1. Switchable Polymer Interfaces for Bottom-up Stimulation of Mammalian CellsIgor Luzinov, Clemson University, DMR 1107786 The Materials Work Network project is within the framework of international cooperation between Clemson University, Clarkson University, UC Davis, Dresden Technical University, Leibniz-Institute for Polymer Research Dresden, University of Göttingen, and Institute for Analytical Sciences (in Berlin) laboratories. The ultimate goal of this project is to design and characterize a responsive polymer brush platform for the stimuli-triggered exposure of functional molecules to the bioengineered interfaces of mammalian cells. We expect to demonstrate stimulation of stem cells from the bottom-up using switchable mixed polymer brush. There are three mixed brush platforms under investigation: temperature, electrochemically, and magnetically responsive. Up to date we developed synthesis of thermoresponsive Poly(N-isopropylacrylamide) [PNIPAM] – Poly(ethylene glycol) [PEG] mixed polymer brushes and studied their thermal response and interaction with proteins. Also we initiated study on the interactions between the brushes and living cells. Schematic of thermoresponsive polymer brush platform: (1) mixed brush, (2) substrate, (3) cell, (4) PS hydrophobic domain, (5) thermoresponsive chains: PNIPAM, (6) repelling chains: PEG, (7) interacting molecule; (8) interacting cell receptor. Optical microscopy images of fibroblast cells on (a and b) monobrush PNIPAM brush and (c and d) binary brush PEG-PNIPAM before and after cooling the samples to room temperature (b and d).

2. Switchable Polymer Interfaces for Bottom-up Stimulation of Mammalian CellsIgor Luzinov, Clemson University, DMR 1107786 Educational activities during the reported period included the training of graduate and undergraduate, students. In Clemson University currently one PhD student is working on the project. During this summer of 2012 REU undergraduate female student supported by supplement to this project was working with the graduate student. One MS student is currently working on the project at Clarkson University. In the April 2012, he presented his results in the International Chemistry Student Research Symposium at the University of Jordan, in Amman. During this summer of 2012 REU undergraduate student supported by supplement to this project was working with the graduate student at Clarkson laboratory. Two researchers are involved in this project at UC Davis, an undergraduate female student and a postdoctoral fellow. Revzin group is interacting actively with materials scientists from Clarkson, Clemson and Germany to determine biocompatibility and cell adhesion properties of polymer brushes. Igor Luzinov and his summer REU and high-school students. Second from the left is Ms. Nadya Klep , undergraduate Clemson University student supported by REU supplement to this project. Matthew Booz , undergraduate Clarkson University student supported by REU supplement to this project. He conducted summer research under the guidance of Sergiy Minko.