title: Enhancement of osteogenesis and biodegradation control by brushite coating on Mg-Nd-Zn-Zr alloy for mandibular bone repair.
abstract: To diminish incongruity between bone regeneration and biodegradation of implant magnesium alloy applied for mandibular bone repair, a brushite coating was deposited on a matrix of a Mg-Nd-Zn-Zr (hereafter, denoted as JDBM) alloy to control the degradation rate of the implant and enhance osteogenesis of the mandible bone. Both in vitro and in vivo evaluations were carried out in the present work. Viability and adhesion assays of rabbit bone marrow mesenchyal stem cells (rBM-MSCs) were applied to determine the biocompatibility of a brushite-coated JDBM alloy. Osteogenic gene expression was characterized by quantitative real-time polymerase chain reaction (RT-PCR). Brushite-coated JDBM screws were implanted into mandible bones of rabbits for 1, 4, and 7 months, respectively, using 316L stainless steel screws as a control group. In vivo biodegradation rate was determined by synchrotron radiation X-ray microtomography, and osteogenesis was observed and evaluated using Van Gieson's picric acid-fuchsin. Both the naked JDBM and brushite-coated JDBM samples revealed adequate biosafety and biocompatibility as bone repair substitutes. In vitro results showed that brushite-coated JDBM considerably induced osteogenic differentiation of rBM-MSCs. And in vivo experiments indicated that brushite-coated JDBM screws presented advantages in osteoconductivity and osteogenesis of mandible bone of rabbits. Degradation rate was suppressed at a lower level at the initial stage of implantation when new bone tissue formed. Brushite, which can enhance oeteogenesis and partly control the degradation rate of an implant, is an appropriate coating for JDBM alloys used for mandibular repair. The Mg-Nd-Zn-Zr alloy with brushite coating possesses great potential for clinical applications for mandibular repair.
authors.affiliation: National Engineering Research Center of Light Alloys Net Forming and State Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University , Shanghai 200240, People's Republic of China.
authors.forename: Xingmin
authors.initials: X
authors.lastname: Guan
authors.forename: Meiping
authors.initials: M
authors.lastname: Xiong
authors.forename: Feiyue
authors.initials: F
authors.lastname: Zeng
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.forename: Lingdi
authors.initials: L
authors.lastname: Yang
authors.forename: Han
authors.initials: H
authors.lastname: Guo
authors.forename: Jialin
authors.initials: J
authors.lastname: Niu
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Chenxin
authors.initials: C
authors.lastname: Chen
authors.forename: Jia
authors.initials: J
authors.lastname: Pei
authors.forename: Hua
authors.initials: H
authors.lastname: Huang
authors.forename: Guangyin
authors.initials: G
authors.lastname: Yuan
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000737:chemistry / Q000627:therapeutic use*; D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects*; D001842:Bone and Bones; D002130:Calcium Phosphates / Q000737:chemistry; D002454:Cell Differentiation / Q000187:drug effects; D008334:Mandible / Q000187:drug effects / Q000254:growth & development; D010012:Osteogenesis / Q000187:drug effects*; D011817:Rabbits; D012394:Rosaniline Dyes; D013193:Stainless Steel / Q000737:chemistry
chemical_list: D000497:Alloys; D002130:Calcium Phosphates; C571250:Mg-Nd-Zn-Zr alloy; D012394:Rosaniline Dyes; D013193:Stainless Steel; C494366:calcium phosphate, dibasic, dihydrate
keywords: Mg−Nd−Zn−Zr alloy; brushite coating; degradation control; mandibular repair; synchrotron radiation