Poly(ester urea) polymers and methods of use
The invention provides high molecular weight, crystalline or semi crystalline biodegradable and biocompatible poly(ester urea) (PEU) polymers useful for making vascular stents and hard tissue replacement implants, such as bone substitutes. The PEU polymers are based on α amino acids and are made by a polycondensation reaction. PEU polymer compositions can contain a therapeutic diol incorporated into the polymer backbone that is released from such an implant in situ. Bioactive agents, such as analgesics, antibiotics, and the like, can also be covalently attached to certain PEU polymers for release into tissue surrounding an implant during biodegradation of the polymer.
1. A crystalline or semi-crystalline poly(ester urea) (PEU) polymer composition having formula (II):
wherein m is about 0.1 to about 0.9; p is about 0.9 to about 0.1; n is about 10 to about 150;
R 1 is independently (C 2 -C 20 ) alkylene, (C 2 -C 20 ) alkenylene, (C 2 -C 8 ) alkyloxy, (C 2 -C 20 ) alkylene, a residue of a saturated or unsaturated therapeutic diol, or a bicyclic-fragment of 1,4:3,6-dianhydrohexitol of formula (III):
each R 2 is independently hydrogen, (C 1 -C 12 ) alkyl or (C 6 -C 10 ) aryl;
the R 3 s, in an individual m monomer, are independently hydrogen, (C 1 -C 6 ) alkyl, (C 2 -C 6 ) alkenyl, (C 2 -C 6 ) alkynyl, or (C 6 -C 10 ) aryl (C 1 -C 6 ) alkyl; and
R 4 is independently (C 2 -C 20 ) alkyl or (C 2 -C 20 ) alkenyl,
wherein the composition has a molecular weight in the range from about 75,000 Da to about 200,000 Da, as measured by gel permeation chromatography and wherein the composition has a tensile strength at break in the range from about 20 MPa to about 150 MPa as measured by tensile measurement.
2. The composition of claim 1 , wherein R 4 is independently (C 2 -C 20 ) alkyl.
3. The composition of claim 1 , wherein R 4 is independently (C 3 to C 6 ) alkyl or (C 3 to C 6 ) alkenyl.
4. The composition of claim 1 , wherein R 4 is independently —(CH 2 ) 4 —.
5. The composition of claim 1 , wherein R 3 is CH 2 Ph.
6. The composition of claim 1 , wherein the bicyclic fragment of 1,4:3,6-dianhydrohexitol of formula (III) is derived from D-glucitol, D-mannitol, or L-iditol.
7. The composition of claim 1 , wherein the R 1 is a residue of a saturated or unsaturated therapeutic diol or a bicyclic-fragment of 1,4:3,6-dianhydrohexitol of formula (III).
8. The composition of claim 7 , wherein the bicyclic-fragment of 1,4:3,6-dianhydrohexitol is a residue of 1,4:3,6-dianhydrosorbitol.
9. The composition of claim 1 , wherein the composition biodegrades over a period of about two weeks to about 9 months.
10. The composition of claim 1 , wherein the composition further comprises at least one bioactive agent covalently attached to the polymer of formula (II).
11. A surgical device comprising a polymer of claim 1 , wherein the device is implantable.
12. The device of claim 11 , wherein the surgical device is completely biodegradable.
13. The device of claim 11 , wherein the surgical device is a bone substitute.
14. The device of claim 11 , wherein the implantable surgical device is a vascular stent.
15. The device of claim 11 , wherein the device is a hard tissue replacement implant.
16. The device of claim 11 , wherein the device is a bone substitute.
17. The device of claim 11 , wherein the device biodegrades over a period of about two weeks to about six years.
18. The device of claim 11 , wherein at least one of R 1 is a therapeutic diol, wherein the device biodegrades to release the therapeutic diol.
19. The device of claim 18 , wherein the therapeutic diol is 17-beta-Estradiol.
20. The device of claim 11 , wherein the polymer has a chemical formula described by structural formula (II) and wherein the composition further comprises at least one bioactive agent conjugated to the polymer.
21. The device of claim 20 , wherein the bioactive agent is an antibiotic.
22. The device of claim 20 , wherein the bioactive agent is an analgesic.