Integrating Macrophages into Human-Engineered Cardiac Tissue.

Heart disease remains a leading cause of morbidity and mortality worldwide, necessitating the development of in vivo models for therapeutic development. Advances in biomedical engineering in the past decade have led to the promising rise of human-based engineered cardiac tissues (hECTs) using novel scaffolds and pluripotent stem cell derivatives. This has led to a new frontier of human-based models for improved preclinical development. At the same time, there has been significant progress in elucidating the importance of the immune system and, in particular, macrophages, particularly during myocardial injury. This review summarizes new methods and findings for deriving macrophages from human pluripotent stem cells (hPSCs) and advances in integrating these cells into cardiac tissue. Key challenges include immune cell infiltration in 3D constructs, maintenance of tissue architecture, and modeling aged or diseased cardiac microenvironments. By integrating immune components, hECTs can serve as powerful tools to unravel the complexities of cardiac pathology and develop targeted therapeutic strategies.