In vitro and in vivo studies on the degradation and biosafety of Mg-Zn-Ca-Y alloy hemostatic clip with the carotid artery of SD rat model

An Mg-Zn-Ca-Y alloy operative clip was developed to overcome the drawbacks of the Ti clips such as ion dissolution inflammation, interference imaging diagnosis, and the potential harm that permanent retention brings to the patient. The structure optimization design of the hemostatic clip was carried out by the finite element numerical simulation method to realize the matching between the structure design and the material properties. Hot extrusion and wire cutting process was used to prepare the Mg-Zn-Ca-Y alloy operative clip. Corrosion degradation behavior of Mg-Zn-Ca-Y alloy in vitro was investigated using electrochemical noise (EN) and immersion test in Simulated body fluid (SBF). The carotid artery of SD rats was clipped using the Mg-Zn-Ca-Y operative clip to evaluate occlusion safety and the complete corrosion degradation behavior and biocompatibility of Mg-Zn-Ca-Y alloy clip in vivo were investigated using micro-computed tomography, histological analysis, and blood biochemical indicators. It was found that the newly designed Mg-Zn-Ca-Y clip can successfully ligate the carotid artery, and no blood leakage occurred after surgery. After eight months, the Mg-Zn-Ca-Y clip degraded utterly. Histological analysis and various blood biochemical parameters in SD rat serum samples collected at different time periods showed no tissue inflammation around the clips.