Natural scaffolds for cardiac tissue engineering. Combined surgical procedure using CorCap ventricular constraint device and collagen scaffold implantation in a sheep ischemic model for myocardial repair and ventricular chamber remodeling. a Introduction of the cell-seeded collagen matrix between the heart and the CorCap polyester device (Shafy et al. [32]). b Autopsy at 3 months showing the CorCap mesh covering both ventricles (arrow) (Shafy et al. [32]). c Left ventricular infarct scar (arrow) (Shafy et al. [32]). d Histology at 3 months of the ischemic/reperfused myocardium. Arrows show the mixed configuration: patchy fibrosis (1) and subnormal myocardium (2) (Shafy et al. [32]). a–c Reproduced, with permission, from [32]. e–g Three-dimensional engineered fibrin-cell patches implanted over infarcted myocardium wounds in mice. e Representative photograph of a mouse heart excised from a post-myocardial infarction (MI) animal at 4 weeks post-implantation of an adhesive fibrin-based patch composed of human umbilical cord blood mesenchymal stem cells (UCBMSCs) (asterisk). Images of Masson’s trichrome staining of cross-sections from the three groups of post-infarcted animals. Scale bar = 1 mm (Roura et al. [62]). Histograms represent the percentage of LV scar thickness (f) and volume (g) (Roura et al. [62]). e–g Reproduced, with permission, from [62]. h Intraoperative injection of the fibrin–alginate composite was performed using a 2 × 2 cm template with injection sites arrayed at 0.5 cm intervals within the region of MI. i At necropsy, the fibrin–alginate (Fib–Alg) could be visualized as amorphous densities within the MI region (LV left ventricle) (Mukherjee et al. [115]); reproduced, with permission, from [115]. j, k Heterotopic heart transplant surgery and hyaluronan-based scaffold (HYAFF®11) implantation in the rat MI model. The heart–lung block was carefully excised, the left lung removed, and the cardiac infarction induced by left descending coronary artery ligation on the bench (Fiumana et al. [126]); reproduced, with permission from [126]. j The allograft was transplanted by end-to-side anastomosis of the aorta to the abdominal aorta of the recipient. Scale bar = 5 mm (Fiumana et al. [126]). k The bioengineered HYAFF®11 was introduced into a pouch made in the thickness of the ventricular wall of the heterotopic heart at the level of the post-infarction scar. Scale bar = 5 mm (Fiumana et al. [126]). l, m Myocardial bioprosthesis implantation in porcine infarcted hearts; reproduced, with permission, from [174]. l A myocardial bioprosthesis, composed by decellularized human pericardium embedded with RAD16-I and mediastinal adipose tissue-derived progenitor cells, was implanted over the ischemic myocardium (Prat-Vidal et al. [174]). m Transversal heart section of a treated pig with the attached bioprosthesis indicated (dotted yellow line) (Prat-Vidal et al. [174])