Chaotic printing of hydrogel carriers for human mesenchymal stem cell expansion

Increasing expansion rate in cell manufacturing systems would allow faster delivery of life-saving treatments to a greater number of patients. Chaotic printing is a novel biofabrication technology that could improve cell expansion capabilities by producing hydrogel filaments layered with open channels, resulting in significantly higher surface area-per-unit-volume of interface between cells and nutrient media compared to existing systems. In this study, we chaotically printed hydrogel filaments laden with clinically-relevant, bone marrow-derived human mesenchymal stem cells. After the first week of a 21-day expansion period, cell-laden hydrogel filaments containing open channels had an optimal expansion rate and 2.1x as many cells as filaments without channels. We then validated a novel bioreactor design for expanding cells under flowing nutrient media conditions.