Li Xiaomeng, Chen Shangwu, Li Jingchao, Wang Xinlong, Zhang Jing, Kawazoe Naoki, Chen Guoping
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
Department of Materials Science and Engineering, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan.
Polymers (Basel). 2016 Jul 26;8(8):269. doi: 10.3390/polym8080269.
Gelatin hydrogels can mimic the microenvironments of natural tissues and encapsulate cells homogeneously, which makes them attractive for cartilage tissue engineering. Both the mechanical and biochemical properties of hydrogels can affect the phenotype of chondrocytes. However, the influence of each property on chondrocyte phenotype is unclear due to the difficulty in separating the roles of these properties. In this study, we aimed to study the influence of hydrogel stiffness on chondrocyte phenotype while excluding the role of biochemical factors, such as adhesion site density in the hydrogels. By altering the degree of methacryloyl functionalization, gelatin hydrogels with different stiffnesses of 3.8, 17.1, and 29.9 kPa Young's modulus were prepared from the same concentration of gelatin methacryloyl (GelMA) macromers. Bovine articular chondrocytes were encapsulated in the hydrogels and cultured for 14 days. The influence of hydrogel stiffness on the cell behaviors including cell viability, cell morphology, and maintenance of chondrogenic phenotype was evaluated. GelMA hydrogels with high stiffness (29.9 kPa) showed the best results on maintaining chondrogenic phenotype. These results will be useful for the design and preparation of scaffolds for cartilage tissue engineering.
明胶水凝胶可以模拟天然组织的微环境并均匀地包裹细胞，这使得它们在软骨组织工程中具有吸引力。水凝胶的机械和生化特性都会影响软骨细胞的表型。然而，由于难以区分这些特性的作用，每种特性对软骨细胞表型的影响尚不清楚。在本研究中，我们旨在研究水凝胶硬度对软骨细胞表型的影响，同时排除生化因素的作用，如水凝胶中粘附位点密度的作用。通过改变甲基丙烯酰化程度，由相同浓度的甲基丙烯酰化明胶（GelMA）大分子制备了杨氏模量分别为3.8、17.1和29.9 kPa的不同硬度的明胶水凝胶。将牛关节软骨细胞包裹在水凝胶中并培养14天。评估了水凝胶硬度对包括细胞活力、细胞形态和软骨生成表型维持在内的细胞行为的影响。高硬度（29.9 kPa）的GelMA水凝胶在维持软骨生成表型方面表现出最佳结果。这些结果将有助于软骨组织工程支架的设计和制备。
