Various approaches of myocardial reconstruction have been developed for the treatment of congestive heart failure resulting from ischemic cardiomyopathy. In this work, we investigated the in situ application of polymers in treating chronic and acute rodent model of ischemic cardiomyopathy. We demonstrate that alginate and fibrin can augment left ventricular wall thickness, resulting in reconstruction of left ventricular geometry and improvement of cardiac function. In histology results, the administration of biopolymers can reduce infarct size and increase arteriogenesis. We furthermore studied the functionalized biopolymer conjugated with RGD peptide and enhancement of treatment effects was observed. These findings suggest that the modified alginate can influence microenvironment by the crosstalk of integrin-ligand interaction.

Combined strategies of scaffold materials with cytokine or cells were also demonstrated in our studies. Our results indicate human mesenchymal stem cells (hMSCs) can be successfully encapsulated in modified alginate microspheres which are small enough to be delivered directly into the infarct with a close-chest injection. Improvement of cell survival, preservation of heart function, inducement of angiogenesis and reduction of scar size compared with control group were seen. These results lead to the conclusion that the application of engineered alginate microsphere is a promising candidate in repairing damaged myocardium and is an ideal agent for cells and signal molecules delivery.