利用肝素化脂肪脱细胞基质构建血管化组织工程脂肪的研究

Repair of the soft tissue defect caused by various reasons are major challenges in the field of plastic surgery. Adipose tissue engineering technology is currently a research focus, but there are still many factors restricting its development. No suitable scaffolds and biological cytokines are two important factors among them．We have demonstrated that scaffolds derived from decellularized adipose tissue (DAT) with the specific native three-dimensional (3-D), porous and well biocompatibility is conducive to cell adhesion and capable to successfully build tissue engineering adipose in the body, but later generation of engineering adipose tissue is not as expected, which the reason of this issue may be the less oxygen and insufficient vascularization in the center of scaffold. On the basis of these data, VEGF was loaded onto the hepafinized decellularized adipose tissue through the electrostatic adsorption between heparin and growth factors, and the duration of VEGF released from the scaffolds were detected by ELISA assay．Then the hepafinized extracellular matrix scaffold combined with VEGF and human ADSCs transplanted subcutaneous to the nude mice．The formation and the level of the vascularized of engineering adipose tissue will be evaluated from morphology and histology, and the mechanism will be explored further. Basing on the construction of vascularized tissue engineering adipose,our project tries to investigate an innovative approach to clinical non-invasive repair of soft tissue defects.

各种原因所造成的软组织缺损的修复是整形外科领域的重大难题，脂肪组织工程技术是目前研究的热点，但支架材料和生物活性因子的选择是制约其发展的重要因素。我们的前期工作表明，脂肪组织脱细胞基质(decellularized adipose tissue ,DAT)具有天然特定的三维结构，组织相容性好，利于细胞粘附生长，体内能够成功构建出成熟脂肪组织，但后期组织工程脂肪的生成量却并如预期可观，究其原因，可能是因为支架中心部分缺氧及血管化不足有关。在此基础上，本研究拟采用肝素修饰DAT支架，利用肝素对细胞因子的亲和性，在DAT支架上负载VEGF ，观察VEGF的缓释效果；将此VEGF-Hep-DAT支架与hADSCs复合后裸鼠体内移植，从形态学及组织学等方面评价组织工程脂肪的生成及血管化水平，并探讨其作用机制。本课题通过构建血管化组织工程脂肪为临床上实现软组织缺损的无损伤修复提供一种全新的思路和方法。

各种原因所造成的软组织缺损的修复是整形外科领域的重大难题，脂肪组织工程技术是目前研究的热点，但支架材料和生物活性因子的选择是制约其发展的重要因素。我们在前期工作的基础上，构建出具有具有天然特定的三维结构、组织相容性好、利于细胞粘附生长的脂肪组织脱细胞基质(decellularized adipose tissue ,DAT)支架，并采用肝素修饰该支架材料，利用肝素对细胞因子的亲和性，进一步在DAT支架上负载VEGF。体外实验证明，VEGF-Hep-DAT支架具有良好的生物学活性，由于富含VEGF生长因子从而使细胞更容易黏附和生长；体内移植实验证明，VEGF-Hep-DATs可诱导hBMSCs内皮细胞分化，并刺激血管内皮标志物CD34、vwf表达的hBMSC表达，从而加速移植组织的血管化。本课题为临床上实现软组织缺损的无损伤修复提供了一种全新的思路和方法。