Analysis And Research Of Biological Performance Of Mg-Zn-Sr Alloy And Preparation Of Biofragmentable Anastomosis Ring Made By It

Objective:Investigate Mg-Zn-Sr alloy’s microstructure, mechanical properties and in vitro corrosion behavior of the microstructure and find changes of mechanical properties, corrosion resistance brought by Sr in order to find better mechanical properties and corrosion resistance magnesium alloy;to evaluate biocompatibility and biological safety of ternary Mg-Zn-Sr magnesium alloy by in vitro and in vivo experiment; to describe the advantage by the assessment of in vitro antibacterial property of magnesium alloy and the possibility of preparation of drug-loaded coating on magnesium alloy; according its properties,devise and prepare the biofragmentable anastomosis ring made by magnesium alloy.Methods:Ternary Mg-Zn-Sr magnesium alloys with different Sr concentrations were prepared by melting and casting process. measured mechanical properties of magnesium alloy. we applid metallographic analysis and XRD analysis to the reseach of alloy microstructure, and adopted weight loss corrosion test, electrochemical corrosion test and scanning electron microscope to test in vitro corrosion behavior of magnesium alloy in order to evaluate the changes of the mechanical properties and corrosion resistance that elements Sr brought to magnesium alloy. The biocompatibility of Mg-Zn-Sr alloy was evaluated by MTT method, in vitro hemolysis experiment, partial thromboplastin time (PTT) test and in vivo muscular implantation test. The antibacterial effect of Mg-Zn-Sr metal on the in vitro growth of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were evaluated in three separate experiments compared to positive and negative controls. The everolimus-releasing PLA-PTMC coating was prepared on the Mg-Zn-Sr alloy. The surface morphology,degradability and drug release mechanism of coating were also evaluated. Devised the the biofragmentable anastomosis ring and manufactured it by the method of laser rapid prototyping.Results:Through testing the mechanical properties and corrosion behavior of Mg-Zn-Sr alloys with different content of element Sr,we found that Sr has improved Mg-Zn alloy’s mechanical properties and corrosion resistance, but needed to strictly control the adding amount of element Sr, because Mg-Zn-0.1Sr alloy exhibited the best corrosion resistance.MTT method, in vitro hemolysis experiment、partial thromboplastin time (PTT) test and in vivo muscular implantation test confirm that the ternary Mg-Zn-Sr magnesium alloy biomaterials have good biocompatibility and biodegradability, implying that magnesium alloy is a promising biomaterial. The magnesium alloy biomaterials exhibit performances of antibacterial effect and coating. Anastomosis ring has been designed on the basis of the feature of metal and prepared by the method of laser rapid prototyping.Conclusions:Mg-Zn-Sr alloy is a novel biomaterial that is feasible for use in preparing biodegradable intestinal anastomosis rings. It exhibits the advantages of good mechanical properties, excellent corrosion resistance, suitable biocompatibility, antibacterial action, and ability for drug coating, which are lacking in existing intestinal anastomosis devices/materials. Preparation of Mg-Zn-Sr intestinal anastomosis rings represents an ideal combination of biomaterials and clinical surgery.