Microstructure characterization and thermal analysis of hybrid block copolymer α-methoxy-poly(ethylene glycol)-block-poly[ε-(benzyloxycarbonyl)-l-lysine] for biomedical applications

Hybrid block copolymers, which combine the economy and processibility of synthetic polymers with the functionality and highly ordered structures of polypeptides, can enhance control over structure formation at the nanoscale, as well as afford interesting materials that interface with Nature for a diversity of biomedical applications, such as drug delivery, tissue engineering and bioimaging. Hybrid block copolymer, α-methoxy-poly(ethylene glycol)-b-poly[ε-(benzyloxycarbonyl)-l-lysine], MPEG-b-PLL(Z), was synthesized by anionic ring-opening polymerization in excellent yield, and fully characterized using IR, 1H, 13C and 2-D NMR, GPC, TGA, DTGA, DSC, MDSC and polarimetry. Its precursor NCA, ε-(benzyloxycarbonyl)-l-lysine N-carboxyanhydride, l-Lys(Z)-NCA, was prepared in 97% yield; and a double doublet observed in the 1850–1750 cm−1 absorption region of its infrared spectrum, for the characteristic NCA carbonyl absorption bands, is discussed.