Influence of structural parameters on the ring-opening polymerization of new alkyl malolactonate monomers and on the biocompatibily of polymers therefrom

The geometry of several alkyl malolactonate monomers was investigated by NMR and semi-empirical computational methods. The results obtained by both techniques indicated that the geometry of the malolactone ring is almost independent of the nature of the side ester group. C-13 NMR analysis of the polymer backbone stereochemistry ruled out the occurrence of stereoelective processes in the polymerization of racemic monomers, The observed influence of the bulkiness of the alkyl group on the polymerization rate was therefore attributed to steric interactions between this group and the polymer growing-end. Preliminary in-vitro investigation of cell adhesion and proliferation on the surface of homopolymers and copolymers of the investigated alkyl malolactonates suggested a possible correlation between polymer hydrophobicity and biocompatibility.