Blends as a strategy towards tailored hydrolytic degradation of poly(ε-caprolactone-co-D,L-lactide)-poly(ethylene glycol)-poly(ε-caprolactone-co-D,L-lactide) co-polymers

Binary blends were prepared from poly(F-caprolactone) (PCL), and P(CL-co-D,L-lactic acid)-P(ethylene glycol) -P(CL-CO-D,L-lactic acid) co-polymers, where the D,L-LA content in the side chains varied from 0 to 70 mol%. Blend discs were fabricated by melt-molding, and the effect of blend composition on hydrolytic degradation was studied. Variations in medium pH were monitored, and morphological changes were observed using scanning electron microscopy. Blending of these co-polymers was found to constitute a simple means by which intermediate rates of water absorption and mass loss were obtained, compared to those observed in pure co-polymer preparations. In one of the blends, prepared from the two components containing 70 or 0 mol% D,L-LA in the side chains and thereby exhibiting large differences in degradation rate, hydrolysis resulted in the formation of a porous material over time. Furthermore, all blend samples maintained their initial shape throughout the study. Such materials may be interesting for further investigations for applications in cellular therapy and controlled release. (c) 2008 Elsevier Ltd. All rights reserved.