Graphene oxide conjugated with doxorubicin: Synthesis, bioactivity, and biosafety

•Bioactivity and biocompatibility of a graphene oxide–doxorubicin (GO-DOX) conjugate were investigated.•An advantage of nanoform of doxorubicin over an individual drug towards cancer cell lines was revealed.•The key mechanism of GO-DOX cytostatic effect is the interaction with DNA molecule (Kb = (3.77 ± 0.27)∙107 M−1)•Substantial haemocompatibility of GO-DOX conjugate was observed. This work presents a method for covalent functionalization of GO with a cytostatic preparation DOX with a loading of 87 %. The resulting nanomaterial was characterized using modern physicochemical methods (13C NMR, Raman, IR, UV/Vis spectroscopy, XPS, XRD, HRTEM). The synthesized conjugate showed significant antiaggregating activity and selective cytotoxicity towards the A549 cell line, significantly superior to individual DOX, as well as low cytotoxicity towards the non-cancer cell line HEK293. The complex biocompatibility study was conducted for the synthesized conjugate including hemocompatibility study, antioxidant activity, interaction with HSA and DNA, geno- and cytotoxicity investigation. At the same time, molecular dynamics investigation was performed in order to determine the features of intermolecular interaction between GO and DOX molecules.