Biodegradable Piezoelectric Implant for Wirelessly Delivering Electrical Stimulation to the Heart under Ultrasound Stress

Abstract

Bioelectricity plays a pivotal role in human physiology and pathology, particularly within the cardiovascular system. Myocardial ischemia disrupts the normal transmission of electrical signals through the heart, leading to cardiomyocyte death, ventricular remodeling, and ultimately heart failure. Electrical stimulation (ES) has been proven to be an effective strategy for treating cardiac diseases. However, invasive electrode implantation and the unique anatomical position of the heart limit the clinical application of ES therapy. Developing wireless ES systems that effectively enhance bioelectric propagation and electrical activity in the heart can significantly advance therapeutic interventions. In this study, a lead-free, biodegradable and the Food and Drug Administration approved poly-L-lactic acid piezoelectric nanofiber is designed for wireless ES to the myocardium under ultrasonic stimulation, thus promoting structural and functional recovery of cardiac tissue in murine myocardial infarction model. Further study shows that the ultrasound-driven wireless ES system significantly enhanced mitochondria function and angiogenesis in vivo and in vitro experiments. Additionally, the ES system can regulate intracellular calcium ion concentration and cardia tissue contraction rhythm of isolated neonatal rat. Collectively, the findings offer a novel approach for the treatment of heart diseases and potential cardiac pacing applications under the ultrasound-driven wireless ES system.