title: Construction of a tethered poly(ethylene glycol) surface gradient for studies of cell adhesion kinetics.
abstract: Surface gradients can be used to perform a wide range of functions and represent a novel experimental platform for combinatorial discovery and analysis. In this work, a gradient in the coverage of a surface-immobilized poly(ethylene glycol) (PEG) layer is constructed to interrogate cell adhesion on a solid surface. Variation of surface coverage is achieved by controlled transport of a reactive PEG precursor from a point source through a hydrated gel. Immobilization of PEG is achieved by covalent attachment of the PEG molecule via direct coupling chemistry to a cystamine self-assembled monolayer on gold. This represents a simple method for creating spatial gradients in surface chemistry that does not require special instrumentation or microfabrication procedures. The structure and spatial distribution of the PEG gradient are evaluated via ellipsometry and atomic force microscopy. A cell adhesion assay using bovine arteriole endothelium cells is used to study the influence of PEG thickness and chain density on biocompatibility. The kinetics of cell adhesion are quantified as a function of the thickness of the PEG layer. Results depict a surface in which the variation in layer thickness along the PEG gradient strongly modifies the biological response.
authors.affiliation: Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904, USA.
authors.forename: K
authors.initials: K
authors.lastname: Mougin
authors.forename: A S
authors.initials: AS
authors.lastname: Ham
authors.forename: M B
authors.initials: MB
authors.lastname: Lawrence
authors.forename: E J
authors.initials: EJ
authors.lastname: Fernandez
authors.forename: A C
authors.initials: AC
authors.lastname: Hillier
mesh_terms: D000818:Animals; D002417:Cattle; D002448:Cell Adhesion / Q000502:physiology*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000502:physiology*; D007103:Immobilization; D007700:Kinetics; D018625:Microscopy, Atomic Force; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013499:Surface Properties
chemical_list: D011092:Polyethylene Glycols