at least two carbon atoms and at least one double bond. In one embodiment, the alkenyl has 2-7 carbon atoms. In another embodiment, the alkenyl has 2-12 carbon atoms. In another embodiment, the alkenyl has 2-10 carbon atoms. In another embodiment, the alkenyl has 3-6 carbon atoms. In another embodiment, the alkenyl has 2-4 carbon atoms. In another embodiment, the alkenyl has 4-8 carbon atoms. In another embodiment hydrophobic alkenyl refers to alkenyl having at least four carbons. In another embodiment hydrophobic alkenyl refers to a C4-C8 alkenyl.
The term “alkynyl” or “alkynylene” refers to a substance that includes at least two carbon atoms and at least one triple bond. In one embodiment, the alkynyl has 2-7 carbon atoms. In another embodiment, the alkynyl has 2-12 carbon atoms. In another embodiment, the alkynyl has 2-10 carbon atoms. In another embodiment, the alkynyl has 3-6 carbon atoms. In another embodiment, the alkynyl has 2-4 carbon atoms. In another embodiment, the alkynyl has 3-6 carbon atoms. In another embodiment, the alkynyl has 4-8 carbon atoms. In another embodiment hydrophobic alkynyl refers to alkynyl having at least four carbons. In another embodiment hydrophobic alkynyl refers to a C4-C8 alkenyl.
The term “alkoxy” refers in one embodiment to an alky as defined above bonded to an oxygen. Non limiting examples of alkoxy groups include: methoxy, ethoxy and isopropoxy.
A “cycloalkyl” group refers, in one embodiment, to a ring structure comprising carbon atoms as ring atoms, which may be either saturated or unsaturated, substituted or unsubstituted. In another embodiment the cycloalkyl is a 3-12 membered ring. In another embodiment the cycloalkyl is a 6 membered ring. In another embodiment the cycloalkyl is a 5-7 membered ring. In another embodiment the cycloalkyl is a 3-8 membered ring. In another embodiment, the cycloalkyl group may be unsubstituted or substituted by a halogen, alkyl, haloalkyl, hydroxyl, alkoxy, carbonyl, amido, alkylamido, dialkylamido, cyano, nitro, CO2H, amino, alkylamino, dialkylamino, carboxyl, thio and/or thioalkyl. In another embodiment, the cycloalkyl ring may be fused to another saturated or unsaturated cycloalkyl or heterocyclic 3-8 membered ring. In another embodiment, the cycloalkyl ring is a saturated ring. In another embodiment, the cycloalkyl ring is an unsaturated ring. Non-limiting examples of a cycloalkyl group comprise cyclohexyl, cyclohexenyl, cyclopropyl, cyclopropenyl, cyclopentyl, cyclopentenyl, cyclobutyl, cyclobutenyl, cycloctyl, cycloctadienyl (COD), cycloctaene (COE) etc. In another embodiment hydrophobic cycloalkyl refers to a cycloalkyl having at least six carbons.
A “heterocycle” group refers, in one embodiment, to a ring structure comprising in addition to carbon atoms, sulfur, oxygen, nitrogen or any combination thereof, as part of the ring. In another embodiment the heterocycle is a 3-12 membered ring. In another embodiment the heterocycle is a 6 membered ring. In another embodiment the heterocycle is a 5-7 membered ring. In another embodiment the heterocycle is a 3-8 membered ring. In another embodiment, the heterocycle group may be unsubstituted or substituted by a halogen, alkyl, haloalkyl, hydroxyl, alkoxy, carbonyl, amido, alkylamido, dialkylamido, cyano, nitro, CO2H, amino, alkylamino, dialkylamino, carboxyl, thio and/or thioalkyl. In another embodiment, the heterocycle ring may be fused to another saturated or unsaturated cycloalkyl or heterocyclic 3-8 membered ring. In another embodiment, the heterocyclic ring is a saturated ring. In another embodiment, the heterocyclic ring is an unsaturated ring. Non limiting examples of a heterocyclic rings comprise pyridine, piperidine, morpholine, piperazine, thiophene, pyrrole, benzodioxole, or indole. In another embodiment hydrophobic heterocyclic group refers to a heterocycle having at least six carbons.
In one embodiment, at least one of R1, R2 and R3 and/or at least one of R1′, R2′ and R3′ of structure (1) is hydrophobic. In one embodiment, at least one of R1 and R2 and/or at least one of R1′ and R2′ of structures (2) and (3) is hydrophobic.
The term “hydrophobic” refers to an alkyl, alkenyl or alkynyl having at least four carbons, or the term hydrophobic refers to terpenoid, to cycloalkyl, aryl or heterocycle having at least six carbons. Each possibility represents a separate embodiment of this invention
In one embodiment, at least one of R1, R2 and R3 and/or at least one of R1′, R2′ and R3′ of structure (1) is a C4-C24 alkyl, C4-C24 alkenyl, C4-C24 alkynyl or a terpenoid. In one embodiment, at least one of R1 and R2 and/or at least one of R1′ and R2′ of structures (2) and (3) is a C4-C24 alkyl, C4-C24 alkenyl, C4-C24 alkynyl or a terpenoid. Each possibility represents a separate embodiment of this invention.
In one embodiment, at least one of R1, R2 and R3 and/or at least one of R1′, R2′ and R3′ of structure (1) is a C4-C8 alkyl, C4-C8 alkenyl, C4-C8 alkynyl or a terpenoid. In one embodiment, at least one of R1 and R2 and/or at least one of R1′ and R2′ of structures (2) and (3) is a C4-C8 alkyl, C4-C8 alkenyl, C4-C8 alkynyl or a terpenoid. Each possibility represents a separate embodiment of this invention.
In one embodiment, R1 and/or R1′ of structures (1) to (6) is a terpenoid. In another embodiment, R1 and/or R1′ is a terpenoid and R2 and/or R2′ is a C1-C4 alkyl. In another embodiment, the core is an organic polymeric core, R3 and/or R3′ is nothing and R1 and/or R1′ is a terpenoid. In another embodiment, the core is an organic polymeric core, R3 and/or R3′ is a hydrogen and R1 and/or R1′ is a terpenoid. In another embodiment, the core is an inorganic core, R3 and/or R3′ is nothing and R1 and/or R1′ is a terpenoid. In another embodiment, the core is an inorganic core, R3 and/or R3′ is a hydrogen and R1 and/or R1′ is a terpenoid. In another embodiment, the core is an inorganic core, R3 and/or R3′ is a C1-C24 alkyl, terpenoid, cycloalkyl, aryl, heterocycle, a conjugated C1-C24 alkyl, C1-C24 alkenyl, C1-C24 alkynyl or any combination thereof and R1 and/or R1′ is a terpenoid.
In one embodiment “p” of structures (1) to (6) defines the surface density of the anti-microbial active units per 1 sq nm of the core surface. In another embodiment “p” is, between 0.01-30 anti-microbial active units per 1 sq nm of the core surface. In another embodiment “p” is, between 0.01-20 anti-microbial active units per 1 sq nm of the core surface. In another embodiment “p” is, between 0.01-10 anti-microbial active units per 1 sq nm of the core surface. In another embodiment “p” is, between 0.01-15 anti-microbial active units per 1 sq nm of the core surface. In another embodiment “p” is, between 0.01-5 anti-microbial active units per 1 sq nm of the core surface.
In one embodiment, n1 of structures (1) to (6) is between 0-200. In another embodiment, n1 is between 0-10. In another embodiment, n1 is between 10-20. In another embodiment, n1 is between 20-30. In another embodiment, n1 is between 30-40. In another embodiment, n1 is between 40-50. In another embodiment, n1 is between 50-60. In another embodiment, n1 is between 60-70. In another embodiment, n1 is between 70-80. In another embodiment, n1 is between 80-90. In another embodiment, n1 is between 90-100. In another embodiment, n1 is between 100-110. In another embodiment, n1 is between 110-120. In another embodiment, n1 is between 120-130. In another embodiment, n1 is between 130-140. In another embodiment, n1 is between 140-150. In another embodiment, n1 is between 150-160. In another embodiment, n1 is between 160-170. In another embodiment, n1 is between 170-180. In another embodiment, n1 is between 180-190. In another embodiment, n1 is between 190-200.
In one embodiment, n2 of structures (1) to (6) is between 0-200. In another embodiment, n2 is between 0-10. In another embodiment, n2 is between 10-20. In another embodiment, n2 is between 20-30. In another embodiment, n2 is between 30-40. In another embodiment, n2 is between 40-50. In another embodiment, n2 is between 50-60. In another embodiment, n2 is between 60-70. In another embodiment, n2 is between 70-80. In another embodiment, n2 is between 80-90. In another embodiment, n2 is between 90-100. In another embodiment, n2 is between 100-110. In another embodiment, n2 is between 110-120. In another embodiment, n2 is between 120-130. In another embodiment, n2 is between 130-140. In another embodiment, n2 is between 140-150. In another embodiment, n2 is between 150-160. In another embodiment, n2 is between 160-170. In another embodiment, n2 is between 170-180. In another embodiment, n2 is between 180-190. In another embodiment, n2 is between 190-200.
In one embodiment, m of structures (1) to (6) is between 1-200. In another embodiment, m is between 1-10. In another embodiment, m is between 10-20. In another embodiment, m is between 20-30. In another embodiment, m is between 30-40. In another embodiment, m is between 40-50. In another embodiment, m is between 50-60. In another embodiment, m is between 60-70. In another embodiment, m is between 70-80. In another embodiment, m is between 80-90. In another embodiment, m is between 90-100. In another embodiment, m is between 100-110. In another embodiment, m is between 110-120. In another embodiment, m is between 120-130. In another embodiment, m is between 130-140. In another embodiment, m is between 140-150. In another embodiment, m is between 150-160. In another embodiment, m is between 160-170. In another embodiment, m is between 170-180. In another embodiment, m is between 180-190. In another embodiment, m is between 190-200.
In one embodiment, the anti-microbial active group of this invention may be selected from: (a) a tertiary amine (i.e. R3 and/or R3′ is nothing) or tertiary ammonium (i.e. R3 and/or R3′ is hydrogen) comprising at least one terpenoid moiety (b) a quaternary ammonium group comprising at least one terpenoid moiety (c) a quaternary ammonium group, comprising at least one alkyl group having from 4 to 24 carbon atoms; and (d) a tertiary amine (i.e. R3 and/or R3′ is nothing) or tertiary ammonium (i.e. R3 and/or R3′ is hydrogen) comprising at least one alkyl group having from 4 to 24 carbon atoms. Each possibility represents a separate embodiment of this invention.
In one embodiment, the particles of this invention represented by structures (1)-(6) comprise an anti-microbial active unit and an inert core, wherein the anti-microbial active unit and the core are linked indirectly.
In some embodiments L1, L2 or L3 is each independently the same or a different linker. In some embodiments, L1, L2 and L3 are connected to each other, in any possible way. In some embodiment, L3 is nothing and L1 or L2 is connected to the core covalently. In another embodiment, L3 is connected to the core covalently and L1 or L2 is connected to L3. In another embodiment, L1 is connected to X, X′ and L3 or core. In another embodiment, a “linker” comprises any possible chemical moiety capable of connecting at least two other chemical moieties which are adjacent to such linker. In another embodiment, the monomeric unit of the anti-microbial active unit comprises a first and/or second linker/s (L1 or L2) and an anti-microbial group. In another embodiment, L1 and/or L2 are/is the backbone of the anti-microbial active unit. In some embodiments, the linker comprises a functional group. In another embodiment, the linker comprises two (same or different) functional groups. In another embodiment, the functional group comprises phosphate, phosphonate, siloxane, silane, ether acetal, amide, amine, anhydride, ester, ketone, or aromatic ring or rings functionalized with any of the preceding moieties. Each possibility represents a separate embodiment of this invention.
In another embodiment, L1 or L2 is a C1 to C18 alkylene, alkenylene, alkynylene or aryl substituted with at least one carboxyl moiety, wherein the carboxyl end is attached to the core. This linker may be derived from a C1 to C18 alkylene substituted with at least one carboxyl moiety and having an amino end which is modified to anti-microbial active group [—+N(R1)(R2)(R3), —+NH(R1)(R2), —N(R1)(R2)—+N(R1′)(R2′)(R3′), —+NH(R1′)(R2′) or —N(R1′)(R2′) (defined in structures (1) to (6))]. This linker may be derived from an amino acid of natural or synthetic source having a chain length of between 2 and 18 carbon atoms (polypeptide), or an acyl halide of said amino acid. Non-limiting examples for such amino acids are 18-amino octadecanoic acid and 18-amino stearic acid. In another embodiment, L1 or L2 is a C1 to C18 alkylene substituted with at least one amine or amide moiety.
In another embodiment, L1, L2, L3 or any combination thereof is a C1 to C18 alkylene, alkenylene, alkynylene or aryl. This linker may be derived from a di-halo alkylene, which is functionalized at each end with the core and anti-microbial active group, respectively, by replacement of the halogen moiety to a functional group that binds to the core and replacement of the halogen moiety to obtain [—+N(R1)(R2)(R3), —+NH(R1)(R2), —N(R1)(R2)—+N(R1′)(R2′)(R3′), —+NH(R1′)(R2′) or —N(R1′)(R2′) (defined in structures (1) to (6))]
In another embodiment, L1, L2, L3 or any combination thereof is an aromatic group derived from non-limiting examples of 4,4-biphenol, dibenzoic acid, dibenzoic halides, dibenzoic sulphonates, terephthalic acid, tetrphthalic halides, and terephthalic sulphonates. This linker is functionalized with the core and anti-microbial active group, respectively, through the functional group thereof (i.e., hydroxyl, carboxy or sulfonate). In another embodiment, this linker is directly attached to the core at one end or indirectly, via a third linker (L3) and is modified at the other end to anti-microbial active group [—+N(R1)(R2)(R3), —+NH(R1)(R2), —N(R1)(R2)—+N(R1′)(R2′)(R3′), —+NH(R1′)(R2′) or —N(R1′)(R2′) (defined in structures (1) to (6))].
In another embodiment, L1, L2, L3 or any combination thereof, is a siloxane or silane group derived and/or selected from non-limiting examples of trialkoxyalkylsilane, trialkoxyarylsilane, trihaloalkylsilane, trihaloarylsilane, 3-aminopropyltriethoxysilane (APTES) and N-2-aminoethyl-3-aminopropyl trimethoxysilane. This linker is functionalized with the core and anti-microbial active group, respectively, through the functional group thereof (i.e., hydroxyl, siloxane, carboxy, amide or sulfonate). In another embodiment, this linker is directly attached to the core at one end directly or indirectly, via a third linker (L3) and is modified at the other end to anti-microbial active group [—+N(R1)(R2)(R3), —+NH(R1)(R2), —N(R1)(R2)—+N(R1′)(R2′)(R3′), —+NH(R1′)(R2′) or —N(R1′)(R2′) (defined in structures (1) to (6))].
In one embodiment, the anti-microbial active group of this invention may be selected from: (a) a tertiary amine (i.e. R3 and/or R3′ is nothing) or tertiary ammonium (i.e. R3 and/or R3′ is hydrogen) comprising at least one terpenoid moiety (b) a quaternary ammonium group comprising at least one terpenoid moiety (c) a quaternary ammonium group, comprising at least one alkyl group having from 4 to 24 carbon atoms; and (d) a tertiary amine (i.e. R3 and/or R3′ is nothing) or tertiary ammonium (i.e. R3 and/or R3′ is hydrogen) comprising at least one alkyl group having from 4 to 24 carbon atoms. Each possibility represents a separate embodiment of this invention.
This linker is functionalized with the core and anti-microbial active group, respectively, through the functional group thereof (i.e., hydroxyl, siloxane, carboxy, amide or sulfonate). In another embodiment, this linker is directly attached to the core at one end or indirectly, via a third linker (L3) and is modified at the other end to anti-microbial active group [—+N(R1)(R2)(R3), —+NH(R1)(R2), —N(R1)(R2)—+N(R1′)(R2′)(R3′), —+NH(R1′)(R2′) or —N(R1′)(R2′) (defined in structures (1) to (6))].
In another embodiment, a monomeric unit within the anti-microbial active unit of this invention is represented by the structure of formula IA:
wherein
R1 and R2 are independently linear or branched alkyl, terpenoid, cycloalkyl, aryl, heteroaryl, alkenyl, alkynyl or any combination thereof; and
R3 is nothing, linear or branched alkyl, terpenoid, cycloalkyl, aryl, heteroaryl, alkenyl, alkynyl or any combination thereof; wherein if R3 is nothing, the nitrogen is not charged
q is an integer between 0 and 16;
wherein said monomeric unit is chemically bound to the surface of an inorganic core directly or via a third linker (L3).
In another embodiment, a monomeric unit within the anti-microbial active unit of this invention is represented by the structure of formula IB:
wherein
R1 and R2 are independently linear or branched alkyl, terpenoid, cycloalkyl, aryl, heteroarylalkenyl, alkynyl or any combination thereof; and
R3 is nothing, linear or branched alkyl, terpenoid, cycloalkyl, aryl, heteroaryl, alkenyl, alkynyl or any combination thereof; wherein if R3 in nothing, the nitrogen is not charged
q and q1 are independently an integer between 0 and 16;
wherein said monomeric unit is chemically bound to the surface of an inorganic core directly or via a third linker (L3).
In another embodiment, a linker molecule within the anti-microbial active unit of this invention is represented by the structure of formula IC:
wherein
Q201, Q202 and Q203 are independently selected from the group consisting of alkoxy, methyl, ethyl, hydrogen, sulfonate and halide, wherein at least one of Q201, Q202 and Q203 is selected from ethoxy, methoxy, sulfonate (e.g., mesyl, tosyl) and halide; and
q is an integer between 0 and 16;
the linker molecule is capable of being chemically bound to the surface of the inorganic core through the silicon atom; and
the anti-microbial active group is introduced by functionalizing the primary amine to obtain an anti-microbial active tertiary amine or quaternary ammonium group containing at least one terpenoid group, as described above.
In another embodiment, a linker molecule within the anti-microbial active unit of this invention is represented by the structure of formula ID:
wherein
Q201, Q202 and Q203 are independently selected from the group consisting of alkoxy, methyl, ethyl, hydrogen, sulfonate and halide, wherein at least one of Q201, Q202 and Q203 is selected from ethoxy, methoxy, sulfonate (e.g., mesyl, tosyl) and halide;
W is selected from the group consisting of NH2, halide, sulfonate and hydroxyl; and
q is an integer between 0 and 16;
said linker is capable of being chemically bound to the surface of said inorganic core through the silicon atom; and
the anti-microbial active group is introduced by substituting the group W with an anti-microbial active group, or converting the group W to an anti-microbial active group.
The particles of this invention demonstrate an enhanced anti-microbial activity. Without being bound by any theory or mechanism, it can be postulated that such activity originates from the presence of closely packed anti-microbial groups on a given core's surface, as well as high density of particles packed on the surface of a host material. This density increases as each anti-microbial active unit in the particles of this invention comprise increasing number of anti-microbial active groups and it yields a high local concentration of active functional groups, which results in high effective concentration of the anti-microbial active groups and enables the use of a relatively small amount of particles to achieve effective bacterial annihilation. The close packing of the anti-microbial groups is due to, inter alia, numerous anti-microbial active units protruding from each particle surface. Accordingly, the anti-microbial groups cover large fraction of the particle's available surface area (width dimension covering the surface). The surface density of the anti-microbial group results in high effective concentration promoting anti-microbial inhibitory effect. According to the principles of this invention, high surface density dictates high anti-microbial efficiency.
The term “nanoparticle” as used herein refers to a particle having a diameter of less than about 1,000 nm. The term “microparticle” as used herein refers to a particle having a diameter of about 1,000 nm or larger.
The anti-microbial particles of this invention are characterized by having a diameter between about 5 to about 100,000 nm, and thus encompass both nanoparticulate and microparticulate compositions. Preferred are particles between about 10 to about 50,000 nm. In other embodiments, the particles are more than 1,000 nm in diameter. In other embodiments, the particles are more than 10,000 nm in diameter. In other embodiment, the particles are between 1,000 and 50,000 nm in diameter. In other embodiment, the particles are between 5 and 250 nm in diameter. In other embodiment, the particles are between 5 and 500 nm in diameter. In another embodiment, the particles are between 5 and 1000 nm in diameter. It is apparent to a person of skill in the art that other particles size ranges are applicable and are encompassed within the scope of this invention.
In one embodiment, the anti-microbial active group of this invention contains at least one terpenoid group, and is selected from: (a) a tertiary amine (R3 and/or R3′ is nothing) or tertiary ammonium (R3 and/or R3′ is H) comprising at least one terpenoid moiety; and (b) a quaternary ammonium group comprising at least one terpenoid moiety.
In some embodiments, the anti-microbial active group of formula (1) to (6) is selected from: (a) a tertiary amine (R3 and/or R3′ is nothing) or tertiary ammonium (R3 and/or R3′ is H), wherein the nitrogen atom of each tertiary amine/ammonium having at least one bond to X1 or X2 and one bond to a terpenoid moiety; (b) a tertiary amine (R3 and/or R3′ is nothing), or tertiary ammonium (R3 and/or R3′ is H), the nitrogen atom of each tertiary amine/ammonium having one bond to X1 or X2 and two bonds to terpenoid moieties which may be the same or different from each other, or a salt of said tertiary amine; (c) a quaternary ammonium group the nitrogen atom of each quaternary ammonium group having at least one bond to X1 or X2 and one or two bonds to terpenoid moieties which may be the same or different from each other; Each possibility represents a separate embodiment of this invention.
The term “terpenoid”, also known as “isoprenoid” refers to a large class of naturally occurring compounds that are derived from five-carbon isoprene units.
In one embodiment, the at least one terpenoid moiety is a cinammyl group derived from cinnamaldehyde, cinnamic acid, curcumin, viscidone or cinnamyl alcohol. In another embodiment, the at least one terpenoid moiety is a bornyl group derived from camphor, bornyl halide or bornyl alcohol. In another embodiment, the at least one terpenoid moiety is derived from citral. In another embodiment, the at least one terpenoid moiety is derived from perilaldehyde. Each possibility represents a separate embodiment of this invention.
Cinnamaldehyde is a natural aldehyde extracted from the genus Cinnamomum. It is known for its low toxicity and its effectiveness against various bacteria and fungi.
Camphor is found in the wood of the camphor laurel (Cinnamomum camphora), and also of the kapur tree. It also occurs in some other related trees in the laurel family, for example Ocotea usambarensis, as well as other natural sources. Camphor can also be synthetically produced from oil of turpentine. Camphor can be found as an R or S enantiomer, a mixture of enantiomers and a racemic mixture. Each possibility represents a separate embodiment of this invention.
Citral, or 3,7-dimethyl-2,6-octadienal or lemonal, is a mixture of two diastereomeric terpenoids. The two compounds are double bond isomers. The E-isomer is known as geranial or citral A. The Z-isomer is known as neral or citral B. Citral is known to have anti-microbial activity.
Perillaldehyde, also known as perilla aldehyde, is a natural terpenoid found most in the annual herb perilla, as well as in a wide variety of other plants and essential oils.
Other examples of terpenoids include, but are not limited to: curcuminoids found in turmeric and mustard seed, citronellal found in Cymbopogon (lemon grass) and carvacrol, found in Origanum vulgare (oregano), thyme, pepperwort, wild bergamot and Lippia graveolens. Each possibility represents a separate embodiment of this invention.
In accordance with the above embodiment, the anti-microbial active terpenoid moieties are selected from the group consisting of:
or any combination thereof;
Each possibility represents a separate embodiment of this invention.
Non-limiting examples of functional anti-microbial active tertiary amine groups or its protonated form in accordance with the principles of this invention are:
wherein R2 is alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof.
Non-limiting examples of anti-microbial active quaternary ammonium groups in accordance with the principles of this invention are:
wherein R2 is alkyl, terpenoid, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
R3 is alkyl, terpenoid moiety, cycloalkyl, aryl, heterocycle, alkenyl, alkynyl or any combination thereof;
The anti-microbial active group of this invention may be in the form of a tertiary amine, or in the form of a protonated said tertiary amine, or in the form of a quaternary ammonium salt, as described hereinabove. Since an ammonium group is positively charged, its charge is balanced with an anion. Preferably, in a particle according to this invention this anion is a halide, e.g. fluoride, chloride, bromide or iodide, and fluoride is most preferred. Other possible anions include, but are not limited to, bicarbonate, nitrate, phosphate, acetate, fumarate, succinate and sulfate. Each possibility represents a separate embodiment of this invention.
In accordance with another embodiment, the anti-microbial active group of this invention [—+N(R1)(R2)(R3), —+NH(R1)(R2), —N(R1)(R2)—+N(R1′)(R2′)(R3′), —+NH(R1′)(R2′) or —N(R1′)(R2′) (defined in structures (1) to (6))] is a quaternary ammonium group, a tertiary amine or a tertiary ammonium, the nitrogen atom of each amine/ammonium group having at least one bond X1 or X2, at least one bond to an alkyl group having from 4 to 24 carbon atoms (R1 and/or R1′). In another embodiment, the nitrogen atom of each amine/ammonium group having one bond to the core, one bond to an alkyl group having from 4 to 24 carbon atoms (R1 and/or R1′).
Since an ammonium group is positively charged, its charge should be balanced with an anion. Any of the counter-ions described above may be used to counter-balance the quaternary ammonium group.
In some embodiments, the nitrogen atom of each quaternary ammonium or tertiary ammonium group has (i) at least one bond to X1 or X2; and (ii) at least one bond to the alkyl group having from 4 to 24 carbon atoms.
In some embodiments, the anti-microbial active group of formula (1) to (6) is selected from: (a) a tertiary amine (R3 and/or R3′ is nothing) or tertiary ammonium (R3 and/or R3′ is H), wherein the nitrogen atom of each tertiary amine/ammonium having at least one bond to X1 or X2 and one bond to the alkyl group having from 4 to 24 carbon atoms; (b) a tertiary amine (R3 and/or R3′ is nothing), or tertiary ammonium (R3 and/or R3′ is H), wherein the nitrogen atom of each tertiary amine/ammonium having one bond to X1 or X2 and two bonds to alkyl groups having from 4 to 24 carbon atoms which may be the same or different from each other, or a salt of said tertiary amine; (c) a quaternary ammonium group wherein the nitrogen atom of each quaternary ammonium group having at least one bond to X1 or X2 and one or two bonds to the alkyl groups having from 4 to 24 carbon atoms which may be the same or different from each other. Each possibility represents a separate embodiment of this invention.
The term “quaternary ammonium group” refers to a group of atoms consisting of a nitrogen atom with four substituents (different than hydrogen) attached thereto. In another embodiment, a “quaternary ammonium group” refers to a group of atoms consisting of a nitrogen atom with four groups wherein each of the group is attached to the nitrogen through a carbon atom. The term “long alkyl group” or chain refers to such an alkyl group or chain which is substituted on the nitrogen atom of the quaternary ammonium group and which has between 4 and 24 carbon atoms. In some currently preferred embodiments, the alkyl group is an alkyl group having 4 to 18 carbon atoms. In some currently preferred embodiments, the alkyl group is an alkyl group having 4 to 8 carbon atoms. In some currently preferred embodiments, the alkyl group is an alkyl group having 4 to 10 carbon atoms. In other currently preferred embodiments, the alkyl group is an alkyl group having 6, 7, or 8 carbon atoms, with each possibility representing a separate embodiment of this invention.
In some embodiments, the core of the anti-microbial particles is an organic polymeric core. In one embodiment, the organic core comprises at least one aliphatic polymer. An “aliphatic polymer” as used within the scope of this invention refers to a polymer made of aliphatic monomers that may be substituted with various side groups, including (but not restricted to) aromatic side groups. Aliphatic polymers that may be included in particles according to this invention comprise nitrogen atoms (as well as other heteroatoms) as part of the polymeric backbone. In one embodiment, the core of the particles is an organic polymeric core including an amine which can be substituted with R1, R2 and/or R3 as defined for structure 1; or including an imine which is chemically modified to amine and then substituted with R1, R2 and/or R3 as defined for structure 1. Non-limiting examples of aliphatic polymers are polystyrene (PS), polyvinylchloride (PVC), polyethylene imine (PEI), polyvinyl amine (PVA), poly(allyl amine) (PAA), poly(aminoethyl acrylate), polypeptides with pending alkyl-amino groups, and chitosan. Each possibility represents a separate embodiment of this invention. In one currently preferred embodiment, the polymer is polyethylene imine (PEI).
In another embodiment, the organic core comprises at least one aromatic polymer selected from the following group: polystyrene, aminomethylated styrene polymers, aromatic polyesters, preferably polyethylene terephthalate, and polyvinyl pyridine.
The polymeric core may be linked to anti-microbial active part directly (i.e. in structures (1)-(3): L3 is a bond) or via a linker. Each possibility represents a separate embodiment of this invention.
In one embodiment, the organic polymeric core includes a combination of two or more different organic polymers. In another embodiment, the organic polymeric core includes a copolymer.
In some embodiments, anti-microbial active unit is linked to the organic polymeric core directly (L3 is a bond) or via a linker (L3). In these embodiments, the linker may be selected from:
(a) a C1 to C18 alkylene substituted with at least one carboxyl moiety. This linker may be derived from an alkylene substituted with at least one carboxyl moiety and at least one amino moiety, wherein the carboxyl end is attached to the core and the amino end is modified to anti-microbial active group [—+N(R1)(R2)(R3), —+NH(R1)(R2), —N(R1)(R2)—+N(R1′)(R2′)(R3′), —+NH(R1′)(R2′) or —N(R1′)(R2′) (defined in structures (1) to (6))]. This linker may be derived from an amino acid of natural or synthetic source having a chain length of between 2 and 18 carbon atoms, or an acyl halide of said amino acid. Non-limiting examples for such amino acids are 18-amino octadecanoic acid and 18-amino stearic acid;
(b) a C1 to C18 alkylene. This linker may be derived from a di-halo alkylene, which is functionalized at each end with the core and anti-microbial active group, respectively, by replacement of the halogen moiety to a functional group that will bind to the core and replacement of the halogen moiety to obtain [—+N(R1)(R2)(R3), —+NH(R1)(R2), —N(R1)(R2)—+N(R1′)(R2′)(R3′), —+NH(R1′)(R2′) or —N(R1′)(R2′) (defined in structures (1) to (6))]; and (c) aromatic molecules derived from 4,4-biphenol, dibenzoic acid, dibenzoic halides, dibenzoic sulphonates, terephthalic acid, terephthalic halides, and terephthalic sulphonates. This linker is functionalized with the core and anti-microbial active group, respectively, through the functional group thereof (i.e., hydroxyl, carboxy or sulfonate). In another embodiment, this linker is attached to the core at one end and is modified at the other end to anti-microbial active group [—+N(R1)(R2)(R3), —+NH(R1)(R2), —N(R1)(R2)—+N(R1′)(R2′)(R3′), —+NH(R1′)(R2′) or —N(R1′)(R2′) (defined in structures (1) to (6))] In another embodiment, the linker comprises alkyl, alkenyl, alkyl phosphate, alkyl siloxanes, carboxylate, epoxy, acylhalides and anhydrides, or combination thereof, wherein the functional group is attached to the core. Each possibility represents a separate embodiment of this invention.
Various polymeric chains may provide a range of properties that themselves may be an accumulation of the various polymer properties, and may even provide unexpected synergistic properties. Examples of such mixed polyamine particles include: crosslinking of aliphatic and aromatic polyamines such as polyethyleneimine and poly(4-vinyl pyridine) via a dihaloalkane; mixture of linear short chain and branched high molecular weight polyethyleneimines; interpenetrating compositions of polyamine within a polyamine scaffold such as polyethyleneimine embedded within crosslinked polyvinyl pyridine particles, or even interpenetrating a polyamine into a low density non-amine scaffold such as polystyrene particles. In other words, the use of polyamine combinations for the purpose of forming particles, either by chemical crosslinking or physical crosslinking (interpenetrating networks) may afford structures of varying properties (such as being able to better kill one bacteria vs. another type of bacteria). Such properties may be additive or synergistic in nature.
In one specific embodiment, the organic polymeric core is cross-linked with a cross-linking agent. The preferred degree of cross-linking is from 1% to 20%, when crosslinking of from about 2% to about 5% is preferable. The crosslinking may prevent unfolding of the polymer and separation of the various polymeric chains that form the particle.
Crosslinking, as may be known to a person skilled in the art of organic synthesis and polymer science, may be affected by various agents and reactions that are per se known in the art. For example, crosslinking may be affected by alkylating the polymer chains with dihaloalkane such as dibromoethane, dibromocyclohexane, or bis-bromomethylbenzene. Alternatively, crosslinking by reductive amination may be used. In this method a polyamine with primary amines is reacted with a diketone or with an alkane dialdehyde to form an imine crosslinker which is then further hydrogenated to the corresponding amine. This amine is further reacted to form an antimicrobial effective quaternary ammonium group. In such a method, instead of dihaloalkanes or dialdehydes, tri or polyhaloalkanes or polyaldehydes or polyketones are used.
The preferred polymers useful for making the polymeric core according to this invention are those having chains made of 30 monomer units, preferably 100 monomer units that may be crosslinked using less than 10% of crosslinking agent. The longer the polymers are, the fewer crosslinking bonds are needed to afford an insoluble core. Branched polymers are preferred for crosslinking as small amount of crosslinking is required to form insoluble core.
In some embodiments, at least about 10% of the amine groups in the organic polymeric core are the anti-microbial active tertiary amine/ammonium or quaternary ammonium groups or salts thereof, as described herein.
In one embodiment, the anti-microbial particles according to this invention have functional groups that are capable of reacting with a host polymer or with monomers thereof. Such functional groups are designed to allow the particles to be bound chemically to a hosting material.
In some embodiments, the core of the anti-microbial particles of this invention is an inorganic core comprising one or more inorganic materials. Inorganic cores have a few advantages over organic polymeric cores: 1) higher stability at elevated temperature; 2) higher chemical stability towards various solvent and reagents; 3) improved mechanical strength; 4) better handling qualities in composites due to their amphipathic nature; and 5) lower cost.
An additional advantage of inorganic cores relates to the insertion of the functionalized particles into a polymeric material within a polymeric matrix (host). In contrast to organic cores which are produced by radical polymerization (e.g. acrylate resins), inorganic cores do not interfere with the polymerization process and hence do not jeopardize the mechanical properties of the finalized substrate, as opposed to organic polymeric cores which tend to interfere with the polymerization reaction.
In one embodiment, the inorganic core comprises silica, metal, metal oxide or a zeolite. Each possibility represents a separate embodiment of this invention.
In one embodiment, the core of the particles of this invention comprises silica (SiO2). The silica may be in any form known in the art, non-limiting examples of which include polyhedral oligomeric silsesquioxane (POSS), amorphous silica, dense silica, aerogel silica, porous silica, mesoporous silica and fumed silica.
The surface density of active groups onto particle surface have proportional impact on its anti-microbial activity. This is applicable both to organic and inorganic particles in same manner. In another embodiment, the core of the particles of this invention comprises glasses or ceramics of silicate (SiO4−4). Non-limiting examples of silicates include aluminosilicate, borosilicate, barium silicate, barium borosilicate and strontium borosilicate.
In another embodiment, the core of the particles of this invention comprises surface activated metals selected from the group of: silver, gold, platinum, palladium, copper, zinc and iron.
In another embodiment, the core of the particles of this invention comprises metal oxides selected from the group of: zirconium dioxide, titanium dioxide, vanadium dioxide, zinc oxide, copper oxide and magnetite.
The inorganic core typically has a solid uniform morphology with low porosity or a porous morphology having pore size diameter of between about 1 to about 30 nm.
In another embodiment, the core of the particles of this invention comprises natural or artificial Zeolites.
In one embodiment, the core may be attached to the anti-microbial unit directly (i.e. in structures (1)-(3): L3 is a bond), or via a linker (L3). Preferably a silica (SiO2) based inorganic core may be attached to the anti-microbial part through a linker (L3), while glasses or ceramicas of silicate (SiO4−4), metals or metal oxides may be attached to anti-microbial unit directly (i.e. in structures (1)-(3): L3 is a bond).
In some embodiments, the inorganic core is directly (i.e. in structures (1)-(3): L3 is a bond) attached to the anti-microbial unit. In other embodiments, the inorganic core is attached to the anti-microbial unit through a linker. In some embodiments, the linker is selected from the following groups: a C1 to C18 alkylene; a C1 to C18 alkylene substituted with at least one silane or alkoxysilane moiety; a C1 to C18 alkylene substituted with at least one phosphate moiety; a C1 to C18 alkylene substituted with at least one anhydride moiety; a C1 to C18 alkylene substituted with at least one carboxylate moiety; and a C1 to C18 alkylene substituted with at least one glycidyl moiety. Each possibility represents a separate embodiment of this invention.
The inorganic core of the particle as described above may generally be in a form selected from a sphere, amorphous polygonal, shallow flake-like and a rod. In some representative embodiments, the inorganic core is spherical and has a diameter between about 5 to about 100,000 nm. In some representative embodiments, the inorganic core is spherical and has a diameter between about 1000-100,000 nm. In some representative embodiments, the inorganic core is spherical and has a diameter between about 100-1000 nm with pore diameter of about 1 to about 100 nm. In another embodiment, the inorganic spherical core has a pore diameter of about 1 to about 50 nm. In another embodiment, the inorganic spherical core has a pore diameter of about 1 to about 30 nm. In another embodiment, the inorganic particle is in a form of a rod, having a diameter of between about 5 to about 1,000 nm and length between about 10 to about 1,000,000 nm. In another embodiment, a length of between 50 to 100,000 nm. In another embodiment, a length of between 100 to 250,000 nm. In another embodiment, a length of between 200 to 500,000 and a pore diameter of about 1 to about 50 nm. Each possibility represents a separate embodiment of this invention.
The particles of this invention may be prepared in accordance to a variety of processes, depending on the nature of the core, the anti-microbial active group, and the presence or absence of linkers. Some non-limiting examples of preparation methods are provided below.
In one embodiment, this invention provides processes for preparing anti-microbial particles, wherein the particles comprise one monomeric unit per one anti-microbial active unit. In the following, such processes will be presented in detail.
A representative method for preparing particles according to this invention wherein the anti-microbial active group is a tertiary amine or a quaternary ammonium group comprising at least one terpenoid moiety is represented in
It is understood that the group
may represents any one or more of the following:
1. An organic core directly bound to NH2.
2. An organic core bound to NH2 through a linker as described herein.
3. An inorganic core directly bound to NH2.
4. An inorganic core bound to NH2 through a linker as described herein.
The exemplified reaction (
The process presented in
A representative method for preparing particles according to this invention wherein the anti-microbial active group is a quaternary ammonium group containing one alkyl group having 4 to 18 carbon atoms is presented in
It is understood that that the group
has any one of the meanings as described above for
It is understood that that the group
may represents any one or more of the following:
1. An organic core directly bound to Y.
2. An organic core bound to Y through a linker as described herein.
3. An inorganic core directly bound to Y.
4. An inorganic core bound to Y through a linker as described herein.
Core functionalization can occur by a solid support method, or a solution method (
Preparation of functionalized particles is conducted in two general steps. First, the linker molecule is allowed to condense onto particles surface (surface functionalization) via hydrolysis of leaving groups to give an intermediate of formula (
Solution Method as Method of Preparation of Anti-Microbial Particles Comprising One Monomeric Unit Per One Anti-Microbial Active Part
In this method, the linker molecule is first functionalized with antimicrobial active group to give an intermediate of formula (
This process is exemplified in
Preparation of Anti-Microbial Particles, Comprising More than One Monomeric Unit Per One Anti-Microbial Active Unit
In one embodiment, this invention provides processes for preparing particles of the composites of this invention, wherein the particles comprise more than one monomeric unit per one anti-microbial active unit. In the following, such processes will be presented in detail.
Solid Support as Method of Preparation of Anti-Microbial Particles Comprising More than One Monomeric Unit Per One Anti-Microbial Active Unit
The solid support method comprises a few stages. First, the linker molecule (dilute solutions of a few percent) is allowed to condense onto particles surface (surface functionalization) via (acid catalyzed) hydrolysis of leaving groups, resulting in the attachment of the linker to the core (
In another embodiment, the same trialkoxysilane linker molecule is used initially, however in a higher concentration (≥10% by wt) and it initially self-polymerizes (
Solution Method as Method of Preparation of Anti-Microbial Particles Comprising More than One Monomeric Unit Per One Anti-Microbial Active Unit
The solution method comprises a few stages. The first step involves elongation of the linker molecule. In another embodiment, this step is achieved synthetically via one step or more. In another embodiment, elongation is achieved by consecutive addition of difunctionalized alkane and diaminoalkane wherein amines (of linker and diaminoalkane) attack electrophilic centers of the difunctionalized alkane (
This process is exemplified in
In another embodiment, the same trialkoxysilane linker molecule is used initially, however in a higher concentration (≥10% by weight) and it initially self-polymerizes (
In some embodiments, the particles of the composites of this invention which comprise one or more monomeric units per one anti-microbial active part, comprise cores which are prepared according to the following.
Porous silica materials can be prepared by reaction of SiCl4 with alcohol or water, followed by drying using centrifugation and/or heating utilizing airflow or under vacuum conditions. Dense fumed silica particles (pyrogenic) were prepared by pyrolysis of SiCl4.
An alternative preparation method of silica core material can be carried by the hydrolysis of tetraethylorthosilicate (TEOS) or tetramethyl orthosilicate (TMS) in the presence of alcohol or water solution and under basic (Stober) or acidic catalytic conditions.
Mesoporous silica particles can be prepared by hydrolysis of TEOS or TMS at low temperatures, preferably in a temperature not exceeding 60° C., followed by dehydration by centrifugation and/or evaporation under airflow or vacuum conditions.
Dense particles can be prepared utilizing intense heating in a process called calcination. Typically, such process takes place at high temperatures at about 250° C.
Composition Comprising the Particles of this Invention
In some embodiments, the composition of this invention comprises the anti-microbial particles of this invention and a polymeric material comprising organic polymers, inorganic polymers or any combination thereof. In some embodiment, the particles as described herein are dispersed in the polymeric material. In another embodiment, the particles are homogeneously dispersed within the polymeric material. In another embodiment, the particles are found in the surface of the polymeric materials. In another embodiment, the particles coat the polymeric materials. In another embodiment, the particles interact weakly or physically (mechanically) with the polymeric material. In another embodiment, the anti-microbial particles are mechanically embedded within the polymeric material. In another embodiment, these particles are three dimensionally “locked” between the polymer chains, preventing them from migrating out from the complex network. The strong hydrophobic nature of these particles also plays a role in preventing the particles from moving into the hydrophilic surrounds such as in the case of physiological, dental, orthopedic or other medical applications. In another embodiment, the polymeric material is inert to the particles and does not react with them. In one embodiment, the particles comprise functional groups, capable of reacting with moieties of the polymeric material. In another embodiment, the particles interact chemically with the polymeric material. In another embodiment, the particles are a mixture of different particles.
In some embodiments, the composition of this invention comprises the anti-microbial particles of this invention and a polymeric material comprising organic polymers, inorganic polymers or any combination thereof. In another embodiment, the polymeric material comprises thermoplastic polymers, thermoset polymers or any combination thereof. In another embodiment, the organic polymer comprises hydrogels, polyolefins such as polyvinylchloride (PVC), polyethylene, polystyrene and polypropylene, epoxy resins, acrylate resins such as poly methyl methacrylate, polyurethane or any combination thereof. In another embodiment, the inorganic polymer comprise silicone polymers such as polydimethylsiloxane (PDMS), ceramics, metals or any combination thereof. In another embodiment, the hydrogel is poloxamer or alginate. In another embodiment, the commercial poloxamer is used or it is formed by a reaction between a polymer and other reagent. In another embodiment, the polymer is poly(ethylene glycol) (PEG) with reactive end groups (such as epoxides in PEG-diglycidyl ether) and the reagent has multiple reactive sites (e.g. diethylenetriamine). Each possibility represents a separate embodiment of this invention.
In some embodiments, the weight ratio of the particles to the polymeric material is between 0.25-5%. In another embodiment, the weight ratio is between 0.5-2%. In another embodiment, the weight ratio is between 1-5%.
Another polymer material to be used in the context of this invention is resins used in dental, surgical, chirurgical and orthopedic composite materials. In such applications, anti-microbial particles could be first dispersed within the resin part or added simultaneously with filler or any other solid ingredients (if any). Most of these resins are acrylic or epoxy type monomers that undergo polymerization in-vivo.
Preparation of the Compositions of this Invention
In some embodiments, the composites of this invention are prepared by embedding the anti-microbial particles into the polymeric materials of this invention. In another embodiment, one type of particle is embedded in the polymeric materials. In another embodiment, a combination of different particle types is embedded in the polymeric materials. In some embodiments, the embedding may be achieved by a variety of methodologies.
In some embodiments, embedding functionalized microparticles into a polymeric material is obtained by two methodologies: A) Extrusion technology: the particles are added into molten thermoplastic polymer into extruder, preferably twin-coned extruder. B) A thermoplastic or thermoset polymer is heated in an organic solvent (non-limiting examples comprise xylene, toluene, their derivatives or any combination thereof) under reflux conditions to achieve the complete dissolution of the polymer. The anti-microbial particles are then dispersed in the same solvent as used for the polymer and the mixture is added to the dissolved polymer using overhead stirrer or homogenizer. After complete dispersion of particles within the polymer, the solvent is evaporated using conventional distillation or evaporation method.
In some embodiments, embedding functionalized microparticles into a silicone based polymeric material is obtained by several methodologies: A) Room temperature vulcanization (RTV) of silicone precursor is achieved, wherein particles are incorporated into unpolymerized or pre-polymerized silicone before final curing at final concentration of 0.5-8% wt particles/silicone polymer. In another embodiment, the curing is activated by moisture. In another embodiment, the curing is activated by heat. B) RTV of silicone precursor is achieved, wherein polymerization is induced by mixing two components of the polymerization mixture. In another embodiment, particles are incorporated into both parts at final concentration of 0.5-8% wt. particles/silicone polymer, or in one of the parts at doubled concentration, giving the 0.5-8% wt. particles/silicone polymer final concentration.
Thus, according to some embodiments, this invention provides a method for preparing a composition comprising embedding a plurality of anti-microbial particles in a polymeric material as described above, wherein the particles are embedded in the material, the method comprises a step of adding the particles as described above, into a molten polymer material utilizing extrusion or to a polymer solution in solvent or via polymerization with the particles and polymer precursors.
In some embodiments, particles according to this invention are homogeneously distributed on the outer surface of the polymeric material in a surface concentration of between about 0.1 to about 100 particles per sq. micrometer. In another embodiment, particles according to this invention are homogeneously distributed on the outer surface of the polymeric material in a surface concentration of between about 1 to about 100 particles per sq. micrometer. The term “homogeneous distribution” is used to denote a distribution, characterized in that the standard deviation of the number of particles per sq. um is no more than the average number of particles per sq. micrometer. A homogeneous distribution is preferred for reproducibility and product specifications. If the distribution is not even, the product may exhibit different properties at different areas. The distribution of the particles away from the outer surface, that is, their bulk concentration, may be similar to that on the outer surface. As a general rule, the total surface of the particles preferably occupies at most about 20% of the surface of the material, preferably between 1% to 15%, more preferably between 1% and 5% and most about between 1% and 3% of the surface of the material.
According to some embodiments, on the average, every sq. micrometer of the outer surface of polymeric material has at least one particle of this invention.
According to another aspect of the invention there is provided a method for inhibition of bacteria, by contacting the bacteria with an anti-microbial particle of this invention, or a composition or pharmaceutical composition comprising the particle(s) of this invention. The term “inhibition” is referred to destruction, i.e. annihilation, of at least 99% of the bacteria, preferably 99.9%, most preferably 99.99% of the bacteria; reduction in the growth rate of the bacteria; reduction in the size of the population of the bacteria; prevention of growth of the bacteria; causing irreparable damage to the bacteria; destruction of a biofilm of such bacteria; inducing damage, short term or long term, to a part or a whole existing biofilm; preventing formation of such biofilm; inducing biofilm management; or bringing about any other type of consequence which may affect such population or biofilm and impose thereto an immediate or long term damage (partial or complete).
The term “biofilm” refers to a population of biological species (bacteria) attached to a solid surface.
The terms “anti-microbial” and “anti-bacterial” are used herein interchangeably. The quaternary ammonium and the tertiary amine groups of this invention [—+N(R1)(R2)(R3), —+NH(R1)(R2), —N(R1)(R2)—+N(R1′)(R2′)(R3′), —+NH(R1′)(R2′) or —N(R1′)(R2′) (defined in structures (1) to (3))] provide the anti-microbial activity. The quaternary ammonium's activity remains strong at any pH. Tertiary amines have high pKa values, therefore are active at almost all pH levels (up to 10, but not higher). The tertiary amine as well as the tertiary ammonium functional groups is less likely to cause undesirable side effects such as irritation of soft tissue, if used in contact with skin or mucosa or if used as a pharmaceutical composition.
In a preferred embodiment, the inhibition is achieved by contacting the bacteria with a matrix containing up to 5% w/w, more preferably up to 1% particles according to this invention, or compositions comprising them.
In one embodiment, this invention further provides a composition or a pharmaceutical composition comprising anti-microbial particles as referred hereinabove. In another embodiment, the composition/pharmaceutical composition comprises one type of particle. In another embodiment, the composition/pharmaceutical composition comprises a combination of different particle types. In one embodiment, non-limiting examples for a composition/pharmaceutical composition of this invention are dental adhesives, bone cement, dental restorative materials such as all types of composite based materials for filling tooth-decay cavities, endodontic filling materials (cements and fillers) for filling the root canal space in root canal treatment, materials used for provisional and final tooth restorations or tooth replacement, including but not restricted to inlays, onlays, crowns, partial dentures (fixed or removable) dental implants, and permanent and temporary cements used in dentistry for various known purposes, dental and orthopedic resin based cements, sealers, composite materials, adhesives and cements, dental restorative composites, bone cements, tooth pastes, lotions, hand-sanitizers, ointments and creams used for dermatology, wound care or in the cosmetic industry, plastic wear for medical and research laboratories; food packaging, mainly for dairy products and fresh meat and fish; pharmaceuticals packaging, paints for ships, that prevent growth of biofilm or treats, breaks down and/or kills a biofilm or bacteria within, paints for bathrooms, paint for hospitals and clean rooms; water filtration media and many others. Each possibility represents a separate embodiment of this invention. In some embodiments, the particles or composition comprising thereof are used for dental and orthopedic resin based cements, sealers, composite materials, adhesinves and cements; for dental and orthopedic metal implants and wires; for surgical sutures; for catheters, metal surgical tools, non-surgical medical devices. Each possibility represents a separate embodiment of this invention.
In one embodiment the composition or composite of this invention is a varnish or glaze which is applied to the tooth surface, a restoration of tooth or a crown comprising the particles of this invention. In another embodiment the varnish or glaze provide a protective coating, lacquer; superficially polished appearance to the tooth surface, restoration or crown of the tooth. In another embodiment, the varnish is a fluoride varnish which is a highly concentrated form of fluoride which is applied to the tooth's surface, as a type of topical fluoride therapy. In another embodiment, the aim of glazing is to seal the open pores in the surface of a fired porcelain. Dental glazes are composed of colorless glass powder, applied to the fired crown surface, so as to produce a glossy surface. Unglazed or trimmed porcelain may also lead to inflammation of the soft tissues it contacts.
In one embodiment, the composition/pharmaceutical composition of this invention is in a form selected from the group consisting of a cream, an ointment, a paste, a dressing and a gel, more preferably, wherein the composition is formulated for topical application or administration. In another embodiment, the composition is intended for administration into an oral cavity. The composition may be formulated as a tooth paste, and/or may be applied to a surface or medical device selected from the group consisting of: a denture cleaner, post hygienic treatment dressing or gel, mucosal adhesive paste, a dental adhesive, a dental restorative composite based material for filling tooth, decay cavities, a dental restorative endodontic filling material for filling root canal space in root canal treatment, a dental restorative material used for provisional and final tooth restorations or tooth replacement, a dental inlay, a dental onlay, a crown, a partial denture, a complete denture, a dental implant and a dental implant abutment.
In one embodiment, the pharmaceutical composition further comprises at least one pharmaceutically active ingredient. In another embodiment, non-limiting examples of pharmaceutically active ingredients include Analgesics, Antibiotics, Anticoagulants, Antidepressants, Anticancers, Antiepileptics, Antipsychotics, Antivirals, Sedatives and Antidiabetics. In another embodiment, non-limiting examples of Analgesics include paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), morphine and oxycodone. In another embodiment, non-limiting examples of Antibiotics include penicillin, cephalosporin, ciprofolxacin and erythromycin. In another embodiment, non-limiting examples of Anticoagulants include warfarin, dabigatran, apixaban and rivaroxaban. In another embodiment, non-limiting examples of Antidepressants include sertraline, fluoxetine, citalopram and paroxetine. In another embodiment, non-limiting examples of Anticancers include Capecitabine, Mitomycin, Etoposide and Pembrolizumab. In another embodiment, non-limiting examples of Antiepileptics include Acetazolamide, Clobazam, Ethosuximide and lacosamide. In another embodiment, non-limiting examples of Antipsychotics include Risperidone, Ziprasidone, Paliperidone and Lurasidone. In another embodiment, non-limiting examples of Antivirals include amantadine, rimantadine, oseltamivir and zanamivir. In another embodiment, non-limiting examples of Sedatives include Alprazolam, Clorazepate, Diazepam and Estazolam. In another embodiment, non-limiting examples of Antidiabetics include glimepiride, gliclazide, glyburide and glipizide.
In another embodiment, the pharmaceutical composition further comprises excipients. In another embodiment, the excipient comprises binders, coatings, lubricants, flavors, preservatives, sweeteners, vehicles and disintegrants. In another embodiment, non-limiting examples of binders include saccharides, gelatin, polyvinylpyrolidone (PVP) and polyethylene glycol (PEG). In another embodiment, non-limiting examples of coatings include hydroxypropylmethylcellulose, polysaccharides and gelatin. In another embodiment, non-limiting examples of lubricants include talc, stearin, silica and magnesium stearate. In another embodiment, non-limiting examples of disintegrants include crosslinked polyvinylpyrolidone, crosslinked sodium carboxymethyl cellulose (croscarmellose sodium) and modified starch sodium starch glycolate.
In one embodiment, the invention is directed to a packaging composition comprising a thermoplastic polymer and/or hydrogel embedded with anti-microbial particles as referred hereinabove. In another embodiment, the thermoplastic polymer and/or hydrogel is embedded with a mixture of two or more different particles. In another embodiment, the packaging composition is used in the packaging of food, beverage, pharmaceutical ingredients, medical devices, surgical equipment before operation, pre operation equipment, cosmetics, and sterilized equipment/materials.
In one embodiment the packaging composition comprises a thermoplastic polymer and/or hydrogel embedded with the particles as referred hereinabove. In another embodiment, the thermoplastic polymer is polyvinylchloride (PVC), polyethylene, polypropylene, silicone, epoxy resin or acrylic polymers. In another embodiment, the thermoplastic polymer is poly methylmethacrylate or polyurethane.
In another embodiment, the packaging composition further comprises binders, coatings, lubricants and disintegrants. In another embodiment, non-limiting examples of binders include saccharides, gelatin, polyvinylpyrolidone (PVP) and polyethylene glycol (PEG). In another embodiment, non-limiting examples of coatings include hydroxypropylmethylcellulose, polysaccharides and gelatin. In another embodiment, non-limiting examples of lubricants include talc, stearin, silica and magnesium stearate. In another embodiment, non-limiting examples of disintegrants include crosslinked polyvinylpyrolidone, crosslinked sodium carboxymethyl cellulose (croscarmellose sodium) and modified starch sodium starch glycolate.
In one embodiment, the packaging composition is used for packaging pharmaceutical ingredients. In another embodiment, non-limiting examples of pharmaceutical ingredients include analgesics, antibiotics, anticoagulants, antidepressants, anti-cancers, antiepileptics, antipsychotics, antivirals, Sedatives and antidiabetics. In another embodiment, non-limiting examples of analgesics include paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), morphine and oxycodone. In another embodiment, non-limiting examples of antibiotics include penicillin, cephalosporin, ciprofloxacin and erythromycin. In another embodiment, non-limiting examples of anticoagulants include warfarin, dabigatran, apixaban and rivaroxaban. In another embodiment, non-limiting examples of Antidepressants include sertraline, fluoxetine, citalopram and paroxetine. In another embodiment, non-limiting examples of anti-cancers include Capecitabine, Mitomycin, Etoposide and Pembrolizumab. In another embodiment, non-limiting examples of antiepileptics include Acetazolamide, Clobazam, Ethosuximide and lacosamide. In another embodiment, non-limiting examples of antipsychotics include Risperidone, Ziprasidone, Paliperidone and Lurasidone. In another embodiment, non-limiting examples of antivirals include amantadine, rimantadine, oseltamivir and zanamivir. In another embodiment, non-limiting examples of sedatives include Alprazolam, Clorazepate, Diazepam and Estazolam. In another embodiment, non-limiting examples of antidiabetics include glimepiride, gliclazide, glyburide and glipizide.
In one embodiment, the packaging composition is used in the packaging of food ingredients. In another embodiment, non-limiting examples of food ingredients packaged with the packaging material of the invention include fresh food, preservatives, sweeteners, color additives, flavors and spices, nutrients, emulsifiers, binders and thickeners. In another embodiment, non-limiting examples of fresh food include: meat, poultry, fish, dairy products, fruits and vegetables. In another embodiment, non-limiting examples of preservatives include Ascorbic acid, citric acid, sodium benzoate, calcium propionate, sodium erythorbate, butylated hydroxy toluene (BHT), silver, chlorhexidine, trichlozan and sodium nitrite. In another embodiment, non-limiting examples of sweeteners include Sucrose (sugar), glucose, fructose, sorbitol, mannitol and corn syrup. In another embodiment, non-limiting examples of color additives include Orange B, Citrus Red No. 2, annatto extract, beta-carotene, grape skin extract, cochineal extract or carmine and paprika oleoresin. In another embodiment, non-limiting examples of flavors and spices include monosodium glutamate, glycine slats, inosinic acid, isoamyl acetate, and limonene and allyl hexanoate. In another embodiment, non-limiting examples of nutrients include Thiamine hydrochloride, riboflavin (Vitamin B2), niacin, niacinamide, folate or folic acid. In another embodiment, non-limiting examples of emulsifiers include Soy lecithin, mono- and diglycerides, egg yolks, polysorbates and sorbitan monostearate. In another embodiment, non-limiting examples of binders and thickeners include Gelatin, pectin, guar gum, carrageenan, xanthan gum and whey.
In one embodiment, this invention provides a method for inhibiting or preventing biofilm formation, comprising applying onto a susceptible or infected surface or a medical device a composition of this invention.
In another embodiment, this invention provides a composition of this invention for use in inhibiting or preventing a biofilm formation.
In one embodiment, this invention provides a method for inhibiting or preventing biofilm formation or growth comprising placing a medical device of this invention (comprising a composition of this invention as referred hereinabove) on the surface to be treated. In another embodiment, the medical device is a wound dressing.
In another embodiment, this invention provides a medical device of this invention for use in inhibiting or preventing biofilm formation or growth.
In one embodiment, this invention provides a method for inhibition of bacteria, the method comprising the step of contacting the bacteria with the pharmaceutical or packaging composition or composite of this invention.
In another embodiment, this invention provides a pharmaceutical or packaging composition or for use in inhibiting bacteria.
In one embodiment, this invention provides a method for treating, breaking down or killing biofilm or bacteria within, comprising applying onto a susceptible or infected surface or a medical device the pharmaceutical or packaging composition or composite of this invention.
In another embodiment, this invention provides a composite or a pharmaceutical or packaging composition of this invention for use in treating, breaking down or killing biofilm or bacteria within.
Applications out of the medical field may for example be in clothing (e.g. for sports or outdoor activity; to prevent bacteria-induced sweat odor), athlete shoes or the inner part of a shoe wherein bacteria tend to collect, sportswear and clothing for outdoor activity, tooth brushes and any brush that are in contact with the human body, air and water filters, water treatment and distribution systems, pet cages as well as other veterinary items, etc.
In some embodiments, the anti-microbial compositions or composites of this invention affect annihilation of at least about 99% of the contacted bacteria, preferably, at least about 99.99% of the contacted bacteria.
It was further surprisingly discovered that the particles within compositions/composites/medical devices of this invention maintain high anti-microbial properties over time without leaching out and with no alteration of the properties of the hosting matrix. Such particles demonstrate enhanced anti-bacterial activity originating from the presence of closely packed anti-bacterial groups on a given particle's surface.
Medical Devices of this Invention
In one embodiment, this invention further provides a medical device comprising a composition of this invention. In one embodiment, non-limiting examples for medical devices of this invention are catheters, stents, surgical mesh, breast implants, joint replacements, artificial bones, artificial blood vessels, artificial heart valves (cardiology), artificial skin, plastic surgery implants or prostheses, intra uterine devices (gynecology), neurosurgical shunts, contact lenses (ophthalmology), intraocular lenses, ocular prosthesis, urethral stents, coating for subcutaneous (such as orthopedic or dental) implants, insulin pumps, contraceptives, pacemakers, tubing and cannulas used for intra venous infusion, tubing and cannulas used for dialysis, surgical drainage tubing, urinary catheters, endotracheal tubes, wound covering (dressing and adhesive bandage) and treatment (e.g. gels, ointments, pastes and creams for wound care which reduce biofilm and bacteria to aid wound healing) materials, sutures, catheters of all kinds that are inserted temporarily or permanently in blood vessels as well as the urinary system, shunt for use in brain applications, surgical gloves, tips for ear examination, statoscope ends and other elements used by the medical personnel; tooth brushes, tooth pick, dental floss, interdental and tongue brushes, surgical sutures, metal surgical tools, non-surgical medical devices, dental, and orthopedic metal implants and wires and surgical drains, syringes, trays, tips, gloves and other accessories used in common medical and dental procedures.
In one embodiment, this invention further provides a medical device comprising a dental appliance. In one embodiment, this invention further provides a medical device comprising an orthodontic appliance. The dental appliance and the orthodontal appliance comprise the particles and composition of this invention. In some embodiments, the orthodontal appliance include an aligner for accelerating the tooth aligning, a bracket, a dental attachment, a bracket auxiliary, a ligature tie, a pin, a bracket slot cap, a wire, a screw, a micro-staple, cements for bracket and attachments and other orthodontic appliances, a denture, a partial denture, a dental implant, a periodontal probe, a periodontal chip, a film, or a space between teeth. In some embodiments, the dental appliance include a mouth guard, used to prevent tooth grinding (bruxer, Bruxism), night guard, an oral device used for treatment/prevention sleep apnea, teeth guard used in sport activities.
In one embodiment, this invention further provides a trans dermal medical device such as orthopedic external fixation screws and wires used for bone fixations and stabilization and trans mucosal elements used in dental implants such as healing caps, abutments (such as multiunit), for screw retained or for cement retained dental prosthesis.
In one embodiment, this invention further provides a medical device comprising an endoscope (rigid and flexible), including, and not limited to a colonoscope, gastroscope, duodenoscope, bronchoscope, cystoscope, ENT scopes, laparoscope, laryngoscope and similar instruments for examination or treatment the inside of the patient's body, including any parts thereof, as well as accessories and other devices used in the procedure which either come in contact with body tissue or fluids; tubes, pumps, containers and connectors (used inside or outside the body) through which fluids, air or gas may be pumped into or suctioned out from the patient and could become contaminated by the patient or transfer contaminants from other patients; items such as brushes, trays, covers, tubes, connectors cabinets and bags used for reprocessing, cleaning, transporting and storing such equipment and can transmit or host biological contaminants, as well as filters for air or water used in dental or medical procedures, hospital surfaces (such as floors, tabletops), drapes, curtains, linen, handles and the like.
The antimicrobial property may protect the patient and the medical staff from cross contamination from patient to patient or from patient to the examiner. Self-sterilizing packaging for medicines and items that enter the operation room are also beneficial.
In one embodiment, this invention further provides processes for preparing the medical devices comprising the composites. In another embodiment, the medical devices are prepared via the steps of: providing a fluid phase of the composite of this invention; shaping the fluid; and hardening of the shaped fluid, affording the desired medical device. In another embodiment, the medical devices are prepared via the steps of: providing a solid phase of the composite; and shaping of the solid, affording the desired medical device. In another embodiment, the shaping is accomplished via extrusion or molding. In another embodiment, fluid phase of the composite comprises melted composite or a composite dissolved in a solvent.
Another polymer material to be used in the context of this invention is resins used in dental, surgical, chirurgical and orthopedic composite materials. In such applications, anti-microbial particles could be first dispersed within the resin part or added simultaneously with filler or any other solid ingredients (if any). Most of these resins are acrylic or epoxy type monomers that undergo polymerization in-vivo.
The following examples are presented in order to more fully illustrate the preferred embodiments of this invention. They should in no way, however, be construed as limiting the broad scope of this invention.
Silica dioxide core particles were prepared by hydrolysis of tetraalkoxy silicate under alkaline conditions. The reaction solution was prepared by mixing 9 parts by weight of ethanol, 0.4 parts of deionized water and 0.1 part of ammonia, keeping the pH within the range of 10-14. Controlling the particle size and the reaction rate is achieved by adjusting the concentration of water and ammonia in the reaction solution. 0.5 parts of tetraethyl orthosilicate (TEOS) was added to the solution in one portion with stirring at 1,000 RPM for 1 hour. The reaction mixture first turned opaque, followed by a white solid precipitation, indicating the reaction endpoint and agglomerates formation of primary particles. The particles were recovered by centrifugation filtration, rinsing with 20 parts of deionized water and drying using freeze drying or heating. Optionally, further surface activation may be performed by shortly rinsing particles in sulfuric acid/hydrogen peroxide solution commonly known as “pirhana solution”. This last step converts most of the particles' surface into hydroxyl form and promotes an efficient surface functionalization.
Nitrogen adsorption method was used to determine the morphology of porous silica dioxide particles by utilizing Barrett-Joyner_Halenda (BJH) model. Non-functionalized mesoporous silica dioxide particles were rinsed in Milli-Q water, dried and then degassed. Pore size was obtained from the adsorption/desorption isotherm by applying BJH model. Average particle size measured using dynamic light scattering method. Therefore, said particles are of 186 nm in diameter and having pore size of 5.0 nm.
Magnetite (Fe3O4) particles were prepared by co-precipitation of Fe2+ and Fe3+ ions, from FeCl2 (1 mol eq) and FeCl3 (0.5 mol eq) in aqueous solution in basic condition utilizing NH4OH (pH˜12). After precipitation, the particles recovered under constant magnetic field. Prior to functionalization, particles were rinsed in Mili-Q water followed by vacuum drying. Surface activation of the obtained magnetite particles was performed by a short rinse of the particles in nitric acid or sulfuric acid and hydrogen peroxide solution. The last step converted most of particles' surface into hydroxy form allowing further functionalization of the core.
Within the solid support method, a few stages were employed. First, the linker 3-aminopropyltrimethoxysilane was allowed to condense onto particles surface (surface functionalization) via hydrolysis of methoxy groups, resulting in the attachment of the linker to the silica core (
Within the solution method, a few stages were employed. In the first stage the linker molecule was elongated by consecutive addition of 1,2-dichloroethane and 1,2-diaminoethane (
Functionalization of silica particles was performed in two stages. Initially, primary amine-functionalized silica particles were prepared. The primary amine was the functionalized by reductive amination to yield a tertiary amine comprising terpenoid groups, or alternatively a quaternary ammonium group comprising one elongated alkyl chain of 8 carbons.
A pretreatment of inorganic cores (for example SiO2, Fe3O4) was essential for removing any of residual organic material such as solvent or other ligands and converts the surface to active hydroxyl group that are ready to undergo functionalization (silanization). The pretreatment included rinsing the particle in 20 to 40% solution of hydrogen peroxide in sulfuric acid or alternatively in 20 to 40% of NH4 solution in sulfuric acid for at least 5 minutes at ambient conditions or at elevated temperature, preferable at least for 30 minutes at 60° C.
Polymerization of the silane groups (
Direct contact between bacteria and the tested materials was achieved by applying 10 μl of bacterial suspension on each tested material sample in a set of 8 wells. The plate was incubated at a vertical position for 1 h at 37 TC. During this incubation period, the suspension's liquid evaporated and a thin layer of bacteria was obtained, ensuring direct contact between the bacteria and the tested material. The plate was then placed horizontally and 220 μl of brain-heart infusion broth were added to each well containing the material. All tests were done using Stapilococcus aureus (S. aureus) and Enterococcus faecalis (E. faecalis) as representative for Graham positive bacteria and Pseudomonas aeruginosa (P. aeruginosa) as representative for Graham negative bacteria.
The kinetic measurement of bacterial growth was done utilizing temperature controlled microplate spectrophotometer (VERSAmax, Molecular Devices Corporation, Menlo Oaks Corporate Centre, Menlo Park, Calif., USA). The microtiter plate was placed in the spectrophotometer, at 37° C. with 5 sec vortex prior to every reading. Bacterial growth was estimated by the OD changes in each well at 650 nm every 20 minutes for 24 hours.
Silica particles of an average diameter of 186 nm functionalized with quaternary dimethyl octyl ammonium were embedded in polypropylene. Samples of polymer films were prepared by hot molding of polypropylene and the functionalized silica particles at 0, 1 and 2% wt/wt of particles. 5×10 mm samples of prepared films were positioned into wells of microtitre plate touching the inside sidewalls of each well.
The anti-bacterial test results demonstrated a consistently low OD (0.1) level during the experiment for the polypropylene samples containing 1 and 2% wt/wt of particles, while the polypropylene sample containing no particles and the control sample containing S. aureus demonstrated a significant OD increase (0.7) (
Similar results were obtained in the presence of P. aeruginosa, where the polypropylene samples containing 2% wt/wt of particles demonstrated a low OD level (0.05) and the sample containing 1% wt/wt of particles showed a slightly higher OD level (0.15). In contrast, the polypropylene sample containing no particles and the control sample containing P. aeruginosa demonstrated a significant OD increase (0.7) (
These results reveal the anti-microbial effect obtained by the modified polypropylene substrate utilizing quaternary ammonium functionalized silica particles. Particles that used in this experiment had large number of 170 anti-microbial active functional group (170=(n1+n2)×m×p; n1, n2, m and p are defined in structure 1) grafted per nm2 of the surface of the core.
Silica particles of an average diameter of 13 μm functionalized with quaternary dimethyl octyl ammonium were embedded in commercially available dental polymerizable methylmethacrylate (Unifast Trad, GC America inc) at concentration of 0 and 1% wt/wt. The methylmethacrylate was mixed in a silicone crucible at a liquid/powder ratio of 2 g/ml respectively, in accordance to manufacturer's instructions and then allowed to polymerize onto sidewalls of microtiter wells at 37° C. for 24 hours prior to the anti-microbial test. Particles that used in this experiment had large number of 170 anti-microbial active functional group grafted per nm2 of the surface of the core (170=(n1+n2)×m×p; n1, n2, m and p are defined in structure 1).
The anti-bacterial test results demonstrated a consistently low OD (0.1) level during the experiment for the methymethacrylate (PMMA) samples containing 1% wt/wt of particles, while the PMMA sample containing no particles and the control sample containing P. aeruginosa demonstrated a significant OD increase (0.8) (
Similar results were obtained in the presence of S. aureus, where PMMA sample containing 1% wt/wt of particles demonstrated a low OD level (0.1) and the sample containing no particles and the control sample containing S. aureus demonstrated a significant OD increase (0.8) (
These results reveal the anti-microbial effect obtained by the modified PMMA substrate utilizing quaternary ammonium functionalized silica macro-size particles.
Silica particles of an average diameter of 186 nm functionalized with di-cinnamyl amine (tertiary amine) were embedded in commercially available dental polymerizable methylmethacrylate (Unifast Trad, GC America Inc.) at concentration of 0 and 1% wt/wt. The methymethacrylate was mixed in a silicone crucible at a liquid/powder ratio of 2 g/ml respectively, in accordance to manufacturer's instructions and then allowed to polymerize onto sidewalls of microtiter wells at 37° C. for 24 hours prior to the anti-microbial test. Particles that were used in this experiment had large number of 170 anti-microbial active functional group grafted per nm2 of the surface of the core (170=(n1+n2)×m×p; n1, n2, m and p are defined in structure 1).
The anti-bacterial test results demonstrated a consistently low OD level during the experiment for the methymethacrylate (PMMA) samples containing 1% wt/wt of particles, while the PMMA sample containing no particles and the control sample containing P. aeruginosa demonstrated a significant OD increase (
Similar results were obtained in the presence of S. aureus, where PMMA sample containing 1% wt/wt of particles demonstrated a low OD level (0.1) and the sample containing no particles and the control sample containing S. aureus demonstrated a significant OD increase (0.7) (
These results reveal the anti-microbial effect obtained by the modified PMMA substrate utilizing di-terpenoid (tertiary amine) functionalized silica-core based particles.
Magnetite (Fe3O4) particles of an average diameter of 78 nm functionalized with quaternary dimethyl octyl ammonium (prepared as described in Example 3) were embedded in commercially available dental polymerizable methylmethacrylate (Unifast Trad, GC America inc) at concentration of 0, 1 and 2% wt/wt. The PMMA was mixed in a silicone crucible at a liquid/powder ratio of 2 g/ml respectively, in accordance to manufacturer's instructions and then allowed to polymerize onto sidewalls of microtiter wells at 37° C. for 24 hours prior to the anti-microbial test.
The anti-bacterial test results demonstrated a consistently low OD level (0.1) during the experiment for the methymethacrylate (PMMA) samples containing 1 and 2% wt/wt of particles, while the PMMA sample containing no particles and the control sample containing E. faecalis demonstrated a significant OD increase (0.8) (
These results reveal the anti-microbial effect obtained by the modified PMMA substrate utilizing quaternary ammonium functionalized magnetite-core based particles.
Silica particles of an average diameter of 186 nm functionalized with quaternary ammonium comprising di-cinnamyl methyl substitutes (prepared as described in Example 4), were embedded in commercially available dental polymerizable methylmethacrylate (Unifast Trad) at concentration of 0, 2 and 3% wt/wt. The PMMA was mixed in a silicone crucible at a liquid/powder ratio of 2 g/ml respectively, in accordance to manufacturer's instructions and then allowed to polymerize onto sidewalls of microtiter wells at 37° C. for 24 hours prior to the anti-microbial test. Both liquid and solid parts of the polymer material were manipulated accordingly to manufacturer's instructions and then allowed to polymerize onto sidewalls of microtiter wells at 37° C. for 24 hours prior to the anti-microbial test.
The anti-bacterial test results demonstrated a low OD (0.1) level during the experiment for the methymethacrylate (PMMA) samples containing 3% wt/wt of particles, and a slightly higher level for the sample containing 2% wt/wt of particles. In contrast, the PMMA sample containing no particles and the control sample containing E. faecalis demonstrated a significant OD increase (0.7) (
These results reveal the anti-microbial effect obtained by the modified PMMA substrate utilizing di-terpenoid quaternary ammonium functionalized silica-core based particles.
Poly methylmethacrylate (Unifast Trad) cylindrical specimens of 0.4 mm in diameter and 10 mm in length were prepared using polypropylene pipe-like molds. Specimens were allowed to polymerize at room temperature for 1 hour within the molds, then stored in DDW at 37° C. for 24 hours prior to testing. Each tested group contained 10 specimens of cured cement with 8% wt/wt NPs. A control group was obtained using the polymer specimens without functionalized particles. Compressive strength test was carried out using universal testing machine (Instron 3366, Canton, Mass.) operated at displacement speed of 1 mm/min. Data was instantly analyzed with Merlin software which calculated the compressive strength and the Young's modulus.
The NPs tested were marked as follows:
1) SiCial—containing 8% wt of silicadioxide particles functionalized with tertiary amine functional group having two cinnamyl substituents with diameter of 186 nm (prepared as defined in Example 4).
2) QPEI—containing 8% wt of dimethyl octyl quaternary ammonium functionalized PEI particles of 24 nm (prepared as defined in Example 5).
3) A sample of unmodified poly methylmethacrylate (PMMA) resin was used as a control.
The results demonstrated relatively high stability of the modified acrylate resin comprising the silica based particles under stress conditions. The compressive strength of unmodified PMMA, SiCial and QPEI are 56.61, 78.79 and 0.43 MPa respectively. The embedment of silica functionalized antibacterial particles did not jeopardize the mechanical properties of the resin, and appeared to be advantageous in terms of stress-stability in comparison to the polymeric functionalized resin (QPEI) (
The samples described on Example 7 were tested for their antibacterial activity by direct contact test as described herein above (Example 6).
The results demonstrate the potent antibacterial effect of the modified resins due to the embedment of the functionalized silica-based and PEI-based particles compared with the unmodified resin control sample and the natural growth of bacteria as depicted in the presence of E. faecalis (
Three glass slides were coated utilizing spraying of a solution containing functionalized silica based particles onto the hydroxylated glass surface. The silane group anchored the functionalized particles to the slide upon hydrolysis of the leaving groups and the slides were further dried at elevated temperature to allow complete condensation of the particles onto to the surface. The glasses were marked as follows: 1) dimethylamine functionalized silica particles; 2) tertiary amine with two cinnamyl groups functionalized silica particles.
S. aureus suspension was applied onto each functionalized slide in a homogeneous manner. The slides were placed in contact with blood agar petri dish facing towards the agar for 15 minutes. Subsequently, the slides were removed and the petri dishes were kept in 37° C. for 24 to allow formation of colonies.
The results revealed that no colonies were formed onto the petri dish which came in contact with functionalized slide 2, demonstrating the advantageous antibacterial activity of the tertiary amine comprising two cinnamyl groups (
Method 1—degree of amine loading onto particle's surface. 1.0 g of dry amine-functionalized silica particles powder having 180 nm diameter was immersed in 20 ml of dry toluene. Then 0.1 g (1.9 mmol) of Fluorenylmethyloxycarbonyl (Fmoc) chloride were added. The mixture was reacted at 60° C. under continuous stirring for 12 hours. Resulting particles were filtered and rinsed 3 times with 5 ml of N-Methyl-2-pyrrolidone (NMP), then 3 times with 5 ml of diethyl ether and then dried in-vacuo. Detachment of Fmoc was performed by immersing 0.01 g of Fmoc-labeled particles in 2 ml of 20% by volume solution of piperidine in NMP and shaked for 30 min followed by filtration of solvent. This procedure repeated once more and both solutions were combined (to a total of 4 ml solution). Concentration of Fmoc in solution was determined using light absorbance in spectrophotometer at 301 nm and calculated in accordance to Beer's law A=EbC, where A is absorbance, E is molar absorption constant (6300 cm−1M−1), b is pathway length (1 cm) and C is molar concentration. Prior to spectrometry readings, solution was diluted at 1:100 ratio in NMP.
Results: A=1.1, therefore C=100×(1.7×10−4)M=0.017M. Therefore, N(moles)=0.017M×0.004L=6.98×10−5 moles. Total loading is therefore 6.98×10−5 mol/0.01 g=0.007 moles/gr. Assuming perfect sphere geometry of particles, the shell surface area of single particles is 102000 nm2 and particle average volume is 3050000 nm3. Particles density calculated using Archimedes method is 2.5 g/(1×1021 nm3), giving a single particle's mass of 7.6×10−16 g. Therefore, the loading of functional groups is ((7.6×10−16 g)×(0.007 moles/g))/102000 nm2=5.2×10−23 moles/nm2, which is approximately 31 amine/ammonium per nm2.
Method 2—degree of functional tertiary amines substituted with two cinnamyl groups. 0.001 g of 186 nm silica particles functionalized with di-cinnamyl amines were immersed in 100 ml of absolute ethanol. Spectrophotometric reading were taken at the wavelength of 327 nm. E(cinnamaldehyde)=25118 cm−1M−1. All calculations were performed as described in Method 1.
Results: A=1.5, therefore total tertiary amines count is 6.0×10−6 moles, which is 3.0×10−3 moles/g.
Therefore the functional groups loading is approximately 13 amine/ammonium per nm2.
Both methods are applicable for all kinds of inorganic and organic core particles, whereas for organic particles (polymeric particles) the Fmoc functionalization is performed after the cross-linking step.
P. aerginosa
S. aureus
As shown in the above table, the polmethylmethacrylate modified particles of the invention showed antibacterial activity for both inorganic and organic cores. The denser functional groups are packed onto particle surface, the stronger antibacterial activity against both tested organisms, for both organic and inorganic cores and for both quaternary ammonium salts and tertiary amines (terpenoids). Such denser packing is found as the number of anti-microbial active groups per one anti-microbial active part increases; for example, first (top) entry in each inorganic core has a ratio of only one anti-microbial active group per one anti-microbial active part, whereas other entries for the inorganic cores comprise higher ratio and those first entries have the lowest exhibited anti-bacterial activity.
Four types of SiO2 based particles were added to soft paraffin at concentration of 2% wt and dispersed until homogeneous paste was formed, while using ceramic pestle and crucible. Samples prepared according to example 4 and were marked as 2% Silicadioxide-di-cinnamylamine for particles having tertiary amine functional groups with two cinnamyl substituents, 2% Silicadioxide-quaternary ammonium for particles having one octyl and two methyls attached to quaternary nitrogen, 2% QPEI for quaternary ammonium polyethyleneimine, 2% Silicadioxide dimethylamino for samples having tertiary amine of two methylenes on the nitrogen and “E. faecalis” for control of paraffin-only group. Direct contact test (DCT) was performed for treated gauze pads with each one of paraffin samples. The results (
Composition of antibacterial toothpaste: glycerol, water, sorbitol, sodium lauryl sarcosine, hydrated silica, titanium dioxide and antibacterial particles. The antibacterial particles comprise SiO2 particles which is commonly used in commercial toothpaste, where some of the particles are modified by covalently binding antibacterial groups. The antibacterial groups may be quaternary ammonium and tertiary amine having two cinnamyl groups or having tertiary amines with two citral groups. Below are shown results of a toothpaste formulation containing 5% wt of antibacterial SiO2 particles having tertiary amine with two cinnamyl groups.
Surface retention experiment: Herein are presented results of particles retention onto glass surfaces examined by simulation of tooth brushing procedure during 1 minute with three compositions of toothpaste: A: commercially available toothpaste (control); B: the toothpaste composition as presented above, without antibacterial particles (control) and C: proposed toothpaste with antibacterial particles retention onto glass slides. After brushing, slides rinsed with same amount of water in same manner. Retention examined visually (
Antibacterial activity experiment: antibacterial activity of proposed toothpaste was examined by dispersing 10 μl of S. mutars (˜106 viable cells) within total volume 220 μl of phosphate buffer saline (PBS) and proposed toothpaste. In this experiment, toothpaste formulation with antibacterial particles was tested, at the following final concentrations (% wt.): 0, 0.25, 0.5, 1 and 2. Each sample performed in 8 repetitions in 96 well plate. Bacteria growth monitored by reading optical density at 650 nm while incubating at 37° C. (
A contact lenses composition comprising antibacterial SiO2 particles with tertiary amine having two cinnamyl groups which are incorporated into polymethylmethacrylate at final concentration of 2% wt were prepared. The polymerization of the polymethylmethacrylate was done in the following method: 48 g of methyl methacrylate monomer were mixed with 1 g of benzoyl peroxide in glass beaker using overhead stirrer at 500 rpm. until complete dissolution of peroxide. In parallel, 50 g of methylmethacrylate were mixed with 1 g of dihydroxyethyl p-toluidine until complete dissolution. Into the methylmethacrylate/dihyhdroxyethyl and p-toluidine solution, 2 g of SiO2 particles having tertiary amine with two cinnamyl groups were added and dispersed using high-shear homogenizer at 3000 rpm until homogeneous solution was obtained. Then both solutions were mixed and allowed to be polymerized onto sidewalls of 96 well plate.
Antibacterial activity experiment: direct contact test (DCT) was performed using E. faecalis as test bacteria at 37° C. during 24 hours.
Bone cement is used in orthopedics for fixation of implants during surgery operations. Bone cement composition: this cement composition is based on liquid monomer methylmethacrylate solution with initiators and solid pre-polymerized polymethylmethacrylate with initiators as activators, as shown above for the contact lenses.
Antibacterial Activity Experiment:
the silica based antibacterial particles of the current invention were added to a solid part of commercially available bone cement. Three samples have been tested for antibacterial activity: (I): SiO2 particles having tertiary amine with two cinnamyl groups, (II): SiO2 particles with quaternary ammonium, wherein the overall concentration of particles in each sample after mixing with liquid part of bone cement was 2% wt and (III) unmodified bone cement as control in this experiment. Samples of bond cement, unmodified and modified with antibacterial particles—were applied onto sidewalls of 96 wells plate and DCT protocol was performed with S. aureus as test bacteria.
1 g of chloromethyl-polystyrene beads (Merrifield resin) was dispersed within 50 ml of dichloromethane. 1 g of SiO2 particles having tertiary amine with two citral groups was dispersed in 10 ml of dichloromethane using high shear homogenizer at 3000 rpm until homogeneous suspension was obtained. Both solutions were combined and stirred for 72 h at room temperature. Subsequently, modified beads with antibacterial particles were rinsed 5 times with 20 ml of DCM, then twice with 20 ml of diethyl ether and eventually were dried under vacuum overnight.
Antibacterial Activity Experiment:
antibacterial test was performed in brain heart infusion (BHI) suspension of the modified beads to study the effect on S. aureus bacteria. 220 μl of BHI suspension with variable concentration of modified beads were poured into wells of 96 wells plate, with 8 wells for each concentration. Subsequently, 10 ul of bacteria (106 viable cells) were added into each tested well and light absorbance was measured at 650 nm each 20 minutes for 24 h. During the experiment, each plate with the sample was kept at 37° C. and shaked for 5 sec before each reading. As shown in
S. mutans
E. faecalis
Table 2 demonstrates the relation between the number of functional groups onto silica particle and the antibacterial activity against two selected bacteria. Entries 1 and 3 has a ratio of only one anti-microbial active group per one anti-microbial active part, whereas other comprise higher ratios. In addition, shown the differences between quaternary ammonium functionality and tertiary amines with two cinnamyl groups. It is concluded that (i) the number of functional groups is proportional to the ability of the particles to inhibit bacteria growth and (ii) quaternary ammonium functionality demonstrate strongest potency to inhibit bacteria growth than tertiary amines with 2 cinnamyl groups.
Typical dental restorative composite was prepared by mixing the following components (weight % in brackets):
A composite of anti-microbial quaternary polyethylene imine (QPEI) particles in silicone polymer was prepared according to the following: two-part room temperature vulcanization silicone material was used as model silicone material used in manufacturing of silicone medical devices, such as breast implants and Foley catheters. Unmodified silicone polymer was used as reference (marked as “silicone”). The silicone precursor was polymerized by pressing with a flat plastic sheet against flat plastic surface which QPEI mixed with the two components were applied to. Obtained silicone sheets were cut to 5×15 mm specimens and placed onto sidewalls of 96-weels plate. Direct contact test (DCT) performed against E. faecalis. As shown in Error! Reference source not found., full inhibition of bacteria grow obtained at 1% wt/wt of QPEI particles.
Anti-microbial particles [silica core functionalized with a methyl octyl ammonium quaternary ammonium groups, wherein n=1-3 (i.e the number of monomeric units per anti-microbial active unit is between 1 to 3) wherein the number of anti-microbial active groups is 174 (structure 1; (n1+n2)×m×p=174) per one sq. nm (nm2) of the core surface] were embedded in commercially available dental polymerizable methylmethacrylate (Unifast Trad, GC America inc) at concentration of 0-2% wt/wt. The methylmethacrylate was mixed in a silicone crucible at a liquid/powder ratio of 2 g/ml respectively, in accordance to manufacturer's instructions and then allowed to polymerize onto sidewalls of microtiter wells at 37° C. for 24 hours prior to the anti-microbial test
The anti-bacterial test (direct contact test, see example 5) results (
Silica-core based particles functionalized with tertiary amine bearing two cinnamaldehyde groups (SNP-Cial,
The hydrogel was prepared by reacting poly(ethylene glycol) diglycidyl ether with diethylenetriamine. Immediately after mixing of both reactants, 2QSi particles [=silica core functionalized with a methyl octyl ammonium quaternary ammonium groups, wherein the number of monomeric units per anti-microbial active unit is 2 [m=2; Structure 1)] were introduced and mixed until uniform suspension obtained. This blend was poured onto flat mold and left to dry at 37° C. for 48 hours to complete polymerization. Subsequently, the thin film of the polymer was dipped in deionized water allowing it to absorb moisture.
The DCT protocol (example 5) was used to evaluate the antibacterial activity of modified hydrogel with 2QSi, as presented in table 3.
As shown in the table, anti-bacterial activity (against E. faecalis) increased as the 2QSi particles concentration within the poloxamer composite was increased.
2QSi particles [=silica core functionalized with a methyl octyl ammonium quaternary ammonium groups, wherein the number of monomeric units per anti-microbial active unit is 2 [m=2; Structure 1)] were incorporated into alginate hydrogel by premixing dry alginate powder with 2QSi particles. Subsequently, sufficient amount of water was added and the compound was mixed until homogeneous paste was formed.
The hydrogel was allowed to dry onto sidewalls of DCT plates and antibacterial activity was evaluated in accordance to the DCT protocol (example 5), as presented in table 4.
As shown in the table, anti-bacterial activity (against E. faecalis) increased as the 2QSi particles concentration within the alginate composite was increased.
Design: The antibacterial activity of 2QSi-POSS particles [=POSS core functionalized with a methyl octyl ammonium quaternary ammonium groups, wherein the number of monomeric units per anti-microbial active unit is 2 [m=2; Structure 1)] incorporated in silicone implants at 2% w/w, implanted subcutaneous was tested. POSS particles having quaternary ammonium functionality with n=2 were incorporated into silicone rods that were implanted in the back of mice on one (right) side of the spine, and identical rods without particles were implanted on the opposite (left) side of the spine as controls. The implants were inoculated with 10 μl of 108/ml E. faecalis either one ex-vivo (before implantation) (Group A, n=10) or 8 times in 2-day intervals in-situ (starting 1 week after implantation, to allow for recovery, Group B, n=4). After explanation, the implants were vortexed and rinsed to remove free (planktonic) bacteria and then rolled on Agar plate to assess biofilm presence on the implant by CFU count (stamp test).
Results: In group A (inoculated ex-vivo), among 9/10 animals available for explantation and analysis, none of the particle-containing implants had biofilm on the stamp test (zero CFU), compared to 6 control (no-particles) implants who had significant growth, 2 with minor growth and 1 with no growth. Similarly, no loosely bound bacteria were detected in the vortexed suspension from the test implants, vs. 1.5×103 recovered from the control implants. In group B (inoculated in-situ), stamp test showed no biofilm in 2 animals on both test and control implants, while in the 2 other animals there was extensive growth on the control implants vs. no growth on the test implant. Results are summarized in Table 5 below.
These results indicate that the antibacterial particles can prevent biofilm growth and significantly reduce overall number of bacteria on silicone subcutaneous implants.
While certain features of this invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of this invention.
This application claims priority from U.S. Provisional Patent Application No. 62/551,806 filed Aug. 30, 2017, U.S. Provisional Patent Application No. 62/551,813 filed Aug. 30, 2017, and to U.S. Provisional Patent Application No. 62/644,604 filed Mar. 19, 2018, which are hereby incorporated by reference by their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62551806 | Aug 2017 | US | |
| 62551813 | Aug 2017 | US | |
| 62644604 | Mar 2018 | US |
