Use of coupling agents to improve the interface in absorbable polymer composites
A composite having a poly(ethylene-co-acrylic acid) coupling agent, a filler, and a biocompatible, biodegradable polymer matrix is disclosed. The composites are useful for biomedical applications such as, tissue engineering, drug delivery, and implantable medical devices.
1. A composite comprising:
a beta-tricalcium phosphate filler comprising coated particles, each particle having an outer surface, and a copolymer of poly (lactic acid);
a coating comprising a 20:80 mole: mole poly (ethylene-co-acrylic) coupling agent, said coating deposited on the outer surface of the particles; and,
a poly (glycolic acid) polymer matrix.
2. The composite of claim 1 wherein the 20:80 moles: mole poly (ethylene-co-acrylic acid) coupling agent comprises a coating on the beta-tricalcium phosphate filler.
3. The composite of claim 1 wherein the copolymer of poly (lactic acid) and poly (glycolic acid) comprises about 70:30 to about 99:1 mole: mole poly (lactic acid): poly (glycolic acid).
4. The composite of claim 3 wherein the copolymer of poly (lactic acid) and poly (glycolic acid) comprises about 85:15 moles: mole poly (lactic acid): poly (glycolic acid).
5. The composite of claim 4 wherein the polymer matrix comprises about 70 to about 99 wt % of the total weight of the composite.
6. The composite of claim 5 wherein the polymer matrix comprises about 90 to about 99 wt % of the total weight of the composite.
7. The composite of claim 6 wherein the polymer matrix comprises about 95 wt % of the total weight of the composite.
8. A composite comprising:
a beta-tricalcium phosphate filler comprising coated particles, each particle having an outer surface; and,
a coating comprising a poly (ethylene-co-acrylic) coupling agent, said coating deposited on the outer surface of the particles; and,
a copolymer of poly (lactic acid) and poly (glycolic acid) polymer matrix wherein the polymer matrix comprises about 95 wt % of the total weight of the composite.
9. The composite of claim 8 further comprising a radio opaque material.
10. The composite of claim 8 further comprising a therapeutic agent.
11. A medical device, comprising:
a composite, said composite comprising:
a beta-tricalcium phosphate filler comprising coated particles, each particle having an outer surface, and a polymer of poly (lactic acid);
a coating comprising a 20:80 mole: mole poly (ethylene-co-acrylic) coupling agent, said coating deposited on the outer surface of the particles; and,
a poly (glycolic acid) polymer matrix.
12. A method of making the composite of claim 1 comprising:
dissolving a poly (ethylene-co-acrylic acid) coupling agent in an organic solvent;
adding beta-tricalcium phosphate filler to the solvent to provide a slurry, said filler comprising particles, each particle having a surface:
mixing the slurry to provide a coating of the coupling agent on at least part of each surface of each particle of the filler;
isolating the poly (ethylene-co-acrylic acid) coated beta-tricalcium phosphate filler;
drying the poly (ethylene-co-acrylic acid) coated beta-tricalcium phosphate filler; and
compounding the poly (ethylene-co-acrylic acid) coated beta-tricalcium phosphate filler with a poly(glycolic acid) polymer matrix.