A bioreactor for subjecting cultured cells to fast-rate intermittent hypoxia

High frequency intermittent hypoxia is one of the most relevant injurious stimuli experienced by patients with obstructive sleep apnea (OSA). Given that the conventional setting for culturing cells under intermittent hypoxia conditions is limited by long equilibration times, we designed a simple bioreactor capable of effectively subjecting cultured cells to controlled high-frequency hypoxic/normoxic stimuli. The bioreactor's operation is based on exposing cells to a medium that is bubbled with the appropriate mixture of gases into two separate containers, and from there it is directed to the cell culture dish with the aid of two bidirectional peristaltic pumps. The device was tested on human alveolar epithelial cells (A549) and mouse melanoma cells (B16-F10), subjecting them to patterns of intermittent hypoxia (20 s at 5% O2 and 50 s at 20% O2), which realistically mimic OSA of up to severe intensity as defined by the apnea hypopnea index. The proposed bioreactor can be easily and inexpensively assembled and is of practical use for investigating the effects of high-rate changes in oxygen concentration in the cell culture medium.

.Highlights► A bioreactor is presented for culturing cells under fast-rate intermittent hypoxia. ► Intermittent hypoxia is related to pathological conditions like obstructive sleep apnea. ► Cell culture medium is exchanged between two distinct containers. ► The medium is equilibrated to the desired O2 concentration in each container. ► The prototype was tested with human alveolar epithelial and mouse melanoma cells.