血管内皮祖细胞促进脂肪移植成活体内外研究

The fat graft were necrosis, diffluence, absorbed after fat transplantaion with insufficient blood supply, which caused lower achievement ratio of fat transplantation, more times and more therapy,and the necrotic fat tissue would harm the health of the organism. The key point of promoting survival rate of fat tissue and lipogenesis of adipose-derived stem cells was to research and develop an co-cultured system containing fat tissue and epithelial progenitor cells(EPCs) with ability of good microvascularization that can establish microcirculation with organism and take the metabolism elements of necrotic fat tissue. The prophase research of our research group indicated that the key point of graft survival was graft vascularization, and cell proliferation was promoted with vascular endothelial cells (VECs) and adipose derived stem cells (ADSCs) co-cultured. In this research, EPCs with brilliant neovascularization capability isolated from peripheral blood and fat tissue with secretion capability of cytokine which can promoting lumen of blood vessel formation were co-cultured together. In vitro and vivo, the properties of complex constructed with fat tissue and EPCs such as cell proliferation,lumen formation, the vascularization of EPCs，the survival of fat tissue, the microvascularization formation were dynamic monitored. The object of this research is to provide the systematized technology for constructing an complex of fat tissue and EPCs with good microvascularization, which can be fit for clinic application.

脂肪移植术后因血供不良，导致移植脂肪坏死、液化、吸收，降低了脂肪移植的成功率，增加治疗次数和时间，且坏死物能对机体造成严重损伤。研发可形成微血管丛，与机体建立微循环的脂肪组织及内皮祖细胞联合培养体系，不仅可促进脂肪组织成活、脂肪干细胞成脂，带走坏死物代谢成分，还可避免反复多次治疗，是脂肪移植临床应用推广的关键。课题组前期研究表明，血管化是促进移植物成活的关键因素，血管内皮细胞与脂肪干细胞联合培养可促进细胞增殖。本研究采用提取的脂肪组织和具有优异新生血管能力的外周血内皮祖细胞（EPCs）构建组织及干细胞联合培养体系，运用脂肪组织分泌的细胞因子促进EPCs形成新生血管，对体外细胞增殖、微血管管腔形成、移植脂肪成活能力、活体内微血管形成等脂肪组织及EPCs联合培养体系的性能进行动态追踪。为构建微血管循环良好的脂肪移植复合物应用于临床提供系统化技术支持。

脂肪移植物血管化目前是整形外科临床治疗面临的主要挑战。脂肪组织是高度血管化的组织，通过良好的血供保证脂肪颗粒的完整及存活，近年来多位学者的研究报道均指出，受区局部血供的情况及移植脂肪获得血液的情况，会使成活率受到明显影响，血供差，脂肪组织血管化不良，将出现移植脂肪成活困难、液化坏死，从而使移植失败或吸收率过高，降低移植成功率。为改善脂肪移植物的血液供应，促进移植脂肪成活，本研究采用自体外周血内皮祖细胞与脂肪组织构建细胞组织联合培养体系，为脂肪组织移植成活率低、需反复治疗提供了新思路。课题研究针对解决脂肪组织移植血管化困难导致的坏死液化、吸收、成活困难、需要反复治疗等问题，对具有优异新生血管能力的内皮祖细胞与能分泌大量促血管生成因子的脂肪基质细胞联合细胞体系进行体内、外研究。研究表明，EPC是参与血管管腔形成的主要细胞，而ASC本身不参与血管形成，但其分泌的大量促血管生成因子有效促进EPC血管化；ASC有效促进EPC的侵袭和迁移能力；二者构建的EPC-ASC联合细胞体系各项血管生成标志物表达明显上调，成血管能力强，在体外能高效形成大量管长较长、管腔分支节点较多的血管管腔；在体内，EPC-ASC体系联合脂肪移植物可有效形成新生微血管并且血流通畅，促进了脂肪组织的成活，改善其与周围组织的相容性，构建起能建立微循环血液灌流的微血管化脂肪移植体系。表明本研究构建的EPC-ASC脂肪组织联合培养体系，在建立移植脂肪组织的微循环、改善血供，提高移植脂肪成活等方面，具有单一脂肪移植无法比拟的优点。课题研究使整个脂肪移植过程变得更加高效，降低不良反应及减少治疗次数，使研究成果更适宜临床推广及运用。