Photodynamic Evaluation of A₂BC Aminoporphyrins: Synthesis, Characterization, and Cellular Impact

This study focuses on the design and evaluation of a series of A₂BC aminoporphyrins, featuring electron-donating substituents like pyrene, carbazole, and phenothiazine to enhance their photophysical and biological performance. Detailed characterization through spectroscopic methods, single-crystal X-ray diffraction, and computational analyses revealed insights into their electronic structure and planarity. Photophysical investigations revealed characteristic Soret and Q bands, along with tunable fluorescence and excited-state lifetimes influenced by the <i>meso</i> substituents. Biological evaluation was conducted using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays and fluorescence microscopy to assess the photodynamic therapeutic efficacy against T24 bladder cancer cells. The porphyrins exhibited pronounced photocytotoxicity upon 660 nm light activation, attributed to reactive oxygen species (ROS) generation. Cellular analysis, including acridine orange/ethidium bromide and 4',6-diamidino-2-phenylindole staining, confirmed apoptosis induction through chromatin condensation and nuclear fragmentation. The findings highlight the potential of these porphyrins as effective photosensitizers for photodynamic therapy, demonstrating enhanced stability and ROS generation efficiency.