Porphyrin-containing amphiphilic block copolymers for photodynamic therapy

Amphiphilic PNIPAM-b-PTPPC6MA block copolymers were first synthesized using porphyrin-containing monomers. The mono-hydroxylphenyl-triphenylporphyrin photosensitizer, TPP-OH, was modified into a porphyrin monomer, and it was further used to construct the amphiphilic PNIPAM-b-PTPPC6MA block copolymers using RAFT polymerization. PNIPAM-b-PTPPC6MA block copolymers can self-assemble into a plethora of morphologies ranging from spheres to vesicular aggregates and further to a single large vesicle. The PNIPAM-b-PTPPC6MA micelles exhibited a high singlet oxygen quantum yield. Moreover, confocal laser scanning microscopy (CLSM) and flow cytometry analysis confirmed that PNIPAM-b-PTPPC6MA micelles could effectively enhance the internalization rate in MCF-7 cells. According to the MTT assay, PNIPAM-b-PTPPC6MA micelles exhibited low dark toxicity and efficient PDT efficacy towards MCF-7 cells. Thus PNIPAM-b-PTPPC6MA block copolymers have the potential application for photodynamic therapy.