Comparative study of aluminum phthalocyanine incorporating into two types of block copolymer: photo-physical property, size, and in vitro photodynamic therapy efficacy

摘要

Nanoparticles of amphiphilic triblock copolymer poly(L-lysine)-b-poly(ethylene glycol)-b-poly(L-lysine) and diblock copolymer methoxypoly(ethylene glycol)-b-poly(L-lysine) were developed to encapsulate tetra(4-sulfoazophenyl-4'-aminosulfonyl) chloride aluminum phthalocyanine, a new photosensitizer used in photodynamic therapy. The mean nanoparticle sizes varied from 10 to 70 nm, and the encapsulation efficacy ranged from 56 to 73 % due to electrostatic self-assembly induced by two types of polymer. The characteristic photophysical parameters including the absorption spectrum profile, fluorescence quantum yield, and fluorescence decay curves for free and encapsulated phthalocyanine were analyzed. The cellular uptake amount and photoactivity of S-AlPc were improved by encapsulation. The aluminum phthalocyanine loaded with poly(L-lysine)-b-poly(ethylene glycol)-b-poly(L-lysine) presented suitable physical stability, improved photophysical properties, and enhanced phototoxicity in vitro, suggesting it may be considered as a promising formulation for PDT.