A tunable self-healing ionic hydrogel with microscopic homogeneous conductivity as a cardiac patch for myocardial...

Conductive hydrogel is a potential therapeutic tool to treat damaged heart muscles in myocardial infarction (MI). However, it is still a quite challenge to optimize the fabrication of a therapeutic hydrogel patch that sustains favorable biocompatibility, electronic and mechanical stability under a complicated MI microenvironment. Herein, a tunable self-healing ionic hydrogel (POG₁) was developed through the introduction of a biocompatible polyacrylic acid (PAA, FDA-approved) into the hydrogel matrix. The fabricated POG₁ hydrogel possessed suitable stretchable (>500% strain) and compressive (>85% strain) properties, comparable modulus with mammalian heart (30-500 kPa, Young's modulus), self-healable, and highly stable conductivity during large deformations (~50% compress strain, ~150% tensile strain). Specifically, the established PAA nano-channels inside of POG₁ endowed the hydrogel with microscopic ultra-homogeneous conductivity. Compared to those seeded in the electronic conductors-embedded (PPy, CNT, rGO) hydrogels, the cardiomyocytes (CMs) seeded in the POG₁ hydrogel exhibited more significantly oriented sarcomeres. This POG₁ engineered cardiac patch (ECP) also exerted robust benefits in attenuating left ventricular remodeling and restoring heart function after implantation in vivo. This paper highlighted a previously unexplored strategy for a biocompatible ionic conductive hydrogel ECP with an excellent MI repair function.