Polyisobutylene urethane, urea and urethane/urea copolymers and medical devices containing the same
The present invention pertains to polyisobutylene urethane, urea and urethane/urea copolymers, to methods of making such copolymers and to medical devices that contain such polymers. According to certain aspects of the invention, polyisobutylene urethane, urea and urethane/urea copolymers are provided, which comprise a polyisobutylene segment, an additional polymeric segment that is not a polyisobutylene segment, and a segment comprising a residue of a diisocyanate. According to other aspects of the invention, polyisobutylene urethane, urea and urethane/urea copolymers are provided, which comprise a polyisobutylene segment and end groups that comprise alkyl-, alkenyl- or alkynyl-chain-containing end groups.
1. An implantable or insertable medical device comprising a polymeric region that comprises: a polyisobutylene urethane, urea or urethane/urea copolymer comprising a polyisobutylene segment, a segment comprising a residue of a diisocyanate and an additional polymeric segment comprising a residue of a polyether diol, wherein the additional polymeric segment is a soft polymeric segment, and wherein a molar ratio of the polyisobutylene to additional polymeric segment is from 1.5:0.5 to 0.5:1.5.
2. The copolymer of claim 1 , wherein the additional polymeric segment comprises a residue of a polytetramethylene oxide diol, or a polyhexamethylene oxide diol.
3. The copolymer of claim 1 , wherein the polyisobutylene segment comprises a residue of a polyisobutylene diol or a polyisobutylene diamine.
4. The copolymer of claim 1 , wherein the diisocyanate is selected from an aromatic diisocyanate, an aliphatic diisocyanate and combinations thereof.
5. The copolymer of claim 1 , wherein the diisocyanate is selected from 4,4′-methylenediphenyl diisocyanate, toluene diisocyanate, 1,5-naphthalene diisocyanate, para-phenylene diisocyanate, 3,3′-tolidene-4,4′-diisocyanate, 3,3′-dimethyl-diphenylmethane-4,4′-diisocyanate, and combinations thereof.
6. The copolymer of claim 1 , further comprising a chain extender residue.
7. The copolymer of claim 6 , wherein the chain extender residue is selected from an aliphatic diol, an aromatic diol, a combination of aliphatic and aromatic diols, an aliphatic diamine, an aromatic diamine and a combination of aliphatic and aromatic diamines.
8. The copolymer of claim 6 , wherein the chain extender is an alpha,omega-C 1 -C10-alkane diol.
9. The copolymer of claim 6 , wherein the chain extender is selected from 1,2-ethane diol, 1,4-butanediol, 1,6-hexanediol, a low molecular weight polyisobutylene diol, and a low molecular weight poly(stryrene-b-isobutylene-b-styrene)diol.
10. The copolymer of claim 1 , further comprising end groups that comprise alkyl, alkenyl or alkynyl chains ranging from 1 to 17 carbons atoms in length.
11. The copolymer of claim 10 , wherein the end groups are selected from [—CH 2 ] n CH 3 groups, [—CH 2 ] n —C(CH 3 ) 3 groups, [—CH 2 ] n —CF 3 groups, [—CH 2 ] n —C(CF 3 ) 3 groups, [—CH 2 ] n —CH 2 OH groups, [—CH 2 ] n —C(OH) 3 groups, [—CH 2 ] n —C 6 H 5 groups, [—CH. 2 ] n -b-[—CH 2 O] n —CH 3 groups, [—CH 2 ] n -b-[—CH 2 O] n —CH 2 CH 2 C(CH 3 ) 3 groups, [—CH 2 ] n -b-[—CH 2 O] n —CH 2 CH 2 CF 3 groups, [—CH 2 ] n -b-[—CH 2 O] n —CH 2 CH 2 C(CF 3 ) 3 groups, [—CH 2 ] n -b-[—CH 2 O] n —CH 2 CH 2 OH groups, [—CH 2 ] n -b-CH 2 O′—C(OH) 3 groups, [—CH 2 ] n -b-[—CH 2 O] n —CH 2 CH 2 —C 6 H 5 groups and combinations thereof, where n ranges from 1 to 20.
12. The implantable or insertable medical device of claim 1 , wherein the medical device is selected from a stent, a heart valve, an implantable electrical lead, a pacemaker, a defibrillator and a heart failure device.
13. The implantable or insertable medical device of claim 1 , wherein the medical device comprises an implantable electrical lead and wherein the polymeric region is a polymeric layer disposed over an electrical conductor.
14. The implantable or insertable medical device of claim 13 , wherein the electrical lead is selected from a cardiac lead and a neurostimulation lead.
15. The implantable or insertable medical device of claim 1 , wherein said polymeric region further comprises a therapeutic agent.
16. The implantable or insertable medical device of claim 1 , wherein said polymeric region further comprises a filler material selected from a silicate material, alumina, silver nanoparticles, and silicate/alumina/silver nanoparticle composites.
17. The copolymer of claim 1 wherein the additional polymer segment comprises poly(tetramethylene oxide).
18. The copolymer of claim 1 wherein a molar ratio of the diisocyanate to polyisobutylene to additional polymer is from 2:1.5:0.5 to 2:0.5:1.5.
19. A pacemaker lead comprising a polyisobutylene urethane, urea or urethane/urea copolymer, the copolymer comprising a polyisobutylene segment, a segment comprising a residue of a diisocyanate and an additional polymeric segment comprising a polyether segment, wherein a molar ratio of the polyisobutylene segment to the polyether segment is from 1.5:0.5 to 0.5:1.5.
20. The pacemaker lead of claim 19 wherein the polyether segment comprises a poly(tetramethylene oxide) segment.
21. The pacemaker lead of claim 20 wherein the polyether segment comprises a residue of a saturated poly(tetramethylene oxide) diol segment.