Tailored microcarriers from solid to porous: Rapid doubling and differentiation behaviors of piscine satellite cells

Microcarriers (MCs) play a crucial role in promoting cells to expand in culture systems for the industries as regenerative medicine products and cell-derived alternative proteins. However, high-performance and biosafe MCs are still urgently needed for cell scale-up expansion under the dynamic shearing environment of bioreactor and pipeline. Here, gelatin was used which is of high biocompatibility and edibility as MC matrix, by TGase-induced crosslinking in combination with emulsification method for piscine satellite cells (PSCs) cultivation. MCs cultivation conditions were optimized in the spinner flasks (6000 MCs/mL, 8:1 ratio of cells to MCs, 50 rpm speed), to achieve about 5 fold of PSCs on Day 9. To further increase the proliferation efficiency, solid MCs were modified to porous MCs through ice templating method, which could lead to ∼6.32 proliferation multiple on Day 9 with high-efficiency differentiation. Also, transcriptome analysis showed that the genes related to cell cycle and DNA replication were obviously upregulated in the MCs groups in comparison to the 2D cultivation group of PSCs. Collectively, these findings demonstrate the ability of porous MCs in realizing large-scale cell expansion and even differentiation.