Publication details

Authors: J., Griebel Adam; E., Schaffer Jeremy; M., Hopkins Tracy; Alaa, Alghalayini; Tinomudaishe, Mkorombindo; O., Ojo Kolade; Zhigang, Xu; J., Little Kevin; K., Pixley Sarah 
Title: An in vitro and in vivo characterization of fine WE43B magnesium wire with varied thermomechanical processing conditions 
Type: Journal Article 
Publisher: Journal of Biomedical Materials Research Part B: Applied Biomaterials 
Year: 2017 
Issue: 2015:00B:000000 
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DOI: 10.1002/jbm.b.34008 
Abstract: Abstract Absorbable implants made of magnesium alloys may revolutionize surgical intervention, and fine magnesium wire will be critical to many applications. Functionally, the wires must have sufficient mechanical properties to withstand implantation and inservice loading, have excellent tissue tolerance, and exhibit an appropriate degradation rate for the application. Alloy chemistry and thermomechanical processing conditions will significantly impact the material's functional performance, but the exact translation of these parameters to implant performance is unclear. With this in mind, fine (127 m) WE43B magnesium alloy wires in five thermomechanical process (TMP) conditions (90% cold work [CW], and 250, 375, 400, and 450C heat treatments) were investigated for their effect on mechanical and corrosion behavior. The TMP conditions gave clear metallurgical differences: transverse grain dimensions ranged from 200 nm (CW) to 3 m (450C), UTS varied from 324 MPa (450C) to 608 MPa (250C), and surgical knotting showed some were suitable (CW, 400C, 450C) while others were not (250C, 350C). In vitro and in vivo corrosion testing yielded interesting and in some cases conflicting results. After 1 month immersion in cell culture medium, wire corrosion was extensive, and TMP conditions altered the macrocorrosion morphology but not the rate or total release of magnesium ions. After 1 month subdermal implantation in mice, all wires were well tolerated and showed very little corrosion (per CT and histology), but differences in localized corrosion were detected between conditions. This study indicates that WE43B wires treated at 450C may be most suitable for surgical knotting procedures. 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017.