Fabrication of gelatin/hydroxyapatite/3D-graphene scaffolds by a hydrogel 3D-printing method

Abstract

In this study, we demonstrate the fabrication of three-dimensional reduced graphene oxide/hydroxyapatite (HA)/Gelatin scaffolds by employing two steps, including a hydrothermal autoclave with hydrogen gas injection to synthesize three-dimensional graphene (3DG)/HA powders and a hydrogel 3D-printing method to fabricate the scaffolds. Evaluations were performed separately for synthesized powders and fabricated scaffolds, which included field emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, inductively coupled plasma, Raman spectroscopy, and instrumented compression experiments. The powders characterization results showed that the nanostructured hybrid powders were successfully synthesized. The graphene sheets were stacked in 3D and the HA nanorods were attached on the surface of the graphene. Interface analysis showed that the two phases (HA/Graphene) are connected coherently and various preferential directions played a role in the growth of hydroxyapatite crystals. Characterization of the scaffolds showed that the addition of HA and graphene/HA powders resulted in smaller pores and higher dimensional accuracy of the fabricated scaffolds. Mechanical evaluation showed that the addition of HA (0.3 gr) increased the mechanical properties of the scaffolds. Also, increasing the small amount of graphene (0.0045 gr) made the mechanical properties much higher than that of pure HA.