Nanotopography Influences Adhesion, Spreading, and Self-Renewal of Human Embryonic Stem Cells

Abstract

Human embryonic stem cells (hESCs) have great potentials for future cell-based therapeutics. However, their mechanosensitivity to biophysical signals from the cellular microenvironment is not well characterized. Here we introduced an effective microfabrication strategy for accurate control and patterning of nanoroughness on glass surfaces. Our results demonstrated that nanotopography could provide a potent regulatory signal over different hESC behaviors, including cell morphology, adhesion, proliferation, clonal expansion, and self-renewal. Our results indicated that topological sensing of hESCs might include feedback regulation involving mechanosensory integrin-mediated cell-matrix adhesion, myosin II, and E-cadherin. Our results also demonstrated that cellular responses to nanotopography were cell-type specific and as such, we could generate a spatially segregated co-culture system for hESCs and NIH/3T3 fibroblasts using patterned nanorough glass surfaces.

Deflection induced cellular focal adhesion and anisotropic growth on vertically aligned silicon nanowires with differing elasticity

“…[1][2][3] In particular, surface topography has been shown to modulate cell adhesion, growth, proliferation and differentiation by altering intracellular signal transduction and gene expression. 4,5 Nanostructured materials with various morphologies have also received much attention over the past few decades in the field of biological research, owing to advances in nanotechnology that have enabled precision controlled nanofabrication. As direct interaction between such in vitro artificial nanostructures and living cells is inevitable, it is necessary to understand the complicated molecular mechanisms occurring at their interface.…”

Substrate topography: A valuable in vitro tool, but a clinical red herring for in vivo tenogenesis

“…electrospun polymeric fibres, extruded collagen fibres and isoelectrically focused collagen fibres) have been shown to maintain tenocyte phenotype and to differentiate stem cells towards tenogenic lineage in vitro and to induce acceptable regeneration in preclinical models, none of these technologies offers precise control over the spatial distribution of the fibres. Imprinting technologies, on the other hand, have demonstrated a diverse effect on a range of permanently differentiated and stem cell functions, including adhesion, orientation, secretome expression and lineage commitment [41][42][43][44][45][46][47][48] and offer significantly greater control over feature dimension and spacing. Specifically to tendon repair, such technologies have been shown to maintain tenocyte phenotype [38]; to promote aligned tendon-specific ECM deposition [39]; and to differentiate stem cells towards tenogenic lineage [40].…”

Pluripotent Stem Cells and Their Dynamic Niche

“…Softer gels allowed for chondrogenic and stiffer gels for osteogenic differentiation [269]. It is assumed that the substrate stiffness induces alterations in the activity of focal adhesion and causes remodelling, which triggers a cascade if signalling pathways enabling cell differentiation [270,271]. In addition, integrins are thought to be a central cell structure for sensing mechanical stimulation [270,271].…”

“…It is assumed that the substrate stiffness induces alterations in the activity of focal adhesion and causes remodelling, which triggers a cascade if signalling pathways enabling cell differentiation [270,271]. In addition, integrins are thought to be a central cell structure for sensing mechanical stimulation [270,271]. A limitation to these studies is the fact that different tissues may have similar stiffness, and hence, it might not be possible to direct stem cell fate by a single mechanical property of the surrounding.…”