Fig. 1. (A) Schematic illustration of preparation of a dense collagen patch via plastic compression technique. (B) A heart after MI induced via permanent ligation of left anterior descending (LAD) artery, which is either untreated or treated with the dense collagen patch. The fibrillar structure of the patch was shown in the scanning electron microscopy image. Reproduced with permission from Ref. [25]. Copyright 2013 Elsevier B. V.

Fig. 2. Schematic illustration of fibrin formation. Reproduced with permission from Ref. [86]. Copyright 2019 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

Fig. 3. Schematic illustration of cross-linking between alginate chains induced by calcium ions as well as covalent bonds between alginate chains and carboxy-functionalized carbon nanotubes (CNTs). Adapted based on Ref. [104].

Fig. 4. Schematic illustration of an alginate/gelatin patch functionalized with IGF-1 via avidin-biotin binding strategy. Adapted based on Ref. [105].

Fig. 5. Process of preparation of a decellularized cardiac tissue. The left ventricle was separated, cut into small pieces, then decellularized and lyophilized. Scale bars = 3 cm. Reproduced with permission from Ref. [113]. Copyright 2020 Wiley-Blackwell.

Fig. 6. The diversity of tissue sources of decellularized tissues for cardiac patches.

Fig. 7. Schematic illustration of preparation of a decellularized matrix-based patch and its effects on infarcted myocardium. Reproduced with permission from Ref. [66]. Copyright 2019 American Chemical Society.

Fig. 8. Schematic illustration of the fabrication of an acellular artificial cardiac patch by embedding polymeric microparticles with CSC-secreted factors in decellularized myocardial ECM. Adapted based on Ref. [74].

Fig. 9. Chemical structures of synthetic polymers commonly used for cardiac patches.

Fig. 10. (A) Synthesis of a ROS responsive polyurethane (PUTK) with a thioketal linker. (B) Degradation of PUTK in response to ROS due to the cleavage of thioketal linkers. (C) Schematic illustration of preparation of a fibrous PUTK patch loaded with methylprednisolone for responsive release. (D) Transplantation of the resulted patch on the infarcted heart surface to restore the cardiac function after MI. Reproduced with permission from Ref. [121]. Copyright 2019 Elsevier B.V.

Fig. 11. Schematic illustration of the perfusion seeding of channeled elastomer scaffolds. Reproduced with permission from Ref. [127]. Copyright 2010 American Institute of Chemical Engineers Biotechnol. Prog.

Fig. 12. Schematic illustration of preparation of a cardiac patch composed of gelatin and conductive polymer and the mechanism of its effects on repairing the infarcted myocardium. Reproduced with permission from Ref. [151]. Copyright 2020 Elsevier B.V.