Bioactive and biodegradable composites of polymers and ceramics or glasses and method to manufacture such composites
Surgical osteosynthesis composite material which has three components: biodegradable polymer reinforcement, bioceramic or bioglass filler reinforcement and biodegradable polymer matrix. This invention relates to biodegradable materials used for bone fracture fixation devices and methods of their manufacture. Unlike other known materials used prior to this application, the composites of this invention have two different reinforcing phases and one matrix phase. One reinforcing element is referred as the polymeric reinforcing element and the other as the ceramic reinforcing element.
1. A biodegradable and bioactive composite material for surgical osteosynthesis applications comprising: i) at least one resorbable polymeric matrix component, ii) at least one resorbable polymeric reinforcing component in fiber form, and iii) at least one bioceramic or bioglass reinforcing component mixed with said matrix component, the diameter of the resorbable polymeric reinforcing component being greater than the diameter or particle size of the bioceramic or bioglass reinforcing component, wherein the bioceramic or bioglass reinforcing component has a particle size between 60 μm and 150 μm.
2. A method of manufacturing a biodegradable composite according to claim 1 , comprising the steps of:
a) selecting at least one first polymer for the matrix;
b) selecting at least one bioceramic material, bioglass material or mixture thereof for use as the bioceramic or bioglass reinforcing component;
c) mixing said first polymer and said bioceramic or bioglass reinforcing component together to form a mixture;
d) selecting at least one second polymer in a fiber form for the resorbable polymeric reinforcing component;
e) placing said second polymer into a desired formation;
f) combining said mixture of step (c) and said formation of step (e) to yield a second mixture; and
g) subjecting the second mixture of step (f) to heat or pressure.
3. The composite material according to claim 1 wherein the at least one resorbable polymeric reinforcing component comprises at least one fiber having a variable thickness.
4. The composite material according to claim 1 wherein the at least one resorbable polymeric reinforcing component is selected from the group consisting of a fabric, a plain polymeric fiber structure, a woven structure and a braided structure.
5. The composite material according to claim 1 wherein the form of the bioceramic or bioglass reinforcing component is selected from the group consisting of powder, flakes, spheres and fibers.
6. The composite material according to claim 1 wherein the amount of bioceramic or bioglass reinforcing component is 0.15 to 0.9 volume fraction.
7. The composite material according to claim 6 wherein the amount of bioceramic or bioglass reinforcing component is 0.2 to 0.6 volume fraction.
8. The composite material according to claim 1 further comprising additives selected from the group consisting of surface modifiers to improve attachment between the resorbable polymeric reinforcing component and the bioceramic or bioglass reinforcing component, a pharmaceutically active agent, and combinations thereof.
9. The composite material according to claim 8 wherein the pharmaceutically active agent is selected from the group consisting of antibiotics, wound-healing agents, chemotherapeutic agents, growth hormones, anticoagulants, and combinations thereof.
10. The composite material according to claim 1 wherein the resorbable polymeric matrix component is selected from the group consisting of polyglycolide, copolymers of glycolide, glycolide/L-lactide copolymers, glycolide/trimethylene carbonate copolymers, polylactides, stereocopolymers of polylactides, poly-L-lactide, poly-DL-lactide, L-lactide/DL-lactide copolymers, copolymers of polylactides, lactide/tetramethylglycolide copolymers, lactide/trimethylene carbonate copolymers, lactide/d-valerolactone copolymers, lactide/e-caprolactone copolymers, polylactide/polyethylene oxide copolymers, polydepsipeptides, unsymmetrically 3,6-substituted poly-1,4-dioxane-2,5-diones, poly-b-hydroxybutyrate, poly-b-hydroxybutyrate/b-hydroxyvalerate copolymers, poly-b-hydroxypropionate, poly-p-dioxanone, poly-d-valerolactone, poly-e-caprolactone, methylmethacrylate-N-vinyl pyrrolidone copolymers, polyesteramides, polyesters of oxalic acid, polydihydropyrans, polyalkyl-2-cyanocrylates, polyurethanes, polyvinylalcohol, polypeptides, poly-b-malic acid, poly-b-alkanoic acids, polycarbonates, polyorthoesters and polyphosphates.
11. The composite material according to claim 1 wherein the bioceramic or bioglass reinforcing component is selected from the group consisting of hydroxyapatite, calcium phosphates, alumina, zirconia, bioactive gel-glass, alpha wollastonite glass ceramic, and mixtures of bioglass and bioceramic materials.
12. The composite material according to claim 1 wherein the composite material exhibits ductile behavior under load.
13. The method according to claim 2 wherein the mixing of step c) is accomplished by melt mixing.
14. The method according to claim 2 wherein the mixing of step c) is accomplished by solvent mixing.
15. The method according to claim 2 wherein step e) is accomplished manually.
16. The method according to claim 2 wherein step e) is accomplished with use of a machine.