title: Cellular responses to patterned poly(acrylic acid) brushes.
abstract: We use patterned poly(acrylic acid) (PAA) polymer brushes to explore the effects of surface chemistry and topography on cell-surface interactions. Most past studies of surface topography effects on cell adhesion have focused on patterned feature sizes that are larger than the dimensions of a cell, and PAA brushes have been characterized as cell repellent. Here we report cell adhesion studies for RBL mast cells incubated on PAA brush surfaces patterned with a variety of different feature sizes. We find that when patterned at subcellular dimensions on silicon surfaces, PAA brushes that are 30 or 15 nm thick facilitate cell adhesion. This appears to be mediated by fibronectin, which is secreted by the cells, adsorbing to the brushes and then engaging cell-surface integrins. The result is detectable accumulation of plasma membrane within the brushes, and this involves cytoskeletal remodeling at the cell-surface interface. By decreasing brush thickness, we find that PAA can be 'tuned' to promote cell adhesion with down-modulated membrane accumulation. We exemplify the utility of patterned PAA brush arrays for spatially controlling the activation of cells by modifying brushes with ligands that specifically engage IgE bound to high-affinity receptors on mast cells.
authors.affiliation: Department of Chemistry and Chemical Biology, Baker Laboratories, Cornell University, Ithaca, New York 14853, United States.
authors.forename: Ethan N
authors.initials: EN
authors.lastname: Chiang
authors.forename: Rong
authors.initials: R
authors.lastname: Dong
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Ober
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Baird
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry* / Q000494:pharmacology*; D000818:Animals; D002417:Cattle; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D004136:Dinitrobenzenes / Q000737:chemistry; D005353:Fibronectins / Q000378:metabolism; D007073:Immunoglobulin E / Q000378:metabolism; D008407:Mast Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D017455:Receptors, IgE / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013499:Surface Properties; D013696:Temperature
chemical_list: D000180:Acrylic Resins; D004136:Dinitrobenzenes; D005353:Fibronectins; D017455:Receptors, IgE; D007073:Immunoglobulin E; C006903:carbopol 940