Abstract

We have realised devices for different bioprocessing applications. In this presentation, a novel, autoclavable, microfluidic cell culture platform with re-sealable culture chambers will be presented. Re sealable culture chambers facilitate the insertion of any kind of biomaterial into an otherwise fully assembled device; for example for the static seeding of cells and the deposition of extra-cellular matrices. The chambers reversibly seal with a TC-PS microscope slide or any other slide as long as it has a smooth, flat surface and the dimensions of a standard microscope slide. This makes a number of materials immediately available for investigation. As a result, this device could be employed to test growth surface candidates from microarray screening, under the defined culture conditions afforded by microfluidics. The dimensions of the re-sealable culture chamber will also allow in the future inserting embryoid bodies, microcarriers or organoids. In our platform, confluency and dissolved oxygen tension levels are monitored on-line and in situ, yielding time profiles of the two and the ability to correlate oxygen consumption with growth data. Furthermore, we applied machine-learning methods to analyse the texture of cell culture images. This enables us to estimate the mean distance between cell nuclei in a cell culture, and therefore estimate cell density. We can thus for the first time show time profiles of cell densities, and calculate in real time specific oxygen uptake rates at different stages of a mouse embryonic stem cell culture in a microfluidic platform, i.e. without disruption of the culture. We thus demonstrate for the first time the real-time measurement of specific oxygen uptake rate without disrupting the stem cell culture. Additionally, our image-processing algorithm is capable to segment images in co-culture situations, and we have demonstrated the detection of human embryonic stem cell colonies grown on inactivated mouse embryonic fibroblasts.