Intramyocardial injection of platelet gel promotes endogenous repair and augments cardiac function in rats with myocardial infarction.

OBJECTIVES: This study sought to explore the therapeutic potential of platelet gel for the treatment of myocardial infarction.
BACKGROUND: Cardiac dysfunction after acute myocardial infarction is a major cause of heart failure. Current therapy relies on prompt reperfusion and blockage of secondary maladaptive pathways by small molecules. Platelet gels are biomaterials rich in cytokines and growth factors, which can be manufactured in an autologous manner and are effective in various models of wound healing. However, the potential utility of platelet gel in cardiac regeneration has yet to be tested.
METHODS: Platelet gel was derived from syngeneic rats and its morphology, biocompatibility, secretion of beneficial factors, and in vivo degradation profile were characterized.
RESULTS: After delivery into infarcted rat hearts, the gel was efficiently infiltrated by cardiomyocytes and endothelial cells. Gel-treated hearts exhibited enhanced tissue protection, greater recruitment of endogenous regeneration, higher capillary density, and less compensatory myocyte hypertrophy. The cardiac function of control-injected animals deteriorated over the 6-week time course, while that of platelet gel-injected animals did not. In addition, the gel did not exacerbate inflammation in the heart.
CONCLUSIONS: Intramyocardial injection of autologous platelet gel ameliorated cardiac dysfunction after myocardial infarction. The striking functional benefits, the simplicity of manufacturing, and the potentially autologous nature of this biomaterial provide impetus for further translation.