Functional modification of biodegradable polyesters through a chemoselective approach: application to biomaterial surfaces

This paper presents an overview of functional modifications of synthetic aliphatic polyesters and a new synthetic route to graft functional moieties onto the polyester backbone by a chemoselective approach. Aminooxy groups react efficiently and selectively with ketones or aldehydes to form oxime linkages under mild reaction conditions without catalysts, even in the presence of other functional groups. Chemoselective coupling of aminooxy-terminated poly(ethylene oxide) (PEO) onto ketone-bearing poly(e-caprolactone) (PCL) was exploited to prepare comb-shaped copolymers that exhibit cell resistance when the PEO content is above 30 wt%. The free hydroxyl groups of PEO chain ends allowed further incorporation of cell signaling peptides including the sequence RGD. The results show chemoselective coupling to be a promising general route for introducing functional pendant groups onto most polyesters obtained by ring-opening polymerization without backbone degradation. (C) 2006 Society of Chemical Industry.