A β-Glycine-Enhanced Poly(l-lactic acid) Biopiezoelectric Patch for Self-Powered Myocardial Infarction Therapy

Cardiac patches, as implantable materials that provide mechanical stabilization and functional support to the heart, have shown promising therapeutic potential for the treatment of myocardial infarction (MI). However, promoting the electrical integration of cardiomyocytes is also crucial for MI treatment, and the related challenges have limited the application of cardiac patch materials lacking electromechanical functionality. Therefore, in this study, we developed a biocompatible, safely degradable, self-powered piezoelectric cardiac patch composed of poly(l-lactic acid) (PLLA) and β-glycine crystals via high-speed electrospinning. The optimized patch (PLLA-Gly-H) exhibited a high piezoelectric coefficient (d₃₃ = 32.4 ± 1.6 pC·N^-1) and sensitivity (21.24 ± 0.81 mV·kPa^-1). In vitro, the patch was proven to have good biocompatibility (L929 cell survival ratio exceeded 99%) and enhanced human umbilical vein endothelial cell (HUVEC) spreading under piezoelectric stimulation (surface HUVEC coverage reached ∼88.5%). In vivo, when implanted in a murine MI model, PLLA-Gly-H significantly improved cardiac function (left ventricular ejection fractions: 47.7% vs 35.0% in the MI group), reduced fibrosis (41.5% reduction compared with that in the MI group), and promoted angiogenesis (vascular density reaching 4.387 ± 0.167 vessels·mm^-2) and connexin-43 expression (1.389 ± 0.183% vs 0.639 ± 0.194% in the MI group). Overall, this work provides a conceptual advance for self-powered, biodegradable patch-mediated therapy for myocardial infarction.