TiO2 bioactive implant surfaces doped with specific amount of Sr modulate mineralization

A I Costa; S Gemini-Piperni; A C Alves; N A Costa; N R Checca; P E Leite; L A Rocha; A M P Pinto; F Toptan; A L Rossi; A R Ribeiro

doi:10.1016/j.msec.2020.111735

TiO₂ bioactive implant surfaces doped with specific amount of Sr modulate mineralization

Mater Sci Eng C Mater Biol Appl. 2021 Jan:120:111735. doi: 10.1016/j.msec.2020.111735. Epub 2020 Nov 14.

Authors

A I Costa¹, S Gemini-Piperni², A C Alves³, N A Costa⁴, N R Checca⁵, P E Leite⁶, L A Rocha⁷, A M P Pinto⁸, F Toptan⁹, A L Rossi⁵, A R Ribeiro¹⁰

Affiliations

¹ CMEMS-UMinho - Center of MicroElectroMechanical Systems, University of Minho, Guimarães, Portugal; DEMM - Department of Metallurgical and Materials Engineering, Faculty of Engineering of the University of Porto, Porto, Portugal. Electronic address: a66848@alunos.uminho.pt.
² Postgraduate Program of Translational Biomedicine, University Grande Rio, Duque de Caxias, Brazil; IBTN/Br - Brazilian Branch of the Institute of Biomaterials, Tribocorrosion and Nanomedicine, São Paulo State University, Bauru, São Paulo, Brazil.
³ CMEMS-UMinho - Center of MicroElectroMechanical Systems, University of Minho, Guimarães, Portugal.
⁴ IBTN/Br - Brazilian Branch of the Institute of Biomaterials, Tribocorrosion and Nanomedicine, São Paulo State University, Bauru, São Paulo, Brazil; Postgraduate Program in Materials Science and Technology, São Paulo State University, Bauru, São Paulo, Brazil.
⁵ CBPF - Brazilian Centre for Research in Physics, Rio de Janeiro, Brazil.
⁶ Directory of Life Sciences Applied Metrology, National Institute of Metrology Quality and Technology, Xérem, Rio de Janeiro, Brazil; Postgraduate Program in Biotechnology, National Institute of Metrology Quality and Technology, Xérem, Rio de Janeiro, Brazil.
⁷ IBTN/Br - Brazilian Branch of the Institute of Biomaterials, Tribocorrosion and Nanomedicine, São Paulo State University, Bauru, São Paulo, Brazil; Faculty of Science, Department of Physics, São Paulo State University, Bauru, São Paulo, Brazil.
⁸ CMEMS-UMinho - Center of MicroElectroMechanical Systems, University of Minho, Guimarães, Portugal; DEM - Department of Mechanical Engineering, University of Minho, Guimarães, Portugal.
⁹ CMEMS-UMinho - Center of MicroElectroMechanical Systems, University of Minho, Guimarães, Portugal; IBTN/Br - Brazilian Branch of the Institute of Biomaterials, Tribocorrosion and Nanomedicine, São Paulo State University, Bauru, São Paulo, Brazil.
¹⁰ Postgraduate Program of Translational Biomedicine, University Grande Rio, Duque de Caxias, Brazil; IBTN/Br - Brazilian Branch of the Institute of Biomaterials, Tribocorrosion and Nanomedicine, São Paulo State University, Bauru, São Paulo, Brazil; Postgraduate Program in Biotechnology, National Institute of Metrology Quality and Technology, Xérem, Rio de Janeiro, Brazil.

PMID: 33545878
DOI: 10.1016/j.msec.2020.111735

Abstract

One of the main problems that remain in the implant industry is poor osseointegration due to bioinertness of implants. In order to promote bioactivity, calcium (Ca), phosphorus (P) and strontium (Sr) were incorporated into a TiO₂ porous layer produced by micro-arc oxidation. Ca and P as bioactive elements are already well reported in the literature, however, the knowledge of the effect of Sr is still limited. In the present work, the effect of various amounts of Sr was evaluated and the morphology, chemical composition and crystal structure of the oxide layer were investigated. Furthermore, in vitro studies were carried out using human osteoblast-like cells. The oxide layer formed showed a triplex structure, where higher incorporation of Sr increased Ca/P ratio, amount of rutile and promoted the formation of SrTiO₃ compound. Biological tests revealed that lower concentrations of Sr did not compromise initial cell adhesion neither viability and interestingly improved mineralization. However, higher concentration of Sr (and consequent higher amount of rutile) showed to induce collagen secretion but with compromised mineralization, possibly due to a delayed mineralization process or induced precipitation of deficient hydroxyapatite. Ca-P-TiO₂ porous layer with less concentration of Sr seems to be an ideal candidate for bone implants.

Keywords: Micro-arc oxidation; Orthopedics implants; Sr; TiO(2).

MeSH terms

Coated Materials, Biocompatible*
Humans
Osseointegration
Strontium*
Surface Properties
Titanium

Substances

Coated Materials, Biocompatible
titanium dioxide
Titanium
Strontium