Switchable polymer interfaces for bottom-up stimulation of mamalian cells

Final Report Abstract

As a main result of the project we were able to successfully design and characterize a responsive thin polymer film platform which comprised of functionalized polymer brushes for the stimuli-triggered exposure of functional molecules to the bioengineered interfaces of cells. We could demonstrate stimulation of cells using this switchable polymer brush platform and present an approach for the functionalization of brush systems with molecules typically used to stimulate cellular responses and developed approaches to design switchable bio-interfaces for guided cell behavior. We determined in particular that by stimulation with temperature and pH local changes in the brush-bio-interface are induced and can result in exposure of functional molecules to the surface. Dedicated techniques like in-situ IR-ellipsometry as well as computer simulations were employed to determine details of the switching mechanism. We studied exposure kinetics and equilibrium using a range of probe techniques and compared results with coarse-grained theoretical modeling. Interactions and stimulation of human hepatoma cells and mouse embryonic stem cells with these switchable surfaces have also been investigated where the influence of functionalization has clear effect. Those results could only be obtained by the joint effort of participating groups in US and Germany bringing together their supplementary expertise.

Publications

• "Chain Extension of Stimuli- Responsive Polymer Brushes: A General Strategy to Overcome the Drawbacks of the "Grafting-to" Approach" Advanced Functional Materials 23 (2013), 5675-5681
  S. Rauch, K.-J. Eichhorn, M. Stamm, D. Kuckling, P. Uhlmann
  
• "In-situ characterization of temperature-sensitive poly(N-isopropylacrylamide)brushes by in-situ spectroscopic ellipsometry" Thin Solid Films 541 (2013), 41-45
  A. Furchner, E. Bittrich, P. Uhlmann, K.-J. Eichhorn, K. Hinrichs
  
• "In-situ infrared ellipsometry for protein adsorption studies on ultra-thin smart polymer brushes in aqueous enviroment" ACS Applied Materials & Interfaces 7 (2015), 12430–12439
  A. Kroning, A. Furchner, D. Aulich, E. Bittrich, S. Rauch, P. Uhlmann, K.-J. Eichhorn, M. Seeber, I. Luzinov, S. M. Kilbey II, B.S. Lockitz, S. Minko, K. Hinrichs
  
• "Nanostructured Biointerfaces: Nanoarchitectonics of Thermoresponsive Polymer Brushes Impact Protein Adsorption and Cell Adhesion" ACS Applied Materials & Interfaces 7 (2015), 12516-12529
  E. Psarra, U. König, Y. Ueda, C. Bellmann, A. Janke, E. Bittrich, K.- J. Eichhorn, P. Uhlmann
  
• “Morphology Modulation of Multicomponent Polymer Brushes in Selective Solvent by Patterned Surfaces”, Macromolecules 48 (2015), 213-228
  F. Léonforte and M. Müller
  
• “Poly(N-isopropylacrylamide)-Based Mixed Brushes: A Computer Simulation Study”, ACS Applied Materials & Interfaces 7 (2015), 12450
  F. Léonforte and M. Müller
  
• „Growth factor-bearing polymer brushes - versatile, bioactive substrates for cell cultivation”, Biomacromolecules 16 (2015), 3530-3542
  E. Psarra, E. Foster, U. König, J. You, Y. Ueda, K.-J. Eichhorn, M. Müller, M. Stamm, A. Revzin and P. Uhlmann
  
• “Adsorption of enzymes on stimuli-responsive polymer brushes: Influence on adsorbed amount and biocatalytic activity”, Colloid Surf. B: Biointerfaces 146 (2016), 737-745
  M. Koenig, E. Bittrich, U. König, B. L. Rajeev, M. Müller, K.-J. Eichhorn, S. Thomas, M. Stamm, P. Uhlmann
  
• “Functional Poly(N-isopropylacrylamide)/Poly(acrylic acid) Mixed Brushes for Controlled Manipulation of Nanoparticles” Macromolecules 49 (2016) 5256-5265
  F. Léonforte and M. Müller
  
• “Probing carbonyl–water hydrogen-bond interactions in thin polyoxazoline brushes”, Biointerphases 11 (2016) 019005-1 - 019005-7
  A. Kroning, A. Furchner, S. Adam, P. Uhlmann, and K. Hinrichs