Synthesis and specific biodegradation of novel polyesteramides containing amino acid residues

Novel polyesteramides were synthesized from p-nitrophenyl, esters of sebaci c or adipic acids and diamines containing alpha -amino acid ester groups. T he optimal polymerization condition was 60 degreesC in N,N-dimethylformamid e. The structures of these polymers were confirmed by IR and NMR. The numbe r-average molecular weights of these polyesteramides ranged from 2280 to 23 ,600 (except for the polymers containing glycine residues), depending an th e nature of the amino acid used. The biodegradability of the polyesteramide s was investigated by in vitro hydrolysis with proteases and a Lipase as ca talysts in berate buffer solutions. The results indicated that the polymers containing L-phenylalanine were hydrolyzed most effectively by alpha -chym otrypsin, subtilisin Carlsberg, and subtilisin BPN '. The polyesteramides c ontaining other amino acid residues also underwent hydrolysis to different extents, reflecting the substrate specificity of the proteases. Lipase had almost no effect on tile hydrolytic degradation of these polyesteramides. T he polymers containing glycine residues were hardly decomposed by any of th e the enzymes used. (C) 2001 John Wiley & Sons, Inc.