BACKGROUND: It is of vital importance to fabricate an interface on the titanium implant surface which can promote early cell adhesion, proliferation, and differentiation, and exert better antibacterial effects with no cytotoxicity.
OBJECTIVE: To prepare a TiN/Ag composite coating on the surface of pure titanium implant, and to explore its antibacterial properties and effects on MC3T3-E1 biobehaviors.
METHODS: Acid etching blasting and multi-arc ion plating were adopted to prepare TiN/Ag composite coating on the smooth surface of pure titanium. Then, MC3T3-E1 cells that grew well were inoculated onto pure titanium plate, sandblasted and acid-etched titanium plate, and TiN/Ag-coated titanium plate. Twenty-four hours later, cell adhesion and viability were observed under confocal laser scanning microscope, and cell morphology was observed under scanning electron microscope. Cell counting kit-8 was used to detect cell proliferation and cytotoxicity at 24, 48, 72 hours after inoculation. In addition, Staphylococus aureus solution was dropped onto the smooth titanium plated, acid-etched and sandblasted titanium and TiN/Ag-coated titanium plate, and the growth of bacteria was observed by the laser confocal scanning microscope at 16 hours.
RESULTS AND CONCLUSION: Under the confocal laser scanning microscope, spindle cells with bipolar or three poles were observed on the smooth titanium surface, and there was less F-actin and filopodia expression; cells on the TiN/Ag-coated titanium surface and sandblasted and acid-etched titanium surface were scattered with a large amount of interconnected filopodia that were fully stretched and adhered to the titanium surface, highly expressed F-actin was detected, and actin fibers were thickened. Under the scanning electron microscope, the cells on the smooth titanium surface were not fully adhered and stretched, and those on the TiN/Ag-coated titanium surface or the sandblasted and acid-etched titanium surface exhibited better adhesion and extension. Findings from the cell counting kit-8 showed that after 72 hours of inoculation, the cells on the smooth titanium surface grew well, with cytotoxicity level 1. In addition,
Staphylococus aureus grew well on the smooth titanium surface under the confocal laser scanning microscope, while a large amount of
Staphylococus aureus died on the TiN/Ag-coated titanium surface or on the sandblasted and acid-etched titanium surface. These findings indicated that TiN/Ag coating has good biocompatibility and antibacterial properties.