Rational Design of Bioavailable Photosensitizers for Manipulation and Imaging of Biological Systems

Abstract

Light-mediated chemical reactions are powerful methods for manipulating and interrogating biological systems. Photosensitizers, compounds that generate reactive oxygen species upon excitation with light, can be utilized for numerous biological experiments, but the repertoire of bioavailable photosensitizers is limited. Here, we describe the synthesis, characterization, and utility of two photosensitizers based upon the widely used rhodamine scaffold and demonstrate their efficacy for chromophore-assisted light inactivation, cell ablation in culture and in vivo, and photopolymerization of diaminobenzidine for electron microscopy. These chemical tools will facilitate a broad range of applications spanning from targeted destruction of proteins to high-resolution imaging.

Keywords: HaloTag; Janelia Fluor; cell ablation; electron microscopy; fluorescence; photochemistry; photosensitizer; reactive oxygen species; rhodamine.