Acrylate end-capped poly(ester-carbonate) and poly(ether-ester)s for polymer-on-multielectrode array devices : synthesis, photocuring, and biocompatibility

Polymeric materials based on epsilon-caprolactone (CL), 1,5-dioxepan-2-one (DXO), and trimethylene carbonate (TMC) were prepared and evaluated as possible candidates for polymer-on-multielectrode (PoM) applications. CL was copolymerized with either DXO or TMC in the presence of the diol initiator 1,4-benzenedimethanol (BDM). The ring-opening polymerization experiments, carried out in bulk and using tin(II) catalysis, yielded the desired low molecular weight random copolymer diols, as evidenced by NMR, IR, MALDI-ToF MS, and DSC techniques. Upon reaction with acryloyl chloride, the corresponding diacrylate end-capped copolymers were obtained. The latter were characterized by NMR and IR spectroscopy, and their photocross-linking (in the presence of a UV initiator) was followed by ATR-FTIR spectroscopy. Transparent and soft thin films of the copoly(ether-ester) and copoly(ester-carbonate) diacrylates were prepared and cured under UV irradiation. The resulting polymeric films showed good biocompatibility properties as far as in vitro neural stem cells proliferation and differentiation to neurons and astrocytes are concerned. Noteworthy are the beneficial effects obtained upon preconditioning the copolymers by means of the cell-culture medium and the excellent properties shown particularly by the CL-TMC copolymer. Moreover, preliminary results show that microchannel formation by photocuring is possible with the synthesized polymers.