Microstructure, morphology, Physico-chemical properties of nanocomposites containing hydroxyapatite/vivianite/graphene oxide for biomedical applications.

Designing a nanocomposite that accumulates biocompatibility and anti-microbial behavior is an essential requirement for biomedical applications. Hydroxyapatite, graphene oxide, and vivianite in one ternary nanocomposite with three phases and shapes led to an increase in the cell viability to 97.6 ± 4 % toward the osteoblast cells in vitro. The obtained nanocomposites were investigated in structural features using x-ray diffraction (XRD), while the microstructure features were analyzed using a scanning electron microscope (SEM) and transmission electron microscope (TEM). The analysis showed decreasing in the crystal size to 13 nm, while the grains of HAP reached 30 nm. The elongated shape of vivianite reached 200 nm upon SEM micrographs. The monoclinic and hexagonal crystal systems of HAP and vivianite were presented in the ternary nanocomposite. The maximum roughness peak height (Rtm) reached 236.1 nm for the ternary nanocomposite from 203.3 nm, while the maximum height of roughness parameter (Rt) reached 440.7 nm for the di-nanocomposite of HAP/GO from 419.7 nm. The corrosion current density reached 0.004 μA/cm2 . The ferrous (Fe2+ ) and calcium (Ca2+ ) ions released were measured and confirmed. Therefore, the morphology of the nanocomposites affected bacterial activity. It is estimated as an inhibition zone and reached 14.5 ± 0.9 and 13.4 ± 1.1 mm against E. coli and S. aureus after 24 h in vitro. The increase in viability and the antibacterial activity refer to the compatibility of the nanocomposite in different medical applications.