A Sn(iv) porphyrin with mitochondria targeting properties for enhanced photodynamic activity against MCF-7 cells

Abstract

Two readily synthesized Sn(IV) porphyrins (SnP, SnPH) have been prepared with and without the cationic triphenylphosphonium moiety (TPP⁺), which have high singlet oxygen quantum yields (ca. 0.72) and long triplet state lifetimes. The Sn(IV) porphyrin with a TPP⁺ moiety (SnPH) exhibits favorable photodynamic activity against MCF-7 cells with IC₅₀ values of 2.9 μM. SnPH exhibits higher cellular uptake than SnP in MCF-7 cells. A Rhodamine 123 (Rh123) assay showed that SnPH targets mitochondria and induces apoptosis by generating reactive oxygen species. The results demonstrate that this structural modification strategy merits further in-depth study.