研制适用于室间隔缺损封堵器的新型可吸收复合材料的研究

我们在前期研究中研制了一种可吸收室间隔缺损封堵器，并成功进行临床研究，解决了完全可吸收及塑形性的问题，但在随访中发现封堵器完全降解时间太长，而且封堵器左侧伞盘比右侧降解快，影响稳定性。为研制新材料提高封堵器性能，结合文献提出研究假设：将不同降解时间的材料按一定比例及方法混合，可以获得新型可吸收复合材料，使封堵器在内皮化前保持稳定且两侧均衡降解，并在内皮化后更快地完全降解。计划采用均匀混合及表面喷涂两种方法混合降解慢的PLLA及降解快的PDLLA。首先将两者按不同的重量比例均匀混合，通过动物实验筛选出最佳混合比例，使封堵器在内皮化前保持机械稳定，在内皮化后更快降解；用最佳混合比例的材料制造封堵器，并在左侧盘面喷涂不同厚度的PLLA，通过动物实验筛选能使两侧伞盘在内皮化前均衡降解的最小厚度；通过两年的随访并与单纯PLLA封堵器对照,评价复合材料封堵器的安全性及有效性。

In the previous study, we developed an absorbable ventricular septal defect occluder and successfully carried out clinical research to solve the problem of complete absorbability and shape ability. However, during the follow-up, it was found that the occluder completely degraded for a long time and the left disk of the device degraded faster than the right disk, which affected the stability in vivo. To improve the performance of the occluder for the development of new materials, the research hypothesis is put forward in combination with the literatures: the materials with different degradation time can be mixed according to a certain proportion and method to obtain a new absorbable composite material, so that the occluder remains stable before the endothelialization and both sides degrade fast and balanced after endothelialization. It is planned to mix the slow-degrading PLLA and the fast-degrading PDLLA by means of uniform mixing and surface spraying. The optimal mixing ratio was screened by animal experiments, so that the occluder remained mechanically stable before endothelialization and degraded quickly after endothelialization; the occluder was made with the best mixing ratio material, and different thickness was sprayed on the left disc surface. The PLLA was screened by animal experiments to minimize the thickness of the umbrella discs before equilibrium in endothelialization. The safety and effectiveness of the composite occluder were evaluated by two years of follow-up and comparison with a simple-PLLA occluder. This study will address the key issues of degradation performance and promote the industrialization of completely absorbable devices.