Biodegradable Fe‐Zn Alloy Microtubes with Good Mechanical Properties, Degradability, and Cytocompatibility Prepared by Electrodeposition

Abstract

Biodegradable iron‐based alloys show significant potential for use in degradable vascular stents due to their excellent mechanical properties and good biocompatibility. However, their application is limited by slow corrosion degradation rates. In this study, iron‐based microtubes alloyed with Zn are fabricated through cathode‐rotated electrodeposition, resulting in accelerated degradation rates. The microstructure, mechanical properties, corrosion behavior, and cytocompatibility of the Fe‐Zn alloy microtubes are systematically investigated. Results show that the Fe‐Zn alloy microtubes have submicron‐sized equiaxed grains and micron‐sized columnar grains. These alloys exhibit excellent mechanical properties, the ultimate tensile strengths of Fe‐2.8Zn and Fe‐5.0Zn alloys are 493 and 525 MPa, respectively, with elongations of 12.2% and 9.8%. Zn is incorporated into the α‐Fe matrix as a solid solution, enhancing electrochemical activity. After 28 days of immersion in simulated body fluid (SBF), Fe‐Zn alloys with up to 5 wt.% Zn exhibit a relatively uniform degradation pattern with corrosion rates exceeding 0.150 mm y−1. Electrochemical tests and immersion experiments reveal the corrosion product formation process and mechanisms. In vitro tests confirm no adverse effects on endothelial cell viability. Analysis shows that Fe‐Zn alloy microtubes, with regulated corrosion behavior and good mechanical properties, are promising candidates for biodegradable vascular stents.