Reinwald Yvonne, Leonard Katherine H L, Henstock James R, Whiteley Jonathan P, Osborne James M, Waters Sarah L, Levesque Philippe, El Haj Alicia J
1 Institute of Science and Technology in Medicine, University of Keele , Stoke-on-Trent, United Kingdom .
Tissue Eng Part C Methods. 2015 Jan;21(1):1-14. doi: 10.1089/ten.tec.2013.0476.
Bioreactors have been widely acknowledged as valuable tools to provide a growth environment for engineering tissues and to investigate the effect of physical forces on cells and cell-scaffold constructs. However, evaluation of the bioreactor environment during culture is critical to defining outcomes. In this study, the performance of a hydrostatic force bioreactor was examined by experimental measurements of changes in dissolved oxygen (O2), carbon dioxide (CO2), and pH after mechanical stimulation and the determination of physical forces (pressure and stress) in the bioreactor through mathematical modeling and numerical simulation. To determine the effect of hydrostatic pressure on bone formation, chick femur skeletal cell-seeded hydrogels were subjected to cyclic hydrostatic pressure at 0-270 kPa and 1 Hz for 1 h daily (5 days per week) over a period of 14 days. At the start of mechanical stimulation, dissolved O2 and CO2 in the medium increased and the pH of the medium decreased, but remained within human physiological ranges. Changes in physiological parameters (O2, CO2, and pH) were reversible when medium samples were placed in a standard cell culture incubator. In addition, computational modeling showed that the distribution and magnitude of physical forces depends on the shape and position of the cell-hydrogel constructs in the tissue culture format. Finally, hydrostatic pressure was seen to enhance mineralization of chick femur skeletal cell-seeded hydrogels.
生物反应器已被广泛认可为用于为工程组织提供生长环境以及研究物理力对细胞和细胞-支架构建体影响的有价值工具。然而，在培养过程中评估生物反应器环境对于确定结果至关重要。在本研究中，通过机械刺激后对溶解氧（O2）、二氧化碳（CO2）和pH变化的实验测量以及通过数学建模和数值模拟确定生物反应器中的物理力（压力和应力），来检验静水力生物反应器的性能。为了确定静水压力对骨形成的影响，将接种了鸡股骨骨骼细胞的水凝胶在0-270 kPa和1 Hz下每天进行1小时（每周5天）的循环静水压力处理，持续14天。在机械刺激开始时，培养基中的溶解O2和CO2增加，培养基的pH降低，但仍保持在人体生理范围内。当将培养基样品置于标准细胞培养箱中时，生理参数（O2、CO2和pH）的变化是可逆的。此外，计算模型表明，物理力的分布和大小取决于组织培养形式中细胞-水凝胶构建体的形状和位置。最后，观察到静水压力可增强接种了鸡股骨骨骼细胞的水凝胶的矿化作用。
