Osteogenic activity of titanium surfaces with hierarchical micro/nano-structures obtained by hydrofluoric acid treatment

Abstract

Jianfei Liang,1,* Shanshan Xu,1,* Mingming Shen,2,* Bingkun Cheng,3 Yongfeng Li,4 Xiangwei Liu,1 Dongze Qin,1 Anuj Bellare,5 Liang Kong1 1State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Disease & Shaanxi Key Laboratory of Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, Xi’an, 2Department of Stomatology, Xinhua Hospital of Beijing, Beijing, 3Department of Oral and Maxillofacial Surgery, School of Stomatology, The Second Hospital of Hebei Medical University, Shijiazhuang, 4Department of Stomatology, Chinese PLA 532 Hospital, Huangshan, People’s Republic of China; 5Department of Orthopedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA *These authors contributed equally to this work Abstract: An easier method for constructing the hierarchical micro-/nano-structures on the surface of dental implants in the clinic is needed. In this study, three different titanium surfaces with microscale grooves (width 0.5–1, 1–1.5, and 1.5–2 µm) and nanoscale nanoparticles (diameter 20–30, 30–50, and 50–100 nm, respectively) were obtained by treatment with different concentrations of hydrofluoric acid (HF) and at different etching times (1%, 3 min; 0.5%, 12 min; and 1.5%, 12 min, respectively; denoted as groups HF1, HF2, and HF3). The biological response to the three different titanium surfaces was evaluated by in vitro human bone marrow-derived mesenchymal stem cell (hBMMSC) experiments and in vivo animal experiments. The results showed that cell adhesion, proliferation, alkaline phosphatase activity, and mineralization of hBMMSCs were increased in the HF3 group. After the different surface implants were inserted into the distal femurs of 40 rats, the bone–implant contact in groups HF1, HF2, and HF3 was 33.17%±2.2%, 33.82%±3.42%, and 41.04%±3.08%, respectively. Moreover, the maximal pullout force in groups HF1, HF2, and HF3 was 57.92±2.88, 57.83±4.09, and 67.44±6.14 N, respectively. The results showed that group HF3 with large micron grooves (1.5–2.0 µm) and large nanoparticles (50–100 nm) showed the best bio-functionality for the hBMMSC response and osseointegration in animal experiments compared with other groups. Keywords: hydrofluoric acid etching, surface modification, micro-/nano-structures, osteogenic activity, titanium implant

Keywords

• hydrofluoric acid etching
• surface modification
• micro/nano- structures
• osteogenic activity