A photo-switchable gold nanoformulation based on the dCas9 protein for spatiotemporal controlled gene editing activation in vivo

Abstract

Genome editing allows for the manipulation of genomic DNA for biotechnology and biomedical applications, but the specificity and control of the editing process remain a challenge. This study introduces a nano-switch for spatiotemporal control of the editing process. The basic module of the nano-switch (the monomer) is composed of a gold nanorod conjugated with the dead Cas9. Based on mathematical models, we established the design and the mechanism of action of the nano-switch. Briefly, when two monomers, guided by their respective guide RNAs, form a dimer onto the DNA and get irradiated with a Near-Infrared pulsed laser resonant at the plasmonic properties of the dimer, they generate a localized heat that triggers a thermal break onto the DNA. The nano-switch was generated, validated, and tested in zebrafish embryos at the 1-cell stage. Molecular analysis of irradiated embryos showed targeted DNA mutations, validating the efficacy of the nano-switch as a tool for conditional gene editing that integrates the if-when-where functions.