title: In vitro and in vivo comparison of binary Mg alloys and pure Mg.
abstract: Biodegradable materials are under investigation due to their promising properties for biomedical applications as implant material. In the present study, two binary magnesium (Mg) alloys (Mg2Ag and Mg10Gd) and pure Mg (99.99%) were used in order to compare the degradation performance of the materials in in vitro to in vivo conditions. In vitro analysis of cell distribution and viability was performed on discs of pure Mg, Mg2Ag and Mg10Gd. The results verified viable pre-osteoblast cells on all three alloys and no obvious toxic effect within the first two weeks. The degradation rates in in vitro and in vivo conditions (Sprague-Dawley® rats) showed that the degradation rates differ especially in the 1st week of the experiments. While in vitro Mg2Ag displayed the fastest degradation rate, in vivo, Mg10Gd revealed the highest degradation rate. After four weeks of in vitro immersion tests, the degradation rate of Mg2Ag was significantly reduced and approached the values of pure Mg and Mg10Gd. Interestingly, after 4 weeks the estimated in vitro degradation rates approximate in vivo values. Our systematic experiment indicates that a correlation between in vitro and in vivo observations still has some limitations that have to be considered in order to perform representative in vitro experiments that display the in vivo situation.
authors.affiliation: Department of Orthopedics and Orthopedic Surgery, Medical University Graz, 8036 Graz, Austria.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Myrissa
authors.affiliation: Institute of Materials Research, Division Metallic Biomaterials, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany.
authors.forename: Nezha Ahmad
authors.initials: NA
authors.lastname: Agha
authors.affiliation: Institute of Materials Research, Division Metallic Biomaterials, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Orthopedics and Orthopedic Surgery, Medical University Graz, 8036 Graz, Austria.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Martinelli
authors.affiliation: Department of Orthopedics and Orthopedic Surgery, Medical University Graz, 8036 Graz, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Eichler
authors.affiliation: Institute of Materials Research, Division Metallic Biomaterials, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany.
authors.forename: Gábor
authors.initials: G
authors.lastname: Szakács
authors.affiliation: Department of Orthopedics and Orthopedic Surgery, Medical University Graz, 8036 Graz, Austria. Electronic address: Claudia.Kleinhans@medunigraz.at.
authors.forename: Claudia
authors.initials: C
authors.lastname: Kleinhans
authors.affiliation: Institute of Materials Research, Division Metallic Biomaterials, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany.
authors.forename: Regine
authors.initials: R
authors.lastname: Willumeit-Römer
authors.affiliation: Department of Experimental Neurotraumatology, Medical University Graz, 8036 Graz, Austria.
authors.forename: Ute
authors.initials: U
authors.lastname: Schäfer
authors.affiliation: Department of Orthopedics and Orthopedic Surgery, Medical University Graz, 8036 Graz, Austria.
authors.forename: Annelie-Martina
authors.initials: AM
authors.lastname: Weinberg
mesh_terms: D000497:Alloys / Q000737:chemistry* / Q000494:pharmacology; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D008274:Magnesium / Q000737:chemistry* / Q000494:pharmacology; D008297:Male; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D019736:Prostheses and Implants; D051381:Rats; D017207:Rats, Sprague-Dawley; D055114:X-Ray Microtomography
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D008274:Magnesium
keywords: Biodegradable implants; Degradation rate; Magnesium alloys; in vitro; in vivo