Investigation on the in vitro cytocompatibility of Mg-Zn-Y-Nd-Zr alloys as degradable orthopaedic implant materials

Abstract

Mg-Zn-Y-Nd-Zr alloy has been developed as a new type of biodegradable orthopaedic implant material by the authors' research group with its excellent mechanical properties and controllable degradation rate. In this study, the cytocompatibility of Mg-Zn-Y-Nd-Zr alloy was systematically evaluated through in vitro cell culture method. MTT assay was applied to evaluate the cytotoxicity of Mg-Zn-Y-Nd-Zr alloy and no toxic effect was observed on L929 and MC3T3-E1 cells followed the protocol of ISO 10993 standard. Considering the potential ion accumulation in the bony environment, this study further investigated the cytotoxic effect of accumulated metallic ions during the alloy degradation by extending the extract preparation time. When the extract preparation time was prolonged to 1440 h, the accumulated metallic ions leaded to severe cell apoptosis, of which the combined ion concentration was determined as 39.5-65.8 µM of Mg, 3.5-5.9 µM of Zn, 0.44-0.74 µM of Y, 0.3-0.52 µM of Nd and 0.11-0.18 µM of Zr for L929, and 65.8-92.2 µM of Mg, 5.9-8.3 µM of Zn, 0.74-1.04 µM of Y, 0.52-0.73 µM of Nd and 0.18-0.25 µM of Zr for MC3T3-E1 cells. Besides the cell viability assessment, high expression of ALP activity and calcified nodules implied that metal elements in Mg-Zn-Y-Nd-Zr alloys can promote the osteogenic differentiation. Hence, excellent cytocompatibility has equipped Mg-Zn-Y-Nd-Zr alloy as a promising candidate for orthopaedic implant application, which can remarkably guide the magnesium-based alloy design and provide scientific evidence for clinical practice in future.

Mg-, Zn-, and Fe-Based Alloys With Antibacterial Properties as Orthopedic Implant Materials

“…However, the clinical application of Mg-Zn alloys is restricted due to rapid degradation ( González et al, 2012 ). Several studies have put their effort into adding the third kind of alloying element for further modification of Mg-Zn alloys ( Fazel Anvari-Yazdi et al, 2016 ; Bian et al, 2018 ; Prakash et al, 2018 ; Song et al, 2018 ; Miao et al, 2019 ). With the increasing attention to the antibacterial properties of alloys, the antimicrobial performance of some developed Mg-Zn alloys started to be explored ( Zhang et al, 2020 ).…”

Investigation of Mg–xLi–Zn alloys for potential application of biodegradable bone implant materials

“…The viability of MG-63 cultured with each extract solution was examined and calculated by a typical MTT assay [40]. The alkaline phosphatase (ALP) activity of MG-63 cultured with each extract solution was also examined to evaluate the cell behavior [41].…”

Preparing a Bioactive (Chitosan/Sodium Hyaluronate)/SrHA Coating on Mg–Zn–Ca Alloy for Orthopedic Implant Applications

“…More specifically, they possess similar mechanical properties to human bone tissue, in addition to outstanding biodegradable properties (Zheng et al, 2010;Hiromoto et al, 2021;Wang et al, 2021). Mg-based alloys used as an implant material have great potential, but the uncontrollable rapid degradation rate of the substrate remains a significant concern (Hermawan et al, 2010;Song et al, 2018). To enhance the corrosion resistance and bioactivity of Mg alloys, calcium phosphate (CaP) has been widely studied as the coating ingredient of the Mg alloy substrate (Wang et al, 2010;Gao et al, 2011a;Gao et al, 2011b;Feng et al, 2017).…”