title: Droplet size influences division of mammalian cell factories in droplet microfluidic cultivation.
abstract: The potential of using droplet microfluidics for screening mammalian cell factories has been limited by the difficulty in achieving continuous cell division during cultivation in droplets. Here, we report the influence of droplet size on mammalian cell division and viability during cultivation in droplets. Chinese Hamster Ovary (CHO) cells, the most widely used mammalian host cells for biopharmaceuticals production were encapsulated and cultivated in 33, 180 and 320 pL droplets for 3 days. Periodic monitoring of the droplets during incubation showed that the cell divisions in 33 pL droplets stopped after 24 h, whereas continuous cell division was observed in 180 and 320 pL droplets for 72 h. The viability of the cells cultivated in the 33 pL droplets also dropped to about 50% in 72 h. In contrast, the viability of the cells in the larger droplets was above 90% even after 72 h of cultivation, making them a more suitable droplet size for 72-h cultivation. This study shows a direct correlation of microfluidic droplet size to the division and viability of mammalian cells. This highlights the importance of selecting suitable droplet size for mammalian cell factory screening assays.
authors.affiliation: Division of Proteomics and Nanobiotechnology, Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Prem Kumar
authors.initials: PK
authors.lastname: Periyannan Rajeswari
authors.affiliation: Division of Proteomics and Nanobiotechnology, Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden.|Novo Nordisk Foundation Center for Biosustainability, KTH Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Haakan N
authors.initials: HN
authors.lastname: Joensson
authors.affiliation: Division of Proteomics and Nanobiotechnology, Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden.|Novo Nordisk Foundation Center for Biosustainability, KTH Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Helene
authors.initials: H
authors.lastname: Andersson-Svahn
mesh_terms: D000818:Animals; D001702:Biopharmaceutics / Q000379:methods*; D016466:CHO Cells; D018929:Cell Culture Techniques / Q000379:methods*; D002470:Cell Survival; D006224:Cricetinae; D003412:Cricetulus; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D010316:Particle Size; D059010:Single-Cell Analysis / Q000379:methods*
keywords: Biopharmaceuticals; Cell factories; Droplet microfluidics; Single cell analysis