Antibacterial properties of biodegradable zinc alloys in vivo

Xie Zhong; Yang Mingzhi; Xue Jingbo; Chen Yong; Peng Lijun; Cai Bin; Zhang Yangyang

doi:10.3969/j.issn.2095-4344.1664

Abstract：BACKGROUND: Zinc, an inorganic antibacterial material, has a suitable degradation rate and good antibacterial property. Adding alloying elements can improve the mechanical properties and biocompatibility of the material, which is the development direction of novel medical biodegradable metal materials. There is still lack a comparable research on the antibacterial properties among zinc-based materials. OBJECTIVE: To investigate the antibacterial properties of pure zine and zinc-based alloys in vivo. METHODS: Eighty Sprague-Dawley rats, SPF grade, were randomized into two groups (n=40/group) , and all rats were injected with Staphylococcus aureus or Escherichia coli solution to prepare infection models. Different materials (Zn, ZnAl, ZnSr, Zn3 Mg, Zn3 Ag, Zn3 Ca and Zn4 Cu; five rats for each material) were implanted into the medullary cavity of femur. The control group without any material was set. At 1, 4, 7 and 14 days after implantation, the changes of body temperature, white blood cell count, serum tumor necrosis factor α and serum zinc content in rats were detected. The secretions and tissues of the surgical site were collected to identify the bacterial species. RESULTS AND CONCLUSION: (1) The body temperature in all the rats was increased to different extents after bacterial infection, but the temperature of the rats implanted with zinc and zinc alloys was always lower than that in the control group at 7 and 14 days (P < 0.05) . The temperature in the Zn3 Ag group was significantly lower than that in the other groups at 7 and 14 days (P < 0.05) . (2) The white blood cell count and tumor necrosis factor α level in the zinc and zinc alloys groups were significantly lower than those in the control group at 7 and 14 days after implantation (P < 0.05) . The white blood cell count and tumor necrosis factor α level in the Zn3 Ag group were significantly lower than those in the other groups (P < 0.05) . (3) The serum zinc content in all groups has no significant difference (P> 0.05) . (4) The bacterial culture results showed S.aureus (+) in the Staphylococcus aureus infection group and E.coli (+) in the Escherichia coli infection group. (5) To conclude, degradable zinc-based alloys exert marked antibacterial effects, and Zn3 Ag alloys have the best antibacterial activity.