Optoelectronic Biohybrid Platform Enables Light-Controlled Cardiac Structural and Functional Feedback.

Cardiac tissues naturally respond to an autoregulatory loop of electrical and mechanical cues, which often influence signal transduction pathways in synergism rather than in isolation. Here, we present a mechanically compliant biointerface fabricated with cardiomyocytes aligned atop a photocurrent-generating elastomeric substrate. Cardiac tissue contractions were optically paced within a normal human heartbeat frequency range without requiring gene modification. Using this biohybrid system as an in vitro model, we investigate how pulsed light input potentiates mechanical tissue response via contractility, and in turn, how contraction-induced tissue strain affects the structure and expression of cellular features responsible for intercellular communication. More specifically, we quantified the effects of this photostimulation approach, with and without the additional influence of actuation, on cytoskeletal/ sarcomeric orientation and gap junction expression. In summary, this biohybrid platform based on an optoelectronic polymer interface enables light-controlled electromechanical feedback useful for in vitro mechanistic investigations of the cardiac structure-function continuum.