In Vitro Prostate Cancer Treatment via CRISPR-Cas9 Gene Editing Facilitated by Polyethyleneimine-Derived Graphene Quantum Dots

CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas9 (CRISPR associated protein 9) is a programmable gene editing tool with a promising potential for cancer gene therapy. This therapeutic function is enabled in the present study via the non-covalent delivery of CRISPR ribonucleic protein (RNP) by cationic glucosamine/PEI-derived graphene quantum dots (PEI-GQDs) that aid in overcoming physiological barriers and tracking genes of interest. PEI-GQD/RNP complex targeting the tumor protein 53 (TP53) gene mutation overexpressed in ∽50% of cancers successfully produces its double-stranded breaks in solution and in prostate cancer (PC-3) cells. Restoring this cancer “suicide” gene can promote cellular repair pathways and lead to cancer cell apoptosis. Its repair to the healthy form performed by simultaneous PEI-GQD delivery of CRISPR RNP and a gene repair template leads to a successful therapeutic outcome: 40% apoptotic cancer cell death, while having no effect on non-cancerous (HeK293) cells. The translocation of PEI-GQD/RNP complex into PC-3 cell cytoplasm is tracked via GQD intrinsic fluorescence, while enhanced green fluorescent protein (EGFP)-tagged RNP is detected in the cell nucleus, showing the successful detachment of the gene editing tool upon internalization. Using GQDs as non-viral delivery and imaging agents for CRISPR-Cas9 RNP sets the stage for image-guided cancer-specific gene therapy.