Control of Degradation of Biocompatible Magnesium in a Pseudo-Physiological Environment by a Ceramic Like Anodized Coating

Abstract

Magnesium alloys are potential biodegradable implant materials. However, magnesium alloys normally corrode rapidly in the in-vivo fluid, resulting in subcutaneous gas bubbles and alkalisation of the in-vivo solution. The paper presents a new approach to control the degradation rate of magnesium in a simulated body fluid (SBF) through employing a recently developed anodising technique. It was found that the ceramic like anodised coating formed on the surface of magnesium can effectively slow down the biodegradation process and hence result in slow hydrogen evolution and solution alkalisation processes. The results imply that an anodised magnesium alloy may be successfully used as a biodegradable implant material.

Influence of ECAP process on mechanical and corrosion properties of pure Mg and ZK60 magnesium alloy for biodegradable stent applications

“…Over and above corrosion rate, critical hydrogen gas bubbles and alkalization resulting from corrosion of Mg in body fluid are also other problematic subjects in fast corrosion-rate processes, leading to accumulation of evolved hydrogen bubbles in gas pockets next to the implant and consequently, causing necrosis of tissues. However, if the corrosion rate of Mg implant can be suitably controlled, hydrogen evolution will not be rapid enough to cause critical subcutaneous bubbles, and the alkalization effect could be easily balanced by metabolic mechanisms in the human body 14 - 16 …”

“…However, if the corrosion rate of Mg implant can be suitably controlled, hydrogen evolution will not be rapid enough to cause critical subcutaneous bubbles, and the alkalization effect could be easily balanced by metabolic mechanisms in the human body. 14 - 16 …”

Corrosion behavior and prevention strategies for magnesium (Mg) alloys

“…This corrosion-related hydrogen evolution is also applicable to Mg alloys in aqueous solutions Atrens, 1998 , 2003 ;Song and St John, 2002 ), including engine coolants St John, 2004 , 2005 ) and simulated body fl uids (SBF) Song, 2006 , 2007 ;Song, 2007b ). In a severe corrosion process, Mg particle undermining may take place (Mg particle falling into solution due to the surrounding material becoming completely corroded).…”

Recent advances in research on magnesium alloys and magnesium–calcium phosphate composites as biodegradable implant materials

“…Some of the surface modifications might be even too protective and it is essential to modify surface by coating with suitable corrosion times. Song 95 developed an anodized coating in some sense similar to a ceramic layer. After one month no hydrogen evolution was observed, so degradation was accelerated by polishing the anodized coating.…”