Targeted delivery of factors and cells for improving cardiac tissue regeneration and heart function following myocardial infarction

Following myocardial infarction (MI), cardiac tissue undergoes irreversible cellular alterations, with cardiomyocytes being replaced by fibrotic tissue. In order to improve tissue regeneration, a previously characterized chitosan-based cryogel, which was designed by our group, was used. The treatment regimen involved the sequential delivery of the cryogel loaded with specific cytokines and growth factors, followed by a separate injection of pre-differentiated cells. Initially, the cryogel loaded with interleukin-10 and transforming growth factor-β was injected into infarcted tissue immediately after MI induction, targeting the acute inflammatory response. On day four post-MI, a second injection was administered, this time utilizing cryogel loaded with vascular endothelial growth factor and fibroblast growth factor-2, aimed at promoting tissue regeneration and angiogenesis. Subsequently, on day six post-MI, the experimental group received cardiomyocyte-like cells, smooth muscle cells, and endothelial cells. The purpose of these cells, in synergy with cytokines and growth factors, was to repopulate the lost cellular populations, thereby enhancing myocardial repair. The treatment improved myocardial tissue regeneration, increased cardiac output, ejection fraction, and reduced fibrotic regions. Thus, the chitosan-based cryogel, enriched with anti-inflammatory and proangiogenic factors and supplemented with pre-differentiated cells, offers a promising platform for controlled release of therapeutics, promoting substantial tissue repair and regeneration following MI.