Photoswitchable Small Molecules for Cancer Therapeutics: Mechanisms, Advances, and Challenges

Spatial distribution of various functional groups in biologically active molecules greatly influences their affinity toward the targets. This spatial distribution can be regulated by external stimuli such as ultrasound, light, etc. Photoswitches are one such example, where light induces isomerization, which leads to the formation of another isomeric form with higher affinity, at a particular wavelength. In this regard, utilizing the isomerization across a double bond under UV or visible light, various small-molecule-based photoswitchable anticancer agents are being designed, that show greater antiproliferative activity in one isomeric form over the other. Herein, some of the recent advances made in this direction have been compiled, which are being developed as potent therapeutics for a spectrum of cancer types.