A Conductive And Adhesive Hydrogel Patch For Myocardial Rebuilding

Cardiac patch has been developed for the treatment of myocardial infarction in recent years.However,the fixation approaches onto the tissue through suture or photo-triggered reaction inevitably cause new damage to the frail myocardium.Herein,a paintable hydrogel was constructed based on Fe³⁺-triggered simultaneous polymerization of covalently linked pyrrole and dopamine in the hyperbranched chains,and thus the resulted hydrogel could be endowed with excellent electrical conductivity and wet adhesion capability.The in situ formed conductive polypyrrole nanoparticles also uniquely served to facilitate formation of a compact and stable network.This conductive and adhesive hydrogel could be conveniently painted as a patch onto the heart surface without adverse liquid leakage.The functional patch whose conductivity was equivalent to that of normal myocardium possessed a wet adhesive strength of 22 kPa,which was strongly bonded to the beating heart in vivo within 4 weeks.The paintable cardiac patch was applied to myocardial infarction model of SD rats,accordingly efficiently boosting ejection fraction?EF?and fractional shortening?FS?values and improving the reconstruction of cardiac functions.What's more,end-diastolic volume?EDV?and end-systolic volume?ESV?were efficiently prevented on negative LV dilation.The smallest infarct size,the least fibrosis area and the thickest LV wall were observed in HPAE-Py/Geln treated hearts.In addition,the paintable conductive patch was proved to promote the transmission of electrophysiological signals and the highest expression of Cx-43,and revascularization of the infarcted myocardium.The suture-free strategy reported in this work is promising to be translated in cardiac tissue engineering.