The research group of Professor Yuan Guangyin of the National Engineering Research Center of Light Alloy Precision Molding of Shanghai Jiaotong University has made important progress in the field of design methods of degradable magnesium alloy vascular stents. ", Published in" Biomaterials ", an authoritative academic journal in the field of biomaterials. This is the second paper published by Professor Yuan Guangyin's research group in" Biomaterials "in the past 5 years.
Degradable magnesium alloy stents have good clinical application prospects. Through comprehensive optimization design of material properties, drug-loaded coatings and structural design, it can achieve better results than bio-absorbable polylactic acid stents, and even further replace existing drug-eluting stents. . This research proposes a shape optimization design strategy based on the finite element method and applies it to a vascular stent made of Mg-Nd-Zn-Zr (JDBM) alloy, which has self-developed materials and has uniform degradation characteristics. Experimental results in accordance with expected results have been obtained in various in vitro mechanical property tests and in vivo degradation process observations.
The study confirmed by micro-area XRD analysis and finite element numerical simulation that large plastic deformation will be introduced into the stent during the crimping process, and the process of crimping deformation was creatively incorporated into the shape optimization of the magnesium alloy vascular stent. By introducing a raised platform structure and optimizing the shape, a parallel and compact arrangement of support rods under the stent-clamping state is achieved, and the best match of various biomechanical properties of the magnesium alloy stent is achieved.
In subsequent animal experiments, the shape-optimized JDBM scaffold was implanted into the iliac artery of New Zealand white rabbits. According to relevant experimental results, the article's biosafety in vivo, its effectiveness in supporting blood vessel walls, and its degradation in animals The behavior was systematically analyzed and discussed.
This study proposed a set of shape optimization strategies and comprehensive numerical simulation prediction schemes based on the finite element method, which were fully confirmed by in vivo and in vitro results, which provided an effective way to further study the deformation process and biomechanical properties of magnesium alloy vascular stents. The technical methods and approaches have been authorized by Chinese invention patents and applied for US patents for protection.
The co-first authors of the thesis are Dr. Chen Chenxin, Dr. Chen Jiahui of Zhongshan Hospital and Dr. Wu Wei of the Politecnico di Milano. The corresponding authors are Professor Yuan Guangyin and Prof. Francesco Migliavacca of Politecnico di Milano. Shanghai Jiaotong University is the first completion unit. The members of the cooperative research team are from Zhongshan Hospital affiliated to Fudan University, Milan University of Technology, Italy, and MIT, USA. The research work was supported by the National Key Research and Development Plan, the National Natural Science Foundation of China, and the Shanghai Science and Technology Commission Fund.
In recent years, under the guidance of Academician Ding Wenjiang, Professor Yuan Guangyin led a research group aimed at clinical applications and achieved a series of important results in the research and development of fully degradable magnesium alloy vascular stent materials, stent structure design, drug loading coating, and degradation mechanism. Related work has been published in Biomaterials 2019, Acta Biomater 69 (2018), Corrosion science 123 (2017), Scientific Reports 37401 (2016), ACS Appl. Mater. Interfaces 7 (2015), Nanoscale 2013 and other well-known journals, forming an international Academic influence. Recently, the cooperative companies of the research group have sent exciting news that the results of the radial support force test of Jiaoda University magnesium alloy vascular stent reached the highest level in the world. It is believed that the internationally advanced fully degradable magnesium alloy vascular stent developed by Shanghai Jiaotong University will soon benefit the majority of patients with cardiovascular disease!