Building a tissue: gingiva- and adipose-derived mesenchymal cell spheroids’ survivability and functionality after 3D extrusion bioprinting

While being the most extensively used cell type for spheroid-based 3D extrusion bioprinting, mesenchymal stromal cells (MSCs) provide a wide spectrum of biological properties depending on their origin. Understanding the specifics of each heterogeneous MSCs population subgroup would allow one to increase the survivability and functionality of the constructed tissue analogues. To answer this need, this study assessed the survivability, metabolic activity, proliferation, sprouting, migration, and differentiation capacity of MSCs spheroids depending on the cell source (adipose tissue, AT-MSCs/gingiva, G-MSCs) and on the tissue construct's geometry (bioprinted/manually mixed). This study has demonstrated that the cell origin defines the dynamics of spheroid reactivation, resulting in a varying construct's morphology after a 14-days-long cultivation period. AT-MSCs migrate in the hydrogel faster, forming clusters of wide and short sprouts. G-MSCs, oppositely, produce thin, long, and branched sprouts. Hence, AT-MSCs can quickly populate the hydrogel volume, achieving a high cell density, while G-MSCs can cover larger areas, but with a more sprout-like phenotype.