A microneedle substrate-based sutureless engineered cardiac patch for myocardial infarction repair

Myocardial infarction (MI) is a challenging condition that results in scar formation on the ventricular wall, causing myocardial 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 manufacturing and fixation challenges. This study introduces a manufacturing strategy for a composite ECP, which comprises an antiadhesion 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.