The effects of hierarchical micro/nanosurfaces decorated with TiO2 nanotubes on the bioactivity of titanium implants in vitro and in vivo

Abstract

Xianglong Ding,1 Lei Zhou,1 Jingxu Wang,2 Qingxia Zhao,3 Xi Lin,1 Yan Gao,1 Shaobing Li,4 Jingyi Wu,1 Mingdeng Rong,4 Zehong Guo,1 Chunhua Lai,1 Haibin Lu,4 Fang Jia11Center of Oral Implantology, Guangdong Provincial Stomatological Hospital, Southern Medical University, 2Department of Stomatology, The First Affiliated Hospital of Guangzhou Medical University, 3Department of Stomatology, Nanfang Hospital, 4Department of Periodontics and Implantology, Guangdong Provincial Stomatological Hospital, Southern Medical University, Guangzhou, People’s Republic of ChinaAbstract: In the present work, a hierarchical hybrid micro/nanostructured titanium surface was obtained by sandblasting with large grit and acid etching (SLA), and nanotubes of different diameters (30 nm, 50 nm, and 80 nm) were superimposed by anodization. The effect of each SLA-treated surface decorated with nanotubes (SLA + 30 nm, SLA + 50 nm, and SLA + 80 nm) on osteogenesis was studied in vitro and in vivo. The human MG63 osteosarcoma cell line was used for cytocompatibility evaluation, which showed that cell adhesion and proliferation were dramatically enhanced on SLA + 30 nm. In comparison with cells grown on the other tested surfaces, those grown on SLA + 80 nm showed an enhanced expression of osteogenesis-related genes. Cell spread was also enhanced on SLA + 80 nm. A canine model was used for in vivo evaluation of bone bonding. Histological examination demonstrated that new bone was formed more rapidly on SLA-treated surfaces with nanotubes (especially SLA + 80 nm) than on those without nanotubes. All of these results indicate that SLA + 80 nm is favorable for promoting the activity of osteoblasts and early bone bonding.Keywords: nanotopography, osseointegration, dental and orthopedic implant, titanium