Cardiovascular diseases constitute a major global health concern. Various complications that affect normal blood flow in arteries and veins, such as stroke, blood clot formation in veins, blood vessel rupture, and coronary artery disease, often require vascular treatments. However, existing vascular stent devices often require complex, invasive deployment procedures, making it necessary to explore novel materials and manufacturing technologies that could enable such medical devices to work more naturally with the human body. Moreover, the development of patient-specific, adaptively deployable vascular stents is crucial to further advance minimally invasive cardiovascular therapies and make vascular treatments safe and less burdensome for both patients and healthcare providers.
In an innovative breakthrough, a team of researchers from Japan and China, led by Professor Shinjiro Umezu from the Graduate School of Advanced Science and Engineering, Waseda University, Japan, has successfully developed a new 4D-printed vascular stent that expands naturally at body temperature, eliminating the need for external heating and potentially enabling safer and less invasive treatments.
The team also included Yannan Li, Yifan Pan, Chaolun Xu, Jianxian He, Jingao Xu, Dr. Kewei Song, and Dr. Ze Zhang from Waseda University, Prof. Chikahiro Imashiro and Dr. Kayo Hirose from The University of Tokyo, Japan, Dr. Chen Gao from Southeast University, China, Dr. Junbo Jiang from South China University of Technology, and Prof. Runhuai Yang from Anhui Medical University, China. Their novel findings have been published online in the journal Advanced Functional Materials on January 15, 2026.
In this study, the researchers leveraged a polycaprolactone-based shape-memory polymer composite to fabricate micro-architected coronary artery stents through projection micro-stereolithography 4D printing technology. This technology utilizes ultraviolet light to create micro-sized objects with high-resolution features. Scientists used this technology to create such micro-coronary artery stents. Notably, they precisely modulated the thermal transition temperature to approximately 37 °C by utilizing diethyl phthalate as a plasticizer, facilitating quick and automatic shape recovery with no external heating.
Finite element simulations and a viscoelastic stress relaxation model confirm that the developed stents remarkably balance mechanical flexibility and radial strength, and demonstrate long-term biomechanical compliance. Moreover, while in vitro studies using human umbilical cells exhibited excellent cytocompatibility, in vivo implantation experiments in mice indicated the potential for clinical application.
Prof. Umezu points out the immense potential of their innovative next-generation technology. "Our work provides a robust platform for next-generation adaptive vascular stents with programmable mechanics, intelligent deployment, smoother integration with human body, and reduced need for complex procedures, offering significant potential for personalized treatment in anatomically complex vascular structure."
The present work may help address challenges in vascular treatments and could be utilized in other implantable medical devices. The coronary artery stents developed in this study highlights high operational feasibility and engineering controllability. These advantages also demonstrate highly tunable and personalized fabrication of stents for diverse patient groups. The findings of the study showcase a generalized approach for the development of vascular implants, with significant potential for clinical translation.
"Consequently, our research could contribute to future vascular stent technologies used in minimally invasive procedures, potentially simplifying deployment and reducing the need for additional equipment. The same approach may be applicable to other implantable medical devices that are designed to respond to the body's natural environment," highlights Prof. Umezu.
