Cell Density Regulates Neural Stem Cells of Cellular Contact and Differentiation in 3D Hydrogel Culture System

Neural Stem Cells (NSCs) of biological behaviors are frequently regulated by the three-dimensional (3D) niches that they located in. The impact of cell density cue inside niche on cellular outcomes are usually underestimated and understudied. In this study, a facile NSCs of 3D culture system was developed using collagen self-assembled fibril hydrogel. We used RNA sequencing and molecular biology technologies to investigate the NSCs of cell contacts and differentiations in developed 3D hydrogel culture system with low (0.75 million/mL), medium (1.5 million/mL), and high (3 million/mL) cell packing density. Compared with low cell density system, cytoskeletal spreading, gap junction, and tight junction mediated cell contacts were significantly improved in high cell density culture. Moreover, high cell density increased NSCs differentiation into immature (Tuj1) neuron, while there is no discrepancy of NSCs differentiation into astrocytes in different cell densities of 3D culturing system. This study provides new understanding in the regulation of 3D cultured NSCs behaviors through niche of cell density cue. Overall design: We used RNA sequencing and molecular biology technologies to investigate the NSCs of cell contacts and differentiations in developed 3D hydrogel culture system with low (0.75 million/mL), medium (1.5 million/mL), and high (3 million/mL) cell packing density.