Silicate biomaterials-based multicellular scaffolds with specific cellular spatial distribution for infarcted myocardium repair.

Constructing artificial myocardial tissue that matches the structure and function of natural myocardium is a promising approach for repairing infarcted myocardium and reconstructing cardiac function. In this study, a biomimetic myocardium scaffold based on bioactive bioinks containing strontium silicate was prepared by bioprinting the specific spatial distribution of cardiomyocytes and aortic endothelial cells. First, the spatial distribution pattern of cardiomyocytes and endothelial cells is regulated through coaxial/parallel multi-channel 3D bioprinting method. The spatial distribution of cells can significantly affect the repair function of multicellular scaffolds by stimulating genes related to pathological homeostasis regulation and intercellular interactions. Second, the multicellular scaffold with a core-shell cellular distribution pattern significantly inhibited myocardial fibrosis, promoted angiogenesis, and effectively improved cardiac function in a rat model of myocardial infarction. Finally, bioink containing strontium silicate can effectively promote the synchronized contraction of cardiomyocytes and their maturation, facilitate angiogenesis, and enhance the interaction between cardiomyocytes and endothelial cells. In summary, through the integrated design of cellular spatial distribution structure and the bioactive composition of bioink, this study has developed a multicellular scaffold for myocardial repair that combines biomimetic structure with repair function, offering the new strategy for myocardial tissue engineering and heart repair.