Segmented polyurethanes for medical applications:: Synthesis, characterization and in vitro enzymatic degradation studies

Degradable segmented poly(ether-ester-urethanes) of variable segment chemistry and content were synthesized and characterized. Polycaprolactone diol. a series of poly(ether-ester) block copolymers, and a diisocyanate giving non toxic degradation products were used to form the prepolymer. Cyclohexane dimethanol and a L-phenylalanine-based diester (Phe diester) were used as chain extenders. The influence of alpha-chimotrypsin on the degradation was investigated by exposing the polymers to buffer and enzyme solutions for 12 days. The SEM, SEC, and gravimetric results showed that a significant erosion of the Phe diester containing polymer compared with the control polyurethane occur-red in the presence of the enzyme but not in a normal buffer solution.