title: Adsorbed layers of oriented fibronectin: a strategy to control cell-surface interactions.
abstract: Fibronectin (Fn) is a matrix protein known to induce cell attachment and spreading through its cell binding site and related synergy sites. Fn-coated surfaces are therefore useful in tissue engineering and other cell contacting applications, but a problem with many immobilization strategies is a random distribution of molecular orientations. We sought to control Fn orientation, and thus enhance the availability of its cell binding site, by immobilizing Fn via a carboxymethyl dextran layer onto which are chemically attached monoclonal antibodies specific to a region near to Fn's C terminus (and thus away from the cell binding site). Using optical waveguide lightmode spectroscopy, we show the presence of chemically coupled antibodies to yield a considerably denser and thicker Fn layer, consistent with a more vertically aligned protein. Human umbilical vein endothelial cells spread significantly faster, and in a more spherically symmetric way, on an oriented Fn layer (i.e., in the presence of immobilized monoclonal antibodies) as compared with a control Fn layer (i.e., in the absence of bound antibodies). However, we observe human umbilical vein endothelial cell spreading on the oriented Fn layer to be similar to that on a Fn layer in the absence of a carboxymethyl dextran layer, suggesting that although orienting Fn is a promising strategy, coupling strategies using linkers other than dextran may be needed.
authors.affiliation: Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, USA.
authors.forename: Claudio
authors.initials: C
authors.lastname: Calonder
authors.forename: Howard W T
authors.initials: HW
authors.lastname: Matthew
authors.forename: Paul R
authors.initials: PR
authors.lastname: Van Tassel
mesh_terms: D000327:Adsorption; D000911:Antibodies, Monoclonal / Q000378:metabolism*; D001665:Binding Sites; D002465:Cell Movement; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000378:metabolism; D003911:Dextrans / Q000737:chemistry / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D005353:Fibronectins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008422:Materials Testing; D011485:Protein Binding; D013997:Time Factors; D014471:Umbilical Veins / Q000033:anatomy & histology
chemical_list: D000911:Antibodies, Monoclonal; D020099:Coated Materials, Biocompatible; D003911:Dextrans; D005353:Fibronectins; C014392:carboxymethyl dextran