Anti-cancer activity of zinc-tetraphenylporphyrin photosensitizer/dextran--polyacrylamide copolymer/Au(Ag) nanoparticle nanohybrids.

A comparative study of anti-cancer photodynamic activities of three-component zinc-tetraphenylporphyrin photosensitizer/dextran--polyacrylamide copolymer/Au(Ag) nanoparticle (ZnTPP/D--PAA/Au(Ag)NP) nanohybrids on LNCaP prostate cancer cells was carried out under 420 nm light irradiation with low power. A significant cytotoxic effect was revealed for both ZnTPP/D--PAA/AgNP and ZnTPP/D--PAA/AuNP nanohybrids, where ZnTPP/D--PAA/AgNP nanohybrids exhibited considerably higher anticancer activity (82%) compared to ZnTPP/D--PAA/AuNP nanohybrids (45%). The higher activity of silver-containing nanohybrids is rationalized based on two factors. The first factor is the resonance of 420 nm light with a absorption Soret peak of the ZnTPP photosensitizer and a localized surface plasmon mode in Ag nanoparticles. Correspondingly, the plasmon enhancement of reactive oxygen species photogeneration by ZnTPP molecules was considerably higher for the nanohybrid containing silver compared to the one containing gold. The second factor is the higher cytotoxicity of Ag nanoparticles compared to Au ones. The study results prove the high potential of D--PAA/Ag(Au)NP nanohybrids combined with 420 nm light irradiation with low power in the photodynamic treatment of prostate cancer.