Biodegradable And/Or Bioabsorbable Thermoplastic Polyurethanes

Abstract

The thermoplastic polyurethane (TPU) compositions described herein have biodegradable and/or bioabsorbable hard and soft segments. The TPU hard segment can be formed from a polyisocyanate and a 2,5-substituted diketopiperazine.

1 . A bioabsorbable thermoplastic polyurethane, comprising the reaction product of:
 a. a polydiisocyanate component;   b. a polyol component; and   c. at least one chain extender component comprising a cyclic dimer of an amino acid having a side chain containing a functional group comprising —OH, —COOH, —NH, —NH 2  or —SH.   
     
     
         2 . The bioabsorbable thermoplastic polyurethane of  claim 1 , wherein the polydiisocyanate component comprises an aliphatic or aromatic diisocyanate. 
     
     
         3 . The bioabsorbable thermoplastic polyurethane of  claim 2 , wherein the aliphatic diisocyanate comprises H12MDI, HDI, HMDI, IPDI, LDI, BDI, PDI, CHDI, TODI, NDI, or combinations thereof. 
     
     
         4 . The bioabsorbable thermoplastic polyurethane of  claim 2 , wherein the aromatic diisocyanate comprises MDI, XDI, TDI or combinations thereof. 
     
     
         5 . The bioabsorbable thermoplastic polyurethane of  claim 1 , wherein the polyol component comprises a polyester polyol comprising poly(L-lactide) (PLA), polglycolide (PGA), or polycaprolactone (PCL) or combinations thereof. 6. The bioabsorbable thermoplastic polyurethane of  claim 1 , wherein the polyol component comprises a polyether polyol comprising poly(propylene glycol), poly(ethylene glycol), poly(tetramethylene ether glycol), and combinations thereof. 
     
     
         6 . The bioabsorbable thermoplastic polyurethane of  claim 2 , wherein the chain extender component comprises a cyclic dimer of glutamic acid, serine, lysine, glycine, aspartic acid, cysteine, arginine, histidine, glutamine, asparagine, threonine, hydroxyproline, tryptophan or tyrosine and optical isomers thereof. 
     
     
         7 . The bioabsorbable thermoplastic polyurethane of  claim 1 , further comprising an additional chain extender. 
     
     
         8 . The bioabsorbable thermoplastic polyurethane of  claim 7 , wherein the additional chain extender comprises at least one diol chain extender of the general formula HO—(CH 2 ) x —OH wherein x is an integer from 2 to 6. 
     
     
         9 . The bioabsorbable thermoplastic polyurethane of  claim 8 , wherein the at least one diol chain extender comprises 1,4-butane diol. 
     
     
         10 . A bioabsorbable thermoplastic polyurethane, comprising the reaction product of:
 a. a polydiisocyanate;   b. a substituted 2,5-diketopiperazine of Formula 2:   
       
         
           
           
               
               
           
         
         wherein: 
         R and R′ are the side chain of an amino acid containing a functional group comprising —OH, —COOH, —NH, —NH 2  or —SH, and R and R′ may be the same or different; and 
         c. a polyol component. 
       
     
     
         11 . The bioabsorbable thermoplastic polyurethane of  claim 10 , wherein the substitution is a symmetrical or asymmetrical substitution. 
     
     
         12 . The bioabsorbable thermoplastic polyurethane of  claim 10 , wherein the substituted 2,5-diketopiperazine is present in an amount from 5 wt % to 45 wt % of the total weight of the thermoplastic polyurethane composition. 
     
     
         13 . The bioabsorbable thermoplastic polyurethane of  claim 10 , wherein the amino acid comprises glutamic acid, serine, lysine, glycine, aspartic acid, cysteine, arginine, histidine, glutamine, asparagine, threonine, hydroxyproline, tryptophan or tyrosine and optical isomers thereof. 
     
     
         14 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of tyrosine. 
     
     
         15 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of lysine. 
     
     
         16 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of serine. 
     
     
         17 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of hydroxyproline. 
     
     
         18 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of glutamic acid. 
     
     
         19 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of glycine. 
     
     
         20 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of aspartic acid. 
     
     
         21 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of cysteine. 
     
     
         22 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of arginine. 
     
     
         23 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of histidine. 
     
     
         24 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of glutamine. 
     
     
         25 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of threonine. 
     
     
         26 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of asparagine. 
     
     
         27 . The bioabsorbable thermoplastic polyurethane of  claim 13 , wherein R and R′ are the side chains of tryptophan. 
     
     
         28 . A method of making a bioabsorbable thermoplastic polyurethane, comprising the step of (I) reacting:
 a) a polydiisocyanate component;   b) a polyol component; and   c) at least one chain extender component comprising a cyclic dimer of an amino acid having a side chain containing a functional group comprising —OH, —COOH, —NH, —NH 2  or —SH.