title: In vitro corrosion and cytocompatibility of ZK60 magnesium alloy coated with hydroxyapatite by a simple chemical conversion process for orthopedic applications.
abstract: Magnesium and its alloys--a new class of degradable metallic biomaterials-are being increasingly investigated as a promising alternative for medical implant and device applications due to their advantageous mechanical and biological properties. However, the high corrosion rate in physiological environments prevents the clinical application of Mg-based materials. Therefore, the objective of this study was to develop a hydroxyapatite (HA) coating on ZK60 magnesium alloy substrates to mediate the rapid degradation of Mg while improving its cytocompatibility for orthopedic applications. A simple chemical conversion process was applied to prepare HA coating on ZK60 magnesium alloy. Surface morphology, elemental compositions, and crystal structures were characterized using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction, respectively. The corrosion properties of samples were investigated by immersion test and electrochemical test. Murine fibroblast L-929 cells were harvested and cultured with coated and non-coated ZK60 samples to determine cytocompatibility. The degradation results suggested that the HA coatings decreased the degradation of ZK60 alloy. No significant deterioration in compression strength was observed for all the uncoated and coated samples after 2 and 4 weeks' immersion in simulated body fluid (SBF). Cytotoxicity test indicated that the coatings, especially HA coating, improved cytocompatibility of ZK60 alloy for L929 cells.
authors.affiliation: Affiliated Tongji Hospital, Tongji University, Shanghai 201804, China. weilu@tongji.edu.cn.
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.forename: Ping
authors.initials: P
authors.lastname: Huang
authors.forename: Caiwen
authors.initials: C
authors.lastname: Ou
authors.forename: Kaikai
authors.initials: K
authors.lastname: Li
authors.forename: Biao
authors.initials: B
authors.lastname: Yan
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
mesh_terms: D000497:Alloys / Q000737:chemistry*; D000818:Animals; D002130:Calcium Phosphates / Q000737:chemistry; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D003343:Corrosion; D017886:Durapatite / Q000737:chemistry*; D055664:Electrochemical Techniques; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D051379:Mice; D013052:Spectrometry, X-Ray Emission
chemical_list: D000497:Alloys; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; C586529:ZK60 magnesium alloy; D017886:Durapatite; C494366:calcium phosphate, dibasic, dihydrate