Microstructure, Mechanical Properties, Corrosion Behavior, and in Vitro Assessment of Mg-Zn-Cu Alloy for Gastrointestinal Anastomosis Staple Application

Abstract

Magnesium (Mg) is an ideal choice in gastrointestinal anastomosis staples due to its well-known biodegradability and biocompatibility. However, the low strength and poor formability of pure Mg pose challenges in the preparation of wire materials suitable for surgical staples, thereby limiting its application as staples in gastrointestinal surgeries. This study investigates the microstructural, mechanical, corrosion, biocompatibility, and antibacterial properties of Mg-2Zn-xCu alloys (x = 0.1, 0.6, 1.2 wt%) with emphasis on the possible application of Mg-2Zn-0.1Cu alloy wire as a biodegradable surgical staple. Mg-2Zn-0.1Cu alloy exhibits good mechanical properties (UTS of 234 MPa, EL of 17.7%) and low corrosion rate of 5.21 mm year⁻¹ with good biosafety and antibacterial capability. Therefore, this alloy is chosen to prepare Φ0.25 mm wire with an excellent balance between tensile strength (274 MPa) and corrosion resistance. The wire bent at 30° maintains excellent structural integrity after immersion for 14 days. The B-shape staple derived from this wire exhibits a strength of 0.8 N, underscoring the suitability of Mg-2Zn-0.1Cu as an outstanding material for surgical staples.