Biodegradation of a poly-(alpha-amino acid) hydrogel. II. In vitro

Proteolytic enzymes have been employed in an in vitro model to simulate the in vivo degradation of a synthetic poly(amino acid) hydrogel. Trypsin and collagenase had no effect on crosslinked poly(2-hydroxyethyl-L-glutamine) but pronase and papain dissolved the hydrogel. The initial effect of papain was to decrease the effective crosslink density without producing soluble material. This effect was similar to that observed previously in vivo. Analysis of the papain digestion products showed that oligomers of degree of polymerization 4-9 were the chief products. The rate at which oligomers were formed increased with increasing crosslink density. This phenomenon was attributed to hydrophobic effects.