title: In vivo degradation behavior of Ca-deficient hydroxyapatite coated Mg-Zn-Ca alloy for bone implant application.
abstract: In present paper, an in vivo study was carried out on uncoated and calcium-deficient hydroxyapatite (Ca-def HA) coated Mg-Zn-Ca alloy to investigate the effect of Ca-def HA coating on the degradation behavior and bone response of magnesium substrate. Magnesium alloy rods were implanted into rabbit femora and evaluated during 24 weeks implantation. The characterization of both implants indicates that in vivo degradation of the Ca-def HA coating and magnesium substrate occurs almost simultaneously, and in vivo valid life of the coating is about 8 weeks, after that the degradation rate of the coated implants increases obviously. The main reasons for the Ca-def HA coating degradation can be attributed to its reaction with body fluid and the substitution of Mg(2+) ions in Ca-def HA. Histopathological examinations show that the Ca-def HA coating has good osteoconductivity and is in favor of the formation of more new bone on the surface of magnesium alloy. So the Ca-def HA coating could not only slow down in vivo degradation of magnesium alloy but also improve its bone response.
authors.affiliation: School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, China.
authors.forename: Huanxin
authors.initials: H
authors.lastname: Wang
authors.forename: Shaokang
authors.initials: S
authors.lastname: Guan
authors.forename: Yisheng
authors.initials: Y
authors.lastname: Wang
authors.forename: Hongjian
authors.initials: H
authors.lastname: Liu
authors.forename: Haitao
authors.initials: H
authors.lastname: Wang
authors.forename: Liguo
authors.initials: L
authors.lastname: Wang
authors.forename: Chenxing
authors.initials: C
authors.lastname: Ren
authors.forename: Shijie
authors.initials: S
authors.lastname: Zhu
authors.forename: Kuisheng
authors.initials: K
authors.lastname: Chen
mesh_terms: D000497:Alloys; D000818:Animals; D002118:Calcium / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery; D008274:Magnesium / Q000737:chemistry*; D019736:Prostheses and Implants; D011817:Rabbits; D011859:Radiography; D015032:Zinc / Q000737:chemistry*
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D008274:Magnesium; D015032:Zinc; D002118:Calcium