In vitro bioactivity, cytotoxicity, and gene silencing of graphene oxide as a Bcl-2 siRNA carrier in osteosarcoma cells with in vivo inflammatory response.

Research on using graphene oxide (GO) as a potential carrier for small interfering RNA (siRNA) in the treatment of osteosarcoma is currently under intense investigation. Here, we focus on evaluating the GO as a carrier of bcl-2 siRNA in osteosarcoma cell lines and assessing its bioactivity, and the inflammatory response of GO in non-tumour models in vivo. GO was synthesized using a modified Hummer’s method, and the physiochemical characterization confirmed its formation. The results of the MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2 H-tetrazolium bromide) experiment confirmed comparable dose-dependent inhibition of viability, while staining of MG-63 cells through PI (propidium iodide) showed comparatively higher viability and concluded that GO alone cannot efficiently induce widespread apoptosis yet boosts cytotoxicity through collaboration with siRNA. GO exhibited an early cytokine expression peak as compared with the control group, with a peak at 7–14 days and then a gradual decline at 21–28 days, indicating an initial adaptive immune response following through adaptation, supporting general biocompatibility but not disease-specific efficacy. The siRNA in vitro assay exhibited a high burst release from the GO sheets and covered approximately 35–40% at 30 h. The biomaterial was observed to be bioactive in vitro and may facilitate osteointegration if applied in vivo. Despite GO’s hydrophilic nature with smooth edges and high oxygen level with a generally low toxic tendency, we still observed a certain notable level of toxicity. If the quantity of GO were increased, then the number of neutrophils (F4/80low, Ly6Chigh) got depleted and was less as compared with those of the control groups and could expose patients to a risk of secondary infection. The qPCR expression study of a number of cytokines (IL-6, TNF-α, TGF-β, IL-1α, IL-10, and MIP-1β) at diversified time points reiterated findings of protein expression. However, modulation of bcl-2 expression using GO as a carrier could contribute toward innovative approaches for osteosarcoma, pending validation in tumour-relevant models.