Hydrothermal synthesis of zirconia-based nanocomposite powder reinforced by graphene and its application for bone scaffold with 3D printing

Abstract

Hydrothermal method is a cheap and green approach for the synthesis of composite powders. In this study, the zirconia (ZrO2)-based nanocomposite powder was reinforced with reduced graphene oxide (ZrO2/RGO) and was synthesized in a one-pot as a precursor for bone scaffold applications. Moreover, for the stimulation of osseointegration in bone scaffolds, Hydroxyapatite (HA) was used in 10 wt%. In this regard, the two types of ZrO2/RGO and ZrO2/RGO/HA precursors were applied for the fabrication of bone scaffolds via 3D printing and finally, the mechanical and biological properties of scaffolds were evaluated. For characterization, the X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), compress strength, and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide as MTT assay protocol were performed. The results demonstrated that the ZrO2/RGO scaffolds with a tolerance of compressive stress of 240.11 MPa depicted better mechanical properties compared with ZrO2/RGO/HA with the compress strength of 141.66 MPa. Moreover, after 7 days of bone scaffolds immersion in simulated body fluid (SBF) the growth of compressive strength began while after 28 days reached 260.15 MPa for ZrO2/RGO and 192.31 for ZrO2/RGO/HA. Finally, the cellular response of the scaffolds indicated the lack of cellular toxicity of the scaffolds during MTT assay.