Simple 3D-Printed Stirred Bioreactor Enhances Retinal Organoid Production Via Improved Oxygenation

To test this hypothesis, we measured dissolved oxygen concentrations at the vessel bottom and found that within hours of media change, oxygen dropped to < 1 %, a level considered non-physiologically hypoxic, which imperils cell viability. This non-physiological hypoxia contributed OV degeneration, hypoxic marker expression, and necrosis. To address this problem, we developed a novel 3D-printed stirred bioreactor (SBR) that maintains physiological oxygen levels between ~4-6%.

This approach significantly improved organoid yield, quality, and reproducibility while being easily adaptable to typical laboratory cell culture workflows. We conclude that non-physiological hypoxia, a previously unappreciated condition, is a limiting factor underlying inconsistent yield and quality in RO production. Physiological oxygenation levels can be restored by the SBR platform, resulting in greater consistency and improved production outcomes.