Novel aliphatic poly(ester-carhonate) with pendant allyl ester groups and its folic acid functionalization

A series of novel poly(ester-carbonate)s bearing pendant allyl ester groups P(LA-co-MAC)s were prepared by ring-opening copolymerization Of L-lactide (LA) and 5-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one (MAC) with diethyl zinc (ZnEt2) as initiator. NMR analysis investigated the microstructure of the copolymer. DSC results indicated that the copolymers displayed a single glass-transition temperature (T-g), which was indicative of a random copolymer, and the Tg decreased with increasing carbonate content in the copolymer. Then NHS-activated folic acid (FA) first reacted with 2-aminoethanethiol to yield FA-SH; grafting FA-SH to P(LA-co-MAC) in the presence of TEA produced P(LA-co-MAC)/FA. The structure of P(LA-co-MAC)/FA and its precursor were confirmed by H-1 NMR and XPS analysis. Cell experiments showed that FA-grafted P(LA-co-MAC) had improved adhesion and proliferation behavior of vero cells on the polymer films. Therefore, the novel FA-grafted block copolymer is expected to find application in drug delivery or tissue engineering. (c) 2008 Wiley Periodicals, Inc.