Abstract:

Biodegradable magnesium-based stents (BMgS) present outstanding potential to revolutionize the treatment of coronary artery diseases, in which full recovery of arteries without long-term irritation of implants is anticipated for averting adverse events associated with the permanent stents. In this talk, firstly, I will introduce the alloy design strategies of a novel patented biodegradable magnesium alloy JDBM aided with first-principal calculations, mechanical properties, biocompatibility and in vitro degradation behavior[1]. Secondly, a novel concept in stent shape optimization with crimping-introducing, via finite element method (FEM) toolkit will be reported. JDBM alloy with uniform degradation behavior served as the basis of our BMgS. Comprehensive in vitro evaluations drove stent optimization, based on observed crimping and balloon inflation performance, measurement of radial strength, and stress condition validation via microarea-XRD. The mechanical properties of BMgS were enhanced by design optimization compared to sine-wave stent, resulting in the decrease of dog-boning effect, longitudinal foreshortening and the increase of the radial strength. With the raised platform and shape optimization, the percentage of high-stress regions of stent and vascular vessel was decreased significantly [2].Thirdly, in order to protect the matrix of BMgS from the biodegradation, a facile copper-incorporated coating system through nonaqueous phase synthesis of polydopamine is developed to facilitate Cu(II) capture along with robust film deposited on easily corrodible Mg, which subsequently enables sustained Cu(II) elution. It remarkably enhances corrosion resistance and impedes Mg degradation, which also contributes to improved, superior cytocompatibility, and abolished hemolysis. Coated-Mg Stent implantation into rabbit abdominal aorta thus exhibits accelerated re-endothelialization completed in a week, and enhanced biological outcomes, alleviated complications and prolonged structural durability in 3-month follow-up [3].
Collectively, combination of special design of matrix material, shape optimization and functional coating, a novel JDBM stent exhibits the bright clinical application prospect.

References
[1] Jialin Niu, Hua Huang, Jia Pei, Zhaohui Jin, Shaokang Guan, Guangyin Yuan* , Research and development strategy for biodegradable magnesium-based vascular stents: a review. Biomaterials Translational, 2021, 2(3): 236
[2] Chenxin Chen, Jiahui Chen, Wei Wu, Yongjuan Shi, Liang Jin, Lorenza Petrini, Li Shen, Guangyin Yuan,* Wenjiang Ding, Junbo Ge, Elazer R. Edelman, Francesco Migliavacca*, In vivo and in vitro evaluation of a biodegradable magnesium vascular stent designed by shape optimization strategy, Biomaterials 221 (2019) 119414
[3] Ling-Yu Li , Zhou Yang, Xiang-xiang Pan, Bo-xuan Feng, Rui Yue, Bo Yu, Yufeng Zheng, Jin-yun Tan⁎, Guang-yin Yuan⁎, Jia Pei⁎, Incorporating Copper to Biodegradable Magnesium Alloy Vascular Stents via a Cu(II)-eluting Coating for Synergistic Enhancement in Prolonged Durability and Rapid Re-endothelialization, Advanced Functional Materials 2022，2205634.

Bio-Sketch
Dr. Guangyin Yuan is a tenured professor of the School of Materials Science and Engineering at Shanghai Jiao Tong University, China. Dr.Yuan received his Ph.D. in Materials Science and Engineering from Southeast University, China in 1999. He then did his postdoctoral research at Shanghai Jiao Tong University and focused on the development of heat-resistant magnesium alloys for automobile powertrain applications. He was promoted to associate professor at Shanghai Jiao Tong University in 2002. Then he went to Tohoku University, Japan, and worked as a JSPS researcher from 2002 to 2004, where he focused on the study of bulk metallic glasses and advanced magnesium alloys reinforced with in-situ quasicrystals. He was promoted to professor in 2008 and tenured professor in 2016. His research fields are mainly involved in the design of advanced materials and correlation between the microstructure and properties of metallic materials, and in recent ten years his research focused on the research and development of novel biodegradable magnesium-based alloys for medical applications. He has published over 150 journal papers in international journals and cited by over 5500 (h-index=45) and owns 28 patents on Mg alloys including 16 patents related to biomedical Mg alloys. Dr. Yuan has been awarded some academic honors by Chinese government and Shanghai Municipality, such as New Century Excellent Talent awarded by Chinese Ministry of Education in 2007, and Shanghai outstanding academic leaders awarded by Shanghai Municipality in 2017.