Graphene quantum dots enhance anticancer activity of cisplatin via increasing its cellular and nuclear uptake.

Using assistant reagents to improve the pharmaceutical performance of cisplatin (CDDP) has been one of promising strategies. Owing to their extraordinary properties, graphene quantum dots (GQDs) have shown great potentials in biomedical applications. Here we demonstrate that the combination of GQDs with CDDP can effectively enhance the cytotoxicity, cell cycle arrest, and DNA fragmentation that induced by CDDP. We also found that the GQDs improved the interaction of CDDP with DNA. Combing these results with our previous finding that graphene oxide could enhance the permeability of the cells, we believe GQDs improve the pharmaceutical performance of CDDP via first increasing its cellular uptake through improving the cell permeability, and then reinforcing its interaction with DNA once it is inside cells. The remarkable enhancement to CDDP cellular uptake in CDDP resistant cells further specifies that GQDs can increase chemotherapy efficacy of anticancer drugs that are suboptimal due to the drug resistance.