Stem cells derived exosome laden oxygen generating hydrogel composites with good electrical conductivity for the tissue-repairing process of post-myocardial infarction

Acute myocardial infarction (AMI) destroys heart cells by disrupting the oxygen supply. Improving oxygen delivery to the injured area may avoid cell death and regenerate the heart. We present the creation of oxygen-producing injectable bio-macromolecular hydrogels using catalase (CAT) loaded alginate (Alg) and fibrin (Fib) incorporated with the Mesenchymal stem cells (MSCs) derived exosomes (Exo). The composite hydrogel additionally incorporates electrical stimulating qualities from gold nanoparticles (AuNPs). In vitro experiments showed that this composite hydrogel (Exo/Hydro/AuNPs/CAT) exhibits electrical conductivity similar to an actual heart and effectively releases CAT. The O_2-generating hydrogel released oxygen for almost 5 days under hypoxia conditions. We showed that after 7 days of in vitro cell culture, produces the same paracrine factors as rat neonatal cardiomyocytes (RNCs), rat cardiac fibroblasts (RCFs), and Human Umbilical Vein Endothelial Cells (HUVECs), imitating capillary architecture and function. Our work demonstrated that the injectable conductive hydrogel loaded with CAT and AuNPs reduced left ventricular remodeling and myocardial dysfunction in rats after MI. Exo/Hydro/AuNPs/CAT boosted infarct margin angiogenesis, decreased cell apoptosis, and necrosis, and elevated Connexm43 (Cx43) expression. The therapeutic benefits and the ease of production of oxygen make this bioactive injectable conductive hydrogel an effective therapeutic agent for MI.