Mussel‐Inspired Conductive Cryogel as Cardiac Tissue Patch to Repair Myocardial Infarction by Migration of Conductive Nanoparticles

Abstract

The engineered cardiac patch (ECP) is a promising strategy to repair infarct myocardium and restore the cardiac function. An ideal ECP should be able to mimic the primary attributes of native myocardium, which includes a high resilience, good cardiomyocyte adhesion, and synchronous contraction. Here, a mussel‐inspired dopamine crosslinker is used to integrate polypyrrole (Ppy) nanoparticles, gelatin‐methyacrylate, and poly(ethylene glycol) diacrylate into a cryogel form. The dopamine crosslinker and Ppy nanoparticles are coordinated to obtain optimal mechanical and superelastic properties for the ECP. The dopamine facilitates the uniform distribution of the Ppy nanoparticles, which migrate and fuse from the scaffold to the surface of the cardiomyocytes, revealing a potential mechanism for restoring infarct myocardium. The incorporated Ppy nanoparticles thus significantly enhance the functionalization of the cardiomyocytes, resulting in excellent synchronous contraction by increasing the expression of α‐actinin and CX‐43. Cardiomyocytes‐loaded ECP can improve the cardiac function in myocardial‐infarction (MI) affected rat models. The results show that the fractional shortening and ejection fraction are elevated by about 50% and that the infarct size is reduced by 42.6%. Collectively, this study highlights an effective cardiac patch based on mussel‐inspired conductive particle adhesion and a superelastic cryogel promising for the restoration of infarcted myocardium.

Ultralight Conductive and Elastic Aerogel for Skeletal Muscle Atrophy Regeneration

“…Mildly reduced GO films are able to absorb larger amount of bovine serum, fibronection, and fibroblast growth factor compared to GO or highly reduced GO . Similarly, the incorporated dopamine in aerogel, as proved in our previously study, is beneficial for the attachment and spreading of cells . Based on the properties mentioned above, PDA/rGO aerogel provides strong and spatial support for attachment, growth, and proliferation of myoblasts.…”

Paintable and Rapidly Bondable Conductive Hydrogels as Therapeutic Cardiac Patches

“…Herein, Fe 3+ was selected as a multifunctional curing agent, where the Fe 3+ possessed two main functions: first, the Fe 3+ initiated the polymerization of the pyrrole groups at the terminal of HPAE–Py. We note that owing to its poor water solubility, the polymerization of free pyrrole is generally conducted in isopropanol or diluted acid accompanied with unavoidable purification process . Comparatively, in this work, the pyrrole groups chemically linked to water‐soluble hyperbranched macromolecules could avoid the toxicity and leakage originated from pyrrole monomer and are polymerized in aqueous solution without introducing organic solvent or small molecules.…”

“…The locations of the tissue sections for immunofluorescence staining were chosen from the central infarct regions of hearts (Figure A). The immunofluorescence of Cx‐43 protein was employed to characterize the electric‐contraction coupling of the myocardium . Figure C shows that the HPAE–Py/Geln group exhibited the highest expression of Cx‐43, which approximates to that of the normal group, suggesting elevated electric‐contraction after the transplantation of HPAE–Py/Geln at 4 weeks.…”

“…It is well known that the electrical pulse signal in the infarct region is interdicted following the occurrence of MI, and introduction of electrical conductivity into the biomaterials has been shown to be an effective approach to promote the cardiac function after MI . However, fixing conductive patches to the myocardium through conventional surgical suture or light irradiation could elicit an inflammatory reaction or multilevel oxidative stress that affects the regeneration process. Therefore, development of conductive adhesive that can be conveniently administered by simply painting on the heart surface will undoubtedly be a more feasible approach to the clinical treatment of MI.…”

Conjugated Polymers in Bioelectronics: Addressing the Interface Challenge

“…As previously discussed, biomaterials can be used as a medium to introduce viable cells post MI. A cryogel system with incorporated PPy nanoparticles and seeded with cardiomyocytes was sutured onto an infarcted heart, resulting in a reduced infarct and improved cardiac function . These studies make up the recent, but compelling, body of evidence that demonstrates the potential therapeutic benefit of CPs in cardiac applications.…”