In vitro degradation behavior and cytocompatibility of biodegradable AZ31 alloy with PEO/HT composite coating.
Biodegradable magnesium-based implants have attracted much attention recently in orthopedic applications because of their good mechanical properties and biocompatibility. However, their rapid degradation in vivo will not only reduce their mechanical strength, but also induce some side effects, such as local alkalization and gas cavity, which may lead to a failure of the implant. In this work, a hydroxyapatite (HA) layer was prepared on plasma electrolytic oxidization (PEO) coating by hydrothermal treatment (HT) to fabricate a PEO/HT composite coating on biodegradable AZ31 alloy. The in vitro degradation behaviors of all samples were evaluated in simulated body fluid (SBF) and their surface cytocompatibility was also investigated by evaluating the adhesion and proliferation of osteoblast cells (MC3T3-E1). The results showed that the HA layer consisted of a dense inner layer and a needle-like outer layer, which successfully sealed the PEO coating. The in vitro degradation tests showed that the PEO/HT composite coating improved the corrosion resistance of AZ31 alloy in SBF, presenting nearly no severe local alkalization and hydrogen evolution. The lasting corrosion resistance of the PEO/HT composite coating may attribute to the new hydroxyapatite formation during the degradation process. Moreover, compared with AZ31 alloy and PEO coating, PEO/HT composite coating was more suitable for cells adhesion and proliferation, indicating improved surface cytocompatibility. The results show that the PEO/HT composite coating is promising as protective coating on biodegradable magnesium-based implants to enhance their corrosion resistance as well as improve their surface cytocompatibility for orthopedic applications.
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China.
Peng
P
Tian
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China. Electronic address: xyliu@mail.sic.ac.cn.
Xuanyong
X
Liu
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China.
Chuanxian
C
Ding
D020341:Absorbable Implants; D000497:Alloys / Q000737:chemistry*; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000494:pharmacology; D003343:Corrosion; D017886:Durapatite / Q000737:chemistry*; D004572:Electrolysis; D051379:Mice; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects; D010084:Oxidation-Reduction; D058626:Plasma Gases / Q000737:chemistry; D013499:Surface Properties
D000497:Alloys; D020099:Coated Materials, Biocompatible; C586533:Mg-Al-Zn-Mn-Si-Cu alloy; D058626:Plasma Gases; D017886:Durapatite
Corrosion resistance; Cytocompatibility; Hydroxyapatite; Magnesium alloy; PEO coating