Establishment of perpendicular protrusion of type I collagen on TiO2 nanotube surface as a priming site of peri-implant connective fibers

Toshiki Nojiri; Chia-Yu Chen; David M Kim; John Da Silva; Cliff Lee; Masahiko Maeno; Arthur A McClelland; Bryan Tse; Shigemi Ishikawa-Nagai; Wataru Hatakeyama; Hisatomo Kondo; Masazumi Nagai

doi:10.1186/s12951-019-0467-1

Establishment of perpendicular protrusion of type I collagen on TiO₂ nanotube surface as a priming site of peri-implant connective fibers

J Nanobiotechnology. 2019 Mar 1;17(1):34. doi: 10.1186/s12951-019-0467-1.

Authors

Affiliations

¹ Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA, USA.
² Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA, USA.
³ Department of Adhesive Dentistry, The Nippon Dental University, 1-9-20 Fujimi, Chiyoda-ku, Tokyo, Japan.
⁴ Center for Nanoscale Systems, Harvard University, 11 Oxford St, Cambridge, MA, USA.
⁵ Department of Prosthodontics and Oral Implantology, School of Dental Medicine, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate, Japan.
⁶ Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, 188 Longwood Avenue, Boston, MA, USA. masazumi_nagai@hms.harvard.edu.

Abstract

Natural teeth are supported by connective tissue collagen fibers that insert perpendicularly in the tooth cementum. Perpendicular insertion plays an important role in the maintenance of the junction between the oral epithelium and the periodontal connective tissue. Most titanium dental implant surfaces have no micro or macro structure to support perpendicularly oriented collagen attachment. Without this tight biologic seal to resist bacterial invasion and epithelial downgrowth, progressive bone loss in peri-implantitis is seen around dental implants. The purpose of this study was to establish the perpendicularly oriented collagen attachment to titanium oxide nanotube (TNT), and to assess its binding stability. TNT was prepared on the titanium-surface by anodization. Scanning electron microscopy (SEM) showed a regularly aligned TNT with an average 67 nm-diameter when anodized at 30 V for 3 h. Subsequently, collagen type I (CoI) was electrophoretically fused to anodic TNT in native polyacrylamide gel system where negatively charged CoI-C term was perpendicularly navigated to TNT. SEM and atomic force microscopy (AFM) were used to analyze CoI on the TiO₂ and TNT surface. Several tens of nanometers of CoI protrusion were recorded by AFM. These protrusions may be long enough to be priming sites for cell-secreted CoI. CoI laid parallel to the titanium surface when fused by a chemical linker. Binding resistance of CoI against drastic ultrasonication was measured by Fourier-transform infrared spectroscopy attenuated total reflection (FTIR-ATR). The electrophoretically fused CoI in the titanium nanotube (TNT-CoI^EPF) showed the significantly greatest binding resistance than the other groups (P < 0.01, a 1-way ANOVA and Tukey HSD post hoc test). Furthermore, TNT-CoI^EPF surface rejected epithelial cell stretching and epithelial sheet formation. Chemically linked horizontal CoI on titanium oxide (TiO₂) facilitated epithelial cell stretching and sheet formation.

Keywords: Collagen; Implant surface; Nanotubes; Perpendicular orientation; Titanium.

MeSH terms

Biocompatible Materials / chemistry
Cell Adhesion / drug effects
Collagen Type I / chemistry*
Connective Tissue / chemistry*
Dental Implants*
Electrochemical Techniques
Epithelial Cells / drug effects
Humans
Nanotubes / chemistry*
Particle Size
Surface Properties
Titanium / chemistry*

Substances

Biocompatible Materials
Collagen Type I
Dental Implants
titanium dioxide
Titanium