MYOCARDIAL BIOPROSTHESIS: MIMICKING N ATURE

SUMMARY Cardiac diseases of ischemic origin are threatening clinical conditions characterized by enlarged dysfunctional hearts and the risk of sudden death, with myocardial infarction being the most common disease. The only definitive treatment at present is a cardiac transplant, but new therapeutic approaches, such as the implantation of isolated cells with regenerative potential (cellular cardiomyoplasty), are emerging as promising alternatives. In this review, we describe the candidate cell types and cell delivery strategies for cardiac regeneration, as well as how limitations in cell-based therapies have inspired the generation of myocardial bioprosthesis and ultimately the challenging concept of an artificial heart. In this context, there has been an intensive search for synthetic and natural materials, as well as growth, proangiogenic and differentiation factors for generating innovative graftable bioimplants. Methods for delivering those materials together with cells to the damaged myocardium have evolved from intramyocardial injection of hydrogels/cell mixtures to implantation of scaffold-free cell sheets, hydrogel patches and artificial or natural scaffolds. Despite numerous issues, results from experimental and clinical studies demonstrated that these emerging techniques have an enormously promising future in cardiac regenerative medicine.