September 17, 2020 – Peter Gee – MaxCyte Field Application Scientist – CRISPR-Cas9 has tremendous potential as a therapeutic tool for treating human diseases. However, prolonged expression of the nuclease and gRNA from viral vectors in an in vivo context may cause unwanted off-target activity and immunogenicity. To overcome these safety issues, a system was recently developed for transient delivery of CRISPR-Cas9 ribonucleoprotein (RNP), recruiting Cas9 protein by chemically-induced dimerization and sgRNA via a viral RNA packaging signal into extracellular nanovesicles.