In Vitro and In Vivo Uncaging and Bioluminescence Imaging by Using Photocaged Upconversion Nanoparticles

摘要

High temporal and spatial regulation of cellular activities, biological pathways, and gene expression is critical in complex biological processes. One remarkable technique that enables such control is the use of light to manipulate compounds that are photoactive (or photocaged) in various biological systems. Previously, this strategy has been used to map cellular functions, monitor the expression of transgenes, and image the dynamic processes of cell-cell interactions in vitro and in vivo. Although all of these attempts were successful in principle, there were significant limitations associated with the use of high-intensity UV or visible light in the photo-activation process. Excessive exposure to UV light can cause photoreactions in nucleic acids and result in cellular damage. Furthermore, short-wavelength UV or visible light does not penetrate into tissue very far, which limits its utility for deep-tissue imaging by photoactivation of the caged compounds.