(Invited) Increasing the Reproducibility and Stability of Temperature-Responsive Elastin-like Polymer Surfaces

Abstract

The coacervation versus solubility of Elastin-Like Polymers (ELPs) in solution can be triggered by different factors including ionic strength and temperature. Therefore, the Lower Critical Solution Temperature (LCST) response of ELPs is relatively well understood. However, tethered or surface-bound ELPs are less understood, and the surface reproducibility and stability still needs to be characterized.Recently our group studied the electrochemical impedance spectroscopy (EIS) response of ELP-modified surfaces associated with changes in ionic strength, and we observed intermediate states of ELP surface collapse.1 Within this work, we present our progress on monitoring the thermal response of surface-bound ELP. Using EIS, We will examine the localized temperature-triggered collapse for I40 ELP (AGCAG(VPGIG)40VPASW). We aim to better understand the way charge transfer changes within a range of temperature and intermediate states. We will report on observed changes in charge transfer resistance from 5 to 40 degrees Celsius. We will discuss protocols we developed to increase the reproducibility of these surfaces. We will also discuss our progress in making these surfaces more stable by looking at the longevity of these surfaces over time.Support was provided by a National Science Foundation EPSCoR award (#2119237).[1] Morales, M.A., Paiva, W.A., Marvin, L., Balog, E.R.M. and Halpern, J.M., 2019. Electrochemical characterization of the stimuli-response of surface-immobilized elastin-like polymers. Soft matter, 15(47), pp.9640-9646.