碳纳米管纳米导电材料促进新生大鼠心脏干细胞分化及其调控机制的研究

Considering the structural and electrical conductive property of native myocardium, the application of scaffolds for cardiac tissue engineering based on conductive nanomaterials is raising growing interest. Carbon nanotubes (CNTs) have been considered as promising materials for nanomedicine applications due to their unique electrical and mechanical properties. Several studies have demonstrated the ability of conductive CNTs-based scaffolds to promote neural and cardiac differentiation from stem cells. However, the molecular mechanisms for beneficial effects of CNTs on the differentiation of stem cells are largely unclear. In addition, no reports are available that CNTs-based scaffolds regulate the cardiac differentiation of cardiac stem cell (CSCs) derived from neonatal rats. In the project, we first prepare the collagen-SWCNTs composite scaffolds and evaluate the characterization and toxicity. Then, the effects and laws that collagen-SWCNTs scaffolds have on the cardiac differentiation of CSCs were systematically investigated by morphological and molecular biological methods. On this basis, we explore the roles and mechanism of CNTs in the differentiation process of CSCs in collagen-SWCNTs scaffolds by gene expression profiling and molecular biology techniques. This study is expected to lay the foundation for the application of CNTs and stem cell to cardiac tissue engineering and the future therapy of cardiovascular diseases and provide important experimental data for the mechanism of the regulation of nanomaterials on stem cell.

鉴于心肌组织独有的电生理特性，近年来将导电纳米材料用于心肌组织工程的研究引起了广泛关注。碳纳米管（CNTs）因其优异的力学特性和导电性，已成为纳米医学应用领域非常有前景的材料，研究表明基于CNTs的支架对干细胞向神经和心肌的分化有促进作用，但相关的分子机制尚不明确，此外，目前尚未见CNTs对新生大鼠心脏干细胞（CSCs）分化影响及机制的研究报道。本项目拟首先运用非共价吸附的方法制备胶原/SWCNTs复合支架，并对其表征及毒性评价；然后通过一系列形态学和分子生物学方法系统研究胶原/SWCNTs支架对CSCs分化的作用及规律。在此基础上，通过分子生物学、基因表达谱芯片等方法，深入研究其促CSCs心肌分化的分子机制，明确CNTs促干细胞分化的关键基因和信号通路。本研究不但可为纳米材料调控干细胞分化的机制提供重要数据，而且对CSCs和CNTs在心肌组织工程应用及未来心血管疾病的治疗均具有重要价值。

本项目针对碳纳米管复合导电纳米材料对种子细胞的行为调控作用规律及其机制开展了一系列实验研究，经过三年研究，取得以下进展：1、合成制备了碳纳米管/胶原复合薄膜、碳纳米管/胶原水凝胶、碳纳米管/GelMA水凝胶等多种功能型复合生物材料，并表征了其理化性能，评估了其生物相容性。2、研究了不同碳纳米管生物活性材料对干细胞、心肌细胞生长与分化的作用，发现了碳纳米管能够促进再造心肌组织闰盘的组装与成熟、棕色脂肪来源的干细胞成心肌分化，其作用机制与β1-integrin介导的信号通路有关。在该项目实施过程中发表SCI论文5篇，培养研究生3名。该项目的实施，不但可为纳米材料调控干细胞分化的机制提供重要数据，而且有助于推动碳纳米管在再生医学中广泛应用的途径。