Effect of Regulation of Surface Charge on Titanium Surfaces for Fibronectin Adsorption

The fibronectin adsorptive capacity of pure titanium surfaces was investigated to improve its biological properties by regulating its surface charge. The different surfaces of titanium sheet were obtained by sandblasting with large grit and acid-etching (SLA), and then immersing in different solutions. Surface morphology, elemental composition, roughness, and surface charge status were studied, and fibronectin adsorption assay was performed for comparative analysis. The results show that the surface morphology of each group is similar, but the surface elements of the different groups are different because of immersion in different liquids. There is no significant difference in the surface roughness of each group. Titanium sheets immersed in calcium chloride solution have the highest protein adsorption capacity (P < 0.01), whereas the control group has the lowest adsorption capacity. Immersion of titanium sheets in calcium chloride solution containing divalent calcium ions can change their surface charge, enhance their protein adsorption capacity, and thus improve their biological properties.