利用糖尿病大鼠模型评价具有内皮祖细胞捕捉活性的人工血管

The aproach of In Vivo Tissue Engineering for small diameter artificial blood vessels means that the grafts need functional modification with endothelial progenitor cells (EPC) bingding molecules which capture EPC from the circulating blood and facilitate rapid enothelialization. The common capture molecules include CD34 antibody, peptide, DNA aptamer, and RGD. In clinical treatment, vascular grafts are mainly used to treat cardiovascular and diabetic patients whose EPC contend and their proliferation and differentiation potential are much lower than the healthy people. The current project will study, under the diabetic condition, how the functional vascular grafts capture stem cells for the blood, the composition of the captured cells and if they can proliferate and differentiate to form functional endothelium as what they do in normal condition. Additionally, we will incorporate VEGF into the grafts and control its release to increase the VEGF level. We also plan to give G-CSF administration to mobilize EPC from the borrow marrow and increase the number of EPC in the circulating blood. We will perform short or long-term rat aorta implantation. By compare with the health rats, we will study the performance of the functional vascular grafts, including the endothelialization, smooth muscle regeneration, patency and the function of the formed vessels.

小口径人工血管的"体内组织工程"研究手段是对材料表面进行修饰，捕捉内皮干细胞，实现快速内皮化，使血管的构建在体内完成。捕捉分子包括CD34抗体，多肽，DNA适配体，RGD等。人工血管主要用于心血管和糖尿病患者，患者血液中的内皮干细胞数量、增殖和分化潜能会显著降低。本项目将深入研究在糖尿病病理条件下，具有内皮干细胞捕捉功能的人工血管在体内如何捕捉干细胞，被捕捉干细胞的组成如何，被捕捉的干细胞能否像在正常生理条件下增殖、分化和形成有功能的血管内皮。同时用VEGF修饰人工血管，通过VEGF控制释放补偿糖尿病大鼠体内的VEGF水平。此外，拟采用G-CSF动员，提高外周血中EPC的数量。开展大鼠腹主动脉移植，比较人工血管在正常和糖尿病大鼠体内内皮形成、平滑肌再生、血管功能和长期通畅性等情况。

开展的研究内容： . 在人工血管结构设计与制备工艺方面，分别采用静电纺丝、冷冻干燥、电喷致孔、熔融纺丝等方法制备聚己內酯（PCL）人工血管，优化血管的纤维和孔径结构，以及纤维排列取向，从而改善细胞迁移和排列。在人工血管活性修饰方面建立了多种先进的方法，分别将生长因子、活性多肽、NO供体、抗体等修饰到血管材料中，控制活性物质的梯度分布和释放速率，保持其生物活性，分别研究这些活性修饰对快速内皮形成、血管平滑肌再生和血管再生的影响。建立了2型糖尿病动物模型，开展了人工血管在2型糖尿病大鼠体内植入研究，比较人工血管在正常和糖尿病大鼠体内内皮形成、平滑肌再生、血管功能和长期通畅性等情况。建立了动脉粥样硬化大鼠模型，进行了人工血管移植实验，发现血管新内膜增生和血管再狭窄在疾病条件下非常严重，因此，进一步研究了抑制平滑肌细胞迁移和增殖的有效方法。..研究成果：. 发表了5篇SCI收录论文和10余篇中文论文，均标注了基金代码。5篇SCI收录论文分别是Biomaterials，J Biomed Nanotechnol，J Bioact Compat Poly，Cell Physiol Biochem 和Biomater Sci。有1项发明专利获得授权 (专利号201410244591.7)。项目负责人获得云南省卫生科技成果二等奖（第一完成人）和天津市科技进步二等奖（第二完成人）。..人才培养与团队建设：. 有十几名研究生参与了本项目，培养博士生1名，硕士生10名。项目负责人入选云南省卫生和计划生育委员会医学学科带头人培养计划。