The role of cell seeding density and nutrient supply for articular cartilage tissue engineering with deformational loading
The role of cell seeding density and nutrient supply for articular cartilage tissue engineering with deformational loading
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DOI：
10.1016/j.joca.2003.08.006
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发表时间：
2003-12-01
影响因子：
7
通讯作者：
Hung, CT
中科院分区：
文献类型：
--
作者：
Mauck, RL;Wang, CCB;Hung, CT
目的：关节软骨的功能组织工程（FTE）涉及使用生理相关的机械信号来促进工程结构的生长。本研究的目的是确定变形载荷在增强软骨细胞接种的琼脂糖水凝胶的机械性能方面的效用，并研究初始细胞接种密度和营养供应在此过程中的作用。 设计：软骨细胞接种的琼脂糖水凝胶在自由膨胀条件下或间歇性变形载荷（10％变形，1 Hz，1小时开/1小时关，每天3小时，每周五天）下培养两个月的培养期。在比以前的研究提供更多的培养基供应（减少细胞/ml补料培养基/天）和增加胎牛血清浓度（10或20% FBS）的情况下，以更低（1000万个细胞/ml）和更高（6000万个细胞/ml）的接种密度接种圆盘。结果：在这些更优化的营养条件下，在更高的接种密度和高血清浓度（20%FIBS）下，动态加载的构建体显示相对于自由膨胀对照，材料性能提高了 2 倍以上。经过两个月的培养，动态加载的结构达到了类似于 185 kPa 的杨氏模量和类似于 1.6 MPa 的动态模量（1 Hz），具有与天然组织类似的频率依赖性响应。这些值分别表示与针对天然组织测量的值的3/4和1/4相似。虽然机械性能存在显着差异，但较高接种密度构建体的蛋白聚糖和胶原含量的染色和批量测量显示自由膨胀组和加载组之间没有显着差异。这一发现表明，变形载荷可能通过结构组织的差异、小连接体 ECM 分子的产生或通过调节大分子蛋白聚糖聚集体的大小来提高材料性能。结论：综上所述，这些结果表明动态变形载荷在工程关节软骨结构的机械预处理中的效用，以及随着细胞接种密度的增加而增加补料培养基体积和血清补充的必要性。 (C) 2003 年国际骨关节炎研究协会。由爱思唯尔有限公司出版。保留所有权利。
Objective: Functional tissue engineering (FTE) of articular cartilage involves the use of physiologically relevant mechanical signals to encourage the growth of engineered constructs. The goal of this study was to determine the utility of deformational loading in enhancing the mechanical properties of chondrocyte-seeded agarose hydrogels, and to investigate the role of initial cell seeding density and nutrient supply in this process.Design: Chondrocyte-seeded agarose hydrogels were cultured in free-swelling conditions or with intermittent deformational loading (10% deformation, 1 Hz, 1 h on/1 h off, 3 h per day, five days per week) over a two-month culture period. Disks were seeded at lower (10 million cells/ml) and higher (60 million cells/ml) seeding densities in the context of a greater medium supply than previous studies (decreasing the number of cells/ml feed medium/day) and with an increasing concentration of fetal bovine serum (10 or 20% FBS).Results: Under these more optimal nutrient conditions, at higher seeding densities and high serum concentration (20% FIBS), dynamically loaded constructs show >2-fold increases in material properties relative to free-swelling controls. After two months of culture, dynamically loaded constructs achieved a Young's modulus of similar to185 kPa and a dynamic modulus (at 1 Hz) of similar to1.6 MPa, with a frequency dependent response similar to that of the native tissue. These values represent similar to3/4 and similar to1/4 the values measured for the native tissue, respectively. While significant differences were found in mechanical properties, staining and bulk measurements of both proteoglycan and collagen content of higher seeding density constructs revealed no significant differences between free-swelling and loading groups. This finding indicates that deformational loading may act to increase material properties via differences in the structural organization, the production of small linker ECM molecules, or by modulating the size of macromolecular proteoglycan aggregates.Conclusions: Taken together, these results point to the utility of dynamic deformational loading in the mechanical preconditioning of engineered articular cartilage constructs and the necessity for increasing feed media volume and serum supplementation with increasing cell seeding densities. (C) 2003 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.