In vivo study of microarc oxidation coated Mg alloy as a substitute for bone defect repairing: degradation behavior, mechanical properties, and bone response

Publication date: Available online 23 May 2019Source: Colloids and Surfaces B: BiointerfacesAuthor(s): Yunfeng Wu, Yaming Wang, Dewei Zhao, Nan Zhang, Hongyu Li, Junlei Li, Yongxuan Wang, Ying Zhao, Jinglong Yan, Yu ZhouAbstractLarge segmental bone defect healing remains a great challenge in clinic. Limited by the source of autograft, bone graft substitute tends to be the research focus. In the present study, we propose a strategy by using microarc oxidation (MAO) coated magnesium scaffold as a large segmental bone graft substitute, utilizing its combination of strength, degradability, and controllable corrosion rate. Bare substrate, 10 μm and 20 μm thick MAO coated Mg scaffolds were implanted into ulna bone of New Zealand white rabbits, employing a 15 mm wide bone defect model. The biocompatibility and in vivo degradation of the implants, the bone defect healing response, and mechanical properties of the injured bone were investigated. The surface cytocompatibility evaluation results show that the MAO coated Mg are more suitable for cell proliferation. Micro-CT results show that abundant new bone formed and initially bridged the 15 mm gap at 8 weeks. Histological results indicate the newly formed bone was full of maturation at 12 weeks. Three point bending tests reveal that the injured bone possessed sufficient mechanical strength after 12 weeks. A 3-step in vivo degradation mechanism was proposed for the implants. In summary, we observed an actual trial of 15 mm...
Source: Colloids and Surfaces B: Biointerfaces - Category: Biochemistry Source Type: research