Collagen Nanofiber Reinforced Alginate Hydrogel Tube Microbioreactors for Cell Culture

Abstract The large-scale production of mammalian cells is pivotal for various applications; however, current bioreactor technologies encounter significant technical and economic challenges. Scaling up cell cultures remains problematic due to excessive cell aggregation, shear stress-induced cell death, batch-to-batch inconsistencies, and limited scalability. We propose that engineering a cell-friendly microenvironment can enhance culture efficiency. Previously, we developed alginate hydrogel microtubes (AlgTubes) that significantly improved cell density and growth rates. Nevertheless, AlgTubes lack adhesion sites essential for anchorage-dependent cells and frequently break, causing cell leakage and production inconsistencies. To address these limitations, this study reinforced AlgTubes with collagen nanofibers, creating collagen-alginate hybrid hydrogel microtubes (ColAlgTubes). Utilizing a novel micro-extruder, we efficiently produced cell-loaded ColAlgTubes. Collagen formed a dense nanofiber network interwoven with the alginate mesh, enhancing the hydrogel’s mechanical properties while providing cell adhesion sites. ColAlgTubes protected cells from hydrodynamic stress and maintained cell mass within a 400 μm diameter, ensuring efficient nutrient exchange and waste removal. This optimized microenvironment resulted in high cell viability, rapid proliferation, and exceptional yields of 5×108 cells/mL - 200 times higher than conventional culture methods. With their scalability, cost-effectiveness, and efficiency, ColAlgTubes offers a transformative solution for large-scale cell production with broad applications in biotechnology, regenerative medicine, and therapeutic manufacturing. Competing Interest Statement Y.L. owns equity in CellGro Technologies, LLC. This financial interest has been reviewed by the University's Individual Conflict of Interest Committee and is currently managed by the University.