Physical confinement signals regulate the organization of stem cells in three dimensions

Abstract

During embryogenesis, the spherical inner cell mass (ICM) proliferates in the confined environment of a blastocyst. Embryonic stem cells (ESCs) are derived from the ICM, and mimicking embryogenesis in vitro, mouse ESCs (mESCs) are often cultured in hanging droplets. This promotes the formation of a spheroid as the cells sediment and aggregate owing to increased physical confinement and cell-cell interactions. In contrast, mESCs form two-dimensional monolayers on flat substrates and it remains unclear if the difference in organization is owing to a lack of physical confinement or increased cell-substrate versus cell-cell interactions. Employing microfabricated substrates, we demonstrate that a single geometric degree of physical confinement on a surface can also initiate spherogenesis. Experiment and computation reveal that a balance between cell-cell and cell-substrate interactions finely controls the morphology and organization of mESC aggregates. Physical confinement is thus an important regulatory cue in the three-dimensional organization and morphogenesis of developing cells.

Pattern-Dependent Mammalian Cell (Vero) Morphology on Tantalum/Silicon Oxide 3D Nanocomposites

“…Results have shown that cellular responses often depend on the mechanical properties, pattern structures, and surface chemistry of the microenvironment surrounding the cells [1,3,4,5,7,8,10,11,12,13,14,15,16,17,18,19,20]; however, work done thus far has been conducted with structures composed of monolithic materials having uniform surface chemical composition. Studies of cell behavior on nanocomposite surfaces are limited [1,3,17,18,19,20].…”

“…Recent studies have used micro- and nanometer-scale engineered structures to mimic extracellular matrices and other biological structures, which have led to a groundbreaking understanding of the physical cues and molecular signal transduction pathways for integrin activated focal adhesion, protein adsorption, and pseudopodia formation [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. Results have shown that cellular responses often depend on the mechanical properties, pattern structures, and surface chemistry of the microenvironment surrounding the cells [ 1 , 3 , 4 , 5 , 7 , 8 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]; however, work done thus far has been conducted with structures composed of monolithic materials having uniform surface chemical composition. Studies of cell behavior on nanocomposite surfaces are limited [ 1 , 3 , 17 , 18 , 19 , 20 ].…”

PCL-Blended Chitosan Substrates for Patterning the Heterotypic Cell Distribution in an Epithelial and Mesenchymal Coculture System

“…In the present study, it is reasonable to assume that Hs68 cell–substrate, HaCaT cell–substrate, HaCaT–HaCaT, Hs68–Hs68, and Hs68–HaCaT cell interactions must be considered simultaneously . The current reports indicate that the formation of spheroids could be promoted when the cell–cell interaction overrides the effect of cell–substrate. − Figures and show that both monocultured HaCaT and Hs68 cells could not spread well or were suspended on the only chitosan substrate or the blended substrates with low PCL content. It is reasonable to suggest the Hs68 cell–substrate and HaCaT cell–substrate interactions might be relatively weak.…”

What’s Happening on the Other Side? Revealing Nano-Meter Scale Features of Mammalian Cells on Engineered Textured Tantalum Surfaces

“…Cell function, adhesion behavior, and morphology are often influenced by their micro-environments [1,2,3,4,5,6,7,8,9,10,11,12,13,14]. When cells adhere to a surface, this micro-environment is highly influenced by the surface itself.…”