An organ-on-a-chip model for pre-clinical drug evaluation in progressive non-genetic cardiomyopathy.

Angiotensin II (Ang II) presents a critical mediator in various pathological conditions such as non-genetic cardiomyopathy. Osmotic pump infusion in rodents is a commonly used approach to model cardiomyopathy associated with Ang II. However, profound differences in electrophysiology and pharmacokinetics between rodent and human cardiomyocytes may limit predictability of animal-based experiments. This study investigates the application of an Organ-on-a-chip (OOC) system in modeling Ang II-induced progressive cardiomyopathy. The disease model is constructed to recapitulate myocardial response to Ang II in a temporal manner. The long-term tissue cultivation and non-invasive functional readouts enable monitoring of both acute and chronic cardiac responses to Ang II stimulation. Along with mapping of cytokine secretion and proteomic profiles, this model presents an opportunity to quantitatively measure the dynamic pathological changes that could not be otherwise identified in animals. Further, we present this model as a testbed to evaluate compounds that target Ang II-induced cardiac remodeling. Through assessing the effects of losartan, relaxin, and saracatinib, the drug screening data implicated multifaceted cardioprotective effects of relaxin in restoring contractile function and reducing fibrotic remodeling. Overall, this study provides a controllable platform where cardiac activities can be explicitly observed and tested over the pathological process. The facile and high-content screening can facilitate the evaluation of potential drug candidates in the pre-clinical stage.