PDF(Pubmed)
Abstract：
The pericellular matrix (PCM) surrounding chondrocytes is essential for articular cartilage tissue engineering. As the current isolation methods to obtain chondrocytes with their PCM (chondrons) result in a heterogeneous mixture of chondrocytes and chondrons, regenerating the PCM using a tissue engineering approach could prove beneficial. In this study, we aimed to discern the behavior of articular chondrocytes (ACs) in regenerating the PCM in such an approach and whether this would also be true for articular cartilage-derived progenitor cells (ACPCs), as an alternative cell source. Bovine ACs and ACPCs were encapsulated in agarose microgels using droplet-based microfluidics. ACs were stimulated with TGF-β1 and dexamethasone and ACPCs were sequentially stimulated with BMP-9 followed by TGF-β1 and dexamethasone. After 0, 3, 5, and 10 days of culture, PCM components, type-VI collagen and perlecan, and ECM component, type-II collagen, were assessed using flow cytometry and fluorescence microscopy. Both ACs and ACPCs synthesized the PCM before the ECM. It was seen for the first time that synthesis of type-VI collagen always preceded perlecan. While the PCM synthesized by ACs resembled native chondrons after only 5 days of culture, ACPCs often made less well-structured PCMs. Both cell types showed variations between individual cells and donors. On one hand, this was more prominent in ACPCs, but also a subset of ACPCs showed superior PCM and ECM regeneration, suggesting that isolating these cells may potentially improve cartilage repair strategies.
摘要：
软骨细胞周围的细胞外基质（PCM）对于关节软骨组织工程至关重要。作为目前的分离方法，以获得软骨细胞与他们的PCM（软骨）导致软骨细胞和软骨的异质混合物，使用组织工程方法再生PCM可以证明是有益的。在这项研究中,我们的目的是辨别关节软骨细胞（AC）在这种方法中再生PCM的行为，以及这是否也适用于关节软骨来源的祖细胞（ACPC），作为替代细胞来源。使用基于液滴的微流体将牛AC和ACPC封装在琼脂糖微凝胶中。用TGF-β1和地塞米松刺激AC，然后用BMP-9刺激ACPC，然后用TGF-β1和地塞米松刺激ACPC。培养0、3、5和10天后，PCM组件,VI型胶原蛋白和Perlecan，和ECM组件，II型胶原蛋白，使用流式细胞术和荧光显微镜进行评估。AC和ACPC都在ECM之前合成PCM。首次发现VI型胶原蛋白的合成总是先于Perlecan。虽然由AC合成的PCM在仅培养5天后类似于天然软骨,ACPC通常制造结构较差的PCM。两种细胞类型都显示出单个细胞和供体之间的差异。一方面,这在ACPC中更为突出，但也有一部分ACPCs表现出优异的PCM和ECM再生，表明分离这些细胞可能会改善软骨修复策略。
