Biodegradation of copoly ( N-hydroxyethyl- d, l-glutamine) in vitro

Abstract

Random copolypeptides (PHEDLG) consisting of N-hydroxyethyl- d-glutamine (HEDG) and N-hydroxyethyl- l-glutamine (HELG) covering the whole range of d, l-copolymer composition were prepared by carrying out aminolysis reactions with 2-amino-1-ethanol ( E) on starting random copolymers consisting of γ-methyl- d-glutamate and γ-methyl- l-glutamate (PMDLG). The effects of copolymer composition and sequential distributions on the rate of hydrolysis by bromelain in a pseudo-extracellular fluid (PECF) at pH 7.4 and 37.0°C simulated in vivo polymer degradation. Degradation data for these samples followed the Michaelis–Menten rate law, being of the first order to the enzyme concentration. It was shown that the rate of degradation by bromelain was controlled by comonomer composition as well as sequential distributions of comonomers in the copolymer chains.