Vascular endothelial growth factor sustained delivery augmented cell therapy outcomes of cardiac progenitor cells for myocardial infarction

Injectable hydrogel-based combination therapy for myocardial infarction: a systematic review and Meta-analysis of preclinical trials

INTRODUCTION

This study evaluates the effectiveness of a combined regimen involving injectable hydrogels for the treatment of experimental myocardial infarction.

PATIENT CONCERNS

Myocardial infarction is an acute illness that negatively affects quality of life and increases mortality rates. Experimental models of myocardial infarction can aid in disease research by allowing for the development of therapies that effectively manage disease progression and promote tissue repair.

DIAGNOSIS

Experimental animal models of myocardial infarction were established using the ligation method on the anterior descending branch of the left coronary artery (LAD).

INTERVENTIONS

The efficacy of intracardiac injection of hydrogels, combined with cells, drugs, cytokines, extracellular vesicles, or nucleic acid therapies, was evaluated to assess the functional and morphological improvements in the post-infarction heart achieved through the combined hydrogel regimen.

OUTCOMES

A literature review was conducted using PubMed, Web of Science, Scopus, and Cochrane databases. A total of 83 papers, including studies on 1332 experimental animals (rats, mice, rabbits, sheep, and pigs), were included in the meta-analysis based on the inclusion and exclusion criteria. The overall effect size observed in the group receiving combined hydrogel therapy, compared to the group receiving hydrogel treatment alone, resulted in an ejection fraction (EF) improvement of 8.87% [95% confidence interval (CI): 7.53, 10.21] and a fractional shortening (FS) improvement of 6.31% [95% CI: 5.94, 6.67] in rat models, while in mice models, the improvements were 16.45% [95% CI: 11.29, 21.61] for EF and 5.68% [95% CI: 5.15, 6.22] for FS. The most significant improvements in EF (rats: MD = 9.63% [95% CI: 4.02, 15.23]; mice: MD = 23.93% [95% CI: 17.52, 30.84]) and FS (rats: MD = 8.55% [95% CI: 2.54, 14.56]; mice: MD = 5.68% [95% CI: 5.15, 6.22]) were observed when extracellular vesicle therapy was used. Although there have been significant results in large animal experiments, the number of studies conducted in this area is limited.

CONCLUSION

The present study demonstrates that combining hydrogel with other therapies effectively improves heart function and morphology. Further preclinical research using large animal models is necessary for additional study and validation.

Elastic and Conductive Melanin/Poly(Vinyl Alcohol) Composite Hydrogel for Enhancing Repair Effect on Myocardial Infarction

Heart failure caused by acute myocardial infarction (MI) still remains the main cause of death worldwide. Development of conductive hydrogels provided a promising approach for the treatment of myocardial infarction. However, the therapeutic potential of these hydrogels is still limited by material toxicity or low conductivity. The latter directly affects the coupling and the propagation of electrical signals between cells. Here, a functional conductive hydrogel by combining hydrophilic and biocompatible poly(vinyl alcohol) (PVA) with conductive melanin nanoparticles under physical crosslinking conditions is prepared. The composite hydrogels prepared by a facile fabrication process of five freeze/thaw cycles possessed satisfying mechanical properties and conductivity close to those of the natural heart. The physical properties and biocompatibility are evaluated in vitro experiments, showing that the introduction of melanin particles successfully improved the elasticity, conductivity, and cell adhesion of PVA hydrogel. In vivo, the composite hydrogels can enhance the cardiac repair effect by reducing MI area, slowing down ventricular wall thinning, and promoting the vascularization of infarct area in MI rat model. It is believed that the melanin/PVA composite hydrogel may be a suitable candidate material for MI repair.

Inhibition of GARS1-DT Protects Against Hypoxic Injury in H9C2 Cardiomyocytes via Sponging miR-212-5p

ABSTRACT

The present study aimed to elucidate the function of long noncoding RNA GARS1-DT in hypoxia-induced injury in ex-vivo cardiomyocytes and explore its underlying mechanism. Hypoxic injury was confirmed in H9C2 cells by the determination of cell viability, migration, invasion, and apoptosis. GARS1-DT expression was estimated in H9C2 cells after hypoxia. We then measured the effects of GARS1-DT knockdown on hypoxia-induced H9C2 cells. The interaction between GARS1-DT and miR-212-5p was also investigated. Hypoxia treatment led to cell damage in H9C2 cardiomyocytes, accompanied with the upregulation of GARS1-DT expression. Transfection of GARS1-DT small interfering RNA remarkably attenuated hypoxia-induced injury by enhancing cell viability, migration, and invasion, and reducing apoptosis. Furthermore, GARS1-DT served as an endogenous sponge for miR-212-5p, and its expression was negatively regulated by GARS1-DT. The effects of GARS1-DT knockdown on hypoxia-induced injury were significantly abrogated by miR-212-5p silence. Besides, suppression of GARS1-DT activated PI3K/AKT pathway in hypoxia-treated H9C2 cells, which were reversed by inhibition of miR-212-5p. Our findings demonstrated the novel molecular mechanism of GARS1-DT/miR-212-5p/PI3K/AKT axis on the regulation of hypoxia-induced myocardial injury in H9C2 cells, which may provide potential therapeutic targets for acute myocardial infarction treatment.