title: Biodegradable magnesium-hydroxyapatite metal matrix composites.
abstract: Recent studies indicate that there is a high demand to design magnesium alloys with adjustable corrosion rates and suitable mechanical properties. An approach to this challenge might be the application of metal matrix composite (MMC) based on magnesium alloys. In this study, a MMC made of magnesium alloy AZ91D as a matrix and hydroxyapatite (HA) particles as reinforcements have been investigated in vitro for mechanical, corrosive and cytocompatible properties. The mechanical properties of the MMC-HA were adjustable by the choice of HA particle size and distribution. Corrosion tests revealed that HA particles stabilised the corrosion rate and exhibited more uniform corrosion attack in artificial sea water and cell solutions. The phase identification showed that all samples contained hcp-Mg, Mg(17)Al(12), and HA before and after immersion. After immersion in artificial sea water CaCO3 was found on MMC-HA surfaces, while no formation of CaCO3 was found after immersion in cell solutions with and without proteins. Co-cultivation of MMC-HA with human bone derived cells (HBDC), cells of an osteoblasts lineage (MG-63) and cells of a macrophage lineage (RAW264.7) revealed that RAW264.7, MG-63 and HBDC adhere, proliferate and survive on the corroding surfaces of MMC-HA. In summary, biodegradable MMC-HA are cytocompatible biomaterials with adjustable mechanical and corrosive properties.
authors.affiliation: Laboratory for Biomechanics and Biomaterials, Department of Orthopedic Surgery, Hannover Medical School, Anna-von-Borries-Str. 1-7, 30625 Hannover, Germany. f.witte@web.de
authors.forename: Frank
authors.initials: F
authors.lastname: Witte
authors.forename: Frank
authors.initials: F
authors.lastname: Feyerabend
authors.forename: Petra
authors.initials: P
authors.lastname: Maier
authors.forename: Jens
authors.initials: J
authors.lastname: Fischer
authors.forename: Michael
authors.initials: M
authors.lastname: Störmer
authors.forename: Carsten
authors.initials: C
authors.lastname: Blawert
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Dietzel
authors.forename: Norbert
authors.initials: N
authors.lastname: Hort
mesh_terms: D000497:Alloys / Q000737:chemistry; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001673:Biodegradation, Environmental; D002119:Calcium Carbonate / Q000737:chemistry; D002448:Cell Adhesion; D002460:Cell Line; D017886:Durapatite / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D006801:Humans; D008274:Magnesium / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D051379:Mice; D010006:Osteoblasts / Q000378:metabolism; D017356:Synchrotrons; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D008670:Metals; D013778:Tetrazolium Salts; D013844:Thiazoles; D017886:Durapatite; C022616:thiazolyl blue; D002119:Calcium Carbonate; D008274:Magnesium