| Bacteria are one of the significant causes of infection in the body after scaffold implantation.
Effective use of nanotechnology to overcome this problem is an exciting and practical solution.
Nanoparticles can cause bacterial degradation by the electrostatic interaction with receptors and
cell walls. Simultaneously, the incorporation of antibacterial materials such as zinc and graphene in
nanoparticles can further enhance bacterial degradation. In the present study, zinc-doped hydroxyapatite/graphene was synthesized and characterized as a nanocomposite material possessing both
antibacterial and bioactive properties for bone tissue engineering. After synthesizing the zinc-doped
hydroxyapatite nanoparticles using a mechanochemical process, they were composited with reduced
graphene oxide. The nanoparticles and nanocomposite samples were extensively investigated by
transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. Their antibacterial
behaviors against Escherichia coli and Staphylococcus aureus were studied. The antibacterial properties of hydroxyapatite nanoparticles were found to be improved more than 2.7 and 3.4 times
after zinc doping and further compositing with graphene, respectively. In vitro cell assessment was
investigated by a cell viability test and alkaline phosphatase activity using mesenchymal stem cells,
and the results showed that hydroxyapatite nanoparticles in the culture medium, in addition to
non-toxicity, led to enhanced proliferation of bone marrow stem cells. Furthermore, zinc doping in
combination with graphene significantly increased alkaline phosphatase activity and proliferation of
mesenchymal stem cells. The antibacterial activity along with cell biocompatibility/bioactivity ofzinc-doped hydroxyapatite/graphene nanocomposite are the highly desirable and suitable biological
properties for bone tissue engineering successfully achieved in this work. |