Functional polymer-dependent 3D culture enhances the immunomodulating potential of human bone marrow mesenchymal stromal cells

Human mesenchymal stromal cells (MSCs) hold great regenerative medicine potential due to their pluripotency and paracrine functions. However, MSCs lose stemness and immunomodulatory capabilities in two-dimensional (2D) culture, which differs from the natural MSC niche. We investigated methods to enhance MSC characteristics by employing an in vivo-like culture using functional polymers. Implementing FP003 polymer-based 3D culture, we observed increased expression of stemness markers (Oct4, Nanog), in hMSCs compared to 2D culture on regular plastic. This 3D environment also enhanced expression COX2 and HO1, known for their immunomodulatory functions. MSCs cultured in 3D exhibited higher secretion of PGE2 and effectively suppressed TNF- release from LPS-stimulated splenocytes, surpassing 2D-cultured MSCs. To explore therapeutic potential in vivo, we administered 3D-cultured MSCs via intravenous injection in a mouse model of neuroinflammation. Remarkably, this approach significantly reduced the expression of Iba1 and GFAP compared to 2D-cultured MSC injection. RNA-seq analysis revealed upregulated adhesion-related genes, including ITGA2, in MSCs cultured in 3D. Ectopic ITGA2 expression notably enhanced immunomodulatory function. In summary, our findings demonstrate that an in vivo mimetic 3D culture provides a beneficial microenvironment for MSCs, enhancing their immunomodulatory function through ITGA2 expression. Engineered MSCs can thus be utilized as an effective cell therapy source.