Copolymer-bioceramic composite implantable medical devices

1 . An implantable medical device comprising a structural element including a bioceramic/copolymer composite, the composite having a plurality of bioceramic particles dispersed within a copolymer, the copolymer comprising a first functional group and a second functional group.

2 . The device of claim 1 , wherein the device comprises a stent.

3 . The device of claim 1 , wherein the copolymer is a random copolymer comprising the first functional group and the second functional group.

4 . The device of claim 1 , wherein the first and second functional groups are stereoisomers.

5 . The device of claim 1 , wherein the second functional group is more hydrolytically active than the first functional group.

6 . The device of claim 1 , wherein the copolymer has a higher degradation rate than a homopolymer comprising the first functional group or the second functional group.

7 . The device of claim 1 , wherein the first functional group is L-lactide and the second functional group is DL-lactide.

8 . The device of claim 7 , further comprising a coating on the structural element comprising poly(DL-lactide).

9 . The device of claim 1 , wherein the first functional group is L-lactide and the second functional group is glycolide.

10 . The device of claim 9 , wherein the copolymer comprises at least 1 wt % glycolide monomers.

11 . The device of claim 1 , wherein the crystallinity of the copolymer is lower than a homopolymer comprising the first functional group or the second functional group.

12 . The device of claim 1 , wherein the second functional group is more hydrophilic or less hydrophobic than the first functional group.

13 . The device of claim 1 , wherein the bioceramic particles are nanoparticles.

14 . The device of claim 1 , wherein the bioceramic particles are biodegradable.

15 . The device of claim 1 , wherein the particles are uniformly or substantially uniformly dispersed within the copolymer.

16 . The device of claim 1 , wherein the bioceramic particles are biodegradable, a degradation rate of the bioceramic particles is greater than the copolymer.

17 . The device of claim 1 , wherein the bioceramic particles are biodegradable, the degradation products of the bioceramic particles being capable of modifying a degradation rate of the copolymer during use of the device.

18 . The device of claim 1 , wherein the bioceramic particles are biodegradable, the degradation products of the particles being basic.

19 . The device of claim 1 , wherein the bioceramic particles are biodegradable, the degradation products of the particles being acidic.

20 . The device of claim 1 , wherein the bioceramic particles are selected from a group consisting of calcium and phosphate compounds.

21 . The device of claim 1 , wherein a surface of the bioceramic particles comprises an adhesion promoter, the adhesion promoter enhancing bonding between the copolymer and the bioceramic particles.

22 . The device of claim 21 , wherein the adhesion promoter comprises coupling agents.

23 . The device of claim 21 , wherein the coupling agents comprise silane coupling agents.

24 . The device of claim 21 , wherein the adhesion promoter is selected from a group consisting of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane and aminopropylmethyldiethoxy si lane.

25 . The device of claim 1 , wherein the particles increase the toughness of the copolymer and the structural element of the device at physiological conditions.

26 . The device of claim 1 , wherein the particles increase the modulus of the copolymer and the structural element of the device at physiological conditions.

27 . An implantable medical device fabricated from a bioceramic/copolymer composite, the composite comprising a plurality of bioceramic particles dispersed within a copolymer, the copolymer including a first functional group and a second functional group.

28 . The device of claim 27 , wherein the copolymer comprises poly(L-lactide-co-glycolide).

29 . The device of claim 27 , wherein the device has a lower degradation time under physiological conditions than a device fabricated from a homopolymer comprising the first functional group or the second functional group.

30 . The device of claim 27 , wherein the device comprises a degradation time of less than a year under physiological conditions.

31 . A stent fabricated in whole or in part from a bioceramic/polymer composite, the composite having a plurality of bioceramic particles dispersed within a copolymer, the copolymer comprising L-lactide and glycolide.

32 . The stent of claim 31 , wherein the copolymer comprises at least 1 wt % glycolide monomers.

33 . The stent of claim 31 , wherein the copolymer comprises at least 50 wt % glycolide monomers.

34 . The stent of claim 31 , wherein the device comprises a degradation time of less than a year under physiological conditions.