摘要Myocardial infarction(MI)is a challenging condition that results in scar formation on the ventricular wall,causing myocar-dial damage and ventricular thinning.Engineered cardiac patches(ECPs)designed to regenerate myocardial tissue have been proposed to repair the ventricular wall and replenish myocardial cells.However,their clinical use is limited by manufactur-ing and fixation challenges.This study introduces a manufacturing strategy for a composite ECP,which comprises an antiad-hesion shell layer,a conductive myocardial tissue,and an exosome-laden microneedle substrate.The ECP can anchor to the infarcted myocardium through its microneedle substrate.Meanwhile,its outer shell prevents nonspecific adhesion,enabling stable and suture-free attachment.Using this microneedle substrate,we applied a 3D-printed ECP in a rat model of post-MI repair.Our results showed that this strategy reduced left ventricular damage,improved cardiac ejection fraction,decreased the fibrotic area,increased ventricular wall thickness,improved microvascular recovery,and thus facilitated the repair of maladaptive ventricular remodeling post-MI.This microneedle substrate holds great promise for use in the fixation of patches during the repair of myocardial tissue and other organs,thereby promoting the clinical application of tissue-engineered patches.