The Sincerest Form of Flattery...Chinese researchers have created some new compounds that have a structure close to that of
TLD1433 but with an iridium instead of a ruthenium base. They tested them as photosenstizers against breast cancer, malignant melanoma, and liver cancer cells.
Only the abstract is available, but for $48 US you can access the article for 48 hours.
Chiral Iridium-Based TLD-1433 Analogues: Exploration of Enantiomer-Dependent Behavior in Photodynamic Cancer Therapy Metallodrug-based photodynamic therapy (PDT) agents have demonstrated significant superiority against cancers, while their different chirality-induced biological activities remain largely unexplored. In this work, we successfully developed a pair of enantiopure mononuclear Ir(III)-based TLD-1433 analogues, Δ-Ir-3T and Λ-Ir-3T, and their enantiomer-dependent anticancer behaviors were investigated. Photophysical measurements revealed that they display high photostability and chemical stability, strong absorption at 400 nm with high molar extinction coefficients (ε = 5.03 × 104 M–1 cm–1), and good 1O2 relative quantum yields (ΦΔ ≈ 47%). Δ- and Λ-Ir-3T showed potent efficacy against MCF-7 cancer cells, with a photocytotoxicity index of ≤44238. This impressive result, to the best of our knowledge, represents the highest value among reported mononuclear Ir(III)-based PDT agents. Remarkably, Λ-Ir-3T tended to be more potent than Δ-Ir-3T when tested against SK-MEL-28, HepG2, and LO2 cells, with consistent results across multiple test repetitions. 