Fluid dynamics characterisation of a rotating bioreactor for tissue engineering.

Biological scaffolds composed of extracellular matrix (ECM) derived from decellularised tissue are increasingly used in regenerative medicine. In this project, a flow perfusion bioreactor (the rotary cell culture system (RCCS), commercially available from Synthecon (Houston, TX)) is used in order to obtain some esophageal extracellular matrix. A theoretical mechanical characterisation of this experimental set-up is provided. Due to the combination of rotation and perfusion, some spiral Poiseuille flow is created inside the tubular esophagus. In a transverse section, a particle (or cell) experiences simultaneously gravitational, Archimedes, centrifugal, Coriolis, and drag forces. In a frame of reference rotating with angular velocity ω, the particle follows a periodic nearly circular path in the clockwise direction, associated with a very slow centrifugal drift towards the esophagus wall. It appears that moderate perfusion rate and rotation speed (ω < 20 rpm and Q < 30 ml/min) are appropriate experimental conditions for esophagus tissue engineering using the RCCS Synthecon bioreactor.