411e Peptide-Modified Responsive Networks with Built-in Logic

Peng Tian, Laurence Newman, and Ryan G. Toomey. Chemical Engineering, University of South Florida, 4202 E. Fowler Ave ENB 118, Tampa, FL 33620

The overall thrust of our research program is to develop well-behaved responsive surfaces without the need for complex circuitry or bulky instrumentation. Our approach is to use surface-attached, cross-linked polymer films that can be toggled from a collapsed to a swollen state or vice-versa in response to an external stimulus. The stimulus alters the balance of hydration forces in the responsive layer, resulting in changes to the swelling of the layer. We aim to build logic directly into the layer structure via embedded peptides that can modify the balance between hydrophobic/hydrophilic interactions depending on the conformation of the peptide. Poly-N-isopropylacylamide (Poly-NIPAAm) is a well-known and studied thermoresponsive polymer. We demonstrate that the transition temperature of poly-NIPAAm networks can be precisely tailored with small peptide sequences. Starting with a poly-NIPAAm network copolymerized with amine terminated monomers, N-(3-aminopropyl)methacrylamide hydrochloride, we demonstrate that we can grow peptides directly in the NIPAAm network using a standard Merrifield solid phase peptide synthesis procedure. Ultimately, this synthetic strategy will lead us to the ability to formulate peptide-modified poly-NIPAAM structures with predictable response characteristics.