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Advanced Biomaterials and Devices in Medicine
June 2015, Volume 2, Issue 1, pp 32–36
Introducing an ultralight, high-strength, biodegradable Mg-4Li-1Ca alloy
S.S. Nene1,2,3, Y. Estrin1,2,4*, B.P. Kashyap1,3, N. Prabhu1,3, T. Al-Samman5, B.J.C. Luthringer6, R. Willumeit6
1 IITB-Monash Research Academy, Powai, Mumbai, 400076 India
2 Centre for Advanced Hybrid Materials, Department of Materials Engineering, Monash University, Clayton, Victoria, 3800 Australia
3 Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
4 Laboratory of Hybrid Nanostructured Materials, Moscow Institute of Steel and Alloys, Moscow, 119049 Russia
5 Institut für Metallkunde und Metallphysik, RWTH Aachen University, Aachen, 52074 Germany
6 Helmholtz-Zentrum Geesthacht, Institute of Metallic Biomaterials, Geesthacht, D-21502 Germany
* Corresponding author: Prof. Yuri Estrin, e-mail: yuri.estrin@monash.edu
Abstract
Mg-4Li-1Ca ternary alloy produced by melting from two binary master alloys was subjected to two-step rolling undergoing 60% thickness reduction in each. The density of the wrought alloy was found to be 1.56  0.3 gm/cm3—lower than the density of any commercial Mg alloys. Rolling resulted in a remarkable improvement in tensile strength (250 MPa) owing to substantial microstructure refinement and a rather uniform dispersion of second phase particles. Biodegradation behaviour in simulated physiological environments confirmed the formation of a hydroxyapatite layer ensuring good biocompatibility of the alloy. The live/dead staining results with osteoblast cells showed a substantial fraction of live cells upon seven days of culture, which indicates excellent cytocompatibility of the alloy. This was further supported by the scanning electron microscopy evidence. We conclude that the new Mg-4Li-1Ca alloy is a promising material for medical implants possessing a favourable combination of properties, including low density, high strength, and promising cell response.
Keywords: Mg-4Li-1Ca alloy, biodegradation, implant application, cytocompatibility, live-dead staining, two step rolling
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