Bone integration capability of a series of strontium-containing hydroxyapatite coatings formed by micro-arc oxidation
Article first published online: 24 JAN 2013
Copyright © 2012 Wiley Periodicals, Inc.
Journal of Biomedical Materials Research Part A
Volume 101A, Issue 9, pages 2465–2480, September 2013
How to Cite
How to cite this article: 2013. Bone integration capability of a series of strontiumcontaining hydroxyapatite coatings formed by micro-arc oxidation. J Biomed Mater Res Part A 2013:101A:2465–2480., , , , .
- Issue published online: 22 JUL 2013
- Article first published online: 24 JAN 2013
- Manuscript Accepted: 28 NOV 2012
- Manuscript Revised: 23 OCT 2012
- Manuscript Received: 16 JUL 2012
- National Basic Research Program of China. Grant Number: 2012CB619103
- Natural National Science Foundation of China. Grant Numbers: 81070862, 51071120
- State key Laboratory for Mechanical Behavior of Materials. Grant Number: 201011008
- Hong Kong Research Grants Council (RGC) General Research Funds (GRF). Grant Number: CityU 112510
- City University of Hong Kong Applied Research Grant (ARG). Grant Number: 9667038
- Sr-doped hydroxyapatite;
- in vivo implantation;
- micro-arc oxidation;
Strontium-containing hydroxyapatites (Sr-HA) combine the desirable bone regenerative properties of hydroxyapatites (HA) with anabolic and anti-catabolic effects of strontium cations. In the present work, a series of SryHA [SryCa(10−y)(PO4)6(OH)2; y = 0, 0.5, 1, 2] coatings on titanium are produced by micro-arc oxidation (MAO), and the effects of the in vivo osseointegration ability of the coatings are investigated by using a rabbit model. All samples are subjected to biomechanical, surface elemental, micro-CT and histological analysis after 4 and 12 weeks of healing. The obtained results show that the MAO-formed coatings exhibit a microporous network structure composed of SryHA/SryHA–SrxCa(1-x)TiO3/SrxCa(1-x)TiO3–TiO2 multilayers, in which the outer SryHA and intermediate SryHA–SrxCa(1-x)TiO3 layers have a nanocrystalline structure. All Sr-HA coated implants induce marked improvements in the behavior of bone formation, quantity and quality of bone tissue around the implants than the control HA implant and in particular, the 20%Sr-HA coating promotes early bone formation as identified by polyfluorochrome sequential labeling. The bone-to-implant contact is increased by 46% (p < 0.05) and the pull-out strength is increased by 103% over the HA group (p < 0.01). Extensive areas of mineralized tissue densely deposit on the 20%Sr-HA coating after biomechanical testing, and the greatest improvement of bone microarchitecture are observed around the 20%Sr-HA implant. The identified biological parameters successfully demonstrate the osteoconductivity of 20%Sr-HA surfaces, which results not only in an acceleration but also an improvement of bone–implant integration. The study demonstrates the immense potential of 20%Sr-HA coatings in dental and orthopedic applications. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 2465–2480, 2013.