An implant may be introduced into a human body to replace, support, or enhance a structure within the body. When a foreign body is introduced into a human body as an implant, it may be encapsulated by scar tissue, forming a capsule. Scar tissue includes the protein collagen, which in scar tissue may be cross-linked and aligned in a single direction. This may cause scar tissue to have relatively lower functional quality than collagen in normal, non-scar tissue. Thus, an implant surrounded by a scar tissue capsule may not be well integrated to the rest of the biological structures within the body, and have an undesirably low level of bio-integration.
There have been various attempts to improve bio-integration of implants. Surface texturing of an implant made of silicone creates a porous, sponge-like surface. Living body tissue may grow into the cavities to fix the implant to the body. However, a living body may react to synthetic material such as silicone by forming a capsule of scar tissue around it (as an oyster forms a pearl around a grain of sand). A non-living tissue implanted in the human body that becomes encapsulated with scar tissue may have several detrimental effects, including bone erosion. Also, if a non-living tissue is exposed through the skin, it may become infected.
Also, materials such as hyaluronic acid, collagen, and polylactic acid may be applied to the surface of an implant. Living tissue will grow into these biologically-active materials, encouraging bio-integration of the implant in the body. However, these small, biologically-active materials may be absorbed into the blood supply within living tissue that grows near the implant.
The above and other deficiencies of the prior art are overcome by, in an embodiment, a composite implant comprising: a mesh comprising a biologically-active material configured to contact biological tissue and blood vessels; a resin disposed on the mesh; and a channel in the mesh which is configured to receive growth of the biological tissue and blood vessels, wherein the resin is biocompatible and non-absorbable.
In another embodiment, a process for preparing a composite implant comprises: disposing a plurality of layers of biologically-active material as an array; contacting the plurality of layers with a resin; and hardening the resin to form the composite implant, wherein a channel in the mesh is configured to receive growth of the biological tissue and blood vessels, and the resin is biocompatible and non-absorbable.
In a further embodiment, a process of using a composite implant comprises: implanting the composite implant into a subject, wherein the implant comprises: a mesh comprising a biologically-active material configured to contact biological tissue and blood vessels; a resin disposed on the mesh; and a channel in the mesh which is configured to receive growth of the biological tissue and blood vessels, wherein the resin is biocompatible and non-absorbable.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments is presented herein by way of exemplification and not limitation with reference to the figures.
Human teeth, nails, and hair have similar structures with each other, in that they are formed from living tissue within the body, and then through a transitional structure become non-living but remain integrally attached to the living tissue of the body. This property improves bio-integration and decreases the ability of teeth, nails, and hair to detach from the body. The base of these structures is living vascularized cellular (i.e., biological) material, while the distal end is non-living, non-vascularized acellular material.
An embodiment includes an implant framework material made of a biocompatible material such as a resin, e.g., silicone. The biocompatible material can include non-absorbable material. The resin, such as a silicone, can be a monomer that forms a polymer (e.g., a thermosetting plastic), oligomer, or a polymer having a reactive functional group. The resin can include a thermoset, thermoplastic, or a combination thereof Moreover, the implant can include a blend of polymers, copolymers, terpolymers, or combinations comprising at least one of the foregoing resins. The resin can also contain an oligomer, homopolymer, copolymer, block copolymer, alternating block copolymer, random polymer, random copolymer, random block copolymer, graft copolymer, star block copolymer, dendrimer, or the like, or a combination comprising at last one of the foregoing.
A “thermoset” solidifies when first heated and thereafter may not melt or mold without destroying the original characteristics. Thermosetting materials can include epoxides, phenolics, melamines, ureas, polyurethanes, polysiloxanes, polymers including a suitable crosslinkable functional moiety, or a combination comprising at least one of the foregoing.
A thermoplastic has a macromolecular structure that repeatedly softens when heated and hardens when cooled. Illustrative examples of thermoplastic polymeric materials include olefin-derived polymers, for example, polyethylene, polypropylene, and their copolymers; polymethylpentane-derived polymers, for example, polybutadiene, polyisoprene, and their copolymers; polymers of unsaturated carboxylic acids and their functional derivatives, for example, acrylic polymers such as poly (alkyl acrylates), poly (alkyl methacrylate), polyacrylamides, polyacrylonitrile, and polyacrylic acid; alkenylaromatic polymers, for example polystyrene, poly-alpha-methylstyrene, polyvinyltoluene, and rubber-modified polystyrenes; polyamides, for example, nylon-6, nylon-66, nylon-11, and nylon-12; polyesters, such as, poly(alkylene dicarboxylates), e.g., poly(ethylene terephthalate) (hereinafter sometimes designated “PET”), poly(1,4-butylene terephthalate) (hereinafter sometimes designated “PBT”), poly(trimethylene terephthalate) (hereinafter sometimes designated “PTT”), poly(ethylene naphthalate) (hereinafter sometimes designated “PEN”), poly(butylene naphthalate) (hereinafter sometimes designated “PBN”), poly(cyclohexanedimethanol terephthalate), poly(cyclohexanedimethanol-co-ethylene terephthalate) (hereinafter sometimes designated “PETG”), and poly(1,4-cyclohexanedimethyl-1,4-cyclohexanedicarboxylate) (hereinafter sometimes designated “PCCD”), and poly(alkylene arenedioates); polycarbonates; co-polycarbonates; co-polyestercarbonates; polysulfones; polyimides; polyarylene sulfides; polysulfide sulfones; and polyethers such as polyarylene ethers, polyphenylene ethers, polyethersulfones, polyetherimides, polyetherketones, polyetheretherketones; or blends or copolymers thereof.
The resin also can include other biocompatible resins such as, for example, a silicone, polysiloxane, poliglecaprone, polydioxanone, polyglactin, caprolactone, polyorthoester, polyethylene glycol, poly terephthalate, tyrosine, poly(ester amide), polyisobutylene, poly(ethylene terephthalate), polytetrafluoroethylene, polyurethane, polystyrene, polyamide, polyimide, bisphenol-alpha-glycidyl methacrylate, triethyleneglycol dimethacrylate, hydroxyethyl methacrylate, poly-p-chloroxylylene, phenolic resins, and the like. Phenolic resins can be obtained by condensation of phenol or substituted phenols with aldehydes. Suitable phenolic resins may include biocompatible phenol-aldehyde resins such as one-stage and two-stage phenol-formaldehyde resins, as well as polyvinyl phenol resins. Suitable one and two-stage phenol formaldehyde resins include resole and novolak resins. Examples of polyvinyl phenolic resins include o-hydroxystyrene, m-hydroxystyrene, p-hydroxy styrene, 2-(o-hydroxyphenyl)propylene, 2-(m-hydroxyphenyl)propylene, and 2-(p-hydroxyphenyl)propylene, and combinations, derivatives, or copolymers thereof
For the implant framework material, other biocompatible materials may be used, such as polytetrafluoroethylene (PTFE, available under the trade mark Teflon), polyethylene, polypropylene, nylon, calcium, coral, acellular bone, calcium hydroxyl apatite, and the like.
According to an embodiment, the biologically-active matrix material can include hyaluronic acid, collagen, and polylactic acid, acellular dermal matrix, protein, amino acid, carbohydrate, polyethylene terephthalate, polycarbonate, polylactic glycolic acid, glycolide, lactide, trimethylene carbonate, or a combination comprising at least one of the foregoing. Exemplary biologically active matrix materials include citrate esters (e.g., acetyl tri-n-butyl citrate, triethyl citrate, and the like), maleic acid esters, adipic acid esters, homopolymers and copolymers of L-lactic acid, D-lactic acid, D,L-lactic acid, glycolic acid, ε-caprolactone, N-methylpyrrolidone, trimethylene carbonate, p-dioxanone, 1,5-dioxepan-2-one, hydroxybutanoic acid, hydroxyvaleric acid, acid anhydrides (sebacic acid anhydride, maleic acid anhydride, dioleic acid anhydride, etc.), amino acids (L-amino acids, D-amino acids, mixtures of L- and D-amino acids) such as glycine, alanine, phenylalanine, tyrosine, asparagine, glutamine, aspartic acid, glutamic acid, ricin, hydroxylysine, arginine, valine, leucine, isoleucine, serine, threonine, cysteine, methionine, tryptophan, histidine, proline, hydroxyproline, etc., and the like; mixtures of such polymers, polyesters, polycarbonates, polyacrylic acids such as poly(α-cyanoacrylate), polyphosphates, amino acid polymers, polyacid anhydrides, proteins (gelatin, collagen, etc.), polyglycosides (chitin, chitosan, starch, etc.), and the like.
The biologically active-matrix can include such commercially-available products as Gore® BioA®, LifeCell™ Alloderm®, Bard™ Allomax™, and LifeCell™ Stratus®. As mentioned, the biologically-active matrix material can also be collagen containing tissue such as acellular dermis obtained from human, porcine, or bovine skin. In an embodiment, the biologically-active matrix material can also be a synthetic material such as Gore® Bio-A®, Ethicon Vicryl®, Coviden Dexon®, polyglycolic acid, Novus TIGR® Matrix, trimethylene carbonate, and the like.
The implant can also include an additive. The additive can be a pharmaceutical agent. Exemplary pharmaceutical agents include a bone growth factor, tissue growth factor, tissue-derived substance (e.g., albumin, globulin, chondroitin sulfate, fibronectin, fibrinogen or elastin), antibiotic (e.g., tetracyclines such as minocycline and doxycycline, macrolides such as clarithromycin or azithromycin, quinolones such as levofloxacin, or ketolides such as telithromycin), anti-inflammatory agent (e.g., non-steroidal anti-inflammatory drugs such as flurbiprofen, and steroids such as dexamethasone), naturally derived substance (e.g., azulene), bone-absorption inhibitor (e.g., bisphosphonate), inorganic compound (e.g., calcium phosphate, tricalcium phosphate, tetracalcium phosphate, hydroxyapatite), biological (e.g., platelet-rich plasma (PRP), fibroblasts, stem cells), and the like. The additive can be disposed in or on a surface of the implant. In an embodiment, the additive is dispersed in the resin or arranged on the biologically-active material.
There are any number of alternative arrangements of the strands 15 in the implant 9 besides that shown in the present exemplary embodiment. For example, the strands can be arranged side to side, top to bottom, side to top, side to bottom, etc., or any combination of these arrangements. The strands 15 may not be straight but can have a curved shape. Further, strands 15 can be grown in by blood vessels 11 and living tissue 10 from more than one side of the implant 9 in certain situations where this may be indicated, e.g., joints.
The process of bio-integration creates three connected regions in the area of the living body where the implant 9 has been implanted. The first region is a living zone 16, which is in the area of the living body where the blood vessels 11 and living tissue 10 grow originally. Next is the transitional zone 17, which contains secondary blood vessels 11 and secondary living tissue 10 that has absorbed the biologically-active matrix material strands 15 and therefore extends into the implant 9. The biologically-active matrix material strands 15 are at least partially bio-integrated in the transitional zone 17. The transitional zone 17 is shown in greater detail in
The three regions in the area of the living body where the implant 9 has been implanted create a junctional structure. As the secondary blood vessels 11 and secondary living tissue 10 penetrate further into the implant 9, they can become smaller and less able to penetrate. However, since the strands 15 of biologically-active matrix material extend into the implant 9 a certain distance, the implant 9 according to the present exemplary embodiment exhibits improved adhesion, strength, and durability once bio-integration has occurred. A scaffold created by the strands 15 due to the junctional structure holds the implant 9 to the blood vessels 11 and the living tissue 10.
By creating a transitional zone, a scar tissue capsule may not form between the implant 9 and the blood vessels 11 and the living tissue 10, and exteriorization of the implant can be facilitated. Thus, dental implants and fixation devices for external prostheses such as ears, noses, and the like can be more easily formed compared with other implants. The transitional implant can also find application in buried prostheses such as joint, facial, chin, and skull implants. In these implants, fixation to the transitional zone can prevent bone resorption commonly seen with conventional implants.
Exemplary embodiments, e.g., as shown in
As shown in
The biologically-active material can be rod, filament, thread-like, strands, tubules, and the like, or any combination thereof With reference to
A cross-sectional view of a composite implant using the three-dimensional array of biologically active material 142 is shown in
To illustrate the bio-integration of the composite implant 151,
In an embodiment, a process for preparing a composite implant includes disposing a plurality of layers of biologically-active material as an array and contacting the plurality of layers with a resin. The resin is hardened to form the composite implant such that a channel in the mesh is configured to receive growth of the biological tissue and blood vessels, and the resin is biocompatible and non-absorbable. The biologically-active material can be coated with the resin and formed into a mesh prior to disposing the plurality of layers of biologically-active material as an array. A number of ways to dispose the resin on the biologically-active material can be used, including dipping the biologically-active material in the resin, spraying the resin on the biologically-active material, and the like. With reference to
While one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation. Embodiments herein are can be used independently or can be combined.
All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. The suffix “(s)” as used herein is intended to include both the singular and the plural of the term that it modifies, thereby including at least one of that term (e.g., the colorant(s) includes at least one colorant). “Optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where the event occurs and instances where it does not. As used herein, “combination” is inclusive of blends, mixtures, alloys, reaction products, and the like. All references are incorporated herein by reference.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. “Or” means “and/or.” It should further be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity). The conjunction “or” is used to link objects of a list or alternatives and is not disjunctive, rather the elements can be used separately or can be combined together under appropriate circumstances.
It will be understood that when an element or layer is referred to as being “on” or “connected to” another element or layer, it can be directly on or directly connected to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on” or “directly connected to” another element or layer, there are no intervening elements or layers present.
This application is a continuation-in-part of U.S. application Ser. No. 13/534,441 filed Jun. 27, 2012, which claims the benefit of U.S. Provisional Application Ser. No. 61/509,369 filed Jul. 19, 2011, the entire disclosure of each of which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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61509369 | Jul 2011 | US |
Number | Date | Country | |
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Parent | 13534441 | Jun 2012 | US |
Child | 13549623 | US |