A novel heterofunctional initiator, synthesized from pentaerythritol in a three step reaction sequence with two ring opening polymerization (ROP) and two atom transfer radical polymerization (ATRP) initiating sites, was used to prepare A(2)B(2) miktoarm star copolymers of poly(c-caprolactone), P epsilon CL, with polystyrene, PS, poly(methyl methaerylate), PMMA, poly(dimethylaminoethyl methacrylate), PDMAEMA, and poly(2-hydroxyethyl methacrylate), PHEMA. A(2)B miktoarm stars, A being PeCL or poly(delta-valerolactone), P delta VL and B PS were also prepared from omega,omega-dihydroxy-PS, synthesized from omega-Br-PS and serinol, by ROP of epsilon CL or delta VL. All polymers were characterized by size exclusion chromatography, H-1 NMR spectroscopy, and membrane osmometry. (c) 2007 Wiley Periodicals, Inc.