ABSTRACT

Replacement of bones by implants could solve major problems after accidents or because of aging. When traditional alloys are used as temporary implant devices, a second surgery is required to remove the implant after tissues have healed. It would be very advantageous if an implant material could be identified that degraded in the physiological environment after completion of the healing process. Magnesium alloys are potential candidates for use as biodegradable temporary implant devices. There are many reactions that occur adjacent to implant degradation in the body. One of these processes is the Fenton reaction, a common process in biological systems that is caused by oxidative stress. A system that includes hydrogen from the corrosion of magnesium, iron ions, hydrogen peroxide, hydroxyl radicals, and Fenton reactants and products, is a complex system that is involved in several reactions. The reactions occur in parallel and could affect each other. The main objective of this research is to investigate the corrosion behavior of pure Magnesium in saline solution containing Fenton reagents. Corrosion tests (hydrogen evaluation and potentiodynamic polarization) were carried out on the pure Mg samples. The oxidation characterization was study by XPS. Fenton reagent affected the hydrogen evolution rate as well as the degradation rate of pure Mg; however, those reagents did not affect the oxidation composition.

INTRODUCTION

There are many studies that deal with the uses of Mg alloys for transportation industries due to their low density and high specific strength [1-6]. Because of their poor corrosion resistance in aqueous solutions, reaction (1), the alloys are suggested for biodegradable implant uses.

Equation

Their mechanical properties are similar to those of natural bone (Mg alloys' density 1.7-2 g/cm3, natural bone density 1.8-2.1 g/cm3) [7, 8], which gives Mg alloys advantages as biodegradable implants. Two major problems could occur in the human body during life, oxidative stress [9, 10] and bone erosion [11, 12]. In biological systems Fenton reaction is the main source of hydroxyl radicals, which are known as the main source of oxidative stress [9, 13, 14]; reaction (2):

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