Synthesis and photodynamic evaluation of SZ-SiPc-I2 in BxPC-3 human pancreatic cancer cells

Silicon phthalocyanine complexes, characterized by two additional axial coordination sites, have gained significant attention as second-generation photosensitizers for Photodynamic Therapy (PDT). In this study, di-(5-methylthiazole-1- ethoxy) axially substituted phthalocyanine (SZ-SiPc) was synthesized and further modified through methyl iodide treatment to produce di-(4-N-methyl-5-methylthiazole-1-ethoxy) axially substituted phthalocyanine diiodide (SZ-SiPc-I2). The cellular uptake, phototoxicity, and dark toxicity of SZ-SiPc-I2 were evaluated in BxPC-3 human pancreatic cancer cells using laser scanning confocal microscopy and cytotoxicity assays. Results revealed that SZ-SiPc-I2 was rapidly and effectively internalized by BxPC-3 cells, exhibited excellent biocompatibility, and demonstrated high phototoxicity under light irradiation. These findings suggest that SZ-SiPc-I2 holds great promise as a novel and effective photosensitizer for PDT, offering potential advancements in cancer therapy.