Reinforced tissue implants and methods of manufacture and use

Abstract

A biocompatible tissue implant, as well as methods for making and using such an implant, is provided. Preferably, the tissue implant is bioabsorbable. The tissue implant comprises one or more layers of a bioabsorbable polymeric foam having pores with an open cell structure. The tissue implant also includes a reinforcement component which contributes both to the mechanical and the handling properties of the implant. Preferably, the reinforcement component of the instant invention is bioabsorbable as well. The tissue implant of the present invention can be used in connection with the surgical repair of soft tissue injury, such as injury to the pelvic floor.

What is claimed is:  
     
         1 . A biocompatible tissue implant, comprising: 
 a bioabsorbable polymeric foam component having pores with an open cell pore structure; and    a reinforcing component formed of a biocompatible, mesh-containing material,    the foam component being integrated with the reinforcing component such that the pores of the foam component penetrate the mesh of the reinforcing component and interlock with the reinforcing component.    
     
     
         2 . The implant of  claim 1 , wherein the foam component is present in one or more layers.  
     
     
         3 . The implant of  claim 1 , wherein the reinforcing component is present in one or more layers.  
     
     
         4 . The implant of  claim 2 , wherein adjacent foam layers are integrated with one another by at least a partial interlocking of pore-forming webs of the foam.  
     
     
         5 . The implant of  claim 1 , wherein the foam component is formed from a polymer selected from the group consisting of aliphatic polyesters, poly(amino acids), copoly(ether-esters), polyalkylene oxalates, polyamides, tyrosine derived polycarbonates, poly(iminocarbonates), polyorthoesters, polyoxaesters, polyamidoesters, polyoxaesters containing amine groups, poly(anhydrides), polyphosphazenes, collagen, elastin, bioabsorbable starches, and combinations thereof.  
     
     
         6 . The implant of  claim 5 , wherein the aliphatic polyesters are homopolymers or copolymers selected from the group consisting of lactides, glycolides, ε-caprolactone, p-dioxanone (1,4-dioxan-2-one), trimethylene carbonate (1,3-dioxan-2-one), alkyl derivatives of trimethylene carbonate, δ-valerolactone, β-butyrolactone, γ-butyrolactone, ε-decalactone, hydroxybutyrate, hydroxyvalerate, 1,4-dioxepan-2-one, 1,5-dioxepan-2-one, 6,6-dimethyl-1,4-dioxan-2-one, 2,5-diketomorpholine, pivalolactone, α,α-diethyl-propiolactone, ethylene carbonate, ethylene oxalate, 3-methyl-1,4-dioxane-2,5-dione, 3,3-diethyl-1,4-dioxan-2,5-dione, 6,8-dioxabicycloctane-7-one, and combinations thereof.  
     
     
         7 . The implant of  claim 1 , wherein the foam component is formed from an elastomeric copolymer selected from the group consisting of ε-caprolactone-co-glycolide, ε-caprolactone-co-lactide, p-dioxanone (1,4-dioxan-2-one)-co-lactide, ε-caprolactone-co-p-dioxanone, p-dioxanone-co-trimethylene carbonate, trimethylene carbonate-co-glycolide, trimethylene carbonate-co-and lactide, and combinations thereof.  
     
     
         8 . The implant of  claim 1 , wherein the polymer from which the foam component is constructed has a percent elongation greater than about 200.  
     
     
         9 . The implant of  claim 8 , wherein the polymer from which the foam component is constructed has a tensile strength greater than about 500 psi.  
     
     
         10 . The implant of  claim 9 , wherein the polymer from which the foam component is constructed has a tear strength greater than about 50 lbs/inch.  
     
     
         11 . The implant of  claim 4 , wherein separate foam layers are constructed of different polymers.  
     
     
         12 . The implant of  claim 11 , wherein the physical properties of the foam component vary throughout a thickness dimension of the implant.  
     
     
         13 . The implant of  claim 1 , wherein the reinforcing component is bioabsorbable.  
     
     
         14 . The implant of  claim 1 , wherein the reinforcing component comprises a mesh-like material having a solid component with a plurality of openings formed therein.  
     
     
         15 . The implant of  claim 14 , wherein the solid component of the mesh is formed from fibers made from a material selected from the group consisting of polylactic acid, polyglycolic acid, polycaprolactone, polydioxanone, trimethylene carbonate, polyvinyl alcohol, copolymers thereof, and combinations thereof.  
     
     
         16 . The implant of  claim 14 , wherein the solid component of the mesh is formed from fibers made from a material selected from the group consisting of bioabsorbable silicate glass, bioabsorbable calcium phosphate glass, and combinations thereof.  
     
     
         17 . The implant of  claim 16 , wherein the fibers are selected from the group consisting of bioabsorbable silicate glass and bioabsorbable calcium phosphate glass and the solid component further comprises from about 1 to 50 percent by volume of an element selected from the group consisting of iron, sodium, magnesium, postassium, and combinations thereof.  
     
     
         18 . The implant of  claim 15 , wherein the fibers are formed of a 90/10 copolymer of polyglycolic acid and polylactic acid.  
     
     
         19 . The implant of  claim 15 , wherein the fibers are formed of a 95/5 copolymer of polylactic acid and polyglycolic acid.  
     
     
         20 . The implant of  claim 14 , wherein the mesh-like material has a mesh density in the range of about 12 to 80%.  
     
     
         21 . The implant of  claim 14 , wherein the solid component is made of coextruded fibers having a core made of a first bioabsorbable polymer that is biologically resorbable at a first rate and that is surrounded by a sheath formed of a second bioabsorbable polymer that is biologically resorbable at a second, different rate.  
     
     
         22 . The implant of  claim 1 , further comprising a fabric barrier layer formed on at least one surface of the implant.  
     
     
         23 . The implant of  claim 22 , wherein the fabric barrier is formed on a top surface and a bottom surface of the implant.  
     
     
         24 . The implant of  claim 22 , wherein the fabric barrier is a dense, fibrous fabric that is effective as a barrier to hyperplasia and tissue adhesion.  
     
     
         25 . The implant of  claim 24 , wherein the fabric barrier is formed of an electrostatically spun aliphatic polyester.  
     
     
         26 . A method for making a reinforced foam, biocompatible tissue implant, comprising: 
 providing a solution of a foam forming polymeric material in a suitable solvent;    providing a mesh-like reinforcing material;    placing the reinforcing material in a mold in a desired postion and at a desired orientation;    adding the solution to the mold in a controlled manner; and    lyophilizing the solution to obtain a tissue implant having a mesh reinforced foam component.    
     
     
         27 . The method of  claim 26 , wherein the polymeric material includes a copolymer.  
     
     
         28 . The method of  claim 26 , wherein the polymeric solution includes a blend of polymers or copolymers.  
     
     
         29 . The method of  claim 28 , wherein the polymeric solution is a blend of ε-caprolactone-co-glycolide and ε-caprolactone-co-lactide at about a molar ratio in the range of about 50:50.  
     
     
         30 . The method of  claim 28 , wherein the polymeric solution is a 35:65 copolymer of polyglycolic acid and polycaprolactone.  
     
     
         31 . The method of  claim 28 , wherein the polyglycolic solution is a 50:50 blend of a 35:65 copolymer of polyglycolic acid and polycaprolactone and 40:60 ε-caprolactone-co-lactide.  
     
     
         32 . The method of  claim 26 , wherein the solution further comprises biocompatible solid particles having an average diameter in the range of about 50 microns to 1 mm, the solid particles being present at about 1 to 50 percent by volume of the solution.  
     
     
         33 . The method of  claim 32 , wherein the solid particles are selected from the group consisting of barium sulfate, demineralized bone, calcium phosphate particles, bioglass particles, calcium sulfate, calcium carbonate, leachable solids, particles of bioabsorbable polymers not soluble in the solvent system, biocompatible metals, bioinert ceramics, non-bioabsorbable polymers, and combinations thereof.  
     
     
         34 . The method of  claim 33 , wherein the leachable solids are selected from the group consisting of non-toxic salts, monosaccharides, disaccharides, polysaccharides, and water soluble proteins.  
     
     
         35 . The method of  claim 33 , wherein the biocompatible metals are selected from the group consisting of stainless steel, coblat chrome, titanium, and titanium alloys.  
     
     
         36 . The method of  claim 33 , wherein the bioinert ceramics are selected from the group consisting of alumina, zirconia, and calcium sulfate.  
     
     
         37 . The method of  claim 33 , wherein the non-bioabsorbable polymers are selected from the group consisting of polyvinylacetate, polymethylmethacrylate, silicone, polyethyleneoxide, polyethylene glycol, polyurethane, polyvinyl alcohol, fluorinated polymers, flurinated copolymers, cellulose, chitin, keratin, silk, and collagen.  
     
     
         38 . The method of  claim 26 , wherein the reinforcing material is placed in the mold so as to be in a substantially flat position.  
     
     
         39 . The method of  claim 38 , wherein the reinforcing material is, at least in part, suspended above a bottom portion of the mold.  
     
     
         40 . The method of  claim 38 , wherein the solution is added to the mold in a manner in which air bubbles are not permitted to form.  
     
     
         41 . The method of  claim 40 , wherein the mold is tilted while the solution is added.  
     
     
         42 . The method of  claim 26 , wherein the polymeric material is a 35:65 copolymer of polyglycolic acid and polycaprolactone and the reinforcing material is a polydioxanone mesh.  
     
     
         43 . The method of  claim 42 , wherein the solvent is dioxane.  
     
     
         44 . The method of  claim 26 , wherein one or more indicators is embedded within the implant in a direction indicative of a dimension of the implant having a desirable property.  
     
     
         45 . A method of repairing a tissue tear, comprising: 
 providing a biocompatible tissue implant comprising a bioabsorbable polymeric foam component having pores with an open cell pore structure and a reinforcing component formed of a biocompatible, mesh-containing material, wherein the foam component is integrated with the reinforcement component such that the pores of the foam component penetrate the mesh of the reinforcing component and interlock with the reinforcing component;    placing the implant in a desired position relative to the tissue tear; and    suturing the implant in the desired postion.    
     
     
         46 . The method of  claim 45 , wherein the implant is bioabsorbable.