Mussel-inspired conductive TiC-cryogel promotes functional maturation of cardiomyocytes and enhances repair of myocardial infarction.

: Researches on conductive engineering cardiac patch (ECP) for myocardial infarction (MI) treatment have achieved some progress in the animal while the availability of traditional conductive materials in ECP is still limited because of their controversial cytotoxicity. Here we aim to introduce a novel hydrophilic biocompatible conductive material: MXene TiC and mussel-inspired dopamine into PEGDA-GelMA cryogel to construct a bio-functional ECP of which the property closes to natural heart for the repair of MI. : MXene TiC was etched from MAX TiAlC, then uniformly dispersed into the prepolymer composed with dopamine-N', N'-methylene-bisacrylamide, methacrylate-gelatin, and poly (ethylene glycol) diacrylate by simple water bath sonication. The resilient conductive TiC-cryogel was fabricated by chemical cryogelation. The conductive ECP was evaluated and transplanted to the MI rat model for MI treatment. : , the 3D vessels-shape framework was observed in TiC-8-cryogel which was seeded with rats aortic endothelial cells. When the TiC-cryogels were cocultured with CMs, remarkably aligned sarcomere and the primitive intercalated disc between the mature CMs were formed on day 7. The as-prepared TiC-8-cryogel ECP also demonstrated rapid calcium transients and synchronous tissue-like beating. When transplanted into the infarcted heart of the MI rat model, the TiC-8-cryogel ECP could improve the cardiac function, reduce the infarct size, and inhibit the inflammatory response. Obvious vasculation especially newly formed arteriole was also found. : A novel conductive TiC-embedded cardiac patch with suitable conductivity and the mechanical property was developed and could be served as an ideal candidate for MI repair.