In Situ Photocurable Janus Hydrogels with Magnetically Guided Anisotropic Conductivity for Myocardial Ischemeia–Reperfusion Injury Treatment and Tissue Adhesion Prevention

Although cardiac patches offered a promising therapeutic strategy, the traditional designs had some limitations, such as invasive implantation, poor electrical integration, and nonspecific tissue adhesion. Here, we introduced an <i>in situ</i> photoinitiated Janus conductive hydrogel patch, namely, HD/G@Fe₃O₄-A, which integrates minimally invasive delivery, spatiotemporal programmed asymmetric adhesion, and magnetically guided anisotropic conductivity.

This shear-thinning hydrogel precursor could be injected through a catheter and uniformly cover the beating heart and then achieve strong myocardial attachment on one side through rapid ultraviolet cross-linking while forming an antiadhesion interface on the other side, resulting in a 60- to 80-fold adhesion contrast. Under magnetic guidance, Fe₃O₄ microspheres were arranged to form conductive pathways, simulating the anisotropic conductivity of natural myocardial tissue and enhancing signal propagation and synchronous contraction. <i>In vitro</i> experiments showed that HD/G@Fe₃O₄-A exhibited excellent cell compatibility and antioxidant activity while promoting the functional maturation of neonatal rat cardiomyocytes.