title: Inverted microcontact printing on polystyrene-block-poly(tert-butyl acrylate) films: a versatile approach to fabricate structured biointerfaces across the length scales.
abstract: The combination of the recently introduced soft lithographic technique of inverted microcontact printing (i-muCP) and spin-coated films of polystyrene- block-poly( tert-butyl acrylate) (PS 690- b-P tBA 1210) as a reactive platform is shown to yield a versatile approach for the facile fabrication of topographically structured and chemically patterned biointerfaces with characteristic spacings and distances that cross many orders of magnitude. The shortcomings of conventional muCP in printing of small features with large spacings, due to the collapse of small or high aspect ratio stamp structures, are circumvented in i-muCP by printing reactants using a featureless elastomeric stamp onto a topographically structured reactive polymer film. Prior to molecular transfer, the substrate-supported PS 690- b-P tBA 1210 films were structured by imprint lithography resulting in lateral and vertical feature sizes between >50 microm-150 nm and >1.0 microm-18 nm, respectively. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and water contact angle measurements provided evidence for the absence of surface chemical transformations during the imprinting step. Following the previously established hydrolysis and activation protocol with trifluoroacetic acid and N-hydroxysuccinimide, amino end-functionalized poly(ethylene glycol) (PEG-NH 2), as well as bovine serum albumin and fibronectin as model proteins, were successfully transferred by i-muCP and coupled covalently. As shown, i-muCP yields increased PEG coverages and thus improved performance in suppressing nonspecific adsorption of proteins by exploiting the high local concentrations in the micro- and nanocontacts during molecular transfer. The i-muCP strategy provides access to versatile biointerface platforms patterned across the length scales, as shown for guided cancer cell adhesion, which opens the pathway for systematic cell-surface interaction studies.
authors.affiliation: Department of Materials Science and Technology of Polymers, MESA Institute for Nanotechnology and Faculty of Science and Technology, University of Twente, PO Box 217, AE Enschede, The Netherlands.
authors.forename: Anika
authors.initials: A
authors.lastname: Embrechts
authors.forename: Chuan Liang
authors.initials: CL
authors.lastname: Feng
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Mills
authors.forename: Michael
authors.initials: M
authors.lastname: Lee
authors.forename: Ilona
authors.initials: I
authors.lastname: Bredebusch
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schnekenburger
authors.forename: Wolfram
authors.initials: W
authors.lastname: Domschke
authors.forename: G Julius
authors.initials: GJ
authors.lastname: Vancso
authors.forename: Holger
authors.initials: H
authors.lastname: Schönherr
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D002460:Cell Line; D018625:Microscopy, Atomic Force; D015394:Molecular Structure; D011137:Polystyrenes / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D000179:Acrylates; D011137:Polystyrenes; C509854:poly(styrene-b-tert-butylacrylate); D012710:Serum Albumin, Bovine