Photocleavable Visible Light-Triggered Anthraquinone-Derived Water-Soluble Block Copolymer for Peroxynitrite Generation in Cancer Therapy.

We report a facile stimuli-responsive strategy to generate reactive oxygen and nitrogen species (ROS and RNS) in the biological milieu from a photocleavable water-soluble block copolymer under visible light irradiation (427 nm, 2.25 mW/cm2 ). An anthraquinone-based water-soluble polymeric nitric oxide (NO) donor ( BCPx-NO ) is synthesized, which exhibits NO release in the range of 40-65 μM within 10 h of photoirradiation with a half-life of 30-103 min. Additionally, BCPx-NO produces peroxynitrite (ONOO- ) and singlet oxygen (1 O2 ) under photoirradiation. To understand the mechanism of NO release and photolysis of the functional group under blue light, we prepared a small-molecule anthraquinone-based N -nitrosamine ( NOD ). The cellular investigation of the effect of spatiotemporally controlled ONOO- and 1 O2 generation from the NO donor polymeric nanoparticles in a triple negative breast adenocarcinoma (MDA-MB-231) under visible light irradiation (white light, 5.83 mW/cm2 ; total dose 31.5 J/cm2 ) showed an IC50 of 0.6 mg/mL. The stimuli-responsive strategy using a photolabile water-soluble block copolymer employed to generate ROS and RNS in a biological setting widens the horizon for their potential in cancer therapy.