随着管腔堵塞疾病发病率逐年增高以及介入治疗技术快速发展，管腔支架在临床上应用日益广泛。可降解形状记忆聚合物用于管腔支架制备已展现巨大潜力，但存在形状回复后力学性能下降，内部降解速率快于表面易形成碎片诱发堵塞等问题。基于此，本课题拟设计制备一种全新聚氨酯，其主链为含有可降解扩链剂的硬段，亲水的软段组分全部位于侧链，旨在获得一类可降解的形状记忆聚氨酯材料，其形状回复后模量成倍增加。并将系统研究这种新型聚氨酯的相结构与性能关系，揭示形状回复后模量升高的机理；调控亲水链段的空间分布以及可降解扩链剂的结构和含量，实现材料表面降解速率快于内部；利用亲水侧链向表面富集，构建具有良好血液相容性和防污能力的表面，最终优化制得新型管腔支架并进行体内外生物学评价，为新型可降解管腔支架材料的设计提供新的思路。

With the increasing morbidity of luminal stenosis disease and rapid development of interventional therapy technology, endoluminal stents have been widely used in clinical practice. Biodegradable shape memory polymers have shown great potential in the preparation of endoluminal stents. However, the mechanical properties are decreased after shape recovery and the internal degradation rate is faster than that of external, which could result in debris formation and induce blockage. To solve these problems, a new type of polyurethane is prepared. The main chains of the polyurethane consist of only hard segments containing degradable chain extenders and the hydrophilic soft segments are all located in the side chains. The aim of the project is to obtain biodegradable polyurethane material with excellent biocompatibility and shape memory properties. Particularly, the modulus of the material would increase sharply after shape recovery. The relationship between the phase structure and properties of the new polyurethane will be systematically studied to reveal the mechanical strengthen mechanism. Via regulating the spatial distribution of hydrophilic segments as well as the structure and content of biodegradable chain extender, the degradation of the material surface would proceed faster than that of the interior. The hydrophilic soft segments are prone to be enriched at the surface feature with prominent blood compatibility and anti-fouling ability. Eventually, a new type of endoluminal stent would be designed and evaluated both in vitro and in vivo. The research provides new ideas for the design of biodegradable endoluminal stents for next-generation.