表面微图形变化的多层形状记忆血管支架的研究

发布时间：2018-05-02 23:55

  本文选题：形状记忆 + 微图形　； 参考：《西南交通大学》2017年硕士论文

【摘要】：由于日益增多的心血管疾病患者,对于小直径血管支架的需求日益增加。传统的静脉支架和人造的聚酯及膨胀聚四氟乙烯血管支架存在着来源不足,长期效果差,失败率高等缺点。基于此,组织工程应运而生,致力于解决这些问题。我们在本论文中采用具有形状记忆性能和良好生物相容性的6臂的聚乙二醇-聚己内酯(6a PEG-PCL)作为支架基底材料,将微图形转移到支架表面,通过卷曲的方式制备出表面微图形变化的多层形状记忆血管支架。使用正方形和长方形来分别调控内皮细胞和平滑肌细胞,通过微图形的调控作用再生出与天然动脉结构相似的新生血管组织。首先我们通过涂覆热压将模板上的图形转移到交联的6臂聚乙二醇-聚己内酯(c-6a PEG-PCL)薄膜上,使一片薄膜上同时具有正方形和长方形两种微图形。使正方形在内侧长方形在外侧,通过卷曲的方式制备出表面微图形变化的多层形状记忆血管支架。在潮湿条件下支架的转变温度为37℃,并具有良好的形状记忆性能。同时,支架具有良好的力学性能和可降解性,体外模拟实验证明了微创植入的可能,而且支架恢复后能够有效地支撑血管。随后,我们考察了正方形和长方形对内皮细胞和平滑肌细胞行为的影响。支架具有良好的生物相容性和血液相容性,能有效防止血小板的粘附和聚集。正方形可以促进内皮的增殖和迁移,长方形能促进平滑肌细胞增殖并诱导其定向的排列。卷曲支架上的共培养发现,正方形能促进内皮细胞层粘连蛋白的表达,长方形能促进平滑肌表达α-平滑肌肌动蛋白。最后,我们进行了体内的支架的血管再生测试。多普勒超声发现,植入后血管支架能有效恢复到永久形状支撑血管,同时保持良好的通透性。表面微图形的血管支架能有效调控新血管的再生和重构,正方形能诱导支架内层的快速内皮化,长方形调控平滑肌层环状定向排列,并且适宜的炎症反应促进新血管组织的再生,支架逐渐降解,最终形成与本体动脉结构非常相似的新生动脉组织。新生血管具有与本体动脉相似的多层结构、细胞外基质含量和爆裂强度。
[Abstract]:As a result of the increasing number of patients with cardiovascular disease, the demand for small diameter stent is increasing. The traditional venous stents, artificial polyester and expanded PTFE vascular stents have some disadvantages, such as insufficient source, poor long-term effect, high failure rate and so on. Based on this, organizational engineering emerged as the times require to solve these problems. In this thesis, we used polyethylene glycol (PEG-PCL), a 6-arm PEG-PCL with shape memory and good biocompatibility, as the substrate material to transfer the micrograph to the surface of the scaffold. A multilayer shape memory vascular stent with surface micrograph changes was fabricated by curling. Square and rectangular cells were used to regulate endothelial cells and smooth muscle cells respectively. The neovascularization tissues similar to the natural artery structure were regenerated by micrographic regulation. First, we transfer the pattern on the template to the cross-linked poly (ethylene glycol) -polycaprolactone (c-6a) PEG-PCL film by hot pressing, and make one thin film have both square and rectangular micrographs. A multi-layer shape memory vascular stent with surface micrograph changes was fabricated by curling the square on the inner rectangle at the outer side. The transition temperature of the scaffold is 37 鈩，

本文编号：1836020