Osteoblast responses of thermally oxidized magnesium-calciummanganese alloy

Abstract

Magnesium alloys are considered as potential biomedical materials due to their mechanical properties, which approximate cortical bone, as well as their biocompatibility. Thermal oxidation is one surface modification method used to increase the corrosion resistance of biomaterial surfaces. Thus, the aim of this study is to assess physical and biological differences of Mg-Ca-Mn alloy depending on oxidation heat treatment methods. The sample were divided into 3 groups: Group II: pure magnesium as a control group; Group II: untreated Mg-Ca-Mn alloy; Group III: Mg-Ca-Mn alloy treated at 500℃ for 2 hours. Scanning electron microscope assessment, immersion test, roughness test, and MTT assay were used to evaluate surface characteristics and physical and biologic properties of each sample. Oxide-treated Mg-Ca-Mn alloy treated thermally (Group III) showed an oxidized layer and precipitate with granular structure on the surface. During the immersion test, no significant difference was shown in pH values between the groups. The roughness measurements in Group I and Group III were significantly higher than the value in Group II, while there was no meaningful difference between Group I and Group III. The cell viability of Group III was higher than that of Group II, and statistically significant differences were observed on the third and fifth days. Also, significant differences were confirmed in Group III on the third and fifth days. Consequently, oxidation heat treatment, among various methods of surface treatment, can be considered as one method to improve properties in biocompatible materials by creating an oxidation layer on Mg-Ca-Mn alloys.