Microbioreactors

Advanced bioreactors that provide multiple molecular and physical regulatory signals, when required in form of spatial and temporal gradients, are of great interest for hESCs, because of the complexity of their regulatory pathways, and uncontrolled variables associated with traditional culture methods. We recently developed a microbioreactor that is the size of a microscope slide and contains twelve independent chambers perfused with culture medium, for cell culture in two-dimensional and three-dimensional settings (Figallo et al. 2007). The microbioreactor array combines the advantages of simple multi-well plates (small volume, high throughput, independent culture wells) with those of perfusion bioreactors (steady-state conditions, enhanced mass transport, application of physical signals).

To take advantage of imaging compatibility of this device, we developed an automated image analysis routine for fast analysis of nuclear and cytoplasmic differentiation markers. In studies of hESCs in this system, we established correlations between the expression of smooth muscle actin with hydrodynamic shear and cell density. The microbioreactor arrays of this kind could be used to study the effects of culture parameters on hESC differentiation, in a systematic manner and with only a minimal consumption of cells and reagents. We are working on prototypes of microbioreactors that are suitable for screening of cells and culture conditions and possibly for studies of disease models and drug screening.