(413f) Photoexcitable Peptidic Biointerfaces for Directing Cardiac Tissue Organization and Behavior

Structural ordering of electroactive units at multiple length scales, which influence the efficiency of charged carrier conduction pathways, is key to both high-performing organic electronic devices and efficient signal transduction in excitable tissues. In this presentation, molecular and fabrication approaches are described for the development of optoelectronically active biomaterials capable of synergistically inducing cardiac tissue anisotropy and photostimulating their contractions in vitro. Here, our approaches leverage defined intermolecular interactions from peptidic sequences to control the order of π-conjugated oligomers under aqueous, physiologically relevant conditions. The assembly behavior of the resulting peptidic nanostructures on surfaces interfaced with cardiomyocytes, serving as an excitable cell model, is then controlled via molecularly engineering the assembly-substrate interactions and through surface conjugation chemistries. The combinatorial influence of optoelectronic peptide composition, topography, and directionality of fields on the anisotropy of resulting cardiac monolayers are also quantified based on cytoskeletal and sarcomeric organization. Lastly, this presentation will also show an approach towards utilizing the atomic precision of inorganic van der Waals crystals in directing the assembly of optoelectronic peptides with pi-stacking distances that match the lattice features, leading to the creation of hybrid surfaces that are photocurrent generating. Overall, we develop topographically defined peptidic biomaterial platforms endowed with properties that enable them suitable as photoexcitable interfaces where the behavior of electroactive cells and tissues can be optically controlled and better investigated at high spatiotemporal resolutions.