This project focuses on design and characterization of a responsive thin polymer film platform comprised of functionalized mixed polymer brushes for the stimuli-triggered exposure of functional molecules to interfaces. The project supports an international US-German research team from Clemson University, Clarkson University, University of California in Davis, Dresden Technical University, Leibniz-Institute for Polymer Research Dresden, University of GÃ¶ttingen, and Leibniz-Institute for Analytical Sciences (in Berlin) consisting of experts in polymer/surface/materials science and bioengineering. Financial support for the German participants is provided by the German Science Foundation (DFG).
Responsive polymer materials with dynamically changing interfacial properties are receiving increased interest, thanks to their great potential for biomedical applications. One of the important properties of such materials is the capability to present, to release, to hide, or to capture different functional groups upon receiving external signals. Therefore, it is proposed to develop and study the responsive mixed brush platform for stimuli-triggered, programmable interfacial exposure of functional molecules (e.g., growth factors) that are important for the survival and differentiation of stem cells. Specifically, the focus of the experimental work is on: (a) precise design and synthesis of functional mixed polymer brushes; (b) comprehensive study of the microstructure and stimuli-triggered dynamical changes in the functionalized mixed brushes; (c) study of the dynamic interactions of the functionalized mixed brush system with functionalized probes; and (e) development of multifunctional dynamic biointerfaces. It is also expected to determine how different stimuli such as temperature, magnetic field, and electrical signals can be used to introduce local changes in the mixed brush biointerface and result in exposure of the functional molecules. The experimental studies will be paralleled by a coarse-grained theoretical modeling using three complementary techniques: (a) self-consistent field (SCF) calculations, (b) single-chain-in-mean-field simulations and molecular dynamics, and (c) phenomenological scaling considerations.
This interdisciplinary project is aimed to impact the field of polymeric materials for cell biology and biotechnology through the use of novel stimuli-responsive polymeric substrates. The project provides extensive opportunities to integrate research and education through cross-disciplinary student training and introduction of new educational modules in the curriculum. The investigators plan to involve both undergraduate and graduate students in the proposed research and to train them to gain (i) expertise in nanofabrication techniques, (ii) familiarity with modern concepts in materials chemistry, (iii) the ability to synthesize and characterize nanostructured polymeric materials and biointerfaces, (iv) the ability to run experiments, gather data, and make discoveries, and (v) the ability to write scientific papers and make effective technical presentations. Students also will greatly benefit from their extensive collaborations among the participating US and German research institutions.