title: Bi-ligand surfaces with oriented and patterned protein for real-time tracking of cell migration.
abstract: A bioactive platform for the quantitative observation of cell migration is presented by (1) presenting migration factors in a well-defined manner on 2-D substrates, and (2) enabling continuous cell tracking. Well-defined substrate presentation is achieved by correctly orienting immobilized proteins (chemokines and cell adhesion molecules), such that the active site is accessible to cell surface receptors. A thiol-terminated self-assembled monolayer on a silica slide was used as a base substrate for subsequent chemistry. The thiol-terminated surface was converted to an immobilized metal ion surface using a maleimido-nitrilotriacetic acid (NTA) cross-linker that bound Histidine-tagged recombinant proteins on the surface with uniform distribution and specific orientation. This platform was used to study the influence of surface-immobilized chemokine SDF-1α and cell adhesion molecule ICAM-1 on murine splenic B lymphocyte migration. While soluble SDF-1α induced trans-migration in a Boyden Chamber type chemotaxis assay, immobilized SDF-1α alone did not elicit significant surface-migration on our test-platform surface. Surface-immobilized cell adhesion protein, ICAM-1, in conjunction with activation enabled migration of this cell type on our surface. Controlled exposure to UV light was used to produce stable linear gradients of His-tagged recombinant SDF-1α co-immobilized with ICAM-1 following our surface chemistry approach. XPS and antibody staining showed defined gradients of outwardly oriented SDF-1α active sites. This test platform can be especially valuable for investigators interested in studying the influence of surface-immobilized factors on cell behavior and may also be used as a cell migration enabling platform for testing the effects of various diffusible agents.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States.
authors.forename: Varadraj N
authors.initials: VN
authors.lastname: Vernekar
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Wallace
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States.
authors.forename: Mina
authors.initials: M
authors.lastname: Wu
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States.
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Chao
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States.
authors.forename: Shannon K
authors.initials: SK
authors.lastname: O'Connor
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States.
authors.forename: Aimee
authors.initials: A
authors.lastname: Raleigh
authors.affiliation: Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States.
authors.forename: Xiaji
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States.
authors.forename: Jason M
authors.initials: JM
authors.lastname: Haugh
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, NC 27708, United States. Electronic address: reichert@duke.edu.
authors.forename: William M
authors.initials: WM
authors.lastname: Reichert
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D054377:Chemokine CXCL12 / Q000737:chemistry; D018799:Intercellular Adhesion Molecule-1 / Q000737:chemistry; D051379:Mice; D008822:Mice, Transgenic; D014466:Ultraviolet Rays
chemical_list: D054377:Chemokine CXCL12; D018799:Intercellular Adhesion Molecule-1
keywords: B lymphocyte; Cell adhesion molecule; Chemokine; Chemotaxis; Surface gradients; Surface immobilization