• Non-porous microcarriers are essential for large-scale adherent cell culture in stirred-tank bioreactors, supporting cell densities of 10^9-10^10 cells/L.
• The material selection for non-porous microcarriers is driven by the need for appropriate surface charge or integrin binding sites to promote cell adhesion.
• Commercialized non-porous microcarriers are primarily made of dextran, polystyrene, and collagen, while chitosan and cellulose-based alternatives show promise but are not yet commercialized.
• Crosslinking is the predominant preparation method for non-porous microcarriers, with novel droplet dispersion systems potentially reducing production costs.