by Keyword: Molecular gradient
Altay, G, Abad-Lázaro, A, Gualda, EJ, Folch, J, Insa, C, Tosi, S, Hernando-Momblona, X, Batlle, E, Loza-Alvarez, P, Fernández-Majada, V, Martinez, E, (2022). Modeling Biochemical Gradients In Vitro to Control Cell Compartmentalization in a Microengineered 3D Model of the Intestinal Epithelium Advanced Healthcare Materials 11, 2201172 
Gradients of signaling pathways within the intestinal stem cell (ISC) niche are instrumental for cellular compartmentalization and tissue function, yet how are they sensed by the epithelium is still not fully understood. Here a new in vitro model of the small intestine based on primary epithelial cells (i), apically accessible (ii), with native tissue mechanical properties and controlled mesh size (iii), 3D villus-like architecture (iv), and precisely controlled biomolecular gradients of the ISC niche (v) is presented. Biochemical gradients are formed through hydrogel-based scaffolds by free diffusion from a source to a sink chamber. To confirm the establishment of spatiotemporally controlled gradients, light-sheet fluorescence microscopy and in-silico modeling are employed. The ISC niche biochemical gradients coming from the stroma and applied along the villus axis lead to the in vivo-like compartmentalization of the proliferative and differentiated cells, while changing the composition and concentration of the biochemical factors affects the cellular organization along the villus axis. This novel 3D in vitro intestinal model derived from organoids recapitulates both the villus-like architecture and the gradients of ISC biochemical factors, thus opening the possibility to study in vitro the nature of such gradients and the resulting cellular response.© 2022 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.
JTD Keywords: 3d architectures, biomolecular gradients, colon, crypt, engineering organoids, hydrogels, identification, in silico modeling, intestinal stem cell niches, light sheet fluorescence microscopy, niche, permeability, photolithography, regeneration, villus, wnt, 3d architectures, Biomolecular gradients, Engineering organoids, In silico modeling, Intestinal stem cell niches, Light sheet fluorescence microscopy, Photolithography, Stem-cell
Lagunas, Anna, Martinez, Elena, Samitier, Josep, (2015). Surface-bound molecular gradients for the high throughput screening of cell responses Frontiers in Bioengineering and Biotechnology 3, Article 132
Chemical gradient surfaces are described as surfaces with a gradually varying composition along their length. Continuous chemical gradients have recently been proposed as alternative to discrete microarrays for the high throughput screening of the effects of ligand concentration in cells. Here we review some of the most recent examples in which gradients have been used to evaluate the effect of a varying ligand concentration in cell adhesion, morphology, growth and differentiation of cells, including some of our recent findings. They show the importance of the organization of ligands at the nanoscale, which is highlighted by abrupt changes in cell behavior at critical concentration thresholds.
JTD Keywords: Cell Adhesion, Cell Differentiation, Cell growth, Cell morphology, Molecular gradient
