The overall goal of this proposal is to extend present steady, laminar flow experiments by characterizing the response of anchorage-dependent cells to shear stresses varying at the frequencies encountered in a bioreactor environment. Idealized single frequency cyclic stresses will be tested as a way of understanding the different responses caused by the spectrum of turbulent shear stresses. These will be compared to the responses to actual turbulent stresses to validate the fluid mechanical simplification. The categories of experiments to be done are: - Comparison of cell response to laminar versus turbulent flows in a flow chamber. - Comparison with cells grown in a turbulent stirred bioreactor. - Effects of low frequency (< 1 Hz) flow changes in the flow chamber. - Effect of high frequency (> 1 Hz) uniaxial shear stresses in a zero-mean-flow system. - Effect of rotating shear stress vectors of various constant magnitudes.
