title: Modulating cell adhesion and spreading by control of FnIII7-10 orientation on charged self-assembled monolayers (SAMs) of alkanethiolates.
abstract: In this work, we demonstrate that surface charge can be used to modulate cell adhesion/spreading through the control of the orientation of adsorbed FnIII(7-10), which is a cell-adhesive protein containing RGD residues. Carboxylic acid (COOH) and amine (NH(2))-terminated self-assembled monolayers (SAMs) of alkanethiolates were used as model negatively and positively charged surfaces, respectively. The adsorbed amount of FnIII(7-10) is controlled to be equivalent on both SAMs as confirmed by the adsorption isotherms determined using I(125)-radiolabeled FnIII(7-10.) The binding of a monoclonal antibody specific for the cell-binding domain of FnIII(7-10) was measured by surface plasmon resonance (SPR) to evaluate FnIII(7-10) orientations on different SAMs. Results indicate that adsorbed FnIII(7-10) on NH(2)-SAM has an orientation with more cell-binding domains accessible than on COOH-SAM, confirming our predictions from Monte Carlo simulations. Both phase contrast images and Vybrant MTT cell proliferation assays show that the adhesion/spreading of bovine aortic endothelial cells (BAECs) on the NH(2)-SAM is significantly better than that on the COOH-SAM coated with an equivalent amount of FnIII(7-10). These results indicate that surface charge can be used to specifically orient cell adhesive proteins such as FnIII(7-10), thus providing a promising strategy to increase the activity of materials incorporating biological moieties.
authors.affiliation: Department of Chemical Engineering, University of Washington, Seattle, 98195, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: He
authors.forename: Buddy D
authors.initials: BD
authors.lastname: Ratner
authors.forename: Shaoyi
authors.initials: S
authors.lastname: Jiang
mesh_terms: D000476:Alkanesulfonates; D000818:Animals; D001672:Biocompatible Materials; D002417:Cattle; D002448:Cell Adhesion / Q000502:physiology; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology; D005353:Fibronectins; D006801:Humans
chemical_list: D000476:Alkanesulfonates; D001672:Biocompatible Materials; D005353:Fibronectins; C501364:fibronectin type III like peptide, human