Synergistic Effect of Zinc Phthalocyanine and B-Phycoerythrin for Enhanced Singlet Oxygen Generation in a Dual Antioxidant-Photosensitizing Hydrogel

Phycoerythrin belongs to the category of phycobiliprotein mainly present in the red algae with marvellous antioxidant and anticancer effects. In this study, we developed a dual antioxidant-photosensitizing hydrogel, CS-ZnPcTA/PE, based on chitosan (CS), zinc phthalocyanine tetra-aldehyde (ZnPcTA), and B-phycoerythrin (B-PE). ZnPcTA served as both a cross-linking and photosensitizing agent, while B-PE acted as an antioxidant and photosensitizer. The hydrogel was characterized using FT-IR, UV-Vis spectroscopy, FE-SEM, and swelling measurements. FE-SEM images confirmed a porous structure with pore sizes ranging from ۵۰ to ۴۷۰ nm, facilitating efficient oxygen transport. The swelling behaviours of the CS-ZnPcTA/PE with respect to different ratio of B-PE to ZnPcTA were investigated in different pHs. Swelling studies revealed that CS-ZnPcTA/PE (۰.۸۵%) exhibited the lowest swelling ratio whereas CS-ZnPcTA showed the highest. The antioxidant activity of B-PE in solution (CS/PE ) and hydrogel network was compared. Radical scavenging efficiency of CS/PE, CS-ZnPcTA/PE (۰.۸۵%), CS-ZnPcTA/PE (۰.۵۵%) and CS-ZnPcTA/PE (۰.۳۴%) were about ۸۰%, ۵۷%, ۴۰% and ۳۸%, respectively. The CS-ZnPcTA/PE activity in photosensitizing process was investigated by measuring the degradation rate of ۱,۳-diphenylisobenzofuran in DMF upon (red) photoexcitation of photosensitizers. The relative singlet oxygen quantum yield of CS-ZnPcTA/PE (۰.۳۴%), ZnPcTA/PE (۰.۵۵%) and ZnPcTA/PE (۰.۸۵%) were ۸, ۴.۵ and ۳.۵, respectively. These results highlight the synergistic effect of ZnPcTA and B-PE, enhancing singlet oxygen generation by up to ۱۶-fold compared to single-photosensitizer systems, making CS-ZnPcTA/PE a promising candidate for cancer therapeutic applications.

کلیدواژه ها:

Chitosan ، reactive oxygen species ، Schiff-base Crosslinking ، Radical scavenging