Development of a coated vascular prosthesis cope with BSE problems

为了解决牛海绵状脑病的问题，研制了一种生物可降解材料涂层的织物血管假体。所有商业上可用的血管假体都涂上了牛胶原蛋白。本项目的目的是获得无牛海绵状脑病的涂层材料，并为涂层作为血管假体提供合适的基础材料。在各种生物可降解材料中，我们选择了非病理蛋白质类物质，如纤维素、超高分子透明质酸、聚乙二醇、聚乙烯醇、甲壳素、壳聚糖及其底物。实验结果表明，甲壳素、壳聚糖和羧甲基纤维素(CMC)是最适合的原料。我们的努力还包括如何将这些材料固定在织物假体上。我们检查了甲醛、戊二醛和碳二亚胺等化学试剂。它们都表现出毒性。根据这些结果，我们采用了伽玛射线辐照、紫外线辐照、电子束辐照、热交联、各材料纤维的纠缠等物理方法。最后，我们选择了纠缠方法。这是一种简单的方法，但没有显示任何毒性反应。我们实验的下一个目标是创建用于涂层的织物血管假体的最佳基质。为此，我们开发了一种由超细聚酯纤维制成的假体。它们可以非常牢固地捕获涂层物质。在这些基础实验的基础上，用CMC、甲壳素和壳聚糖包覆的超细涤纶纤维制成了织物假体。我们将制造的假体植入狗的胸降主动脉。移植物达到了预期的效果。我们目前正在对这些血管移植物进行体内实验观察，以便进行长期分析。

In order to cope with bovine spongious encepharopathy problems, a fabric vascular prosthesis coated with biodegradable materials was developed. All the blood vessel prostheses commercially available are coated with bovine collagen. Our project was aimed to obtain coating materials free from bovine spongious encepharopathy, and suitable basic materials for the coating as a vascular prostheses. Among various biodegradable materials, we selected non-pathological protein free substances, such as cellulose, extremely high molecule hyaluronic acid, polyethylene glycol, polyvinyl alcohol, chitin, chitosan, and their substrates. After examinations, our experiments showed that the most suitable materials for this purpose were chitin, chitosan, and carboxymethyl cellulose(CMC). Our efforts were also on how to fix these materials on fabric prostheses. We checked chemical reagents such as formaldehyde, glutarardehyde and carbodiimide. All of them showed toxicity. From these results, we adopted physical methods such as gamma-ray irradiation, ultraviolet irradiation, electron beam irradiation, heat cross-linking, entanglement of each material fiber. Finally, we chose entanglement method. This was a simple method, but it did not show any toxic reactions. Next target of our experiment was to create a best matrix of the fabric vascular prosthesis for the coating. For this purpose, we developed a prosthesis fabricated with ultra-fine polyester fibers. They can trap the coated substance very firmly. With these basic experiments, fabric prostheses made of ultrafine polyester fibers coated with CMC, Chitin, and chitosan. We implanted the created prostheses into the thoracic descending aortae of dogs. The graft showed expected results. We are now underway to observe these vascular grafts with in vivo experiment for long-term analysis.