Graphene (GN) and its derivatives (rGOs) show anticancer properties in
glioblastoma multiforme (GBM) cells in vitro and in
tumors in vivo. We compared the anti-
tumor effects of rGOs with different
oxygen contents with those of GN, and determined the characteristics of rGOs useful in anti-
glioblastoma therapy using the U87
glioblastoma line. GN/ExF, rGO/Term, rGO/ATS, and rGO/TUD were structurally analysed via transmission electron microscopy, Raman spectroscopy, FTIR, and AFM. Zeta potential,
oxygen content, and electrical resistance were determined. We analyzed the viability, metabolic activity, apoptosis, mitochondrial membrane potential, and cell cycle.
Caspase- and mitochondrial-dependent apoptotic pathways were investigated by analyzing gene expression. rGO/TUD induced the greatest decrease in the metabolic activity of U87 cells. rGO/Term induced the highest level of apoptosis compared with that induced by GN/ExF. rGO/ATS induced a greater decrease in mitochondrial membrane potential than GN/ExF. No significant changes were observed in the cytometric study of the cell cycle. The effectiveness of these
graphene derivatives was related to the presence of
oxygen-containing functional groups and electron clouds. Their cytotoxicity mechanism may involve electron clouds, which are smaller in rGOs, decreasing their cytotoxic effect. Overall, cytotoxic activity involved depolarization of the mitochondrial membrane potential and the induction of apoptosis in U87
glioblastoma cells.