干细胞在小口径人工血管内皮化中的应用

Application of stem cells in endothelialization of small-diameter blood vessel prosthesis

背景:小口径人工血管移植后由于血栓形成和内膜增生等原因造成管腔狭窄甚至闭塞,运用干细胞作为种子细胞实现人工血管的内皮化有助于改善血管移植后的远期通畅率。目的:总结干细胞在小口径人工血管内皮化中应用的研究进展。方法:由第一作者检索Pub Med和万方数据库2013-2023年发表的相关文献,英文检索词为“vascular graft,tissue-engineered blood vessel/vascular tissue engineering,endothelialization,stem cells,endothelial progenitor cells,mesenchymal stem cells,induced pluripotent stem cells,embryonicstemcells”,中文检索词为“人工血管,组织工程血管/血管组织工程,内皮化,干细胞,内皮祖细胞,间充质干细胞,诱导多能干细胞,胚胎干细胞”,检索近10年国内外关于干细胞应用于小口径人工血管内皮化的相关文献,初检文献552篇,根据纳排标准最终选取81篇文献进行综述。结果与结论:(1)远期通畅率不理想限制了小口径人工血管的临床应用,造成远期通畅率低下的主要原因是血栓形成和内膜增生。天然血管内皮层具有良好的抗血栓及内膜增生性能,内皮化可以模拟天然血管的特性,是提升远期通畅率的有效手段。(2)小口径人工血管植入体内后会经历体内内皮化过程,但难以形成完整的内皮层。干细胞具有分化为内皮细胞的潜能,体内招募干细胞或将其作为种子细胞种植在人工血管内表面是实现内皮化的研究策略。(3)将内皮祖细胞、间充质干细胞、诱导多能干细胞及胚胎干细胞等作为种子细胞种植均能够一定程度改善小口径人工血管的远期通畅率,且它们各具优势。内皮祖细胞便于获取且可直接用于种植;间充质干细胞来源广泛且具有旁分泌和调节免疫的功能;诱导多能干细胞来源丰富且可消除免疫原性;胚胎干细胞增殖能力强且能多向分化。(4)将干细胞用于人工血管的研究目前仍未转化至临床,未来需要进一步研究并促进临床转化。

BACKGROUND:The small-diameter blood vessel prosthesis faces the problem of lumen stenosis or even occlusion due to thrombogenesis and intimal hyperplasia after transplantation.The application of stem cells as seed cells to achieve endothelialization of blood vessel prosthesis helps to improve the longterm patency rate after vascular graft transplantation.OBJECTIVE:To summarize the research progress of the application of stem cells in the endothelialization of small-diameter blood vessel prosthesis.METHODS:The relevant articles published on Pub Med and Wan Fang databases from 2013 to 2023 were retrieved by the first author.Chinese and English search terms included “vascular graft,tissue-engineered blood vessel/vascular tissue engineering,endothelialization,stem cells,endothelial progenitor cells,mesenchymal stem cells,induced pluripotent stem cells,embryonic stem cells.” The relative articles in the domestic and overseas about the application of stem cells in the endothelialization of small-diameter blood vessel prosthesis in the past 10 years were retrieved.A total of 552 articles were initially found and we finally selected 81 articles to review according to inclusion and exclusion criteria.RESULTS AND CONCLUSION:(1) The low long-term patency rate restricts the application of small-diameter blood vessel prosthesis in clinic.The main causes of low long-term patency rate are thrombogenesis and intimal hyperplasia.The endothelium of native vessels has the function of anti-thrombogenesis and intimal hyperplasia.Endothelialization can simulate the function of native vessels,which is an effective way to improve long-term patency rate.(2) The smalldiameter blood vessel prosthesis will undergo in vivo endothelialization after being implanted,but it is difficult to form complete endothelium.Stem cells have the potential to differentiate into endothelial cells.Recruiting stem cells in vivo or seeding them on the inner surface of blood vessel prosthesis in vitro is research strategy to achieve endothelialization.(3) The long-term patency rate of small-diameter blood vessel prosthesis has been improved to a certain extent through seeding endothelial progenitor cells,mesenchymal stem cells,induced pluripotent stem cells,and embryonic stem cells.Each has its own advantages.Endothelial progenitor cells are easy to obtain and can be directly used for seeding.Mesenchymal stem cells come from a wide range of sources and have the function of paracrine and immunological regulation.Induced pluripotent stem cells are rich in sources and the immunogenicity can be eliminated.Embryonic stem cells have a strong proliferative ability and can differentiate into many cells.(4) The application of stem cells in blood vessel prosthesis has not yet been transformed into clinic.Further researches are needed to promote clinical translation.