Enhanced osteogenic and antibacterial properties of titanium implant surface modified with Zn-incorporated nanowires: Preclinical in vitro and in vivo investigations

Objective: This study aimed to synthesize zinc-incorporated nanowires structure modified titanium implant surface (Zn-NW-Ti) and explore its superior osteogenic and antibacterial properties in vitro and in vivo. Materials and methods: Zn-NW-Ti was synthesized via displacement reactions between zinc sulfate solutions and the titanium (Ti) surface, which was pretreated by hydrofluoric acid etching and hyperthermal alkalinization. The physicochemical properties of the Zn-NW-Ti surface were examined. Moreover, the biological effects of Zn-NW-Ti on MC3T3-E1 cells and its antibacterial property against oral pathogenic bacteria (Staphylococcus aureus, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans) compared with sandblasted and acid-etched Ti (SLA-Ti) and nanowires modified Ti (NW-Ti) surface were assessed. Zn-NW-Ti and SLA-Ti modified implants were inserted into the anterior extraction socket of the rabbit mandible with or without exposure to the mixed bacterial solution (S. aureus, P. gingivalis, and A. actinomycetemcomitans) to investigate the osteointegration and antibacterial performance via radiographic and histomorphometric analysis. Results: The Zn-NW-Ti surface was successfully prepared. The resultant titanium surface appeared as a nanowires structure with hydrophilicity, from which zinc ions were released in an effective concentration range. The Zn-NW-Ti surface performed better in facilitating the adhesion, proliferation, and differentiation of MC3T3-E1 cells while inhibiting the colonization of bacteria compared with SLA-Ti and NW-Ti surface. The Zn-NW-Ti implant exhibited enhanced osseointegration in vivo, which was attributed to increased osteogenic activity and reduced bacterial-induced inflammation compared with the SLA-Ti implant. Conclusions: The Zn-incorporated nanowires structure modified titanium implant surface exhibited improvements in osteogenic and antibacterial properties, which optimized osteointegration in comparison with SLA titanium implant surface.