title: Probing cellular mechanobiology in three-dimensional culture with collagen-agarose matrices.
abstract: The study of how cell behavior is controlled by the biophysical properties of the extracellular matrix (ECM) is limited in part by the lack of three-dimensional (3D) scaffolds that combine the biofunctionality of native ECM proteins with the tunability of synthetic materials. Here, we introduce a biomaterial platform in which the biophysical properties of collagen I are progressively altered by adding agarose. We find that agarose increases the elasticity of 3D collagen ECMs over two orders of magnitude with modest effect on collagen fiber organization. Surprisingly, increasing the agarose content slows and eventually stops invasion of glioma cells in a 3D spheroid model. Electron microscopy reveals that agarose forms a dense meshwork between the collagen fibers, which we postulate slows invasion by structurally coupling and reinforcing the collagen fibers and introducing steric barriers to motility. This is supported by time lapse imaging of individual glioma cells and multicellular spheroids, which shows that addition of agarose promotes amoeboid motility and restricts cell-mediated remodeling of individual collagen fibers. Our results are consistent with a model in which agarose shifts ECM dissipation of cell-induced stresses from non-affine deformation of individual collagen fibers to bulk-affine deformation of a continuum network.
authors.affiliation: Department of Bioengineering, University of California, Berkeley, CA 94720-1762, USA.
authors.forename: Theresa A
authors.initials: TA
authors.lastname: Ulrich
authors.forename: Amit
authors.initials: A
authors.lastname: Jain
authors.forename: Kandice
authors.initials: K
authors.lastname: Tanner
authors.forename: Joanna L
authors.initials: JL
authors.lastname: MacKay
authors.forename: Sanjay
authors.initials: S
authors.lastname: Kumar
mesh_terms: D001696:Biomechanical Phenomena / Q000187:drug effects; D018929:Cell Culture Techniques / Q000379:methods*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D004548:Elasticity / Q000187:drug effects; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism*; D024022:Fibrillar Collagens / Q000494:pharmacology*; D005782:Gels; D005910:Glioma / Q000473:pathology; D006801:Humans; D008648:Mesoderm / Q000187:drug effects / Q000473:pathology; D008855:Microscopy, Electron, Scanning; D009361:Neoplasm Invasiveness; D016062:Porosity / Q000187:drug effects; D012685:Sepharose / Q000494:pharmacology*; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D024022:Fibrillar Collagens; D005782:Gels; D012685:Sepharose