A Cyclometalated IrIII Complex as a Lysosome‐Targeted Photodynamic Therapeutic Agent for Integrated Imaging and Therapy in Cancer Cells. Issue 43 (10th July 2018)

• Record Type: Journal Article
• Authors: Sudheesh, Karivachery V.; Jayaram, Prasad S.; Samanta, Animesh; Bejoymohandas, Kochan S.; Jayasree, Ramapurath S.; Ajayaghosh, Ayyappanpillai
• Is Part Of: Chemistry. Volume 24:Issue 43(2018)
• Page Start: 10999
• Page End: 11007
• Publication Date: 2018-07-10
• Subjects: apoptosis -- cell imaging -- lysosomes -- singlet oxygen -- theranostic agents; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201801918
• Languages: English
• ISSNs: 0947-6539

Abstract

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 a lysosome‐targeted theranostic probe.Ir‐Bp‐Ly exhibits exceptional photophysical properties, with 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 localizes mostly in lysosomes due to the presence of morpholine units, suggesting its potential use as a lyso‐tracker.Ir‐Bp‐Ly displays a notable PDT effect in C6 glioma cells, efficiently generating reactive oxygen species owing to close proximity between the energy levels of its triplet state and those of molecular oxygen ( 3 O2 ). The mechanism of cell death has been studied through caspase‐3/7 and flow cytometry analyses, which clearly established the apoptotic pathway. Abstract : Ir III ‐based probe : A water‐soluble cyclometalated Ir III complex, Ir‐Bp‐Ly, works as a luminescent probe with high triplet quantum yield (0.9) and singlet oxygen quantum yield ( φ Δ =0.71 at pH 4). High lysosomal specificity leads to increased efficacy of the photosensitizer for organelle‐targeted photodynamic therapy and imaging (see figure).