title: Bone-like matrix formation on magnesium and magnesium alloys.
abstract: Mg metal and its alloys have promise as a biocompatible, degradable biomaterials. This work evaluates the potential of in vitro cell culture work with osteoblast-like cells on Mg based materials, and investigates cell differentiation and growth on Mg alloyed with various non-toxic or low-toxicity elements. Mg based substrates support the adhesion, differentiation and growth of stromal cells towards an osteoblast-like phenotype with the subsequent production of a bone like matrix under in vitro conditions. No significant difference in the final tissue layer is observed on pure Mg, an AZ21 alloy or a 0.5 wt% Ca alloy. Only a 0.8 wt% Ca alloy which shows complete structural disintegration shows minimal cell growth. Due to association of non-soluble degradation products formed when Mg is incubated in physiological-like fluid, mass changes typically used to report Mg degradation are not viable estimates of degradation. Methods quantifying the time dependent change in the mechanical integrity of samples as a function of incubation time are required for a proper assessment of Mg degradation. We conclude that in vitro cell culture of bone cells on Mg substrates is expected to be a viable screening technique to assess the relative biological activity of Mg-based materials.
authors.affiliation: Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, New Zealand. alexis.pietak@gmail.com
authors.forename: Alexis
authors.initials: A
authors.lastname: Pietak
authors.forename: Patricia
authors.initials: P
authors.lastname: Mahoney
authors.forename: George J
authors.initials: GJ
authors.lastname: Dias
authors.forename: Mark P
authors.initials: MP
authors.lastname: Staiger
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000497:Alloys; D000818:Animals; D001842:Bone and Bones / Q000378:metabolism; D002118:Calcium / Q000737:chemistry; D002448:Cell Adhesion; D002454:Cell Differentiation; D049109:Cell Proliferation; D008274:Magnesium / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000378:metabolism; D010641:Phenotype; D051381:Rats; D017154:Stromal Cells / Q000166:cytology; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D000497:Alloys; D000469:Alkaline Phosphatase; D008274:Magnesium; D002118:Calcium