title: The formation of an organic coat and the release of corrosion microparticles from metallic magnesium implants.
abstract: Magnesium alloys have been proposed as prospective degradable implant materials. To elucidate the complex interactions between the corroding implants and the tissue, magnesium implants were analyzed in a mouse model and the response was compared to that induced by Ti and by the resorbable polymer polyglactin, respectively. One month after implantation, distinct traces of corrosion were apparent but the magnesium implants were still intact, whereas resorbable polymeric wound suture implants were already fragmented. Analysis of magnesium implants 2weeks after implantation by energy-dispersive X-ray spectroscopy indicated that magnesium, oxygen, calcium and phosphate were present at the implant surface. One month after implantation, the element composition of the outermost layer of the implant was indicative of tissue without detectable levels of magnesium, indicating a protective barrier function of this organic layer. In agreement with this notion, gene expression patterns in the surrounding tissue were highly similar for all implant materials investigated. However, high-resolution imaging using energy-filtered transmission electron microscopy revealed magnesium-containing microparticles in the tissue in the proximity of the implant. The release of such corrosion particles may contribute to the accumulation of calcium phosphate in the nearby tissue and to bone conductive activities of magnesium implants.
authors.affiliation: Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124 Braunschweig, Germany.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Badar
authors.forename: Heinrich
authors.initials: H
authors.lastname: Lünsdorf
authors.forename: Florian
authors.initials: F
authors.lastname: Evertz
authors.forename: Muhammad Imran
authors.initials: MI
authors.lastname: Rahim
authors.forename: Birgit
authors.initials: B
authors.lastname: Glasmacher
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Hauser
authors.forename: Peter P
authors.initials: PP
authors.lastname: Mueller
mesh_terms: D020341:Absorbable Implants; D000327:Adsorption; D000818:Animals; D003343:Corrosion; D005260:Female; D008274:Magnesium / Q000032:analysis / Q000737:chemistry*; D008422:Materials Testing; D051379:Mice; D008807:Mice, Inbred BALB C; D008863:Microspheres; D009930:Organic Chemicals / Q000138:chemical synthesis*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D009930:Organic Chemicals; D008274:Magnesium