可注射脱细胞基质/PRP水凝胶对半月板修复与再生的研究

Meniscus repair and regeneration represent one of the most significant clinical challenges. Decellularized meniscus extracellular matrix (dmECM) is a novel natural material and contains numerous meniscus tissue-specific bioactive components. Platelet-rich plasma (PRP) is composed of concentrated platelets. Upon activation, PRP is capable of releasing multiple growth factors to promote tissue repair and regeneration. However, both dmECM and PRP have their limitations in the application. In the current proposal, we intend to take full use of the advantages of both materials to develop an injectable hydrogel, in which dmECM chemically and structurally mimics the extracellular matrix (ECM) of the native meniscus, and PRP provides critical bioactive molecules to stimulate cellular growth and tissue regeneration. Based on the platform of the dmECM/PRP hydrogel, we will conduct investigations as follow: (1) combining the hydrogel with meniscus fibrochondrocytes and mesenchymal stem cells for three-dimensional culture to mimic the growth and development of meniscus; (2) evaluating the capacity of dmECM/PRP hydrogel in advancing in situ meniscus repair and regeneration via ex vivo and in vivo studies. This project is expected to uncover the essential cellular and molecular mechanisms in meniscus development and to boost meniscus tissue engineering, as well as to provide proof-of-concept of injectable biomedical materials for meniscus repair and regeneration.

半月板修复与再生是临床医学最具挑战性的课题之一。半月板脱细胞基质（dmECM）是一种新型天然材料，它含有大量的半月板组织特异性生物活性成分。富血小板浆（PRP）中含有高浓度血小板，激活后能释放多种生长因子，促进组织修复与再生。然而，这两种材料在实际应用中都有各自的不足。本项目拟采取材料优势互补的策略，发展一种可注射型仿生水凝胶：利用dmECM从成分和结构上仿生半月板细胞外基质；PRP提供多重生长因子来促进细胞生长和组织修复与再生。我们将以dmECM/PRP水凝胶为平台展开如下研究：1）水凝胶复合半月板纤维软骨细胞和间充质干细胞进行三维培养来模拟半月板生长和发育过程；2）组织体外培养和动物实验评估该水凝胶促进半月板原位修复与再生的能力。本项目有望阐明半月板生长发育过程中关键的细胞分子生物学机制，推动半月板组织工程的发展，为可注射型生物医用材料在半月板修复与再生的应用提供理论依据。

本课题研究目标是制备并优化基于脱细胞半月板基质（dmECM）的支架，使其能够促进半月板细胞（MFC）和间充质干细胞（MSC）生长与分化并维持稳定的纤维软骨形态。我们成功制备了dmECM，也通过细胞负载实验证明了其良好的细胞相容性。我们研究了软骨细胞、MFC、MSC在dmECM多孔支架和静电纺dmECM纳米纤维支架生长与分化并维持稳定的纤维软骨形态。我们证明了两种支架组织特异性生物活性成分对纤维软骨细胞形态的维持有决定性作用：软骨细胞在支架上保持软骨表达特性；MSC细胞在支架上呈成纤维细胞分化；MFC在支架上呈纤维软骨分化。这些结果证明dmECM是半月板组织修复与再生的优选生物材料。.基于对两种支架良好的细胞相容性，我们开展皮下大鼠包埋实验验证其体内植入效果及生物相容性。我们结果表明，两种支架都支持良好的细胞浸润，即细胞能在体内条件下，能够快速长入支架内部，适合新生组织形成。但是，我们发现两种支架植入物均在早期表现出一定强度的异物反应（FBR），这可能与其生物活性成份和大孔结构有关。我们采取了相应策略，引入抗炎成分，制成抗炎dmECM多孔支架，进行体内原位半月板组织修复。三个月后观察效果良好。