Biofunctionalized anti-corrosive silane coatings for magnesium alloys

Abstract

Biodegradable magnesium alloys are advantageous in various implant applications, as they reduce the risks associated with permanent metallic implants. However, a rapid corrosion rate is usually a hindrance in biomedical applications. Here we report a facile two step procedure to introduce multifunctional, anticorrosive coatings on Mg alloys, such as AZ31. The first step involves treating the NaOH-activated Mg with bistriethoxysilylethane to immobilize a layer of densely crosslinked silane coating with good corrosion resistance; the second step is to impart amine functionality to the surface by treating the modified Mg with 3-amino-propyltrimethoxysilane. We characterized the two-layer anticorrosive coating of Mg alloy AZ31 by Fourier transform infrared spectroscopy, static contact angle measurement and optical profilometry, potentiodynamic polarization and AC impedance measurements. Furthermore, heparin was covalently conjugated onto the silane-treated AZ31 to render the coating haemocompatible, as demonstrated by reduced platelet adhesion on the heparinized surface. The method reported here is also applicable to the preparation of other types of biofunctional, anti-corrosive coatings and thus of significant interest in biodegradable implant applications.Keywords coatings, magnesium, alloys, corrosive, biofunctionalized, silane, anti Disciplines Engineering | Physical Sciences and Mathematics Publication DetailsLiu, X., Yue, Z., Romeo, T., Weber, J., Scheuermann, T., Moulton, S. & Wallace, G. (2013). Biofunctionalized anti-corrosive silane coatings for magnesium alloys. Acta Biomaterialia, 9 (10), 8671-8677. AuthorsXiao Liu, Zhilian Yue, Tony Romeo, Jan Weber, Torsten Scheuermann, Simon E. Moulton, and Gordon G. Wallace AbstractBiodegradable magnesium (Mg) alloys are advantageous in various implant applications, as they reduce the risks associated with permanent metallic implants. However, the fast corrosion rate is usually a hindrance in biomedical applications. Here we report a facile twostep procedure to introduce multifunctional, anticorrosive coatings on Mg alloys, such as AZ31. The first step involves treating the NaOH-activated Mg with bistriethoxysilylethane (BTSE) to immobilise a layer of densely crosslinked silane coating with good corrosion resistance; the second step is to impart amine functionality to the surface by treating the modified Mg with 3-amino-propyltrimethoxysilane (γ-APS). We characterised the two-layer anticorrosive coating of AZ31 Mg alloy by Fourier transform infrared spectroscopy, static contact angle measurement and optical profilometry, potentiodynamic polarization and AC impedance measurements. Furthermore, heparin was covalently conjugated onto the silane treated AZ31 to render the coating haemocompatible, as demonstrated by reduced platelet adhesion on the heparinised surface. The method reported here is also applicable to the preparation of other types of biofunctional, anticorrosive coatings, and thus of significant interest in biodegradable implant applications.

Enhanced Anti-corrosion Ability and Biocompatibility of PLGA Coatings on MgZnYNd Alloy by BTSE-APTES Pre-treatment for Cardiovascular Stent

“…Moreover, no such characteristic bands showed on naked MgZnYNd substrates as expected. Besides, our FT-IR results are similar with previously reported bistriethoxysilylethane (BTSE) and 3-amino-propyltrimethoxysilane (γ-APS, with the same -NH 2 group as APTES) treated Mg, Al, Fe and Mg based materials [18,37,39,40] .…”

Corrosion protection afforded by praseodymium conversion film on Mg alloy AZNd in simulated biological fluid studied by scanning electrochemical microscopy

“…The aim of this study is to help for better understanding of the degradation mechanism of a Pr conversion layer in a simulated biological environment. [29]. The pH was adjusted to 7.40 ± 0.05 using 1 M NaOH (Sigma) solution.…”

Fabrication of the Superhydrophobic Surface on Magnesium Alloy and Its Corrosion Resistance

“…Up to now, numerous surface treatments have been adopted to enhance the corrosion resistance of magnesium alloys, including chemical conversion coatings [1][2][3] , polymer coatings [4,5] , microarc oxidation (MAO) [6,7] , and silane coatings [8] . Among the above mentioned methods, some preparations are subject to special equipments or techniques, severe processing conditions, and even require toxic reagent.…”