Fabrication, microstructure, and properties of a biodegradable Mg-Zn-Ca clip.

An Mg-Zn-Ca alloy biodegradable clip was fabricated by combining hot extrusion and blanking processing. Microstructure evolution was investigated by optical microscopy and electron backscattering diffraction and the occlusion properties of Mg-Zn-Ca alloy clip were evaluated in vitro and in vivo. It was found that the as-extruded Mg-Zn-Ca alloy exhibited a typical fiber microstructure. After blanking, the basal texture intensity increased because of the work hardening effect. Subsequent annealing treatment of the blanking clip can significantly weaken the texture while improving the ductility of the Mg-Zn-Ca alloy. It was found that Mg-Zn-Ca clips can maintain closure performance for 2 weeks in in vitro immersion tests while in vivo tests indicated that the Mg-3Zn-0.2Ca alloy clips fabricated by this preparation processing successfully occluded the blood vessels. These results suggest that the developed Mg-3Zn-0.2Ca alloy clip is a suitable candidate for biodegradable soft tissue fixation devices such as surgical clips.