Modification of a SLA titanium surface with calcium-containing nanosheets and its effects on osteoblast behavior

Abstract

Objective: The aim of this study was to present a procedure to prepare a calcium-containing nanosheets-modified sandblasted and acid etched (SLA) titanium surface and explore its effects on osteoblast behavior. Materials and methods: Through hydrothermal treatment with a mixed solution of Ca(OH)₂ and H₂O₂, calcium-containing nanosheets were synthesized on a pretreated SLA titanium substrate. Different ratios of Ca(OH)₂ to H₂O₂ in the mixed solution diversified the calcium-containing nanosheets-modified SLA titanium surfaces. Samples of two experimental groups (Ti-SLA-1/1 and Ti-SLA-5/1) were prepared with different mixed solutions, in which the ratios of Ca(OH)₂ to H₂O₂ were 1 : 1 and 5 : 1, respectively. Physical properties, including surface topography, elemental composition, wettability, surface roughness, adhesion strength of coatings, and calcium release, were observed and measured. Assays of adhesion, spreading, proliferation, and differentiation of MC3T3-E1 cells, an osteoblast-like cell line, on the samples were investigated. Results: Two modified titanium surfaces were successfully prepared and appeared as calcium-containing nanosheet-like structures, which revealed excellent superhydrophilicity and could release Ca²⁺ ions into phosphate buffer saline in a sustained manner. In addition, the modified titanium surfaces have satisfactory surface roughness and coating adhesion. The results of the in vitro study showed that the two modified titanium surfaces, especially the Ti-SLA-5/1 surface, exhibited satisfactory osteocompatibility and upregulated the cell adhesion, spreading, proliferation, and differentiation abilities as compared to the control SLA titanium surface. Conclusions: The modified nanosheet-like titanium surfaces demonstrated the ability to improve osteoblast behavior and exhibited the potential to improve bone-titanium integration.