Nanostructured titanate with different metal ions on the surface of metallic titanium: A facile approach for regulation of rBMSCs fate on titanium implants

Titanium (Ti) is widely used for load-bearing bio-implants, however, it is bio-inert and exhibits poor osteo-inductive properties. Calcium and magnesium ions are considered to be involved in bone metabolism and play a physiological role in the angiogenesis, growth, and mineralization of bone tissue. In this study, a facile synthesis approach to the in situ construction of a nanostructure enriched with Ca²⁺ and Mg²⁺ on the surface of titanium foil is proposed by inserting Ca²⁺ and Mg²⁺ into the interlayers of sodium titanate nanostructures through an ion-substitution process. The characteriz 0.67, and 0.73 nm ation results validate that cations can be inserted into the interlayer regions of the layered nanostructure without any obvious change of morphology. The cation content is positively correlated to the concentration of the solutions employed. The biological assessments indicate that the type and the amount of cations in the titanate nanostructure can alter the bioactivity of titanium implants. Compared with a Na⁺ filled titanate nanostructure, the incorporation of divalent ions (Mg²⁺, Ca²⁺) can effectively enhance protein adsorption, and thus also enhance the adhesion and differentiation ability of rat bone-marrow stem cells (rBMSCs). The Mg²⁺/Ca²⁺- titanate nanostructure is a promising implantable material that will be widely applicable in artificial bones, joints, and dental implants. A titanate nanostructure incorporating Na⁺, Mg²⁺, or Ca²⁺ can be synthesized by a facile method based on a hydrothermal technique and followed by an ion-substitution process. Both Mg²⁺ and Ca ²⁺ in the titanate nanostructure can enhance the proliferation and osteogenic differentiation of MSCs, compared to titanate nanostructures incorporating Na⁺.