Buxton Amanda N, Zhu Junmin, Marchant Roger, West Jennifer L, Yoo Jung U, Johnstone Brian
Oregon Health and Science University, Portland, OR 97239, USA.
Tissue Eng. 2007 Oct;13(10):2549-60. doi: 10.1089/ten.2007.0075.
Mesenchymal stem cells (MSCs) are used extensively in cartilage tissue engineering. We have developed a photopolymerizable poly(ethylene glycol diacrylate) (PEGDA) and poly(ethylene glycol) (PEG) semi-interpenetrating network that facilitates the in vitro chondrogenesis of human MSCs (hMSCs). Network parameters were altered and tested for their effects on subsequent matrix elaboration. The mesh size, calculated for each network based on equilibrium swelling ratios, was larger with lower PEGDA:PEG ratios and with higher PEGDA molecular weight. Changes in xi correlated with changes in extracellular matrix content and deposition in hMSC-seeded networks cultured in vitro for 6 weeks in defined chondrogenic medium. Networks constructed with PEGDA (6 kDa) and PEG (88 kDa) at 1:2 displayed intercellular deposition of proteoglycan. Furthermore, their proteoglycan contents were significantly higher than with PEGDA (6 kDa) hydrogels constructed without the PEG component and those constructed at a PEGDA:PEG ratio of 2:1, which both exhibited pericellular proteoglycan deposition. However, networks constructed with PEGDA (12 and 20 kDa) and PEG (88 kDa) exhibited intercellular deposition of proteoglycan regardless of the ratio employed. Collagen content was lower in networks constructed with PEGDA (12 and 20 kDa) and PEG (88 kDa) at a ratio of 1:2 than in those fabricated at the same PEGDA molecular weights at a ratio of 2:1. This study demonstrated that semi-interpenetrating network parameters influence not only extracellular matrix content, but also the deposition of the matrix molecules by hMSCs undergoing chondrogenesis. It is important that these parameters be considered carefully when creating scaffolds for tissue-engineered cartilage.
间充质干细胞（MSCs）广泛应用于软骨组织工程。我们开发了一种可光聚合的聚（乙二醇二丙烯酸酯）（PEGDA）和聚（乙二醇）（PEG）半互穿网络，该网络促进了人MSCs（hMSCs）的体外软骨形成。改变网络参数并测试其对后续基质形成的影响。根据平衡溶胀率计算的每个网络的网孔尺寸，在较低的PEGDA:PEG比例和较高的PEGDA分子量下更大。在特定软骨形成培养基中体外培养6周的hMSC接种网络中，ξ的变化与细胞外基质含量和沉积的变化相关。以1:2比例构建的PEGDA（6 kDa）和PEG（88 kDa）网络显示蛋白聚糖的细胞间沉积。此外，它们的蛋白聚糖含量显著高于没有PEG成分构建的PEGDA（6 kDa）水凝胶以及以2:1的PEGDA:PEG比例构建的水凝胶，后两者均表现出细胞周围蛋白聚糖沉积。然而，无论采用何种比例，用PEGDA（12和20 kDa）和PEG（88 kDa）构建的网络都显示出蛋白聚糖的细胞间沉积。以1:2比例构建的PEGDA（12和20 kDa）和PEG（88 kDa）网络中的胶原蛋白含量低于以相同PEGDA分子量、2:1比例构建的网络。这项研究表明，半互穿网络参数不仅影响细胞外基质含量，还影响正在经历软骨形成的hMSCs的基质分子沉积。在创建用于组织工程软骨的支架时，仔细考虑这些参数很重要。
