title: Alkalization is responsible for antibacterial effects of corroding magnesium.
abstract: Magnesium alloys are presently investigated as potential medical implant materials for temporary applications. Magnesium has been reported to have antibacterial activities and could therefore be used to prevent antibiotic treatment-resistant bacterial implant infections. For characterizing the effects of magnesium on infectious bacteria, bioluminescent S. aureus or P. aeruginosa were employed. The proliferation of both types of bacteria was suppressed in the presence of metallic magnesium and also in aqueous magnesium corrosion extracts. Of the two soluble corrosion products, magnesium ions were well tolerated while antibacterial activities correlated with increased pH levels of the supernatants. The alkaline pH alone was sufficient for the antibacterial effects which were completely abolished when the pH of the corrosion supernatants was neutralized. These results demonstrate that pH increases are necessary and sufficient for the antibacterial activity of metallic magnesium. In an animal model magnesium implants showed an enhanced but variable resistance to bacterial colonization.
authors.affiliation: Helmholtz Centre for Infection Research, Inhoffenstrasse 7, Braunschweig, 38124, Germany.
authors.forename: Muhammad Imran
authors.initials: MI
authors.lastname: Rahim
authors.affiliation: Institute of Materials Science, Leibniz University Hannover, an Der Universität 2, Garbsen, 30823, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Eifler
authors.affiliation: Helmholtz Centre for Infection Research, Inhoffenstrasse 7, Braunschweig, 38124, Germany.
authors.forename: Bushra
authors.initials: B
authors.lastname: Rais
authors.affiliation: Helmholtz Centre for Infection Research, Inhoffenstrasse 7, Braunschweig, 38124, Germany.
authors.forename: Peter P
authors.initials: PP
authors.lastname: Mueller
mesh_terms: D000468:Alkalies / Q000737:chemistry*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D003343:Corrosion; D004195:Disease Models, Animal; D005260:Female; D006863:Hydrogen-Ion Concentration; D021621:Imaging, Three-Dimensional; D007477:Ions; D008274:Magnesium / Q000494:pharmacology*; D008807:Mice, Inbred BALB C; D008826:Microbial Sensitivity Tests; D016459:Prosthesis-Related Infections / Q000188:drug therapy; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012995:Solubility; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000468:Alkalies; D000900:Anti-Bacterial Agents; D007477:Ions; D008274:Magnesium
keywords: antibacterial implant; degradable implant material; implant infection; magnesium