Polymer Matrix‐Based 3D Culture Significantly Enhances the Differentiation and Immunomodulatory Functions of Human Adipose‐Derived Stem Cells

Human adipose-derived stem cells (hADSCs) possess immunomodulatory and multipotent properties, making them attractive candidates for regenerative therapies. However, conventional tissue culture plate (TCP)-based 2D adherent cultures or widely used ultra-low attachment (ULA) spheroid systems often compromise differentiation potential and therapeutic efficacy of hADSCs. Here, we report a synthetic polymer matrix, poly-Z, that enables the formation of hADSC spheroids with significantly enhanced biological functions. Compared to ULA or TCP culture systems, poly-Z-cultured hADSC spheroids exhibited improved cell viability, enriched extracellular matrix deposition, elevated pluripotency marker expression, and superior tri-lineage differentiation capacity. Notably, poly-Z spheroids displayed a distinct immunomodulatory signature characterized by significantly elevated secretion of indoleamine-pyrrole 2,3-dioxygenase (IDO) and prostaglandin E2 (PGE2), and showed enhanced in vivo persistence after transplantation. In mouse models of acute colitis and acetaminophen-induced liver injury, poly-Z-cultured hADSC spheroids markedly alleviated inflammation, reduced tissue damage, and modulated pro- and anti-inflammatory cytokine levels more effectively than ULA or TCP-derived cells. These findings establish the poly-Z matrix as a potent 3D culture platform that enhances the functional and therapeutic potential of hADSCs for clinical applications.