ENZYMATIC DEGRADATION OF SEQUENTIAL POLYMERS CONTAINING A TRIPEPTIDE SEQUENCE L-ALANINE-L-LEUCINE GAMMA-ETHYL L-GLUTAMATE AND AN ALPHA-HYDROXY ACID L-LACTICE ACID OR ALPHA-AMINO-ACID L-ALANINE

A study was made with the objective to obtain sequential polymers having good biocompatibility and biodegradability. For this purpose, a sequential polydepsipeptide of three alpha -amino acids such as L-alanine (Ala), L-leucine (Leu), and gamma -ethyl L-glutamate (Glu(OEt)) and one alpha -hydroxy acid such as L-lactic acid (Lac), poly(Ala-Leu-Glu(OEt)-Lac), was synthesized by polycondensation of tetradepsipeptide active ester. The sequential polymers were then degraded by three kinds of enzymes, lipase as an esterase, papain as an endopeptidase, in order to learn the differences in enzymatic degradation between two polymers. The in vivo degradation was attempted by implanting the polymers subcutaneously in the back of rats, for the comparison with the above enzymatic degradation.