Biodegradable polyurethanes

• US 6,221,997 B1
• Filed: 04/27/1998
• Issued: 04/24/2001
• Est. Priority Date: 04/28/1997
• Status: Expired due to Fees

• Current Assignee: Gary Alan Skarja, Kimberly Ann Woodhouse
• Original Assignee: Gary Alan Skarja, Kimberly Ann Woodhouse
• Inventors: Skarja, Gary Alan, Woodhouse, Kimberly Ann
• Primary Examiner(s): Gorr, Rachel
• Application Number:
  US09/067,080
• Time in Patent Office: 1,093 Days
• Field of Search: 528/61, 528/84
• US Class Current: 528/61
• CPC Class Codes: C08G 18/12 using two or more compounds having active hydrogen in the first polymerisation step
• CPC Class Codes: C08G 18/3821 Carboxylic acids; Esters thereof with monohydroxyl compounds
• CPC Class Codes: C08G 18/3825 containing amide groups C08G18/3821 takes precedence
• CPC Class Codes: C08G 18/4018 Mixtures of compounds of group C08G18/42 with compounds of group C08G18/48
• CPC Class Codes: C08G 18/4277 Caprolactone and/or substituted caprolactone
• CPC Class Codes: C08G 18/73 acyclic
• CPC Class Codes: C08G 2230/00 Compositions for preparing biodegradable polymers

Abstract

Disclosed herein is a biodegradable polyurethane material having a backbone containing at least one amino acid group. The amino acid group is in a condition rendering it recognizable by a biological agent.

Claims

1. A biodegradable polyurethane material having a backbone containing at least one amino acid group and formed by reaction of a polyol, a diisocyanate and a chain extender, said chain extender being formed by reaction of an amino acid with a diol, said amino acid group being present in said chain extender and in a condition rendering it recognizable by a biological agent.

2. A polyurethane as defined in claim 1 wherein said biological agent is an enzyme.

3. A polyurethane as defined in claim 2 wherein said enzyme is an endogenous enzyme.

4. A polyurethane as defined in claim 3 wherein said amino acid group is naturally occurring.

5. A polyurethane as defined in claim 4 wherein said amino acid group includes amino acid residues of the L configuration.

6. A polyurethane as defined in claim 1 wherein said amino acid group includes at least one amino acid residue having a side which is substantially unaltered.

7. A polyurethane as defined in claim 6 wherein said amino acid is selected from the group consisting of L-phenylalanine and L-lysine.

8. A polyurethane as defined in claim 1 wherein said diisocyanate is an amino acid lysine-based diisocyanate.

9. A polyurethane as defined in claim 1 wherein said diisocyanate is an aliphatic diisocyanate.

10. A polyurethane as defined in claim 1 wherein said chain extender is formed by reaction of a plurality of amino acids.

11. A polyurethane as defined in claim 1 wherein said chain extender has a plurality of amino acid groups.

12. A polyurethane as defined in claim 1 wherein said diol is an aliphatic diol.

13. A polyurethane as defined in claim 1 wherein said polyol is selected form the group consisting of polyethylene oxide and polycaprolactone diol.

14. A method for forming a biodegradable polyurethane material having a backbone containing at least one amino acid group, the method comprising the steps of:

forming a chain extender by reacting an amino acid with a diol;

reacting said chain extender with a diisocyanate and a polyol in suitable conditions to form said polyurethane, in such a manner that said amino acid is in a condition rendering it recognizable by a biological agent.

15. A method as defined in claim 14 wherein said the reacting step includes the steps of:

reacting said diisocyanate with said polyol to in suitable conditions to yield a prepolymer; and

reacting said prepolymer with said chain extender in suitable conditions to yield said polyurethane.

16. A biodegradable polyurethane material having a backbone containing at least one amino acid group and formed by reaction of a polyol selected from the group consisting of polyethylene oxide, polypropylene oxide, polytetramethylene oxide, polyethylene adipate, polytetramethylene adipate and polycaprolatone diol, a diisocyanate and a chain extender, said chain extender being formed by reaction of an amino acid with a diol, and in a condition rendering it recognizable by a biological agent.

17. A biodegradable segmented polyurethane material having a backbone containing at least one amino acid group and formed by reaction of a polyol, a diisocyanate and a chain extender, said chain extender being formed by reaction of an amino acid with a diol, and in a condition rendering it recognizable by a biological agent.

18. A segmented polyurethane material having a backbone containing at least one amino acid group and formed by reaction of a polyol, a diisocyanate and a chain extender, said chain extender being formed by reaction of an amino acid with a diol, and in a condition rendering it recognizable by a biological agent, wherein the polyurethane is formed from constituents which are selected so as to be degradable to substantially non toxic constituents.

19. A segmented polyurethane material having a backbone containing, as constituents, at least one amino acid group and formed by reaction of a polyol, a diisocyanate and a chain extender, said chain extender being formed by reaction of an amino acid with a diol, and in a condition rendering it recognizable by a biological agent, wherein the constituents which are selected to minimize toxicity in the enzymatic digests thereof.

20. A substrate suitable for use as a biomaterial and formed from a biodegradable segmented polyurethane material having a backbone containing at least one amino acid group and formed by reaction of a polyol, a diisocyanate and a chain extender, said chain extender being formed by reaction of an amino acid with a diol, and in a condition rendering it recognizable by a biological agent.

21. A substrate as defined in claim 20 wherein the substrate is in a form useful as an artificial skin, a wound dressing or a tissue engineering scaffold.

22. A substrate as defined in claim 20 having a molecular weight ranging from approximately 25,000 to 140,000.

23. A biodegradable segmented polyurethane material having a backbone containing at least one amino acid group and formed by reaction of a polyol, a diisocyanate and a chain extender, said chain extender being formed by reaction of an amino acid with a diol, and in a condition rendering the amino acid recognizable by a biological agent, thereby to form a hard segment containing a number of enzymatically cleavable sites containing the amino acid and at least one hydrolytically cleavable site containing an ester.