Shi Daokun, Kang Yahong, Wang Weijie, Liu Ruili, Tang Quansheng, Li Zhaomin, Jiang Hongyan, Ding Jiandong
State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200438, China.
Shanghai Key Laboratory of Interventional Medical Devices and Equipment, Shanghai MicroPort Medical Group Co, Ltd, Shanghai 201203, China.
Regen Biomater. 2025 Mar 20;12:rbaf016. doi: 10.1093/rb/rbaf016. eCollection 2025.
Atrial septal defect (ASD) is one of the major congenital heart diseases, and transcatheter closure with a cardiac occluder is a modern method to treat ASD with the advantage of mini-invasiveness over traditional surgical closure. While current occlusion devices are mainly made of non-degradable nitinol with superelasticity, the permanent existence of a metal may trigger potential complications and especially has an adverse effect on the heart development for children. However, it is challenging to invent a superelasticity-free occluder that can be delivered through a catheter but firmly locked after being opened at the target site; it is also much desired for research and development to quickly assess the feasibility of a superelasticity-free occluder . Herein, a biodegradable poly(L-lactide) (PLLA) occluder composed of a braided PLLA frame as the skeleton and a nonwoven PLLA fabric as the flow-blocking membrane is developed, and a controllable locking structure is designed to enable firm closure for a device even without superelasticity. We also suggest and justify a series of methods to assess the efficacy of the biodegradable occluder, and the results confirm the reliability of locking, water-blocking, mechanical strength and degradability. It is found that the PLLA fabric with moderate fiber density is optimal for surface endothelialization. We also carry out biological assessments; significant endothelialization and alleviated inflammation response are observed after 6 months of subcutaneous implantation into rabbits. The porcine model illustrates that the biodegradable polymeric occluder can be successfully implanted into the atrial septum via transcatheter intervention; the follow-ups have confirmed the safety and efficacy of this biodegradable polymeric occluder with the controllable locking structure.
房间隔缺损（ASD）是主要的先天性心脏病之一，使用心脏封堵器进行经导管封堵是治疗ASD的一种现代方法，与传统外科手术封堵相比具有微创优势。虽然目前的封堵装置主要由具有超弹性的不可降解镍钛诺制成，但金属的永久存在可能引发潜在并发症，尤其对儿童心脏发育有不良影响。然而，发明一种无超弹性的封堵器具有挑战性，这种封堵器要能通过导管输送，在目标部位打开后能牢固锁定；快速评估无超弹性封堵器的可行性也是研发中非常期望的。在此，开发了一种可生物降解的聚（L-丙交酯）（PLLA）封堵器，它由编织的PLLA框架作为骨架和非织造PLLA织物作为阻流膜组成，并设计了一种可控锁定结构，以使即使没有超弹性的装置也能牢固闭合。我们还提出并论证了一系列评估可生物降解封堵器疗效的方法，结果证实了锁定、阻水、机械强度和降解性的可靠性。发现纤维密度适中的PLLA织物最适合表面内皮化。我们还进行了生物学评估；将其皮下植入兔子6个月后，观察到明显的内皮化和炎症反应减轻。猪模型表明，可生物降解聚合物封堵器可通过经导管介入成功植入房间隔；随访证实了这种具有可控锁定结构的可生物降解聚合物封堵器的安全性和有效性。
