title: In vitro corrosion resistance and cytocompatibility of nano-hydroxyapatite reinforced Mg-Zn-Zr composites.
abstract: Due to good biocompatibility and mechanical properties, magnesium (Mg) and its alloys are considered promising degradable materials for orthopedic applications. In this work, a Mg metal matrix composite (MMC) was fabricated using Mg-2.9Zn-0.7Zr alloy as the matrix and 1 wt% nano-hydroxyapatite (n-HA) particles as reinforcements. In vitro corrosion behavior and cytocompatibility of a Mg-Zn-Zr/n-HA composite and a Mg-Zn-Zr alloy were investigated. In contrast with the Mg-Zn-Zr alloy, the MMC has better properties. The average corrosion rate of MMC is 0.75 mm/yr after immersion in simulated body fluid (SBF) for 20 days, and the surface of MMC is covered with white Ca-P precipitates. The electrochemical test results show that the corrosion potential (E(corr)) of MMC increases to -1.615 V and its polarization resistance (R(p)) is 2.56 KOmega with the addition of n-HA particles. The co-cultivation of MMC with osteoblasts results in the adhesion and proliferation of cells on the surface of the composite. The maximum cell density is calculated to be (1.85+/-0.15) x 10(4)/l after 5 days of co-culture with osteoblasts. The average cell numbers for two groups after culturing for 3 and 5 days (P<0.05) are significantly different. All the results demonstrate that the Mg-Zn-Zr/n-HA composite can be potentially used as biodegradable bone fixation material.
authors.affiliation: School of Materials Science and Engineering, Tianjin University of Technology, Tianjin, China.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Ye
authors.forename: Minfang
authors.initials: M
authors.lastname: Chen
authors.forename: Meng
authors.initials: M
authors.lastname: Yang
authors.forename: Jun
authors.initials: J
authors.lastname: Wei
authors.forename: Debao
authors.initials: D
authors.lastname: Liu
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000737:chemistry; D000818:Animals; D000831:Animals, Newborn; D001826:Body Fluids / Q000502:physiology; D018786:Bone Substitutes / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology; D003343:Corrosion; D017886:Durapatite / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology; D008274:Magnesium / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology; D008422:Materials Testing; D053761:Nanocomposites / Q000009:adverse effects / Q000737:chemistry*; D009984:Orthopedic Fixation Devices; D010006:Osteoblasts / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013499:Surface Properties; D015032:Zinc / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology; D015040:Zirconium / Q000009:adverse effects / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000497:Alloys; D018786:Bone Substitutes; D020099:Coated Materials, Biocompatible; D017886:Durapatite; D015040:Zirconium; D008274:Magnesium; D015032:Zinc