<p>Biodegradable magnesium (Mg) alloys are promising for biomedical implants due to their favorable mechanical properties and safe degradation within the human body. However, the rapid corrosion of Mg remains a challenge, necessitating a deeper understanding of its behavior in physiological environments. This study evaluates the in vitro corrosion performance of a lean Mg-Zn-Ca alloy processed via equal channel angular pressing to refine the grain size and enhance the mechanical properties. Corrosion behavior was assessed in Hank’s balanced salt solution (HBSS), Earle’s balanced salt solution (EBSS) buffered with 5% <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11837_2025_7176_Article_IEq1.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="TEX">${\hbox {CO}}_{2}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mtext>CO</mtext> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation>, and Dulbecco’s modified eagle medium (DMEM) with 10% fetal bovine serum (FBS) buffered with 5% <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11837_2025_7176_Article_IEq1.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="TEX">${\hbox {CO}}_{2}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mtext>CO</mtext> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation>. Significant differences in corrosion rates were observed across media, with HBSS exhibiting the lowest rates and EBSS the highest. DMEM with 10% FBS produced intermediate corrosion rates under conditions that closely mimic physiological environments. The effect of <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11837_2025_7176_Article_IEq1.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="TEX">${\hbox {CO}}_{2}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mtext>CO</mtext> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation> buffering in HBSS was also evaluated, demonstrating enhanced pH control below 7.5, which simulates physiological pH. Additionally, increasing the volume of HBSS, both with and without <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="11837_2025_7176_Article_IEq1.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="TEX">${\hbox {CO}}_{2}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mtext>CO</mtext> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation> buffering, led to reduced corrosion rates and greater pH stabilization. These results demonstrate how testing conditions influence corrosion rates and pH stability, advancing our understanding of biodegradable Mg alloys for biomedical applications.</p>

Evaluating In-Vitro Corrosion Testing of ECAP-Processed Lean Magnesium Alloys: The Critical Role of Degradation Media Composition, Buffering, and Volume

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发表日期：

2025年2月18日

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Sreenivas Raguraman,
Beril Ulugun,
Tunde Ayodeji,
Rida Chowdhury,
Adam Griebel,
Timothy Weihs

摘要

Biodegradable magnesium (Mg) alloys are promising for biomedical implants due to their favorable mechanical properties and safe degradation within the human body. However, the rapid corrosion of Mg remains a challenge, necessitating a deeper understanding of its behavior in physiological environments. This study evaluates the in vitro corrosion performance of a lean Mg-Zn-Ca alloy processed via equal channel angular pressing to refine the grain size and enhance the mechanical properties. Corrosion behavior was assessed in Hank’s balanced salt solution (HBSS), Earle’s balanced salt solution (EBSS) buffered with 5% ${\hbox {CO}}_{2}$ ${CO}_{2}$ , and Dulbecco’s modified eagle medium (DMEM) with 10% fetal bovine serum (FBS) buffered with 5% ${\hbox {CO}}_{2}$ ${CO}_{2}$ . Significant differences in corrosion rates were observed across media, with HBSS exhibiting the lowest rates and EBSS the highest. DMEM with 10% FBS produced intermediate corrosion rates under conditions that closely mimic physiological environments. The effect of ${\hbox {CO}}_{2}$ ${CO}_{2}$ buffering in HBSS was also evaluated, demonstrating enhanced pH control below 7.5, which simulates physiological pH. Additionally, increasing the volume of HBSS, both with and without ${\hbox {CO}}_{2}$ ${CO}_{2}$ buffering, led to reduced corrosion rates and greater pH stabilization. These results demonstrate how testing conditions influence corrosion rates and pH stability, advancing our understanding of biodegradable Mg alloys for biomedical applications.