Novel photopolymerizable biodegradable triblock polymers for tissue engineering scaffolds: synthesis and characterization

For use in micro-patterned scaffolds in tissue engineering novel diacrylated triblock macromers (PLA-b-PLA-b-PLA, PGA-b-PCL-b-PGA and PCL-b-PEO-b-PCL) were synthesized and characterized by Fourier transform infrared spectroscopy (NMR) and gel permeation chromatography (GPC). All diacrylated polymers were designed as triblock copolymers and involved biodegradable blocks of relatively non-polar epsilon-caprolactone (CL) and polar monomers such as glycolide (GA), lactide (LA) or ethylene oxide (EO). All triblock polymers were prepared in molecular weights of a (ROP) of the corresponding lactide; glycolide or caprolactone using stannous octoate [An(Oct)(2)] as catalyst. The polymers had low polydispersity indices, ranging from 1.23 to 1.56. Biodegradable polymers networks were prepared with conversions of 72-84% via photopolymerization of the triblock diacrylated polymers with 2,2-dimethoxy-2-pheny-lacetophenone (DMPA) as photoinhibitor. PLA-b-PCL-b-PLA copolymers crumbled easily and were not suitable for micro-patterning. PGA-b-PCL-b-PGA copolymers had higher water contact angles than PCL-b-PEO-b-PCl and were also cytocompatible with Fibroblasts 3T3.