Scaling down bioproduction processes became a major driving force for more accelerated and efficient process development over the last decades. Especially expensive and time-consuming processes like the production of biopharmaceuticals with mammalian cell lines benefit clearly from miniaturisation, due to higher parallelisation and increased insights while at the same time decreasing experimental time and costs. Lately, novel microfluidic methods have been developed, especially microfluidic single-cell cultivation (MSCC) devices proofed to be valuable to miniaturise the cultivation of mammalian cells. So far growth characteristics of microfluidic cultivated cell lines were not systematically compared to larger cultivation scales, however validation of a miniaturisation tool against initial cultivation scales is mandatory to proof its applicability for bioprocess development. Here, we systematically investigate growth, morphology, and eGFP-production of CHO-K1 cells in different cultivation scales including microfluidic chip (230 nL), shake flask (60 mL), and lab-scale bioreactor (1.5 L). Our study shows a high comparability regarding growth rates, cellular diameters, and eGFP production which proofs the feasibility of MSCC as miniaturised cultivation tool for mammalian cell culture. In addition, we demonstrate that MSCC allows insights into cellular heterogeneity and single-cell dynamics concerning growth and production behaviour which, when occurring in bioproduction processes, might severely affect process robustness. Eventually, by providing insights into cellular heterogeneity, MSCC has the potential to be applied as a novel and powerful tool in the context of cell line development and bioprocesses implementation.
Genetic screens in isogenic mammalian cell lines without single cell cloning
