In Vitro Degradation of Pure Magnesium―The Effects of Glucose and/or Amino Acid

Yu Wang,Lan-Yue Cui,Rong-Chang Zeng,Yu-Hong Zou,Shuo-Qi Li,En-Hou Han

doi:10.3390/ma10070725

Abstract

The influences of glucose and amino acid (L-cysteine) on the degradation of pure magnesium have been investigated using SEM, XRD, Fourier transformed infrared (FTIR), X-ray photoelectron spectroscopy (XPS), polarization and electrochemical impedance spectroscopy and immersion tests. The results demonstrate that both amino acid and glucose inhibit the corrosion of pure magnesium in saline solution, whereas the presence of both amino acid and glucose accelerates the corrosion rate of pure magnesium. This may be due to the formation of -C=N- bonding (a functional group of Schiff bases) between amino acid and glucose, which restricts the formation of the protective Mg(OH)2 precipitates.

Highlights

Ageing of the global population has aroused public concern regarding health and biomedical materials and has generated huge demands for degradable implants and absorbable stents [1].Magnesium (Mg) and its alloys have received much attention due to their good biocompatibility and biodegradability [2]
The lower hydrogen evolution rate (HER) in solution #3 compared to solution #1 after 20 h was due to the diminishment of glucose because glucose transformed into gluconic acid in saline solution and promoted corrosion on the pure Mg surface [23]
The polarization, electrochemical impedance spectroscopy (EIS) and hydrogen evolution tests indicate that glucose or amino acids (L-cysteine) delay the corrosion of pure Mg in saline solutions, whereas L-cysteine coupled with glucose enhances the corrosion rate of the samples

Summary

Introduction

Ageing of the global population has aroused public concern regarding health and biomedical materials and has generated huge demands for degradable implants and absorbable stents [1].Magnesium (Mg) and its alloys have received much attention due to their good biocompatibility and biodegradability [2]. Mg is essential to the human body; it can promote bone healing and growth [3]. It is challenging to find successful biomedical applications of Mg alloys because of their rapid corrosion rate in the micro-environment of human body tissues [7]. These tissues contain inorganic ions (i.e., Cl− , HPO4 2− , HCO3 − , and Ca2+ ) as well as organic molecules (e.g., glucose, protein or amino acid) [8,9,10] that have a critical impact on the degradation behavior of Mg alloys

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Results

Discussion

Conclusion