title: Ex vivo examination of the biocompatibility of biodegradable magnesium via microdialysis in the isolated perfused bovine udder model.
abstract: OBJECTIVE
  Being biodegradable, magnesium is considered a promising future implant material but very little is known about the biocompatibility for the tissues in direct contact with it. In this study, the degradation of pure magnesium implants in the skin of an isolated bovine udder was examined over a period of five hours.
  
  
  METHODS
  Microdialysis technique was used in order to investigate the reactions at the interface of implant and tissue. Pure titanium implants served as control. Degradation behavior and biocompatibility were evaluated via extracellular magnesium ion concentration and PGE2 and TNF alpha served as indicators of inflammation.
  
  
  RESULTS
  Concentrations of 5.5 mmol/l Mg2+ were detected at the beginning, which decreased to a plateau of about 3.5 mmol/l after approximately two and a half hours. PGE2 and TNF alpha concentrations indicated no major inflammatory tissue response to the degradation.
  
  
  CONCLUSIONS
  These results give an idea of the ion burden at the implantation site of degrading magnesium and suggest good biocompatibility even at the tissue-implant interface.
authors.affiliation: Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Foundation, Hannover - Germany. stephan.schumacher@tiho-hannover.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Schumacher
authors.forename: Jessica
authors.initials: J
authors.lastname: Stahl
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bäumer
authors.forename: Jan-Marten
authors.initials: JM
authors.lastname: Seitz
authors.forename: Friedrich-Wilhelm
authors.initials: FW
authors.lastname: Bach
authors.forename: Lars J
authors.initials: LJ
authors.lastname: Petersen
authors.forename: Manfred
authors.initials: M
authors.lastname: Kietzmann
mesh_terms: D020341:Absorbable Implants; D000497:Alloys / Q000737:chemistry / Q000633:toxicity*; D000818:Animals; D002417:Cattle; D015232:Dinoprostone / Q000378:metabolism; D005260:Female; D020007:Implants, Experimental; D066298:In Vitro Techniques; D007249:Inflammation / Q000139:chemically induced* / Q000276:immunology; D018836:Inflammation Mediators / Q000378:metabolism; D008274:Magnesium / Q000737:chemistry / Q000633:toxicity*; D008321:Mammary Glands, Animal / Q000187:drug effects* / Q000276:immunology; D008422:Materials Testing; D017551:Microdialysis; D010477:Perfusion; D011474:Prosthesis Design; D012995:Solubility; D013718:Tensile Strength; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000497:Alloys; D018836:Inflammation Mediators; D014409:Tumor Necrosis Factor-alpha; D008274:Magnesium; D015232:Dinoprostone