eCM (Eur Cell Mater / e Cells & Materials) Not-for-profit Open Access
Created by Scientists, for Scientists
 ISSN:1473-2262         NLM:100973416 (link)         DOI:10.22203/eCM

2015   Volume No 29 – pages 290-302

Title: Enhanced in vitro biological activity generated by surface characteristics of anodically oxidized titanium – the contribution of the oxidation effect

Author: Wurihan, A Yamada, D Suzuki, Y Shibata, R Kamijo, T Miyazaki

Address: Department of Conservative Dentistry, Division of Biomaterials & Engineering, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan

E-mail: yookun at dent.showa-u.ac.jp

Key Words: Titanium, hydroxyl radical, osteoblast, gene expression, nanoindentation.

Publication date: May 20th 2015

Abstract: Anodically oxidized titanium surfaces, prepared by spark discharge, have micro-submicron surface topography and nano-scale surface chemistry, such as hydrophilic functional groups or hydroxyl radicals in parallel. The complexity of the surface characteristics makes it difficult to draw a clear conclusion as to which surface characteristic, of anodically oxidized titanium, is critical in each biological event. This study examined the in vitro biological changes, induced by various surface characteristics of anodically oxidized titanium with, or without, release of hydroxyl radicals onto the surface. Anodically oxidized titanium enhanced the expression of genes associated with differentiating osteoblasts and increased the degree of matrix mineralization by these cells in vitro. The phenotypes of cells on the anodically oxidized titanium were the same with, or without, release of hydroxyl radicals. However, the nanomechanical properties of this in vitro mineralized tissue were significantly enhanced on surfaces, with release of hydroxyl radicals by oxidation effects. In addition, the mineralized tissue, produced in the presence of bone morphogenetic protein-2 on bare titanium, had significantly weaker nanomechanical properties, despite there being higher osteogenic gene expression levels. We show that enhanced osteogenic cell differentiation on modified titanium is not a sufficient indicator of enhanced in vitro mineralization. This is based on the inferior mechanical properties of mineralized tissues, without either being cultured on a titanium surface with release of hydroxyl radicals, or being supplemented with lysyl oxidase family members.

Article download: Pages 290-302 (PDF file)
DOI: 10.22203/eCM.v029a22