Effect of dynamic culture conditions on the production of an erythroid progenitor cell line within fluidised bed bioreactors

Red blood cells (RBCs) are an essential therapeutic resource; however, insufficient supply and risks of blood-borne infections drive the need for alternative sources. The Bristol Erythroid Lineage – Adult (BEL-A) erythroid progenitor cell line provides a new source for the indefinite production of cultured RBCs, but efficient and scalable bioprocessing strategies are yet to be established. Fluidised bed bioreactors (FBBs), with their low-shear environments and high mass transfer capabilities, can support high-density cultures, particularly at large scales, offering a promising manufacturing platform for BEL-A expansion. However, their optimal operating conditions and effects on BEL-A cell have yet to be defined. Using a design of experiments statistical approach, we systematically investigated how dynamic culture conditions impact BEL-A proliferation within FBBs. A lower media perfusion velocity, reduced initial cell seeding number, and a higher cell density (cells/ml) enhanced cellular proliferation. We demonstrate that FBB culture achieved productivity comparable to static culture whilst offering scalability and reduced manual handling. Importantly, no spontaneous differentiation of BEL-A cells was observed, confirming the system’s suitability for maintaining progenitor cell characteristics. This study is the first to demonstrate the feasibility of FBBs for mammalian single-cell suspension culture, using BEL-A as a model system. Furthermore, our work represents a critical step towards the clinical-scale manufacture of BEL-A cells and unlocking their therapeutic potential as a source of cultured RBCs.