Silanization Improves the Performance of Reduced Graphene Oxide as Biomaterial for Drug Delivery Applications

Reduced graphene oxide (rGO) is a potential biomaterial for tissue engineering, photothermal therapy, and drug delivery. However, the hydrophobic nature of rGO results in poor dispersibility in a physiologically relevant aqueous environment, limiting its biomedical applications. To surmount this problem, here, we have developed a silanized derivative of reduced graphene oxide (rSiGO) using 3-Aminopropyl) triethoxysilane and evaluated its impact on [I] stability of rGO in different aqueous solvents, [ii] drug loading capacities, and [iii] biocompatibility. The physico-chemical characterization suggested that silanization alters the 2D carbon skeleton of rGO to a certain extent and improves its aqueous dispersibility and drug-loading capacity. The in vitro cytocompatibility study showed that rSiGO was compatible with the human dermal fibroblasts and murine fibroblast cell lines. It was also found that rSiGO possesses a higher loading capacity for hydrophilic drugs than rGO. The drug-loaded rSiGO showed higher cytotoxicity against hepatocarcinoma cells by inducing intracellular reactive oxygen species production, apoptosis, and nuclear fragmentation. In vivo systemic toxicity studies in mice showed that the rSiGO is nontoxic at the tested concentration. These results clearly showed that silanization improves the aqueous dispersibility, drug loading capacity, and biocompatibility of rGO making it a better candidate for various biomedical applications.