Abstract
Multi-component random copolypeptides consisting of N-hydroxyethyl-L-glutamine, L-glutamicacid, and L-lysine were prepared by aminolysis with aminoalcohols, such as 2-amino-1-ethanol (E) and 5-amino-1-pentanol (Pe), followed by crosslinking with octamethylene diamine (OMDA). The effective crosslink density was proportional to the content of OMDA in the reaction mixture. The tensile properties of these hydrophilic membranes (hydrogels) were highly dependent on the swelling ratio q in the pseudo-extracellular fluid PECF, hydrophobicity of the side chains, and the effective charge density of hydrogels. Their mechanical behavior was similar to that of elastomer. Biodegradation of the membranes in vitro by bromelain indicated that the degradation took place through the bulk phase of the hydrogels not only the surface region. The rate of degradation was also highly dependent on the swelling ratio q of hydogel, as well as on the hydrophobicity and effective chatge density of side chains of copolypeptides.
