Graphene oxide-mediated Cas9/sgRNA delivery for efficient genome editing

Direct cellular delivery of CRISPR/Cas9 complexes is of great significance for genome editing and other recently developed applications, such as gene expression regulation and RNA/DNA imaging. Here, we first constructed a graphene oxide (GO)-polyethylene glycol (PEG)-polyethylenimine (PEI) nanocarrier for the delivery of high-molecular-weight Cas9/single-guide RNA (sgRNA) complexes for endocytosis, endosomal escape, nuclear entry, and gene editing. The results demonstrate that the nanocarrier can be used successfully for efficient gene editing in human AGS cells with an efficiency of ∼39%. The results also show that this nanocarrier can protect sgRNA from enzymatic degradation, thus exhibiting extremely high stability, which is critical for future in vivo applications. Thus, this GO-mediated Cas9/sgRNA delivery system has potential as a new approach for biomedical research and targeted gene engineering applications.