Biodegradable polyester resins were prepared via photo crosslinking of functional polyesters obtained by copolymerization of epsilon-caprolactone and the functional cyclic esters gamma-acryloyloxy-epsilon-caprolactone (ACL) and gamma-methacryloyloxy-epsilon-caprolactone (MCL). The cyclic esters were prepared via Baeyer-Villiger oxidation of the corresponding 4-acyloyloxy-cyclohexanone derivatives. Copolymers with different content of either acryloyloxy or methacryloyloxy functional groups were prepared via catalyzed ring-opening polymerization (ROP) of gamma-acyloyloxy-epsilon-caprolactones and epsilon-caprolactone using Al(OiPr)(3) as catalyst and initiator. 2D- and 3D-micropatterning of the copolymers was performed via LTV-crosslinking of polymer films on a suitable substrate and by UV replica molding on both rigid and elastic masters, showing the processability of these novel functional polyesters and their potential as substrates for biomedical devices. (c) 2008 Wiley Periodicals, Inc.