Differential Cytotoxic Effects of Graphene Oxide and Its Functionalized Derivatives on Colon 26 Carcinoma Cells: Implications for Cancer Therapeutic Applications

Graphene oxide (GO)-based nanomaterials hold significant potential for targeted cancer therapy owing to their tunable physicochemical properties and surface versatility. In this study, we systematically evaluated the cytotoxicity of pristine GO (graphene oxide) and its surface-functionalized derivatives, GO-CH4 (methyl), GO-NH2 (amine), and GO-O2 (carboxyl), against murine Colon 26 carcinoma cells. Cell morphology, adhesion, and proliferation were assessed after three days of exposure using fluorescein diacetate (FDA) live/dead staining and the WST-1 mitochondrial activity assay. Distinct material-dependent biological responses were observed: GO-CH4 (methyl) and GO-O2 (carboxyl) exhibited pronounced cytotoxicity, reducing cell adhesion and proliferation by more than 50% relative to controls, whereas GO-NH2 (amine) induced only moderate effects. Pristine GO (graphene oxide) showed minimal impact on cell viability and morphology, consistent with its limited cellular internalization. These results demonstrate that surface functionalization critically governs GO (graphene oxide) biocompatibility and cytotoxicity, underscoring its potential as a tunable platform for developing graphene-based cancer therapeutics, implant coatings, and biointerfaces with controlled cellular responses.