Elastin-like polypeptides (ELPs), naturally inspired by the hydrophobic domain of tropoelastin, are repeating pentapeptide sequences of VPGXG (X can be any amino acid except proline) representing a fascinating area of study due to their soluble-to-insoluble transition in response to various stimuli, including ionic strength, temperature, pH, and concentration. This transition involves conformational changes from extended to collapsed states. Tailoring ELP hydrophobicity through sequence adjustments allows precise modulation of this transition, making them valuable for diverse applications such as switchable interfaces, tissue engineering, cell culture, and drug delivery. While the transition behavior of amino acids is well-characterized in solution, our understanding of surface-tethered ELPs remains limited, impeding crucial surface-based applications in sensing, cell sheet engineering, and targeted drug release.
In this study, we utilized novel electrochemical approaches to characterize the transition behavior of surface-bound ELPs for five designed sequences with different hydrophobicity and investigated the effect of different stimuli, including salt concentration and temperature. By comparing these surface-based transition behaviors via electrochemistry with solution-phase transition temperature, via UV-Vis spectroscopy, we aim to provide insights into ELP behavior on solid surfaces. Our results demonstrated electrochemistry as a reliable technique for quantifying the surface-bound transition, offering a pathway for developing predictive models and enhancing understanding of surface-based elastin biotechnology.
