In Vitro Genotoxicity Assessment of Commercially Available Graphene Quantum Dots in Human Peripheral Blood Cells and...

Commercially available graphene quantum dots (GQDs) are promising nanomaterials for applications in research and preclinical diagnostics, drug delivery, and bioimaging. Their bioactivity is highly dependent on dose, route of exposure, duration, cell type, uptake mechanisms, tissue and cellular distribution, and physicochemical properties. This study aimed to evaluate genotoxic, cytotoxic, and cytostatic endpoints of blue- (B-GQDs) and green-emitting (G-GQDs) GQDs in human blood and salivary leukocytes. GQDs were tested at concentrations ranging from 2.5 to 100 µg/mL using distinct treatment periods. Fourier transform infrared spectroscopy (FTIR), trypan blue exclusion, comet, and cytokinesis-block micronucleus cytome (CBMN cyt) assays were performed. FTIR analysis revealed that G-GQDs, unlike B-GQDs, exhibit an absorption band typically associated with amine functional groups, which may contribute to their pronounced genotoxic effects. Peripheral blood mononuclear cells and salivary leukocytes showed higher sensitivity to G-GQDs compared to whole blood samples. Although no cytotoxic effects were observed, both GQDs induced significant DNA damage, with G-GQDs demonstrating greater genotoxic potential. These findings demonstrate that GQDs can induce DNA damage in the absence of detectable cytotoxic effects under the conditions tested, highlighting the importance of considering both physicochemical properties and cellular models in the safety assessment of nanomaterials.