title: Tailoring the degradation and biological response of a magnesium-strontium alloy for potential bone substitute application.
abstract: Bone defects are very challenging in orthopedic practice. There are many practical and clinical shortcomings in the repair of the defect by using autografts, allografts or xenografts, which continue to motivate the search for better alternatives. The ideal bone grafts should provide mechanical support, fill osseous voids and enhance the bone healing. Biodegradable magnesium-strontium (Mg-Sr) alloys demonstrate good biocompatibility and osteoconductive properties, which are promising biomaterials for bone substitutes. The aim of this study was to evaluate and pair the degradation of Mg-Sr alloys for grafting with their clinical demands. The microstructure and performance of Mg-Sr alloys, in vitro degradation and biological properties including in vitro cytocompatibility and in vivo implantation were investigated. The results showed that the as-cast Mg-Sr alloy exhibited a rapid degradation rate compared with the as-extruded alloy due to the intergranular distribution of the second phase and micro-galvanic corrosion. However, the initial degradation could be tailored by the coating protection, which was proved to be cytocompatible and also suitable for bone repair observed by in vivo implantation. The integrated fracture calluses were formed and bridged the fracture gap without gas bubble accumulation, meanwhile the substitutes simultaneously degraded. In conclusion, the as-cast Mg-Sr alloy with coating is potential to be used for bone substitute alternative.
authors.affiliation: Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China; Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Han
authors.affiliation: Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China. Electronic address: pwan@imr.ac.cn.
authors.forename: Peng
authors.initials: P
authors.lastname: Wan
authors.affiliation: Shengjing Hospital of China Medical University, 36 Sanhao Street, Shenyang 100004, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Ge
authors.affiliation: Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
authors.forename: Xinmin
authors.initials: X
authors.lastname: Fan
authors.affiliation: Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Tan
authors.affiliation: Shengjing Hospital of China Medical University, 36 Sanhao Street, Shenyang 100004, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Li
authors.affiliation: Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China. Electronic address: kyang@imr.ac.cn.
authors.forename: Ke
authors.initials: K
authors.lastname: Yang
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000497:Alloys / Q000494:pharmacology*; D000818:Animals; D018786:Bone Substitutes / Q000494:pharmacology*; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000187:drug effects / Q000601:surgery; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D020099:Coated Materials, Biocompatible / Q000494:pharmacology; D003343:Corrosion; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D051379:Mice; D010084:Oxidation-Reduction; D056951:Photoelectron Spectroscopy; D019919:Prosthesis Implantation; D011817:Rabbits; D011859:Radiography; D051381:Rats; D013052:Spectrometry, X-Ray Emission; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; C573915:Mg-Sr alloy; D000469:Alkaline Phosphatase
keywords: Bone substitutes; Degradation; In vivo; Magnesium alloys; Strontium