电化学场刺激表面引发原子转移自由基聚合构筑血液相容性聚醚砜膜仿生表面

Blood purification apparatus, such as hemodialysis, hemofiltation and blood seperation, is often needed to treat the blood-assotiated disease, while the prous membrane is its key component. Among the materials used, polyethersulfone (PES) show outstanding oxidative, thermal and hydrolytic stability as well as good mechanical and film-forming properties，and is widely used in blood purification fields. However, the hemocompatibility of PES is inadequate and unstable, and injections of anticoagulants are needed during hemodialysis. Hence, preparation of bionic surface for hemocompatibility PES membranes via surface-initiated and electrochemically mediated atom-transfer radical polymerization (SI-eATRP) is proposed in this project. It aimed at constructing a membrane surface with certain hydrophilicity, charge density and polysaccharde structure to simulate surface performance of blood vessel wall. Compared with the method of direct blending amphiphilic block copolymer as additives, the proposed SI-eATRP method combining living polymerization and electrochemistry will architecture-controlled fabricate the membrane surface, and systematically investigate the effects of surface structure and properties on hemocompatibility. Furthermore, compared with the conventional chemical graft modifying method, the proposed method is simple and efficient, and can be used to modify the hollow fiber membranes. Based on above studies, the hemocompatibility PES membrane may be prepared, which can be easily produced with large quantities,and used in blood purification fields.

治疗与血液相关的疾病需要利用血液净化装置（如血液透析、血液滤过和血浆分离等），其技术核心是膜关键材料。临床上普遍使用的聚醚砜膜材料具有优异的物理机械性能、物化稳定性和成膜性能，但其血液相容性尤其是抗凝血性能仍然不够理想、不够持久，而基于共混两亲性嵌段共聚物的改性方法难以实现表面功能结构的可控制备。本项目提出采用电化学场刺激表面引发原子转移自由基聚合（SI-eATRP）在膜表面引入功能性分子刷，模拟血管内壁结构以构筑具有一定亲疏水平衡、电荷密度和多糖结构的抗凝血仿生表面。SI-eATRP聚合技术在保持共混工艺优点的前提下，将电化学和可控聚合成功"联姻"，实现功能性聚合物膜表面的可控构筑与制备，预计将解决膜材料表面结构、性质与血液相容性关系的基础科学问题。和传统的表面化学接枝相比，本项目所采用的方法简单有效、可改性中空纤维膜，有望制备易于批量生产的血液相容性聚醚砜膜材料，并应用于血液净化领域。

表面引发原子转移自由基聚合(SI-ATRP)是表面引发的可控/活性聚合，是近年来高分子材料合成与设计的新方法。该方法利用化学键或自组装技术在基底表面形成均匀的ATRP引发剂层，再用传统ATRP方法将功能单体聚合到基底表面，形成致密的功能基层。以PES 膜为基材，本课题结合共混改性和表面接枝改性的优点采用可控聚合与大分子设计技术制备两亲性嵌段共聚物改性剂，构筑具有类肝素结构的膜表面，旨在通过模仿肝素的结构特征与抗凝血活性，提高PES膜材料的血液相容性，并纺制永久抗凝性PES中空纤维膜，应用于血液净化器。本项目得到以下主要结果：（1）采用SI-eATRP技术制备出一系列表面形态平整、微孔结构完整的聚醚砜改性膜，并对其合成过程进行了优化；（2）在聚醚砜膜上成功接枝上PVP、PSSNa、PAANa和多糖等聚合物链段刷，并研究了分子结构和血液相容性之间的关系；（3）制备的聚醚砜膜具有良好的抗凝血性能及血液相容性并有望应用于血液净化领域。