Effects of grain refinement on the biocorrosion and in vitro bioactivity of magnesium.
Magnesium is a new class of biodegradable metals potentially suitable for bone fracture fixation due to its suitable mechanical properties, high degradability and biocompatibility. However, rapid corrosion and loss in mechanical strength under physiological conditions render it unsuitable for load-bearing applications. In the present study, grain refinement was implemented to control bio-corrosion demonstrating improved in vitro bioactivity of magnesium. Pure commercial magnesium was grain refined using different amounts of zirconium (0.25 and 1.0 wt.%). Corrosion behavior was studied by potentiodynamic polarization (PDP) and mass loss immersion tests demonstrating corrosion rate decrease with grain size reduction. In vitro biocompatibility tests conducted by MC3T3-E1 pre-osteoblast cells and measured by DNA quantification demonstrate significant increase in cell proliferation for Mg-1 wt.% Zr at day 5. Similarly, alkaline phosphatase (ALP) activity was higher for grain refined Mg. Alloys were also tested for ability to support osteoclast differentiation using RAW264.7 monocytes with receptor activator of nuclear factor kappa-β ligand (RANKL) supplemented cell culture. Osteoclast differentiation process was observed to be severely restricted for smaller grained Mg. Overall, the results indicate grain refinement to be useful not only for improving corrosion resistance of Mg implants for bone fixation devices but also potentially modulate bone regeneration around the implant.
Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261, USA.
Partha
P
Saha
Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261, USA.
Mangal
M
Roy
Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261, USA; Center for Complex Engineered Multifunctional Materials, University of Pittsburgh, Pittsburgh, PA 15261, USA.
Moni Kanchan
MK
Datta
Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261, USA.
Boeun
B
Lee
Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261, USA; Center for Complex Engineered Multifunctional Materials, University of Pittsburgh, Pittsburgh, PA 15261, USA; Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, PA 15261, USA; Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, PA 15261, USA; School of Dental Medicine, University of Pittsburgh, PA 15261, USA; McGowan Institute of Regenerative Medicine, University of Pittsburgh, PA 15261, USA. Electronic address: pkumta@pitt.edu.
Prashant N
PN
Kumta
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001826:Body Fluids / Q000737:chemistry*; D018786:Bone Substitutes / Q000138:chemical synthesis* / Q000494:pharmacology; D019245:Compressive Strength; D003343:Corrosion; D008274:Magnesium / Q000737:chemistry* / Q000494:pharmacology; D008422:Materials Testing; D051379:Mice; D010010:Osteoclasts / Q000187:drug effects; D010084:Oxidation-Reduction; D000067996:RAW 264.7 Cells; D013314:Stress, Mechanical; D015040:Zirconium / Q000737:chemistry* / Q000494:pharmacology
D001672:Biocompatible Materials; D018786:Bone Substitutes; D015040:Zirconium; D008274:Magnesium
ALP; Biocompatibility; Biocorrosion; Grain refinement; Magnesium; TRAP assay