控温反向挤压-拉拔Mg-Zn-Sr合金超细薄壁管变形机理及生物相容性研究

The cardiovascular disease is the most dangerous disease threatening human health, which morbidity and mortality are ranked first. The coronary stent is an important material treating cardiovascular disease, which quality is required to improve and the dosage is also required to increase constantly. The magnesium alloy is a new coronary stent material bringing international attention. At present, many questions need to be solved urgently as follows: the superfine thin-wall tube of a new magnesium alloy consisted by all of the nutrient compositions needs to be studied, which mechanical properties can still be guaranteed, as well as the degradation performance and biological compatibility meet coronary stent material requirements. Then, the basic science questions for preparation technology of superfine thin-wall tube of magnesium alloy have to be resolved. Therefore, the project is put forward to study the deformation mechanism and biological compatibility of superfine thin-wall tube of Mg-Zn-Sr alloy prepared through temperature control backward extrusion-drawing technique. Through studying its deformation mechanism, the effect of alloy composition and heat treatment rule to its forming process, microstructure and properties as well as its biological compatibility and degradation law, a new superfine thin-wall tube of magnesium alloy applied for coronary stent is prepared. The studies involve materials, materials processing, biomedical and pathology and other disciplines of knowledge belonging to the interdisciplinary frontier science research, which have important scientific and practical significance.

心血管疾病是对人类威胁最大的疾病，其发病率和死亡率都高居首位。冠状动脉支架是治疗心血管疾病的重要材料，对其品质的要求越来越高，用量也愈来愈大。高品质冠状动脉支架需从国外进口。镁合金是国际高度重视的新型冠状动脉支架材料，目前需要迫切解决如下问题：研发全部由营养元素组成的新型镁合金超细薄壁管，且保证其力学性能、降解性能和生物相容性满足冠状动脉支架材料的要求。这就需要解决新型镁合金超细薄壁管制备技术的基本科学问题。 为此，本项目提出研究控温反向挤压-拉拔Mg-Zn-Sr合金超细薄壁管变形机理及生物相容性，通过研究镁合金超细薄壁管控温反向挤压-拉拔塑性变形机理，合金成分及热处理对成形过程及制品组织性能的影响规律，镁合金超细薄壁管生物相容性及降解规律，以制备出适于植入要求的超细镁合金薄壁管。研究涉及材料学、材料加工、生物医学和病理学等学科知识，属于前沿交叉科学问题研究，具有重要的科学意义和实用价值。

心血管疾病是对人类威胁最大的疾病，其发病率和死亡率都高居首位。冠状动脉支架是治疗心血管疾病的重要材料，对其品质的要求越来越高，用量也愈来愈大。目前，高品质冠状动脉支架需从国外进口，而且对于临床治疗存在严重缺陷，即支架植入后不可降解，冠状动脉血管经治疗功能恢复后支架也不能取出，容易造成新的堵塞。为避免形成新的堵塞，患者需要长期服用药物，不仅增加经济负担，而且危害健康。另外，一旦堵塞这种情况再次发生，将不能再进行支架治疗，危及生命，因此可降解支架是临床应用迫切需要的。镁合金是国际高度重视的新型可降解冠状动脉支架材料，目前需要迫切解决如下问题：研发全部由营养元素组成的新型镁合金超细薄壁管，且保证其力学性能、降解性能和生物相容性满足冠状动脉支架材料的要求。这就需要解决新型镁合金超细薄壁管制备技术的基本科学问题。.为此，本项目提出控温反向挤压-拉拔Mg-Zn-Sr合金超细薄壁管变形机理及生物相容性的研究，研究了镁合金超细薄壁管控温反向挤压-拉拔塑性变形机理，优化了Mg-Zn-Sr合金超细薄壁管的制备工艺，通过表面改性降低了合金在生物体内的降解速率，系统研究了合金体外的生物相容性及植入后对小鼠的肾功、肝功等器官的病理学研究，为其临床应用奠定了基础。研究涉及材料学、材料加工、生物医学和病理学等学科知识，属于前沿交叉科学问题研究，具有重要的科学意义和实用价值。