Enhanced Osseointegration of Titanium Implants by Surface Modification with Silicon-doped Titania Nanotubes
Authors Zhao X, You L, Wang T, Zhang X, Li Z, Ding L, Li J, Xiao C, Han F, Li B
Received 1 July 2020
Accepted for publication 15 September 2020
Published 3 November 2020 Volume 2020:15 Pages 8583—8594
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 3
Editor who approved publication: Dr Lei Yang
Xijiang Zhao,1,* Linna You,1,* Tao Wang,1 Xianjun Zhang,1 Zexi Li,2 Luguang Ding,2 Jiaying Li,2 Can Xiao,2 Fengxuan Han,2 Bin Li2
1Department of Orthopedics, The Affiliated Hospital of Jiangnan University, Wuxi, Jiangsu 214062, People’s Republic of China; 2Departments of Orthopaedic Surgery and Stomatology, The First Affiliated Hospital, Orthopaedic Institute, Soochow University, Suzhou, Jiangsu 215006, People’s Republic of China
*These authors contributed equally to this work
Correspondence: Bin Li
Soochow University (South Campus), 708 Renmin Road, Rm 308 Bldg 1, Suzhou, Jiangsu 215007, People’s Republic of China
Tel/Fax (+86) 512-6778-1163
The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu 215006, People’s Republic of China
Introduction: Despite great progress made in developing orthopedic implants, the development of titanium (Ti) implants with ideal early osseointegration remains a big challenge. Our pilot study has demonstrated that Si-TiO2 nanotubes on the surface of Ti substrates could enhance their osteogenic activity. Hence, in this study, we aim to comprehensively evaluate the effects of silicon-doped titania (Si-TiO2) nanotubes on the osseointegration property of Ti implants.
Materials and Methods: The Ti implants were surface modified with Si-TiO2 nanotubes through in situ anodization and Si plasma immersion ion implantation (PIII) method. Three groups were divided as Ti implants (Ti), Ti modified with TiO2 nanotubes (TiO2-NTs) and Ti modified with Si-TiO2 nanotubes (Si-TiO2-NTs). The morphology of Si-TiO2 nanotubes was observed by scanning electron microscope. The growth and osteogenic differentiation of MC3T3-E1 cells on the Ti implants were evaluated. Further, the pull-out tests and in vivo osseointegration ability evaluation were performed after implanting the screws in the femur of Sprague Dawley rats.
Results: The Si-TiO2 nanotubes could be seen on the surface of Ti implants. The MC3T3-E1 cells could grow on the surface of Ti, TiO2-NTs and Si-TiO2-NTs, and showed fast proliferation rate on the Si-TiO2-NTs. Moreover, the production of some osteogenesis-related proteins (ALP and Runx2) at one week and calcium deposition at four week was also enhanced in Si-TiO2-NTs rather than other groups. In vivo osseointegration results showed that Si-TiO2 nanotube-modified Ti screws had higher pullout force at two and four weeks as well as enhanced new bone formation at six weeks compared to bare Ti screws and Ti screws modified with TiO2 nanotubes alone.
Discussion: The modification of Si-TiO2-NTs on the Ti substrate could generate a nanostructured and hydrophilic surface, which can promote cell growth. Moreover, the existence of the TiO2 nanotubes and Si element also can improve the in vitro osteogenic differentiation of MC3T3-E1 cells and early bone formation around the implanted screws. Together, findings from this study show that surface modification of Ti implants with Si-TiO2 nanotubes could enhance early osseointegration and therefore has the potential for clinical applications.
Keywords: osseointegration, implant, silicon, titanium dioxide, nanotubes