title: High-resolution imaging of cellular processes across textured surfaces using an indexed-matched elastomer.
abstract: Understanding and controlling how cells interact with the microenvironment has emerged as a prominent field in bioengineering, stem cell research and in the development of the next generation of in vitro assays as well as organs on a chip. Changing the local rheology or the nanotextured surface of substrates has proved an efficient approach to improve cell lineage differentiation, to control cell migration properties and to understand environmental sensing processes. However, introducing substrate surface textures often alters the ability to image cells with high precision, compromising our understanding of molecular mechanisms at stake in environmental sensing. In this paper, we demonstrate how nano/microstructured surfaces can be molded from an elastomeric material with a refractive index matched to the cell culture medium. Once made biocompatible, contrast imaging (differential interference contrast, phase contrast) and high-resolution fluorescence imaging of subcellular structures can be implemented through the textured surface using an inverted microscope. Simultaneous traction force measurements by micropost deflection were also performed, demonstrating the potential of our approach to study cell-environment interactions, sensing processes and cellular force generation with unprecedented resolution.
authors.affiliation: Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411 Singapore, Singapore.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ravasio
authors.affiliation: Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411 Singapore, Singapore.
authors.forename: Sree
authors.initials: S
authors.lastname: Vaishnavi
authors.affiliation: Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411 Singapore, Singapore; Institut Jacques Monod, Université Paris, 7 Bâtiment Buffon, 15 rue Hélène Brion, 75205 Paris CEDEX 13, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Ladoux
authors.affiliation: Mechanobiology Institute, National University of Singapore, 5A Engineering Drive 1, 117411 Singapore, Singapore; Department of Biological Science, National University of Singapore, 14 Science Drive 4, 117543 Singapore, Singapore; CNRS, UMI 3639, 5A Engineering Drive 1, 117411 Singapore, Singapore. Electronic address: virgile.viasnoff@espci.fr.
authors.forename: Virgile
authors.initials: V
authors.lastname: Viasnoff
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects; D002450:Cell Communication / Q000187:drug effects; D004285:Dogs; D020724:Elastomers / Q000494:pharmacology*; D004847:Epithelial Cells / Q000166:cytology*; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D021621:Imaging, Three-Dimensional; D061985:Madin Darby Canine Kidney Cells; D051379:Mice; D041681:NIH 3T3 Cells; D053758:Nanoparticles / Q000737:chemistry; D055620:Optical Phenomena; D013050:Spectrometry, Fluorescence; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D000199:Actins; D020724:Elastomers; D005353:Fibronectins
keywords: Cell adhesion; Epithelial cell; Microstructure; Stress analysis; Surface texture