Biocompatibility assessment of chemically modified GONRs with hemoglobin and histopathological studies for its toxicity evaluation.

Transition metal-Schiff base complexes are found to be important for biomedical applications but have demerits of being homogeneous complexes, thus their synthesis on the surface of graphene oxide nanoribbons (GONRs), materials of specific interest, can be beneficial for preparing advanced graphene-based materials for biomedical applications. Of foremost importance is their safety and biocompatibility with biological systems. In this study, a transition metal-Schiff base complex has been synthesized on the surface of a GONR (Ni-S-GNR) using 3-aminopropyltriethoxysilane and pyridine-2-carbaldehyde and complexing nickel. This Ni-S-GNR was characterized well by various physicochemical techniques. The evaluation of biocompatibility of Ni-S-GNR with hemoglobin confirmed binding interactions and influence on the native structure of hemoglobin. It was found that there was alteration in the secondary and tertiary structures of hemoglobin. In addition, histopathological studies on the liver and kidney cells of rats revealed non-toxicity of Ni-S-GNR towards these cells. Overall, Ni-S-GNR was found to be compatible with protein as the native structure was not destroyed and was non-toxic to cells.