A Reversible Adhesive Microfluidic Device for Culture of 3D Cell Pellets

Many of the findings in cell biology have come from cultures of cells grown in flat receptacles, but the limitations of considering biology solely in two dimensions are now becoming clear. Researchers are increasingly turning to 3D cell cultures, where they believe patterns of biological activities are more similar to those occurring in living organisms. Three dimensional (3D) cell cultures have been widely used since the early decades of last century, but providing an appropriate environment where cells can be cultured in 3D is no easy matter. Recently some researchers used simple gels containing collagen fibers, whereas others made their own gels by extracting ECM material from relevant tissues. Here we developed a microfluidic device for the generation of 3D chondrocyte pellets within a microfluidic perfused environment. Pellets were generated by means of gravity sedimentation without the need of a centrifugation step. In order to characterize the generated pellets, a reversible bonded microfluidic device was also developed, so as to be able to use traditional biological techniques. At 6 days of culture the measured metabolic activity were greatest in the perfused pellets compared to the non-perfused one. The pellets generated within the microfluidic device were also homogeneously populated with interposed matrix and were surrounded by a thin peripheral layer, densely cell- populated without interposed matrix. The system should be readily applicable for culture of various other types of cells in a physiological 3D setting. These results could favourably exploited in tissue engineering applications.