Amphiphilic Star-Shaped Poly(ε-caprolactone)-block-poly(L-Lysine) Copolymers with Porphyrin Core: Synthesis, Self-Assembly, and Cell Viability Assay

Star-shaped copolymers poly(epsilon-caprolactone)-bolck-poly(epsilon-benzyloxycarbonyl-l-lysine) (SPPCL-b-PZLLs) with porphyrin core were synthesized by a sequential ring-opening polymerization (ROP) of CL and N epsilon-Benzyloxycarbonyl-l-lysine N-Carboxyanhydride. After the deprotection of benzyloxycarbonyl groups in polylysine blocks, the star-shaped amphiphilic copolymers SPPCL-b-PLLs were obtained. These amphiphilic copolymers can self-assemble into micelles or aggregates in aqueous solution. Investigation shows that the morphology of micelles/aggregates varied according to the change of pH values of media, indicating the pH-responsive property of SPPCL-b-PLL copolymers. Furthermore, associated with conjugated porphyrin cores, the SPPCL-b-PLL copolymers micelles showed a certain degree of Photodynamic Therapy (PDT) effects on tumor cells, suggesting its potential application as carrier for hydrophobic drug with additional therapeutic ability of inherent porphyrin segments. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40097.