Functionalization of graphene oxide as a way to increase biocompatibility

Abstract

Introduction. Now, one of the most promising areas for the use of graphene-based materials, in particular graphene oxide, is biomedicine. Due to the wide variety of functional groups and the possibility of chemical modification of graphene oxide, the creation of composite materials for biomedical use is promising. These nanomaterials have a unique structure and properties, which determines their use for creating targeted drug delivery systems, in tissue engineering, bioimaging, as well as for creating new materials with antimicrobial and antiviral properties.The objective was to perform synthesis and identification of graphene oxide and its conjugate with glycine, and to study the biocompatibility of the obtained nanomaterials: the effect on haemolysis and platelet aggregation, genotoxicity and cytotoxicity.Methods and materials. Graphene oxide was synthesized from graphite using the modified Hummers and Offeman method, after which the graphene oxide-glycine conjugate was also obtained. Identification was carried out using nuclear magnetic resonance spectroscopy. Estimation of biocompatibility of the obtained nanomaterials included the study of their hemolytic activity, effect on collagen-induced platelet aggregation, cyto- and genotoxicity.Results. Graphene oxide and its conjugate with glycine were synthesized. Identification with using nuclear magnetic resonance spectroscopy confirmed the structure and composition of the substances. The study of the biocompatibility of the obtained nanomaterials showed the absence of hemolytic activity (the degree of hemolysis did not exceed 2.5% at the studied concentration range); the presence of antiplatelet properties (at C=10–100 mg·ml–1); the absence of geno- and cytotoxicity (graphene oxide at C=0.25–25 mg·L–1 does not affect the viability of HEK293 cells; in turn, the conjugate with glycine at C=100–200 mg·L–1 causes a dose-dependent increase proliferation of HEK293 cells).Conclusion. The study demonstrates that functionalization of the graphene surface with oxygen-containing groups and amino acids leads to increased hemocompatibility, as well as to the production of nanomaterials that do not exhibit genoand cytotoxicity.