title: Thermoresponsive PNIPAM Coatings on Nanostructured Gratings for Cell Alignment and Release.
abstract: Thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) has been widely used as a surface coating to thermally control the detachment of adsorbed cells without the need for extreme stimuli such as enzyme treatment. Recently, the use of 2D and 3D scaffolds in controlling cell positioning, growth, spreading, and migration has been of a great interest in tissue engineering and cell biology. Here, we use a PNIPAM polymer surface coating atop a nanostructured linear diffraction grating to controllably change the surface topography of 2D linear structures using temperature stimuli. Neutron reflectometry and surface diffraction are utilized to examine the conformity of the polymer coating to the grating surface, its hydration profile, and its evolution in response to temperature variations. The results show that, in the collapsed state, the PNIPAM coating conforms to the grating structures and retains a uniform hydration of 63%. In the swollen state, the polymer expands beyond the grating channels and absorbs up to 87% water. Such properties are particularly desirable for 2D cell growth scaffolds with a built-in nonextreme tissue-release mechanism. Indeed, the current system demonstrates advanced performance in the effective alignment of cultured fibroblast cells and the easy release of the cells upon temperature change.
authors.affiliation: †National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Zhernenkov
authors.affiliation: ‡Materials Science and Engineering Department, University of Maryland, College Park, Maryland 20742, United States.|§Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States.
authors.forename: Rana
authors.initials: R
authors.lastname: Ashkar
authors.affiliation: ∥Center for the Exploration of Energy and Matter and Physics Department, Indiana University, Bloomington, Indiana 47405 United States.
authors.forename: Hao
authors.initials: H
authors.lastname: Feng
authors.affiliation: ⊥Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, Florida 33620, United States.
authors.forename: Olukemi O
authors.initials: OO
authors.lastname: Akintewe
authors.affiliation: #Department of Mechanical Engineering, University of South Florida, Tampa, Florida 33620, United States.
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Gallant
authors.affiliation: ⊥Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, Florida 33620, United States.
authors.forename: Ryan
authors.initials: R
authors.lastname: Toomey
authors.affiliation: ∇Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
authors.forename: John F
authors.initials: JF
authors.lastname: Ankner
authors.affiliation: ∥Center for the Exploration of Energy and Matter and Physics Department, Indiana University, Bloomington, Indiana 47405 United States.|○Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.
authors.forename: Roger
authors.initials: R
authors.lastname: Pynn
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry* / Q000627:therapeutic use; D000327:Adsorption; D002448:Cell Adhesion; D002465:Cell Movement / Q000187:drug effects; D006801:Humans; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry / Q000627:therapeutic use*; D013499:Surface Properties; D013696:Temperature; D023822:Tissue Engineering
chemical_list: D000180:Acrylic Resins; C052970:poly-N-isopropylacrylamide
keywords: PNIPAM coating; cell alignment and release; neutron reflectometry; thermoresponsive nanostructured scaffolds