3D-embedding of human gingiva-derived mesenchymal stromal cells in "VitroGel^® MSC" hydrogel alters their immune...

Human gingiva-derived mesenchymal stromal cells (hG-MSCs) are promising candidates for cell-based therapy due to their immunomodulatory ability. Culturing in 3D hydrogels has emerged as a promising strategy to improve cell survival in the host and enhance clinical efficacy. This study assesses how embedding hG-MSCs in "VitroGel^® MSC" hydrogel affects their immunomodulatory profile in various inflammatory environments, compared with conventional 2D cultures.

hG-MSCs from six donors were either 3D-embedded in commercially available "VitroGel^® MSC", cultured on "VitroGel^® MSC", or in 2D on tissue culture plastic under resting conditions or in the presence of interferon (IFN)-γ, interleukin (IL)-1β, or tumor necrosis factor (TNF)-α. Metabolic activity and cell viability were assessed by MTT assay and live/dead staining, respectively. Gene expression of IL-8, cyclooxygenase (COX)-2, indoleamine-2,3-dioxygenase (IDO)-1, programmed cell death ligand 1 (PD-L1), PD-L2, and TNF-stimulated gene (TSG)-6 were analyzed by RT-qPCR, and IL-8 and prostaglandin E₂ (PGE₂) protein levels were determined by ELISA.

Metabolic activity was reduced in 3D-embedded hG-MSCs independently of the environment, but only in the presence of IFN-γ and TNF-α, a slight decrease in cell viability was observed. Hydrogel-embedded and -exposed hG-MSCs exhibited increased IL-8 expression under resting and IFN-γ conditions, and consistently upregulated COX-2 and PGE₂. The immunomodulatory mediator TSG-6 was elevated in 3D-embedded hG-MSCs, while the expression of IDO-1, PD-L1, and PD-L2 upon transition to 3D hydrogel was differently altered depending on the inflammatory environments.

These results demonstrate that 3D microenvironments reshape hG-MSC immunomodulatory potential, underscoring the relevance of 3D models for optimizing MSC-based therapies.