Injectable Hydrogels for Cardiac Tissue Repair after Myocardial Infarction

Abstract

Cardiac tissue damage due to myocardial infarction (MI) is one of the leading causes of mortality worldwide. The available treatments of MI include pharmaceutical therapy, medical device implants, and organ transplants, all of which have severe limitations including high invasiveness, scarcity of donor organs, thrombosis or stenosis of devices, immune rejection, and prolonged hospitalization time. Injectable hydrogels have emerged as a promising solution for in situ cardiac tissue repair in infarcted hearts after MI. In this review, an overview of various natural and synthetic hydrogels for potential application as injectable hydrogels in cardiac tissue repair and regeneration is presented. The review starts with brief discussions about the pathology of MI, its current clinical treatments and their limitations, and the emergence of injectable hydrogels as a potential solution for post MI cardiac regeneration. It then summarizes various hydrogels, their compositions, structures and properties for potential application in post MI cardiac repair, and recent advancements in the application of injectable hydrogels in treatment of MI. Finally, the current challenges associated with the clinical application of injectable hydrogels to MI and their potential solutions are discussed to help guide the future research on injectable hydrogels for translational therapeutic applications in regeneration of cardiac tissue after MI.

Scaffold‐Based microRNA Therapies in Regenerative Medicine and Cancer

“…[131] High porosity, tissue anastomosis and mechanical strength are relevant aspects for orthopedic applications; however, favorable rheological properties, including responsiveness to different physical stimuli and a good viscoelastic component are the main factors to optimize in the case of hydrogel formulations. [132] Overall, the scaffold architecture must allow the ingrowth of neovascularization for the successful application of nearly every biomaterial in RM, and recently, the impact of material nanotopography is also gaining recognition. [133] In order to specifically adapt any scaffold to miRNA delivery, the material must retain the miRNA complexes while facilitating their sufficient exposure to the infiltrating cells.…”

Hydrogels for Cardiac Tissue Repair and Regeneration

“…Only polyethylene glycol (PEG), polylactide (PLA) and polylactide -glycolic acid (PLGA) have been approved by the FDA for clinical applications [7,14,15]. The last case is represented by natural and synthetic polymer -based hydrogels (ECM -fi brin hydrogels, ECM -polyethylene glycol hydrogels, fi brin -polyethylene glycol hydrogels, alginatepolypirrole, etc) to combine the advantages of both natural and synthetic materials [7,16]. The key steps involved in the preparation of an injectable hydrogel for cardiac tissue repair and/or regeneration are presented in Figure 2.…”

“…In the second case, the materials are synthetic (poly (acrylic acid) derivatives, polyethylene glycol, polyethylene oxide, polyvinyl alcohol, polypeptides, etc) and these materials present the advantages that provide consistent, controllable and precise mechanical properties like stiffness, porosity and elasticity, but present the disadvantages that some of these materials can induce cytotoxicity. Only polyethylene glycol (PEG), polylactide (PLA) and polylactide -glycolic acid (PLGA) have been approved by the FDA for clinical applications [7,14,15]. The last case is represented by natural and synthetic polymer -based hydrogels (ECM -fi brin hydrogels, ECM -polyethylene glycol hydrogels, fi brin -polyethylene glycol hydrogels, alginatepolypirrole, etc) to combine the advantages of both natural and synthetic materials [7,16].…”

“…The preparation of gelatin refers to the post breakage treatment of the collagen structure, gelatin of type A is obtained with acidic treatment while gelatin of type B is obtained with alkaline treatment. Gelatin is a natural polymer with a high potential for application in cardiac repair after MI, due to their high biocompatibility, biodegradation, complete bioresorbability and simplicity [7].…”

“…Molecules (with repair and/or regeneration capacities of the damaged tissue) are encapsulated in the hydrogel and released locally over time (the hydrazone bond is then broken and occurs the molecules release from nanoparticles). In several studies it was reported that polymer matrices can be used to sustain the release of encapsulated molecules for up to 100 days and the release profi le initially showed a quick release followed by a slower release rate [6][7][8][9][10]. …”