Patent Application
20180303740
Dental enamel is a thin, hard layer of calcified material that covers the crown of teeth. The major mineral component of dental enamel is hydroxyapatite, a crystalline form of calcium phosphate. Chemical erosion of dental enamel may arise from tooth exposure to acidic food and drinks or to stomach acids arising from gastric reflux. The erosion of dental enamel can lead to enhanced tooth sensitivity due to increased exposure of the dentin tubules and increased dentin visibility leading to the appearance of more yellow teeth. The salivary pellicle (a thin layer of salivary glycoproteins deposited on teeth) is integral in protecting the teeth against an erosive challenge. As a result, people that experience xerostomia are more susceptible to acid erosion damage.
Existing methods developed to help prevent enamel erosion include incorporating a source of free fluoride into oral care compositions. Fluoride reduces damage to the enamel, through the formation of fluorapatite, which dissolves at a lower pH than hydroxyapatite and so is more resistant to acid damage. Stannous salts have also been incorporated into dentifrice formulations to protect the enamel surface similarly, by forming a more acid resistant mineral layer. Polymers have also been described that coat and protect the enamel surface.
Acids are also generated in the oral cavity when plaque containing cariogenic bacteria metabolize carbohydrates. Since plaque forms a barrier controlling the kinetics of proton and mineral diffusion through the enamel, plaque acids cause carious lesions. Incorporating fluoride ions in dentifrice formulations is the most common method to mitigate the effects of plaque acids. Fluoride reduces the rate of demineralization and enhances remineralization. Several approaches have also been developed to stabilize calcium phosphate salts or control the plaque pH to enhance remineralization.
Although methods have been developed to mitigate the effects of non-bacteria and bacteria generated acids on the teeth, there is still the need to provide improved oral care compositions that effectively repair the enamel from the effects of acid erosion and bacteria acids.
WO2011/157497 discloses a foamable oral care composition comprising less than 1.5% anionic surfactant (by total weight anionic surfactant based on the total weight of the composition), abrasive cleaning agent and hydrophobin.
The present inventors have unexpectedly found that Hydrophobin-like Proteins (HLPs) are effective in repairing or mitigating the effects of dental erosion, promoting dental remineralization, and enhancing the anti-cavity effects of fluoride.
For example, in one embodiment, HLPs are prepared for formulation with ingredients of a suitable orally acceptable carrier, by diluting in buffer, e.g., a phospate buffer such as Na2HPO4 buffer (1.5 mM) and CaCl2 (2.5 mM), to provide a buffered solution having approximately neutral or slightly basic pH, e.g., pH 7-8, e.g., about pH 7.5, filtering and centrifuging the solution to obtain a filtrate comprising the HLP. A biocide (for example cetylpyridinium chloride at 0.1%) and fluoride may be added to the filtrate. The HLP may then be combined with components of an orally acceptable carrier, for example a toothpaste or mouthwash base, to provide an oral care composition for repairing or mitigating the effects of dental erosion, promoting dental remineralization, and enhancing the anti-cavity effects of fluoride.
This disclosure thus relates to an oral care composition (Composition 1), for example a dentifrice, comprising:
A particular novel embodiment of Composition 1 is a dentifrice comprising
In one aspect, the disclosure provides any of Compositions 1, et seq. for use in repairing or inhibiting dental erosion, promoting remineralization, and/or enhancing the anti-cavity effects of fluoride; for example for use in any of the following methods according to Method 1, et seq.
In another aspect, the disclosure provides a method (Method 1) of repairing or inhibiting dental erosion, promoting dental remineralization, and/or enhancing the anti-cavity effects of fluoride comprising applying to the teeth a composition, e.g., any of Composition 1, et seq. for example an oral care composition comprising:
In another embodiment, the disclosure provides the use of an HLP in the manufacture of an oral care composition, for example according to any of Compositions 1, et seq. for repairing or inhibiting dental erosion, promoting remineralization, and/or enhancing the anti-cavity effects of fluoride, e.g., in any of Methods 1, et seq.
In another aspect, the disclosure provides a method (Method 2) of making an oral care product, e.g. an oral care product useful for repairing or inhibiting dental erosion, promoting dental remineralization, and/or enhancing the anti-cavity effects of fluoride, e.g., a product according to any of Composition 1, et seq., comprising
For example, the disclosure provides an oral care composition comprising HLP, e.g., a composition according to any of Composition 1, et seq., wherein the oral care composition is obtained or obtainable by the process of Method 2, et seq.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls.
Unless otherwise specified, all percentages and amounts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight. The amounts given are based on the active weight of the material.
Hydrophobine-like Proteins (HLPs) according to this invention are proteins from organisms such as certain fungi and bacteria that have either an authentic hydrophobine sequence (=Hydrophobins) or a polypeptide sequence related to an authentic hydrophobin which confers hydrophobin-like properties, such as changing the contact angle as described below.
Hydrophobins are small proteins of about 100 AA which are characteristic for filamentous fungi and do not occur in other organisms. Recently, hydrophobin-like proteins were found in Streptomyces coelicolorthat are referred to as “Chaplins” and likewise have highly surface-active properties. Chaplins may assemble at water-air interfaces to give amyloid-like fibrils (Classen et al. 2003 Genes Dev 1714-1726; Elliot et al. 2003, Genes Dev. 17, 1727-1740).
Hydrophobins are distributed in a water-insoluble form on the surface of various fungal structures such as, for example, aerial hyphae, spores, fruit bodies. The genes for hydrophobins were isolated from ascomycetes, deuteromycetes and basidiomycetes. Some fungi comprise more than one hydrophobin gene, for example Schizophyllum commune, Coprinus cinereus, Aspergillus nidulans. Evidently, various hydrophobins are involved in different stages of fungal development. Said hydrophobins are presumably responsible for different functions (van Wetter et al., 2000, Mol. Microbiol., 36, 201-210; Kershaw et al. 1998, Fungal Genet. Biol, 1998, 23, 18-33).
A biological function of hydrophobins which is described in addition to reducing the surface tension of water for generating aerial hyphae is also the hydrophobization of spores (Wosten et al. 1999, Curr. Biol., 19, 1985-88; Bell et al. 1992, Genes Dev., 6, 2382-2394). Furthermore, hydrophobins are used for lining gas channels in fruit bodies of lichens and as components in the system of identifying plant surfaces by fungal pathogens (Lugones et al. 1999, Mycol. Res., 103, 635-640; Hamer & Talbot 1998, Curr. Opinion Microbiol., Volume 1, 693-697).
Complementation experiments have demonstrated that hydrophobins can be functionally replaced up to a certain degree within a single class. Previously disclosed hydrophobins can be prepared only with moderate yield and purity using customary protein-chemical purification and isolation methods. Attempts of providing larger amounts of hydrophobins with the aid of genetic methods have also not been successful up to now.
HLPs also relate to polypeptides of the general structural formula (I)
Xn-C1-X1-50-C2-X0-5-C3-X1-100-C4-X1-100-C5-X1-50-C6-X0-5-C7-X1-50-C8-Xm (I)
where X may be any of the 20 naturally occurring amino acids (Phe, Leu, Ser, Tyr, Cys, Trp, Pro, His, Gin, Arg, lie, Met, Thr, Asn, Lys, Val, Ala, Asp, Glu, Gly) and the indices at X indicate the number of amino acids, with the indices n and m being numbers between 0 and 500, preferably between 15 and 300, and C being cystein, with the proviso that at least one of the peptide sequences abbreviated as Xn or Xm is a peptide sequence of at least 20 amino acids in length which is not linked to a hydrophobin naturally, which polypeptides change the contact angle by at least 20° after coating of a glass surface.
The cysteins designated by C1 to C8 may either be in the reduced form or form disulfide bridges with one another in the proteins of the invention. Particular preference is given to the intramolecular formation of C—C bridges, in particular those having at least one, preferably 2, particularly preferably 3, and very particularly preferably 4, intramolecular disulfide bridges selected from the following group: C1 with C2; C3 with C4, C5 with C6, C7 with C8. If cysteins are also used in the positions designated by X, the numbering of the individual cystein positions in the general formulae may change accordingly.
Particularly advantageous polypeptides are those of the general formula (II)
Xn-C1-X3-25-C2-X0-2-C3-X5-50-C4-X2-35-C5-X2-15-C6-X0-2-C7-X3-35-C8-Xm (II)
where X may be any of the 20 naturally occurring amino acids (Phe, Leu, Ser, Tyr, Cys, Trp, Pro, His, Gin, Arg, Ile, Met, Thr, Asn, Lys, Val, Ala, Asp, Glu, Gly) and the indices at X indicate the number of amino acids, with the indices n and m being numbers between 2 and 300 and C being cystein, with the proviso that at least one of the peptide sequences abbreviated as Xn or Xm is a peptide sequence of at least 35 amino acids in length which is not linked to a hydrophobin naturally, which polypeptides change the contact angle by at least 20° after coating of a glass surface. Very particularly advantageous are those polypeptides of the general formula (III)
Xn-C1-X5-9-C2-C3-X11-39-C4-X2-23-C5-X5-9-C6-C7-X6-18-C8-Xm (III)
where X may be any of the 20 naturally occurring amino acids (Phe, Leu, Ser, Tyr, Cys, Trp, Pro, His, Gin, Arg, Ile, Met, Thr, Asn, Lys, Val, Ala, Asp, Glu, Gly) and the indices at X indicate the number of amino acids, with the indices n and m being numbers between 0 and 200 and C being cystein, with the proviso that at least one of the peptide sequences abbreviated as Xn or Xm is a peptide sequence of at least 40 amino acids in length which is not linked to a hydrophobin naturally, which polypeptides change the contact angle by at least 20° after coating of a glass surface.
Preferred embodiments of the described invention are polypeptides having the general structural formula (I), (II) or (III), this structural formula comprising at least one Class I hydrophobin, preferably at least one dewA, rodA, hypA, hypB, sc3, basf1, basf2, hydrophobin, or parts or derivatives thereof. Said hydrophobins are structurally characterized in the sequence listing below. It is also possible for a plurality, preferably 2 or 3, structurally identical or different hydrophobins to be linked to one another and to a corresponding suitable polypeptide sequence which is not connected with a hydrophobin naturally.
Particularly preferred embodiments of the present invention are the novel proteins having the polypeptide sequences depicted in SEQ ID NO: 20, 22, 24 and the nucleic acid sequences coding therefor, in particular the sequences as defined in SEQ ID NO: 19, 21, 23. Particularly preferred embodiments are also proteins which arise from substitution, insertion or deletion of at least one, up to 10, preferably 5, particularly preferably 5% of all, amino acids, starting from the polypeptide sequences depicted in SEQ ID NO: 22, 22, or 24, and which still have at least 50% of the biological property of the starting proteins. Biological property of the proteins here means the change in the contact angle, as described in Example 1.
Such HLPs and their manufacture are disclosed e.g. in EP1848733 which is herewith incorporated by reference.
These proteins have in at least one position abbreviated by Xn or Xm a polypeptide sequence comprising at least 20, preferably at least 35, particularly preferably at least 50, and in particular at least 100, amino acids (also referred to as fusion partner hereinbelow), which is not linked naturally to a hydrophobin. This is intended to express the fact that the proteins of the invention consist of a hydrophobin moiety and a fusion partner moiety which do not occur together in this form in nature.
The fusion partner moiety may be selected from a multiplicity of proteins. It is also possible to link a plurality of fusion partners to one hydrophobin moiety, for example at the amino terminus (Xn) and at the carboxy terminus (Xm) of the hydrophobin moiety. However, it is also possible to link, for example, two fusion partners to a single position (Xn or Xm) of the protein of the invention.
Particularly preferred fusion partners are those polypeptide sequences which enable the protein of the invention to coat glass surfaces and cause the protein-treated glass surface to become resistant to a treatment with detergents, as described in detail in the experimental section (Example 10) (e.g. 1% SDS/80° C./10 min).
Particularly suitable fusion partners are polypeptides which occur naturally in microorganisms, in particular in E. coli or Bacillus subtilis. Examples of such fusion partners are the sequences yaad (SEQ ID NO: 15 and 16), yaae (SEQ ID NO: 17 and 18) and thioredoxin. Very useful are also fragments or derivatives of said sequences which comprise only part, preferably 70-99%, particularly preferably 80-98%, of said sequences or in which individual amino acids or nucleotides have been altered in comparison with said sequence. For example, additional amino acids, in particular two additional amino acids, preferably the amino acids Arg, Ser, may be attached to the C-terminal end of the yaad and yaae sequences. It is also possible with preference for additional amino acids, for example amino acid No. 2 (Gly) in SEQ ID NO: 17 and 18, to be inserted in the yaae sequence compared to the naturally occurring sequence.
Furthermore, it is also possible to insert at the junctions of two fusion partners additional amino acids which are the result of either newly creating or inactivating recognition sites for restriction endonucleases at the nucleic acid level.
It is further still possible for the polypeptide sequence of the proteins of the invention to be modified, for example by glycosylation, acetylation or else by chemical crosslinking, for example with glutardialdehyde.
One property of the proteins of the invention is the change in surface properties, when said surfaces are coated with said proteins. Said change in the surface properties can be determined experimentally by measuring the contact angle of a water drop, before and after coating of the surface with the protein of the invention, and determining the difference of the two measurements.
The exact experimental conditions for measuring the contact angle are laid down in the experimental section in Example 1. Under these conditions, the proteins of the invention have the property of increasing the contact angle by at least 20, preferably 25, particularly preferably 30 degrees.
The positions of polar and unpolar amino acids in the hydrophobin moiety of the previously disclosed hydrophobins are conserved, resulting in a characteristic hydrophobicity plot. Differences in the biophysical properties and in hydrophobicity caused the previously disclosed hydrophobins to be divided into two classes, I and II (Wessels et al. 1994, Ann. Rev. Phytopathol., 32, 413-437).
The assembled membranes of Class I hydrophobins are insoluble to a high degree (even with respect to 1% SDS at elevated temperature) and can be dissociated again only by concentrated trifluoroacetic acid (TFA) or formic acid. In contrast, the assembled forms of Class II hydrophobins are less stable. They may be dissolved again even by 60% strength ethanol or 1% SDS (at room temperature).
A comparison of the amino acid sequences reveals that the length of the region between cystein C3 and C4 is distinctly shorter in Class II hydrophobins than in Class I hydrophobins.
Furthermore, Class II hydrophobins have more charged amino acids than Class I.
The invention further relates to methods for producing the proteins of the invention. These polypeptides can be produced chemically by known methods of peptide synthesis, for example solid phase synthesis according to Merrifield.
Particularly useful, however, are genetic methods in which two nucleic acid sequences, in particular DNA sequences, coding for the fusion partner and the hydrophobin moiety, respectively, are combined in such a way that gene expression of the combined nucleic acid sequence generates the desired protein in a host organism.
Suitable host organisms (producer organisms) here may be prokaryotes (including Archaea) or eukaryotes, particularly bacteria including halobacteria and methanococci, fungi, insect cells, plant cells and mammalian cells, particularly preferably Escherichia coli, Bacillus subtilis, Bacillus megaterium, Aspergillus oryzea, Aspergillus nidulans, Aspergillus niger, Pichia pastoris, Pseudomonas spec., Lactobacillen, Hansenula polymorpha, Trichoderma reesei, SF9 (or related cells), and others.
The invention moreover relates to expression constructs comprising a nucleic acid sequence coding for a polypeptide of the invention under the genetic control of regulatory nucleic acid sequences, and also vectors comprising at least one of said expression constructs.
Preference is given to such constructs of the invention comprising a promoter 5′ upstream of the particular coding sequence and a terminator sequence 3′ downstream, and also, if appropriate, further customary regulatory elements, in each case operatively linked to said coding sequence.
An “operative linkage” means the sequential arrangement of promoter, coding sequence, terminator and, if appropriate, further regulatory elements in such a way that each of the regulatory elements is able to fulfill its function in accordance with its intended use in connection with expressing the coding sequence.
Examples of sequences which can be operatively linked are targeting sequences and also enhancers, polyadenylation signals and the like. Further regulatory elements comprise selectable markers, amplification signals, origins of replication and the like. Examples of suitable regulatory sequences are described in Goeddel, Gene Expression Technology: Methods in Enzymology 185, Academic Press, San Diego, Calif. (1990).
In addition to these regulatory sequences, the natural regulation of these sequences may still be present upstream of the actual structural genes and, if appropriate, have been genetically modified such that the natural regulation has been switched off and expression of the genes has been increased.
A preferred nucleic acid construct advantageously also comprises one or more of the enhancer sequences already mentioned which are functionally linked to the promoter and enable expression of the nucleic acid sequence to be increased. Additional advantageous sequences such as further regulatory elements or terminators may also be inserted at the 3′ end of the DNA sequences.
The nucleic acids of the invention may be present in the construct in one or more copies. The construct may comprise still further markers such as antibiotic resistances or genes which complement auxotrophies, for selecting for the construct, if appropriate.
Examples of regulatory sequences which are advantageous for the method of the invention are present in promoters such as the cos, tac, trp, tet, trp-tet, lpp, lac, lpp-lac, laclq-T7, T5, T3, gal, trc, ara, rhaP(rhaPBAD) SP6, lambda-PR or lambda-P promoter, which are advantageously used in Gram-negative bacteria. Further examples of advantageous regulatory sequences are present in the Gram-positive promoters amy and SP02, in the yeast or fungal promoters ADC1, MFalpha, AC, P-60, CYC1, GAPDH, TEF, rp28, ADH. It is also possible to use artificial promoters for regulation.
To be expressed in a host organism, the nucleic acid construct is advantageously inserted into a vector such as, for example, a plasmid or a phage, which enables the genes to be expressed optimally in the host. Apart from plasmids and phages, vectors also mean any other vectors known to the skilled worker, i.e., for example, viruses such as SV40, CMV, baculovirus and adenovirus, transposons, IS elements, phasmids, cosmids, and linear or circular DNA and also the Agrobacterium system.
These vectors may either replicate autonomously in the host organism or be replicated chromosomally. These vectors constitute another embodiment of the invention. Examples of suitable plasmids are pLG338, pACYC184, pBR322, pUC18, pUC19, pKC30, pRep4, pHS1, pKK223-3, pDHE19.2, pHS2, pPLc236, pMBL24, pLG200, pUR290, pIN-III″3-B1, tgt11 or pBdCl in E. coli, pIJ101, pIJ364, pIJ702 or pIJ361 in Streptomyces, pUB110, pC194 or pBD214 in Bacillus, pSA77 or pAJ667 in Corynebacterium, pALS1, pIL2 or pBB116 in fungi, 2alpha, pAG-1, YEp6, YEp13 or pEMBLYe23 in yeasts or pLGV23, pGHlac+, pBIN19, pAK2004 or pDH51 in plants. Said plasmids are a small selection of the possible plasmids. Further plasmids are well known to the skilled worker and can be found, for example, in the book Cloning Vectors (Eds. Pouwels P. H. et al. Elsevier, Amsterdam-New York-Oxford, 1985, ISBN 0 444 904018).
Advantageously, the nucleic acid construct additionally comprises, for the purpose of expressing the other genes present, also 3′- and/or 5′-terminal regulatory sequences for increasing expression which are selected for optimal expression depending on the host organism and gene or genes selected.
These regulatory sequences are intended to enable the genes and protein expression to be expressed specifically. Depending on the host organism, this may mean, for example, that the gene is expressed or overexpressed only after induction or that it is expressed and/or overexpressed immediately.
In this connection, the regulatory sequences or factors may preferably have a beneficial influence on, and thereby increase, gene expression of the introduced genes. Thus the regulatory elements can advantageously be enhanced at the transcriptional level by using strong transcription signals such as promoters and/or enhancers. Apart from that, however, it is also possible to enhance translation by improving mRNA stability, for example.
In another embodiment of the vector, the vector comprising the nucleic acid construct of the invention or the nucleic acid of the invention may also advantageously be introduced in the form of a linear DNA into the microorganisms and integrated into the genome of the host organism by way of heterologous or homologous recombination. Said linear DNA may consist of a linearized vector such as a plasmid, or only of the nucleic acid construct or the nucleic acid of the invention.
In order to achieve optimal expression of heterologous genes in organisms, it is advantageous to modify the nucleic acid sequences according to the specific codon usage employed in the organism. The codon usage can be readily determined on the basis of computer analyses of other known genes of the organism in question.
An expression cassette of the invention is prepared by fusing a suitable promoter to a suitable coding nucleotide sequence and a terminator signal or polyadenylation signal. For this purpose, use is made of familiar recombination and cloning techniques as are described, for example, in T. Maniatis, E. F. Fritsch and J. Sambrook, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1989) and also in T. J. Silhavy, M. L. Berman and L. W. Enquist, Experiments with Gene Fusions, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1984) and in Ausubel, F. M. et al., Current Protocols in Molecular Biology, Greene Publishing Assoc. and Wiley Interscience (1987).
For expression in a suitable host organism, the recombinant nucleic acid construct or gene construct is advantageously inserted into a host-specific vector which enables the genes to be expressed optimally in the host. Vectors are well known to the skilled worker and can be found, for example, in “Cloning Vectors” (Pouwels P. H. et al., Eds. Elsevier, Amsterdam-New York-Oxford, 1985).
The vectors of the invention can be used to prepare recombinant microorganisms which are transformed, for example, with at least one vector of the invention and may be used for producing the polypeptides of the invention. Advantageously, the above-described recombinant constructs of the invention are introduced into and expressed in a suitable host system. Preference is given here to using common cloning and transfection methods known to the skilled worker, such as, for example, coprecipitation, protoplast fusion, electroporation, retroviral transfection and the like, in order to express said nucleic acids in the particular expression system. Suitable systems are described, for example, in Current Protocols in Molecular Biology, F. Ausubel et al., Eds. Wiley Interscience, New York 1997, or Sambrook et al. Molecular Cloning: A Laboratory Manual, 2nd Ed., Cold Spring Harbor Laboratory, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989.
It is also possible according to the invention to prepare homologously recombined microorganisms. For this purpose, a vector is prepared which comprises at least one section of a gene of the invention or of a coding sequence, into which, if appropriate, at least one amino acid deletion, addition or substitution has been introduced in order to modify, for example functionally disrupt, the sequence of the invention (knockout vector). The introduced sequence may, for example, also be a homolog from a related microorganism or be derived from a mammalian, yeast or insect source. The vector used for homologous recombination may alternatively be designed such that the endogenous gene mutates or is modified in some other way during homologous recombination but still encodes the functional protein (for example, the upstream regulatory region may have been modified in a way which modifies expression of the endogenous protein). The modified section of the gene of the invention is in the homologous recombination vector. The construction of suitable vectors for homologous recombination is described, for example, in Thomas, K. R. and Capecchi, M. R. (1987) Cell 51: 503.
Any prokaryotic or eukaryotic organisms are in principle suitable for being used as recombinant host organisms for the nucleic acid of the invention or to the nucleic acid construct. Advantageously used host organisms are microorganisms such as bacteria, fungi or yeasts. Gram-positive or Gram-negative bacteria, preferably bacteria of the families Enterobacteriaceae, Pseudomonadaceae, Rhizobiaceae, Streptomycetaceae or Nocardiaceae, particularly preferably bacteria of the genera Escherichia, Pseudomonas, Streptomyces, Nocardia, Burkholderia, Salmonella, Agrobacterium or Rhodococcus, are advantageously used.
Depending on the host organism, the organisms used in the method of the invention are grown or cultured in a manner known to the skilled worker. Microorganisms are usually grown in a liquid medium comprising a carbon source usually in the form of sugars, a nitrogen source usually in the form of organic nitrogen sources such as yeast extract or salts such as ammonium sulfate, trace elements such as iron, manganese, magnesium salts, and, if appropriate, vitamins, at temperatures of between 0 and 100° C., preferably between 10 and 60° C., while being gassed with oxygen. The pH of the nutrient liquid may or may not be maintained here at a fixed value, i.e. regulated during growth. Growth may take place batch-wise, semibatch-wise or continuously. Nutrients may be introduced initially at the beginning of the fermentation or be subsequently fed in semicontinuously or continuously. The enzymes may be isolated from the organisms using the method described in the examples or be used for the reaction as a crude extract.
The invention furthermore relates to methods of recombinantly producing polypeptides of the invention or functional, biologically active fragments thereof, which methods comprise culturing a polypeptide-producing microorganism, if appropriate inducing expression of said polypeptides and isolating them from the culture. In this way the polypeptides may also be produced on an industrial scale if desired. The recombinant microorganism may be cultured and fermented by known methods. For example, bacteria can be propagated in TB medium or LB medium and at a temperature of from 20 to 40° C. and a pH of from 6 to 9. Suitable culturing conditions are described in detail in, for example, T. Maniatis, E. F. Fritsch and J. Sambrook, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1989).
If the polypeptides are not secreted into the culture medium, the cells are then disrupted and the product is isolated from the lysate by known methods of isolating proteins. The cells may optionally be disrupted by high-frequency ultrasound, by high pressure, for example in a French pressure cell, by osmolysis, by the action of detergents, lytic enzymes or organic solvents, by using homogenizers or by a combination of several of the methods listed.
The polypeptides may be purified by means of known, chromatographic methods such as molecular sieve chromatography (gel filtration), such as Q-Sepharose chromatography, ion exchange chromatography and hydrophobic chromatography, and also by means of other customary methods such as ultrafiltration, crystallization, salting out, dialysis and native gel electrophoresis. Suitable methods are described, for example, in Cooper, F. G., Biochemische Arbeitsmethoden [original title: The tools of biochemistry], Verlag Water de Gruyter, Berlin, N.Y. or in Scopes, R., Protein Purification, Springer Verlag, New York, Heidelberg, Berlin.
It may be advantageous, for the purpose of isolating the recombinant protein, to use vector systems or oligonucleotides which extend the cDNA by particular nucleotide sequences and thereby encode altered polypeptides or fusion proteins which facilitate purification, for example. Examples of such suitable modifications are “tags” acting as anchors, for example the modification known as hexahistidine anchor, or epitopes which can be recognized by antibodies as antigens (described, for example, in Harlow, E. and Lane, D., 1988, Antibodies: A Laboratory Manual. Cold Spring Harbor (N.Y.) Press). Further suitable tags are, for example, HA, calmodulin-BD, GST, MBD; chitin-BD, streptavidin-BD-Avi tag, Flag tag, T7, etc. These anchors may be used for attaching the proteins to a solid support, such as, for example, a polymer matrix which may have been introduced into a chromatographic column, for example, or to a microtiter plate or any other support. The corresponding purification protocols can be obtained from the commercial affinity tag suppliers.
In some embodiments, the HLP is present in the composition in an amount of from 0.01 weight % to 3 weight % by total weight of the composition. In some embodiments, the HLP is present in the composition in an amount of from 0.1 weight % to 3 weight %, or from 0.1 weight % to 2 weight %, or from 0.1 weight % to 1 weight % by total weight of the composition. In other embodiments, the HLP is present in the composition in an amount of from 0.05 weight % to 1 weight %, or from 0.1 weight % to 0.5 by total weight of the composition. In further embodiments, the HLP is present in the composition in an amount of from 0.5 weight % to 3 weight %, or from 0.5 weight % to 2 weight %, or from 0.5 weight % to 1 weight % by total weight of the composition. In still further embodiments, the HLP is present in the composition in an amount of from 1 weight % to 3 weight %, or from 1 weight % to 2 weight % by total weight of the composition.
The expression “orally acceptable carrier” as used herein denotes a carrier made from materials that are safe and acceptable for oral use in the amounts and concentrations intended, for example materials as would be found in conventional toothpaste and mouthwash. Such materials include water or other solvents that may contain a humectant such as glycerin, sorbitol, xylitol and the like. In some aspects, the term “orally acceptable carrier” encompasses all of the components of the oral care composition except for the HLP and the fluoride. In other aspects, the term refers to inert or inactive ingredients that serve to deliver the hydrolyzed plant protein, and/or any other functional ingredients, to the oral cavity.
Orally acceptable carriers for use in the invention include conventional and known carriers used in making mouth rinses or mouthwashes, toothpastes, tooth gels, tooth powder, lozenges, gums, beads, edible strips, tablets and the like. Carriers should be selected for compatibility with each other and with other ingredients of the composition.
The following non-limiting examples are provided. In a toothpaste composition, the carrier is typically a water/humectant system that provides a major fraction by weight of the composition. Alternatively, the carrier component of a toothpaste composition may comprise water, one or more humectants, and other functional components other than the hydrolyzed wheat protein or hydrolyzed rice protein. In a mouth rinse or a mouthwash formulation, the carrier is typically a water/alcohol liquid mixture in which the hydrolyzed wheat protein or hydrolyzed rice protein is dissolved or dispersed. In a dissolvable lozenge, the carrier typically comprises a solid matrix material that dissolves slowly in the oral cavity. In chewing gums, the carrier typically comprises a gum base, while in an edible strip, the carrier typically comprises one or more film forming polymers.
The oral care compositions provided herein may further comprise one or more additional ingredients selected from abrasives, pH modifying agents, surfactants, foam modulators, thickening agents, viscosity modifiers, humectants, anti-calculus or tartar control agents, sweeteners, flavorants, colorants and preservatives. These ingredients may also be regarded as carrier materials. Non-limiting examples are provided below.
In one embodiment a composition of the invention comprises at least one abrasive, useful, for example, as a polishing agent. Any orally acceptable abrasive can be used, but the type, fineness (particle size) and amount of abrasive should be selected so that tooth enamel is not excessively abraded during normal use of the composition. Suitable abrasives include, without limitation, silica, for example in the form of silica gel, hydrated silica or precipitated silica, alumina, insoluble phosphates, calcium carbonate, resinous abrasives such as urea-formaldehyde condensation products and the like. Among insoluble phosphates useful as abrasives are orthophosphates, polymetaphosphates and pyrophosphates. Illustrative examples are dicalcium orthophosphate dihydrate, calcium pyrophosphate, [beta]-calcium pyrophosphate, tricalcium phosphate, calcium polymetaphosphate and insoluble sodium polymetaphosphate. One or more abrasives are optionally present in the oral care compositions of the present invention in an amount of 1 weight % to 5 weight % by total weight of the composition. The average particle size of an abrasive, if present, is generally 0.1 to 30 μm, and preferably, 5 to 15 μm.
In a further embodiment an oral care composition of the invention comprises at least one bicarbonate salt, useful, for example, to impart a “clean feel” to teeth and gums due to effervescence and release of carbon dioxide. Any orally acceptable bicarbonate can be used, including, without limitation, alkali metal bicarbonates such as sodium and potassium bicarbonates, ammonium bicarbonate and the like. One or more bicarbonate salts are optionally present in a total amount of 1 weight % to 10% by weight of the composition.
In a still further embodiment, an oral care composition of the invention comprises at least one pH modifying agent. Such agents include acidifying agents to lower pH, basifying agents to raise pH and buffering agents to control pH within a desired range. For example, one or more compounds selected from acidifying, basifying and buffering agents can be included to provide a pH of 2 to 10, or in various illustrative embodiments a pH of 2 to 8, 3 to 9, 4 to 8, 5 to 7, 6 to 10, or 7 to 9. Any orally acceptable pH modifying agent can be used, including, without limitation, carboxylic, phosphoric and sulfonic acids, acid salts (for example, monosodium citrate, disodium citrate, monosodium malate), alkali metal hydroxides such as sodium hydroxide, carbonates such as sodium carbonate, bicarbonates, borates, silicates, phosphates (for example, monosodium phosphate, trisodium phosphate, pyrophosphate salts) imidazole and the like. One or more pH modifying agents are optionally present in a total amount effective to maintain the composition in an orally acceptable pH range.
In a still further embodiment a composition of the invention comprises at least one surfactant, useful, for example, to provide enhanced stability to the composition and the components contained therein, to aid in cleaning a dental surface through detergent action, and to provide foam upon agitation (for example, during brushing with a dentifrice composition of the invention). Any orally acceptable surfactant, including those which are anionic, nonionic or amphoteric, can be used. Suitable anionic surfactants include, without limitation, water-soluble salts of C8-20 alkyl sulfates, sulfonated monoglycerides of C8-20 fatty acids, sarcosinates, taurates and the like. Suitable nonionic surfactants include, without limitation, poloxamers, polyoxyethylene sorbitan esters, fatty alcohol ethoxylates, alkylphenol ethoxylates, tertiary amine oxides, tertiary phosphine oxides, dialkyl sulfoxides and the like. Suitable amphoteric surfactants, without limitation, derivatives of C8-20 aliphatic secondary and tertiary amines having an anionic group such as carboxylate, sulfate, sulfonate, phosphate or phosphonate. A suitable example is cocoamidopropyl betaine. One or more surfactants are optionally present in a total amount of 0.01 weight % to 10 weight %, for example, from 0.05 weight % to 5 weight % or from 0.1 weight % to 2 weight % by total weight of the composition.
In a still further embodiment, an oral care composition of the invention comprises at least one foam modulator, useful, for example, to increase the amount, thickness or stability of foam generated by the composition upon agitation. Any orally acceptable foam modulator can be used including, without limitation, polyethylene glycols (PEGs). One or more PEGs are optionally present in a total amount of from 0.1 weight % to 10 weight by total weight of the composition.
In a still further embodiment, an oral care composition of the invention comprises at least one thickening agent, useful, for example, to impart a desired consistency and/or mouth feel to the composition. Any orally acceptable thickening agent can be used including, without limitation, carbomers (carboxyvinyl polymers), carrageenans, cellulosic polymers such as hydroxyethylcellulose, carboxymethylcellulose (CMC) and salts thereof, natural gums such as karaya, xanthan, gum arabic and tragacanth, colloidal magnesium aluminum silicate, colloidal silica and the like. One or more thickening agents are optionally present in a total amount of 0.01 weight % to 15 weight %, by total weight of the composition.
In a still further embodiment a composition of the invention comprises at least one viscosity modifier, useful, for example, to inhibit settling or separation of ingredients or to promote re-dispersion of ingredients upon agitation of a liquid composition. Any orally acceptable viscosity modifier can be used including, without limitation, mineral oil, petrolatum, clays, silica and the like. One or more viscosity modifiers are optionally present in a total amount of 0.01 weight % to 10 weight %, by total weight of the composition.
In a still further embodiment, an oral care composition of the invention comprises at least one humectant which may be used to prevent hardening of a toothpaste upon exposure to air. Any orally acceptable humectant can be used, including, without limitation, polyhydric alcohols such as glycerin, sorbitol, xylitol or low molecular weight PEGs. Most humectants also function as sweeteners. One or more humectants are optionally present in a total amount of 1 weight % to 50 weight % by total weight of the composition.
In a still further embodiment, an oral care composition of the invention comprises at least one sweetener which enhances taste of the composition. Any orally acceptable natural or artificial sweetener can be used including, without limitation, dextrose, sucrose, maltose, dextrin, mannose, xylose, ribose, fructose, levulose, galactose, corn syrup, partially hydrolyzed starch, hydrogenated starch hydrolysate, sorbitol, mannitol, xylitol, maltitol, isomalt, aspartame, neotame, saccharin and salts thereof, dipeptide-based intense sweeteners, cyclamates and the like. One or more sweeteners are optionally present in a total amount of 0.005 weight % to 5 weight % by total weight of the composition.
In a still further embodiment, an oral care composition of the invention comprises at least one flavorant which enhances the taste of the composition. Any orally acceptable natural or synthetic flavorant can be used including, without limitation, vanillin, sage, marjoram, parsley oil, spearmint oil, cinnamon oil, oil of wintergreen (methylsalicylate), peppermint oil, clove oil, bay oil, anise oil, eucalyptus oil, citrus oils, fruit oils and essences, and the like. Also encompassed within flavorants are ingredients that provide fragrance and/or other sensory effects in the mouth, including cooling or warming effects. Such ingredients illustratively include menthol, menthyl acetate, menthyl lactate, camphor, eucalyptus oil, eucalyptol, eugenol, cassia, oxanone, α-irisone, thymol, linalool, benzaldehyde, cinnamaldehyde, N-ethyl-p-menthan-3-carboxamine, N,2,3-trimethyl-2-isopropylbutanamide, 3-(1-menthoxy)-propane-1,2-diol, cinnamaldehyde glycerol acetal (CGA), menthone glycerol acetal (MGA) and the like. One or more flavorants are optionally present in a total amount of 0.01 weight % to 5 weight %, by total weight of the composition.
In a still further embodiment, an oral care composition of the invention comprises at least one colorant. A colorant can serve a number of functions. These include providing a white or light-colored coating on a dental surface, indicating locations on a dental surface that have been effectively contacted by the composition, and/or modifying the appearance of the composition to enhance attractiveness to the consumer. Any orally acceptable colorant can be used including, without limitation, talc, mica, magnesium carbonate, calcium carbonate, magnesium silicate, magnesium aluminum silicate, silica, titanium dioxide, zinc oxide, iron oxide, ferric ammonium ferrocyanide, manganese violet, titaniated mica, bismuth oxychloride and the like. One or more colorants are optionally present in a total amount of 0.001 weight % to 20 weight % by total weight of the composition.
In a still further embodiment, an oral care composition of the invention comprises a preservative. The preservative may be selected from parabens, potassium sorbate, benzyl alcohol, phenoxyethanol, polyaminopropryl biguanide, caprylic acid, sodium benzoate and cetylpyridinium chloride. In some embodiments, the preservative is present at a concentration of from about 0.001 to about 1 weight %, by total weight of the composition.
In a still further embodiment, an oral care composition of the invention is a chewing gum comprising gum base, flavor, sweetening agent and HLP. The gum base is present from about 4.8% to about 90%, the flavor from about 0.1% to about 10%, the sweetening agent from about 0.1% to about 95% and the HLP from about 0.01% to about 0.5%.
The following examples illustrate compositions of the invention and their uses. The exemplified compositions are illustrative and do not limit the scope of the invention.
Coating/evaluation of surfaces with HLPs
Glass (window glass, Suddeutsche Glas, Mannheim, Germany):
Bovine teeth are cut, ground and polished to obtain enamel blocks having approximate dimensions of 3 mm×3 mm×2 mm. The thickness of the enamel is approximately 1 to 2 mm, and the thickness of dentin is approximately 1 mm. All measurements are taken on the enamel surface.
The surface roughness of enamel blocks is measured before and after acid etching. Acid etching is achieved by placing the enamel blocks in 1% citric acid solution (pH 3.8) until the surface roughness (Sq) reaches 100-200. This Sq value is recorded as the surface roughness of etched enamel. (Sq is a standard measurement defined in ISO 25178 basically as the root mean square height relative to the arithmetical mean height of the surface being measured, so it corresponds to the mean of all absolute distances of the profile from the center plane within the measuring area, such that if it is higher, it means that that there are more pronounced peaks and valleys on the surface, i.e., the surface is rougher, and if it is lower, the surface is smoother.). The HLPs, e.g. BioMin 145 is diluted to the final concentration using a Na2HPO4 buffer (1.5 mM) and CaCl2 (2.5 mM). After neutralizing to a pH of 7.5, the solution is filtered and centrifuged. Acid-etched enamel blocks are subsequently incubated with a solution comprising the BioMin 145 at a concentration of 17 μM (2 ml solution per block) for 60 minutes.
After the 60 minute incubation period, the enamel blocks are incubated in artificial saliva (AS) solution (0.4 g NaCl, 0.4 g KCl, 0.8 g CaCl2, 0.69 g NaH2PO4, 1 g urea, 1 liter distilled water; pH 7 (adjusted using 1M NaOH)) for 22 hours. The enamel blocks are then treated a second time with HLP BioMin 145, and incubated again with artificial saliva for 22 hours. The blocks are then rinsed with deionized (DI) water and air-dried prior to measuring their surface roughness. Enamel blocks treated with 0.5% PBS are used as a negative control for the experiment. The results are illustrated in Table 1. The % repair represents the % reduction in surface roughness (Sq) achieved by protein treatment, relative to the surface roughness of (untreated) acid-etched enamel.
See
As indicated in Table 1, BioMin 145 is effective in reducing the surface roughness of acid-etched enamel blocks at a concentration of 17 μM.
Enamel blocks are prepared as described in Example 1. Acid-etching is achieved by placing the enamel blocks in 1% citric acid solution (pH 3.8) for 15 minutes. The nanohardness and Young's modulus at 500 nm depth are measured prior to and after etching. Etched enamel blocks are incubated with a solution of HLPs e.g. BioMin 145, at a concentration of 20 μM, for 30 minutes (2 ml solution/block), followed by an incubation with AS solution as described in Example 1, for 22 to 24 hours. The HLP and AS incubation steps are repeated two additional times, after which the enamel blocks are rinsed with DI water and air-dried. The nanohardness and Young's modulus of the treated enamel blocks are measured at 500 nm depth to assess the enamel repair effects of the HLP. A solution of 500 ppm fluoride is used as a positive control for the experiment. The results are illustrated in Tables 2 and 3.
As can be seen in Tables 2 and 3, BioMin 145 is effective in repairing acid-eroded enamel.
Enamel blocks are prepared as described in Example 1. Microhardness is measured using a Micromet 6020 Micro-hardness Tester with a Knoop Diamond Indenter and a 50 g load (Buehler, Lake Bluff, Ill., USA). Blocks with a Knoop hardness (KH) of at least 300 are selected. The blocks are etched by immersing in 30% phosphoric acid for 15 seconds. The KH on the left and right sides of the blocks are measured. Subsequently, the right side of the blocks are covered with tape prior to treating the blocks with 20 μM solution of HLPs e.g. BioMin 93, each neutralized as described in example 1, for two terms of 30 minutes. (The tape on the right hand side of the blocks prevents exposure of this side to the protein solution and serves as an internal control). The blocks are washed twice with DI water @ 5 minutes, 500 PRM between the two treatments and after the second treatment. Subsequently, the tape is removed and the blocks are incubated in AS solution (0.2 mM MgCl2, 1 mM CaCl2.H2O, 20 mM HEPES buffer, 4 mM KH2PO4, 16 mM KCl, 4.5 mM NH4Cl, 300 ppm NaF, 0.05 wt. % NaN3, at pH 7 (adjusted with 1M NaOH)) for 7 days. After rinsing the enamel blocks with DI water and air-drying the rinsed blocks, microhardness is measured again. Surface microhardness regain (SMHL, Remin %) as a percent is calculated as ((Microhardnessrepaired−Microhardnessetched)/(Microhardnesssound−Microhardnessetched))*100. The results of the microhardness assay are illustrated in Table 4.
37%
It can be seen from Table 4 that BioMin 93 is effective in remineralizing the enamel surface of acid-etched enamel blocks. Note that for all of the microhardness tests, the reminineralization percentage from the right/internal control side, which was immersed artificial salvia as well and had some repair from artificial salvia, is subtracted from the results, so that the data present the differential effect of the HLP.
While particular embodiments of the invention have been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the appended claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/075648 | 10/25/2016 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62246161 | Oct 2015 | US |
