title: Assessment of fibronectin conformation adsorbed to polytetrafluoroethylene surfaces from serum protein mixtures and correlation to support of cell attachment in culture.
abstract: Surfaces of polytetrafluoroethylene (PTFE) were exposed to buffered aqueous solutions containing radio-labeled human fibronectin ([125I]Fn), Fn/bovine serum albumin (BSA) binary mixtures of various ratios or whole human plasma dilutions for 1 h. Total adsorbed Fn and albumin adsorption following rinsing was quantified on this surface. 125I-labeled monoclonal antibodies against either the tenth type-III Fn repeat unit (containing the cell-binding RGDS integrin recognition motif) or the Fn amino-terminal domain were used to probe the accessibility of each of these respective Fn regions post-adsorption. Human umbilical vein endothelial cells (HUVECs) were cultured on PTFE surfaces pre-exposed to each of these protein adsorption conditions and compared to identical conditions on tissue culture polystyrene (TCPS). Fn adsorption to PTFE is dependent upon the concentration of albumin co-adsorbing from solution: albumin out-competes Fn for PTFE surface sites even at non-physiological Fn/HSA ratios 10-100-fold biased in Fn. Antibodies against Fn do not readily recognize Fn adsorbed on PTFE as the HSA co-adsorption concentration in either binary mixtures or in plasma increases, indicating albumin masking of adsorbed Fn. At Fn/HSA ratios rich in Fn (1:1, 1:100), albumin co-adsorption actually improves anti-Fn antibody recognition of adsorbed Fn. HUVEC attachment efficiency to PTFE after protein adsorption correlates with amounts of Fn adsorbed and levels of anti-Fn antibody recognition of Fn on PTFE, linking cell attachment to integrin recognition of both adsorbed Fn density and Fn adsorbed conformation on PTFE surfaces.
authors.affiliation: Department of Chemistry, Colorado State University, Ft. Collins, CO 80523-1872, USA. grainger@lamar.colostate.edu
authors.forename: David W
authors.initials: DW
authors.lastname: Grainger
authors.forename: Graciella
authors.initials: G
authors.lastname: Pavon-Djavid
authors.forename: Veronique
authors.initials: V
authors.lastname: Migonney
authors.forename: Marcel
authors.initials: M
authors.lastname: Josefowicz
mesh_terms: D000327:Adsorption; D000818:Animals; D001798:Blood Proteins; D002417:Cattle; D002448:Cell Adhesion; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology; D005353:Fibronectins / Q000097:blood* / Q000737:chemistry* / Q000276:immunology; D006801:Humans; D011138:Polytetrafluoroethylene / Q000737:chemistry*; D011487:Protein Conformation
chemical_list: D001798:Blood Proteins; D005353:Fibronectins; D011138:Polytetrafluoroethylene