Graphene Quantum Dots for siRNA Delivery in Gene Silencing Cancer Therapy

Small interfering RNA (siRNA) technology in particular has become an advantageous tool in gene therapy for cancer treatment. However, the primary obstacle to this method is the inability of gene transfection of the cells on their own, their lack of stability in blood, and the lack of monitoring capabilities able to track gene delivery. Recently, graphene quantum dots (GQDs) have emerged as a platform allowing targeted drug delivery and fluorescence image-tracking in the visible and near-infrared regions. These capabilities can aid in overcoming obstacles to siRNA gene delivery. Here, for the first time, we have utilized biocompatible nitrogen and neodymium-doped graphene quantum dots (GQDs) for the delivery of Kirsten rat sarcoma virus (KRAS) and epidermal growth factor receptor (EGFR) siRNAs. The non-covalent loading of siRNA on GQDs was estimated by electrophoretic mobility shift assay and zeta potential. Successful siRNA delivery was confirmed by testing protein expression levels and using visible and near-infrared confocal fluorescence microscopy. The results show that GQDs/siRNA complex is biocompatible at the concentrations of 375-750 ug/mL and leads to protein knockdown in Hela cells at nanomolar siRNA concentrations. This shows the promising potential of GQDs for the delivery of siRNA and genes in general, complemented by multiwavelength image-tracking.