The advent of conductive self-healing (CSH) hydrogels, a class of novel materials mimicking human skin, may change the trajectory of the industrial process because of their potential applications in soft robots, biomimetic prostheses, and health-monitoring systems. Here, the development of a mechanically and electrically self-healing hydrogel based on physically and chemically cross-linked networks is reported. The autonomous intrinsic self-healing of the hydrogel is attained through dynamic ionic interactions between carboxylic groups of poly(acrylic acid) and ferric ions. A covalent cross-linking is used to support the mechanical structure of the hydrogel. Establishing a fair balance between the chemical and physical cross-linking networks together with the conductive nanostructure of polypyrrole networks leads to a double network hydrogel with bulk conductivity, mechanical and electrical self-healing properties (100% mechanical recovery in 2 min), ultrastretchability (1500%), and pressure sensitivity. The practical potential of CSH hydrogels is further revealed by their application in human motion detection and their 3D-printing performance.

The engineered cardiac patch (ECP) is a promising strategy to repair infarct myocardium and restore the cardiac function. An ideal ECP should be able to mimic the primary attributes of native myocardium, which includes a high resilience, good cardiomyocyte adhesion, and synchronous contraction. Here, a mussel‐inspired dopamine crosslinker is used to integrate polypyrrole (Ppy) nanoparticles, gelatin‐methyacrylate, and poly(ethylene glycol) diacrylate into a cryogel form. The dopamine crosslinker and Ppy nanoparticles are coordinated to obtain optimal mechanical and superelastic properties for the ECP. The dopamine facilitates the uniform distribution of the Ppy nanoparticles, which migrate and fuse from the scaffold to the surface of the cardiomyocytes, revealing a potential mechanism for restoring infarct myocardium. The incorporated Ppy nanoparticles thus significantly enhance the functionalization of the cardiomyocytes, resulting in excellent synchronous contraction by increasing the expression of α‐actinin and CX‐43. Cardiomyocytes‐loaded ECP can improve the cardiac function in myocardial‐infarction (MI) affected rat models. The results show that the fractional shortening and ejection fraction are elevated by about 50% and that the infarct size is reduced by 42.6%. Collectively, this study highlights an effective cardiac patch based on mussel‐inspired conductive particle adhesion and a superelastic cryogel promising for the restoration of infarcted myocardium.

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