Engineering biomaterials for myocardial regeneration and repair

Augmentation of myocardial tissue regeneration processes in injured hearts represents a major challenge in cardiology as current therapeutic approaches do not regenerate the myocardial tissue. Herein, we describe three emerging biomaterial-based strategies to treat heart injuries, as stand-alone therapies or in combination with regeneration- inducing signals and/or cells. One strategy relies on the injection of acellular biomaterials, at an early stage after myocardial infarction (MI); these materials replace the damaged extracellular matrix, maintain left ventricular (LV) thickness, and prevent the negative LV remodeling and progression to heart failure. This strategy is currently being investigated in advanced clinical trials using a novel alginatebased biomaterial. The second strategy employs engineered biomaterials, spatially presenting multiple regeneration-inducing factors, to promote myocardial tissue regeneration in chronic infarcted hearts. The recent attempts to understand the "natural capacity" of the myocardium to heal and the factors involved in these processes are promising to advance this therapy. The third strategy applies biomaterials to promote cardiac tissue engineering and create a pre-vascularized cardiac patch to replace damaged or missing myocardial tissue. Collectively, this review emphasizes the increasing importance of biomaterials in cardiology, describes the engineering schemes used in their fabrication, and their implementation in various therapeutic strategies aimed at cardiac tissue regeneration and repair. It mainly highlights the contribution of our group in developing these strategies.