Cyclometalated Ir(III) complex as lysosome targeted photodynamic therapeutic agent for integrated imaging and therapy in cancer cells.

Sudheesh, KV; Jayaram, PS; Samanta, A; Kochan, S; Bejoymohandas, KS; Jayasree, RS; Ajayaghosh, A

Cyclometalated Ir(III) complex as lysosome targeted photodynamic therapeutic agent for integrated imaging and therapy in cancer cells.

Date

2018-06

Authors

Publisher

Chemistry - A European Journal

Abstract

Organelle targeted photosensitizers (PSs) having luminescence properties are potential theranostic agents for simultaneous luminescence imaging and photodynamic therapy. Herein, we report a water soluble luminescent cyclometalated Ir(III) complex, Ir-Bp-Ly as lysosome targeted theranostic probe. Ir-Bp-Ly exhibits exceptional photophysical properties of good triplet state quantum yield (0.90), singlet oxygen generation quantum yield (0.71 at pH 4) and long lifetime (1.47 µs). Interestingly, Ir-Bp-Ly localized mostly in the lysosome because of the presence of morpholine units, suggesting its potential as a lyso-tracker. Ir-Bp-Ly displayed notable PDT effect in C6 glioma cells, as these PS efficiently generated ROS owing to the close proximity energy levels between triplet energy states of Ir-Bp-Ly and molecular oxygen (3O2). The mechanism of cell death was studied through caspase-3/7 and flow cytometry analysis that clearly established the apoptotic pathway.

Citation

Sudheesh KV, Jayaram PS, Samanta A, Kochan S. Bejoymohandas KS, Jayasree RS, and Ajayaghosh A. Cyclometalated Ir(III) complex as lysosome targeted photodynamic therapeutic agent for integrated imaging and therapy in cancer cells. Chemistry - A European Journal. 2018