Department of Astronautical Science and Mechanics, Harbin Institute of Technology (HIT), Harbin 150001, China.
Center for Composite Materials and Structures, Harbin Institute of Technology (HIT), Harbin 150080, China.
ACS Appl Mater Interfaces. 2021 Mar 24;13(11):12668-12678. doi: 10.1021/acsami.0c17192. Epub 2021 Jan 4.
The significant mismatch of mechanical properties between the implanted medical device and biological tissue is prone to cause wear and even perforation. In addition, the limited biocompatibility and nondegradability of commercial Nitinol-based occlusion devices can easily lead to other serious complications, such as allergy and corrosion. The present study aims to develop a 4D printed patient-specific absorbable left atrial appendage occluder (LAAO) that can match the deformation of left atrial appendage (LAA) tissue to reduce complications. The desirable bioinspired network is explored by iterative optimization to mimic the stress-strain curve of LAA tissue and LAAOs are designed based on the optimal network. In vitro degradation tests are carried out to evaluate the effects of degradation on mechanical properties. In addition, 48 weeks of long-term subcutaneous implantation of the occluder shows favorable biocompatibility, and the 20-cycle compression test demonstrates outstanding durability of LAAO. Besides, a rapid, complete, and remote-controlled 4D transformation process of LAAO is achieved under the trigger of the magnetic field. The deployment of the LAAO in an isolated swine heart initially exhibits its feasibility for transcatheter LAA occlusion. To the best of our knowledge, this is the first demonstration of the 4D printed LAA occlusion device. It is worth noting that the bioinspired design concept is not only applicable to occlusion devices, but also to many other implantable medical devices, which is conducive to reducing complications, and a broad range of appealing application prospects can be foreseen.
植入医疗器械与生物组织之间力学性能的显著不匹配，容易导致磨损甚至穿孔。此外，商业用的基于镍钛诺的封堵装置的生物相容性和可降解性有限，容易导致其他严重的并发症，如过敏和腐蚀。本研究旨在开发一种 4D 打印的、可个体化定制的、可吸收的左心耳封堵器（LAAO），以匹配左心耳（LAA）组织的变形，从而减少并发症。通过迭代优化来探索理想的仿生网络，以模拟 LAA 组织的应力-应变曲线，并基于最优网络设计 LAAO。进行体外降解试验来评估降解对机械性能的影响。此外，将封堵器进行长达 48 周的皮下植入，结果显示出良好的生物相容性，20 次循环压缩试验表明 LAAO 具有出色的耐久性。此外，LAAO 可以在磁场的触发下快速、完全、远程控制地实现 4D 变形。LAAO 在离体猪心内的部署初步显示了其经导管 LAA 封堵的可行性。据我们所知，这是首次展示 4D 打印的 LAA 封堵装置。值得注意的是，仿生设计理念不仅适用于封堵装置，还适用于许多其他可植入的医疗器械，有利于减少并发症，并具有广泛的吸引人的应用前景。
