Abstract: Objective This paper investigates the optimal modification process of 3D printed nickel-titanium alloys by bioactive treatments such as sandblasting, acid etching, and dealloying. Methods The surface structure and properties of specimens were examined by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and contact angle measurement. In this study, bone marrow mesenchymal stem cells (hBMSCs) were used to study the biocompatibility and osteogenic activity of different surfaces. Results The hydrophilicity of the dealloying surface was improved. EDS results showed that the surface nickel elementdecreased from 52.1wt% to 18.6wt%, which not only accelerated the differentiation and proliferation of cells on the surface, but also enhanced the adhesion ability of cells. Conclusion The dealloyed surface constructed a more abundant nanoscale mesh structure, which significantly promoted the osteogenic differentiation and functional expression of cells, which was of great importance for improving the osseointegration ability and long-term stability of implants.

Key words: Nickel-titanium alloy, Surface treatment, Dealloying, Cytocompatibility