Document Type
Article
Publication Date
2-28-2018
Department
Department of Biomedical Engineering; Department of Materials Science and Engineering
Abstract
Efforts to develop metallic zinc for biodegradable implants have significantly advanced following an earlier focus on magnesium (Mg) and iron (Fe). Mg and Fe base alloys experience an accelerated corrosion rate and harmful corrosion products, respectively. The corrosion rate of pure Zn, however, may need to be modified from its reported ~20 µm/year penetration rate, depending upon the intended application. The present study aimed at evaluating the possibility of using Fe as a relatively cathodic biocompatible alloying element in zinc that can tune the implant degradation rate via microgalvanic effects. The selected Zn–1.3wt %Fe alloy composition produced by gravity casting was examined in vitro and in vivo. The in vitro examination included immersion tests, potentiodynamic polarization and impedance spectroscopy, all in a simulated physiological environment (phosphate-buffered saline, PBS) at 37 °C. For the in vivo study, two cylindrical disks (seven millimeters diameter and two millimeters height) were implanted into the back midline of male Wister rats. The rats were examined post implantation in terms of weight gain and hematological characteristics, including red blood cell (RBC), hemoglobin (HGB) and white blood cell (WBC) levels. Following retrieval, specimens were examined for corrosion rate measurements and histological analysis of subcutaneous tissue in the implant vicinity. In vivo analysis demonstrated that the Zn–1.3%Fe implant avoided harmful systemic effects. The in vivo and in vitro results indicate that the Zn–1.3%Fe alloy corrosion rate is significantly increased compared to pure zinc. The relatively increased degradation of Zn–1.3%Fe was mainly related to microgalvanic effects produced by a secondary Zn11Fe phase.
Publication Title
Metals
Recommended Citation
Kafri, A.,
Ovadia, S.,
Goldman, J.,
Drelich, J. W.,
&
Aghion, E.
(2018).
The suitability of Zn–1.3% Fe alloy as a biodegradable implant material.
Metals,
8(3).
http://doi.org/10.3390/met8030153
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/150
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Version
Publisher's PDF
Included in
Biomedical Engineering and Bioengineering Commons, Materials Science and Engineering Commons
Publisher's Statement
©2018 by the authors. Licensee MDPI, Basel, Switzerland. Article deposited here in compliance with publisher policies. Publisher's version of record: https://doi.org/10.3390/met8030153