A Cyclometalated IrIII Complex as a Lysosome-Targeted Photodynamic Therapeutic Agent for Integrated Imaging and Therapy in Cancer Cells.
Karivachery V SudheeshPrasad S JayaramAnimesh SamantaKochan S BejoymohandasRamapurath S JayasreeAyyappanpillai AjayaghoshPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2018)
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 IrIII 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.
Keyphrases
- photodynamic therapy
- energy transfer
- cell death
- fluorescence imaging
- quantum dots
- cancer therapy
- flow cytometry
- water soluble
- living cells
- reactive oxygen species
- high resolution
- fluorescent probe
- drug delivery
- molecular dynamics
- sensitive detection
- stem cells
- human health
- single molecule
- mass spectrometry
- signaling pathway
- solid state
- replacement therapy
- pi k akt