M.S. Thesis Presentation by Amanda C. Weber

(Dr. G. Paul Neitzel, advisor)

"Visualization and Quantitative Measurements of Flow Within a Perfused Bioreactor"

Abstract

Common methods of investigating fluid mechanics may be useful in understanding the growth of tissue constructs in bioreactors.  Specifically, qualitative and quantitative analyses of fluid flow through a perfused bioreactor may provide insight regarding the tissue engineering of cartilage-like constructs.  A dynamic fluid environment may enhance the transfer of nutrients, oxygen, and waste between cells and the culture medium.  However, fluid shear stresses may also cause cell damage or death. The research presented may be useful in understanding the nature of tissue growth, may improve methods of in vitro tissue growth, and may be used as a tool to improve bioreactor design.

A unique bioreactor, employing plug-flow perfusion of a three-dimensional polymer scaffold, was investigated to gain a deeper understanding of the fluid dynamics within the vessel.  An experimental model of the bioreactor was designed and constructed to allow visualization of the internal flow without distortion due to the curvature of the outer wall.  The experimental fluid was refractive-index-matched to the material of construction of the bioreactor model to eliminate distortions due to the curvature of the inner wall.  Flow visualization was used to qualitatively assess the flow field within the bioreactor.  Particle-image velocimetry was utilized to quantify the velocity field both upstream and downstream of the three-dimensional polymer scaffold.