Advances in Optical Regulation of the CRISPR/Cas9 System

CRISPR/Cas9 gene editing system consists of clustered regularly interspaced short palindromic repeats (CRISPR) sequences and CRISPR-associated protein 9 (Cas9), characterized by its simple structure, easy modification, and strong gene editing ability. It has great potential for application in genome editing, transcriptional perturbation, epigenetic regulation, and other fields. Despite its significant advantages in gene editing, the CRISPR/Cas9 system fails to achieve precise spatial and temporal control over the editing process and its cell and tissue-specific recognition capability requires improvement. The potential off-target phenomenon of genotoxicity will be further aggravated with increased Cas9 activity, greatly limiting its application in complex biological systems. Therefore, developing gene editing systems capable of precisely controlling the expression of multiple endogenous genes has become a hot topic of current CRISPR/Cas9 research. Light, as a non-invasive medium with high spatiotemporal resolution, is easy to regulate in terms of duration, location, wavelength, and intensity. Optical regulation, as a novel spatiotemporal regulation strategy of CRISPR/Cas9, has attracted much attention due to its characteristics of minimal toxic side effects, high spatiotemporal resolution, and real-time controllability. Optical regulation strategies can also be used in conjunction with imaging technologies such as fluorescence imaging and photoacoustic imaging to track the delivery process, greatly reducing the difficulty and safety risks of gene editing in vivo, thereby achieving visual delivery and precise spatiotemporal control of CRISPR systems. This review aims to summarize various optical modulation strategies employed in CRISPR/Cas9 system in recent years, evaluating the advantages and disadvantages of these strategies, and provide an outlook on the challenges and prospects of optical modulation in the CRISPR/Cas9 system.