Modification of low nickel biograde stainless steel with graphene oxide for enhanced corrosion resistance and in vivo biocompatibility

This study investigates the integration of graphene oxide (GO) into low nickel bio-grade stainless steel (LNBGSS) to enhance its corrosion resistance and assess its biocompatibility. Three concentrations of GO (0.5, 1.0, and 1.5 wt%) were added to the steel matrix using the powder metallurgy method and annealed in a nitrogen environment. X-ray diffraction and field-emission scanning electron microscopy analyses reveal that while the crystal structure of the steel remains largely unchanged, the morphology of the prepared samples exhibits minimal alteration post-GO integration. The average particle sizes (D_av) of the studied samples were calculated. It was found that D_av slightly changed with the content of GO. Based on the electrochemical analysis, the inhibition efficiency was determined in different ways and it increased markedly with increasing GO content in LNBGSS composites. Subsequently, biocompatibility assessment was conducted through in vivo studies on albino rats. Thirty-six rats were randomly allocated into six groups. The hematological parameters revealed a nonsignificant (P > 0.05) difference except for the rats treated with the low-nickel bio-grade stainless steel powder (LNBGSS) (S0), which had the lowest complete blood count in comparison with other groups. In spite, the hematological parameters of all groups were within the normal reference ranges. The biochemical indices also were not significantly (P > 0.05) different by assessment of liver enzymes and kidney functions for all examined groups. These findings suggested that the use of GO in modifying low nickel bio-grade stainless steel alloy is biologically safe and recommendable for enhancing this alloy's properties.