In vitro comparison of harvesting site effects on cardiac extracellular matrix hydrogels.

Cardiac extracellular matrix (cECM) derived hydrogel has been investigated to treat myocardial infarction through animal studies and clinical trials. The tissue harvesting site commonly selects porcine left ventricle (LV) because heart attack majorly takes place in LV. However, little is known about whether the region of cardiac tissue harvesting is critical for downstream applications. In this work, in vitro studies to compare cECM hydrogels derived from adult porcine whole heart (WH), LV, and right ventricle (RV) were performed. The cECM from WH has similar chemical composition compared with cECM from LV and RV. All three types of cECM hydrogels share many similarities in terms of their microstructure, gelation time, and mechanical properties. WH-derived cECM hydrogels have larger variations in storage modulus (G') and complex modulus (G*) compared with the other two types of cECM hydrogels. Both human cardiomyocytes and mesenchymal stem cells could maintain high cell viability on all hydrogels without significant difference. In terms of above results, the cECM hydrogels from WH, LV and RV exhibited similarity in material properties and cell response in vitro. Thus, future fabrication of cECM hydrogels from WH would increase the yield, which would decrease processing time and production cost.