Biological Cardiac Patch Based on Extracellular Vesicles and Extracellular Matrix for Regulating Injury-Related Microenvironment and Promoting Cardiac Tissue Recovery

Cardiac patches are widely investigated to repair or regenerate diseased and aging cardiac tissues. While numerous studies looked into engineering the biochemical/biomechanical/cellular microenvironment and components in the heart tissue, the changes induced by cardiac patches and how they should be controlled to promote cardiac tissue repair/regeneration remains an important yet untapped direction, especially immunological responses. In this study, we designed and fabricated a bilaminated cardiac patch based on extracellular matrix (ECM) materials loaded with the extracellular vesicles (EVs) derived from mesenchymal stromal cells. The function of the biological material to modulate the injury-related microenvironment in a cardiac infarction model in mice was investigated. The study showed that the treatment of EV-ECM patches to the infarcted area increased the level of immunomodulatory major histocompatibility complex class II