A high throughput system for long term application of intermittent cyclic hydrostatic pressure on cells in culture

The process of bone remodeling is governed by mechanical stresses and strains. Studies on the effects of mechanical stimulation on cell response are often difficult to compare as the nature of the stimuli and differences in parameters applied vary greatly. Experimental systems for the investigation of mechanical stimuli are mostly limited in throughput or flexibility and often the sum of several stimuli is applied. In this work, a flexible system that allows the investigation of cell response to isolated intermittent cyclic hydrostatic pressure (icHP) on a high throughput level is shown. Human bone derived cells were cultivated with or without mechanical stimulus in the presence or absence of chemical cues triggering osteogenesis for 7-10 days. Cell proliferation and osteogenic differentiation were evaluated by cell counting and immunohistochemical staining for bone alkaline phosphatase as well as collagen 1, respectively. In either medium, both cell proliferation and level of differentiation were increased when the cultures were mechanically stimulated. These initial results therefore qualify the present system for studies on the effects of isolated icHP on cell fate and encourage further investigations on the details behind the observed effects.