The Current State of Extracellular Matrix Therapy for Ischemic Heart Disease

Lab-grown, 3D extracellular matrix particles improve cardiac function and morphology in myocardial ischemia

The promise of injection of extracellular matrix (ECM) from animal hearts as a treatment of myocardial ischemia has been limited by immune reactions and harsh ECM-damaging extraction procedures. We developed a novel method to produce lab-grown human three-dimensional (3-D) acellular ECM particles from human mesenchymal stem cells (MSCs) to mitigate product variability, immunogenicity, and preserve ECM architecture. We hypothesized that intramyocardial injection (I/M) of this novel ECM (dia ∼ 200 microns) would improve cardiac function in a postmyocardial infarction (MI) murine model. WT mice aged 8-10 wk underwent ligation of the left anterior descending coronary (LAD) artery and I/M injection of 10 μL ECM or normal saline (n = 10/group). Compared with control, ECM-treated hearts showed significant reduction in infarct size (P = 0.04), increased capillary density in ischemic myocardium (P = 0.01), and increased fractional shortening (FS) (P < 0.05) on postoperative days (POD) 14, 21, and 28 by echocardiography. There were no significant differences in immunogenic response as determined by TNFα, IL6, CD86, or CD163 levels (P > 0.05 for all) in the hearts. Biodistribution of fluorophore-conjugated ECM demonstrated localized epifluorescence in the heart after I/M injection, without significant peripheral end organ epifluorescence. Proteomic analysis of ischemic and perfused myocardium from control and ECM-treated hearts using LC-MS/MS (n = 3/group) detected significant changes in proteins involved in cardiomyocyte contractility and fatty acid metabolism. These findings suggest that 3-D ECM particles induce recovery of ischemic myocardium, by upregulating protein networks involved in cellular contractility and metabolism. Taken together, 3-D ECM particles represent a promising therapy for MI and warrant confirmatory studies in a high-fidelity large animal model.NEW & NOTEWORTHY Our novel lab-grown, human 3-D extracellular matrix (ECM) represents a novel therapeutic approach to prevent pathological remodeling and heart failure in an animal model of heart attack. This novel finding may help develop nonsurgical therapeutic modalities aimed at reducing the global burden of cardiovascular disease.

Changes in various forms of fibronectin in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass - a prospective, observational study

Coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) is associated with the transient activation of a systemic inflammatory response. Fibronectin (FN), an endogenous inflammatory mediator, is a key component of the extracellular matrix. This study aimed to detect changes in cellular and plasma FN levels, as well as its potential fragmentation or FN-fibrin complex formation, in 40 patients undergoing CABG with CPB. Our results indicate that CPB was associated with changes in the levels of cellular and plasma FN and with intensified FN fragmentation. Moreover, FN-fibrin complexes were detected in all patients, indicating activation of the coagulation process during CPB. In a multivariate regression analysis, a history of arterial hypertension and CPB duration influenced plasma FN levels at 6 h (β = -0.458, p = 0.001; -0.375, p = 0.008, respectively) and 12 h (β = -0.293, p = 0.026; -0.554, p = 0.000) after surgery. Alterations in FN concentration, intensified FN degradation, and the presence of FN-fibrin complexes after surgery may suggest that these changes are related to the remodelling of the extracellular matrix resulting from cardiac surgery and the associated repair processes. The results indicate that FN has clinical potential as a marker of repair processes.

Decellularized adipose-derived matrix from Superficial layers of abdominal adipose tissue exhibits superior capacity of adipogenesis compared to deep layers

The adipogenic property of decellularized adipose-derived matrix (DAM) varies widely across reports, making it difficult to make a horizontal comparison between reports and posing challenges for the stable clinical translation of DAM. It is possibly due to differences in donor characteristics, but the exact relationship remains unclear. Despite extensive research on the differences between superficial and deep layers of abdominal subcutaneous fat, a main donor of DAM, little is known about their extracellular matrix (ECM) which is promising in regenerative medicine. In this study, we first confirmed the distinct compositional profiles and adipogenic potential between superficial and deep DAM (S-DAM and D-DAM). Both in vitro and in vivo assays confirmed superior adipogenic induction potential in S-DAM over D-DAM. Total amounts of ECM proteins like collagen and laminin were similar, however, the predominant types differed, with collagen I dominating S-DAM and collagen XIV prevailing in D-DAM. S-DAM was enriched with mitochondrial and immunological proteins, whereas D-DAM featured more neuronal, vascular, muscular, and endocrine-related proteins. More proteins involved in mRNA processing were found in D-DAM, with Protein-Protein Interaction (PPI) analysis revealing HNRNPA2B1, HNRNPA1, and HNRNPC as the most tightly interacting members. These findings not only deepen our comprehension of the structural and functional heterogeneity of adipose tissues but also become one of the reason for the large variability between batches of DAM products, providing guidance for constructing more efficient and stable bio-scaffolds.

Exploring Electrospun Scaffold Innovations in Cardiovascular Therapy: A Review of Electrospinning in Cardiovascular Disease

Cardiovascular disease (CVD) remains the leading cause of mortality worldwide. In particular, patients who suffer from ischemic heart disease (IHD) that is not amenable to surgical or percutaneous revascularization techniques have limited treatment options. Furthermore, after revascularization is successfully implemented, there are a number of pathophysiological changes to the myocardium, including but not limited to ischemia-reperfusion injury, necrosis, altered inflammation, tissue remodeling, and dyskinetic wall motion. Electrospinning, a nanofiber scaffold fabrication technique, has recently emerged as an attractive option as a potential therapeutic platform for the treatment of cardiovascular disease. Electrospun scaffolds made of biocompatible materials have the ability to mimic the native extracellular matrix and are compatible with drug delivery. These inherent properties, combined with ease of customization and a low cost of production, have made electrospun scaffolds an active area of research for the treatment of cardiovascular disease. In this review, we aim to discuss the current state of electrospinning from the fundamentals of scaffold creation to the current role of electrospun materials as both bioengineered extracellular matrices and drug delivery vehicles in the treatment of CVD, with a special emphasis on the potential clinical applications in myocardial ischemia.