title: In vitro and in vivo evaluations on osteogenesis and biodegradability of a β-tricalcium phosphate coated magnesium alloy.
abstract: Magnesium (Mg) alloys have been demonstrated to be potential orthopedic implants due to their biodegradability in vivo. To enhance its corrosion resistance and improve its osteogenesis, β-tricalcium phosphate (β-TCP) was coated on a Mg alloy (Mg-3AI-1Zn) by phosphating process. In vitro, the human osteosarcoma cell line (SaOS-2) showed significantly good adherence and proliferation on the surface of the β-TCP coated Mg alloy after 24-h incubation. The growth factor bone morphogenetic protein 2 (BMP-2) was highly expressed in SaOS-2 cultured with the β-TCP coated Mg alloy by Western blot analysis (p < 0.05). In vivo, the newborn bone at the implant/bone interface was formed at week 1 and matured at week 4 postimplantation. Villous tissue was found at the implant/bone interface at week 12 postimplantation. The contents of phosphorus and calcium on the surface of the β-TCP coated Mg alloy were decreased at week 4 and week 12 postimplantation, respectively. Immunohistochemical analysis of the experiment results demonstrated that the β-TCP coated Mg alloy implants provided a high BMP-2 expression during the first 4 weeks postimplantation. Compared with the naked Mg alloy which was degraded for 33% in vivo, only 17% of the β-TCP coated Mg alloy was degraded at week 12 postimplantation (p < 0.05). The in vitro cell tests showed that the β-TCP coating provided the Mg alloy with a significantly better surface cytocompatibility, and in vivo results also confirmed that the β-TCP coating exhibited greatly improved osteoconductivity and osteogenesis in the early 12 weeks postoperation period. Moreover, in vivo experiment demonstrated that the β-TCP coating layer could slow down the degradation of the naked Mg alloy at the early stage of implantation.
authors: Department of Orthopedic Surgery, First Affiliated Hospital, China Medical University, Shenyang 110001, China.
authors: Hongwei
authors: H
authors: Chai
authors: Lei
authors: L
authors: Guo
authors: Xiantao
authors: X
authors: Wang
authors: Xiaoyu
authors: X
authors: Gao
authors: Kui
authors: K
authors: Liu
authors: Yuping
authors: Y
authors: Fu
authors: Junlin
authors: J
authors: Guan
authors: Lili
authors: L
authors: Tan
authors: Ke
authors: K
authors: Yang
mesh_terms: D000497:Alloys / Q000494:pharmacology*; D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism; D001842:Bone and Bones / Q000187:drug effects / Q000473:pathology; D002130:Calcium Phosphates / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D006801:Humans; D008856:Microscopy, Fluorescence; D010012:Osteogenesis / Q000187:drug effects*; D019736:Prostheses and Implants; D017208:Rats, Wistar; D013052:Spectrometry, X-Ray Emission; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; C586533:Mg-Al-Zn-Mn-Si-Cu alloy; C485817:beta-tricalcium phosphate