Development and validation of a system for the growth of cells and tissues under intermittent hydrostatic pressure

Various cell populations have been shown to respond to hydrostatic pressure; however, many of the culture systems suffer from shortcomings in design or methodology. Of particular interest to us is the potential role of pressure and other environmental factors in modulating stem cell behavior in intervertebral disk repair. A system was developed for the growth of cells and tissues under intermittent hydrostatic pressure. The system was validated with NIH 3T3 fibroblasts for sterilizability and cytotoxicity. Further experiments were conducted with canine mesenchymal stem cells under various levels of pressure, oxygen, glucose, and conditioned medium. The culture system showed no cytotoxicity and was able to demonstrate that the proliferation and metabolism of mesenchymal stem cells are sensitive to medium glucose and oxygen concentration and hydrostatic pressure. The cells exposed to hydrostatic pressure differed in their morphology from nonexposed cells. The system is capable of supporting long-term cell culture and examining the role of mechanical and environmental stimulation in vivo.