仿生II型/III型胶原-PRP复合支架荷载脂肪干细胞修复关节软骨缺损的作用及机制研究

Adipose stem cells (ADSCs) transplantation has become a hot topic in cartilage defect repair in recent years. And scaffold and in vivo microenvironment are two important factors restricting the efficacy of ADSCs in cartilage defect repair. We previously constructed a rabbit bionic II/II collagen scaffold and platelet-rich plasma (PRP), and found the scaffold is a good 3D scaffold for ADSCs and PRP can provide a suitable microenvironment for chondrogenic differentiation of ADSCs. In addition, related studies showed that PRP regulates the key signal pathway for chondrogenic differentiation of ADSCs: TGFβ/BMPs and Wnt/β-catenin pathway. Therefore, we intend to construct a composite scaffold with the bionic II/II collagen scaffold and PRP, which can provide a good 3D structure and a suitable microenvironment for chondrogenic differentiation of ADSCs and also the cartilage defect repair. In this project, we will construct this new bionic II/III collagen-PRP composite scaffold and investigate the regulating role of the bionic scaffold in the regulation of chondrogenic differentiation of ADSCs and the related signal pathway in vitro. Furthermore, we will validate that the effect and mechanism of the composite of the scaffold and ADSCs in articular cartilage defects repair in vivo. The result of study will provide new insights and methods for the repair of articular cartilage defects.

脂肪干细胞(ADSCs)移植已成为软骨缺损修复的研究热点，支架和体内微环境是制约其修复疗效的主要因素。我们前期构建了仿生II型/II型胶原支架和兔富血小板血浆(PRP)，并发现该支架是荷载ADSCs的良好三维支架，PRP可为ADSCs成软骨分化提供良好的微环境。此外，研究表明PRP可调控ADSCs成软骨分化的关键信号通路TGFβ/BMPs和Wnt/β-catenin通路。因此，我们设想将仿生I型/II型胶原支架与PRP结合，构建既能模拟体内三维结构，又能提供良好微环境的复合支架，以提高ADSCs成软骨分化能力和修复软骨缺损的疗效。在本项目，我们拟构建新型的仿生II型/III型胶原-PRP复合支架，并在体外水平研究该支架对ADSCs成软骨分化和上述信号通路的调控作用，并在体内水平验证该支架荷载ADSCs修复关节软骨缺损的作用及机制。本研究结果将为探索关节软骨缺损修复提供新的思路和方法。

脂肪干细胞(ADSCs)移植是软骨缺损修复的研究热点，支架和体内微环境是制约其修复疗效的主要因素。我们构建了仿生II型/III型胶原支架-富血小板血浆(PRP)复合支架，采用扫描电镜观察支架的表征，并检测了支架的力学性能和缓释生长因子的特性。将最佳比例的复合支架荷载ADSCs，构建了既能模拟体内三维结构，又能提供良好微环境的复合支架，以提高ADSCs成软骨分化能力和修复软骨缺损的疗效。分为5个不同组别进行研究，分别为ADSCs组、ADSCs+仿生II型/III型胶原支架组，ADSCs+PRP组，ADSCs+仿生II型/III型胶原支架+PRP组，ADSCs+仿生II型/III型胶原支架TMV (烟草花叶病毒)修饰+PRP组。在不同的时间点，在基因和蛋白水平检测软骨细胞特异分子的表达、合成情况。在不同时间点检测TGF-β/BMPs和Wnt/β-catenin信号通路的激活水平。并建立了兔膝软骨缺损的模型，将荷载ADSCs的仿生II型/III型胶原支架植入软骨缺损区。