Strontium‐substituted apatite coating grown on Ti6Al4V substrate through biomimetic synthesis

Abstract

During the last few years Strontium has been shown to have beneficial effects when incorporated at certain doses in bone by stimulating bone formation. It is believed that its presence locally at the interface between an implant and bone will enhance osteointegration and therefore, ensure the longevity of a joint prosthesis. In this study we explore the possibility of incorporating Sr into nano-apatite coatings prepared by a solution-derived process according to an established biomimetic methodology for coating titanium based implants. The way this element is incorporated in the apatite structure and its effects on the stereochemistry and morphology of the resulting apatite layers was investigated, as well as its effect in the mineralization kinetics. By using the present methodology it was possible to incorporate increasing amounts of Sr in the apatite layers. Sr was found to incorporate in the apatite layer through a substitution mechanism by replacing Ca in the apatite lattice. The presence of Sr in solution induced an inhibitory effect on mineralization, leading to a decrease in the thickness of the mineral layers. The obtained Sr-substituted biomimetic coatings presented a bone-like structure similar to the one found in the human bone and therefore, are expected to enhance bone formation and osteointegration.

Advances in Biomimetic Apatite Coating on Metal Implants

“…Oliveira et al incorporated different amounts of Sr into nano-apatite coatings by adding SrCl 2 in SBF solution with higher concentrations of Ca 2+ and HPO 4 2-than that of human blood plasma. The presence of Sr ions in solution inhibited the apatite formation and resulted in the decrease of coating thickness, and it incorporated in the apatite layer by replacing Ca in the apatite lattice (Oliveira et al, 2007 (Bracci et al, 2009). In addition, cobalt, copper, zinc, strontium and fluoride with varying concentrations were incorporated in the calcium phosphate films by using a biomimetic approach consisting of precalcification and calcification steps.…”

Preparation and Characterization of Aminated Hydroxyethyl Cellulose-Induced Biomimetic Hydroxyapatite Coatings on the AZ31 Magnesium Alloy

“…Recently, thermal spraying, sputtering coating, pulsed laser deposition, sol-gel, biomimetic coating, electrophoretic deposition, and many other methods are used to prepare hydroxyapatite coatings of magnesium alloy [14][15][16][17][18]. Biomimetic mineralization is environmentally friendly, cheap, simple, and biocompatible, thus has attracted much attention and investigation [14].…”

Strontium and Silicon Co-Doped Apatite Coating: Preparation and Function as Vehicles for Ion Delivery

“…Studies have shown that ion doped HA, i.e. hydroxyapatite containing foreign ions, is a promising way to improve the cell proliferation and in vivo bone tissue response without the addition of pharmaceutical agents [6][7][8]. Compared to pure HA, these modified HA have different solubility, crystallinity and topography, all of which are factors that are expected to influence the bone response around the implant [9].…”

“…The preparation of co-doped hydroxyapatite ceramics, mostly based on powder techniques, has previously been reported [14][15][16][17]. Some work has also been reported on preparation of Sr or Si containing hydroxyapatite coatings by a mineralization method [7,[18][19][20].…”