The Manufacture of Resorbable Suture Material from Magnesium

Abstract

AbstractMagnesium alloys present an alternative to medical cases in which polymeric sutures may not be ideal. To date, no efficient and low‐cost manufacturing process for the fabrication of magnesium‐based sutures can be found. To obtain an alternative, the previously characterised magnesium alloys ZEK100 (98% Mg), AX30 (96.2% Mg), AL36 (91% Mg) and MgCa0.8 (99.2% Mg) were cast, extruded into 30 mm diameter bars and extruded into 0.5 mm diameter wires. To determine the mechanical properties of the wires, grain size measurements, tensile tests as well as qualitative bending tests were carried out. The ZEK100 alloy's wires showed the finest microstructure having grains of 1.2 µm in diameter. Coarser microstructures were observed for MgCa0.8, AX30 and AL36. The alloy ZEK100 had the highest tensile stress (367 MPa) also revealing a brittle behaviour due to its fine microstructure. The tensile test, carried out for AX30 as well as AL36, resulted in comparable high fracture strains (10.6%) and tensile stresses (300 MPa). However, MgCa0.8 showed a tensile strength of 315 MPa and a low strain of 1.6%. Within the qualitative bending test wires made of the alloy AL36 were able to form tight knots, which is a key feature for suture applications. The comparison of the magnesium sutures with commercially available polymeric sutures revealed lower strength and elongation for the magnesium alloys. Yet, the wires exhibited mechanical properties that can meet the requirements of a suture material.