Antiarrhythmic and Anti-Inflammatory Effects of Sacubitril/Valsartan on Post-Myocardial Infarction Scar.

BACKGROUND: Sacubitril/valsartan (Sac/Val) is superior to angiotensin-converting enzyme inhibitors in reducing the risk of heart failure hospitalization and cardiovascular death, but its mechanistic data on myocardial scar after myocardial infarction (MI) are lacking. The objective of this work was to assess the effects of Sac/Val on inflammation, fibrosis, electrophysiological properties, and ventricular tachycardia inducibility in post-MI scar remodeling in swine. METHODS: After MI, 22 pigs were randomized to receive ß-blocker (BB; control, n=8) or BB+Sac/Val (Sac/Val, n=9). The systemic immune response was monitored. Cardiac magnetic resonance data were acquired at 2-day and 29-day post MI to assess ventricular remodeling. Programmed electrical stimulation and high-density mapping were performed at 30-day post MI to assess ventricular tachycardia inducibility. Myocardial samples were collected for histological analysis. RESULTS: Compared with BB, BB+Sac/Val reduced acute circulating leukocytes (P=0.009) and interleukin-12 levels (P=0.024) at 2-day post MI, decreased C-C chemokine receptor type 2 expression in monocytes (P=0.047) at 15-day post MI, and reduced scar mass (P=0.046) and border zone mass (P=0.043). It also lowered the number and mass of border zone corridors (P=0.009 and P=0.026, respectively), scar collagen I content (P=0.049), and collagen I/III ratio (P=0.040). Sac/Val reduced ventricular tachycardia inducibility (P=0.034) and the number of deceleration zones (P=0.016). CONCLUSIONS: After MI, compared with BB, BB+Sac/Val was associated with reduced acute systemic inflammatory markers, reduced total scar and border zone mass on late gadolinium-enhanced magnetic resonance imaging, and lower ventricular tachycardia inducibility.

Implantation of a double allogeneic human engineered tissue graft on damaged heart: insights from the PERISCOPE phase I clinical trial.

BACKGROUND: In preclinical studies, the use of double allogeneic grafts has shown promising results in promoting tissue revascularization, reducing infarct size, preventing adverse remodelling and fibrosis, and ultimately enhancing cardiac function. Building upon these findings, the safety of PeriCord, an engineered tissue graft consisting of a decellularised pericardial matrix and umbilical cord Wharton's jelly mesenchymal stromal cells, was evaluated in the PERISCOPE Phase I clinical trial (NCT03798353), marking its first application in human subjects. METHODS: This was a double-blind, single-centre trial that enrolled patients with non-acute myocardial infarction eligible for surgical revascularization. Seven patients were implanted with PeriCord while five served as controls. FINDINGS: Patients who received PeriCord showed no adverse effects during post-operative phase and one-year follow-up. No significant changes in secondary outcomes, such as quality of life or cardiac function, were found in patients who received PeriCord. However, PeriCord did modulate the kinetics of circulating monocytes involved in post-infarction myocardial repair towards non-classical inflammation-resolving macrophages, as well as levels of monocyte chemoattractants and the prognostic marker Meteorin-like in plasma following treatment. INTERPRETATION: In summary, the PeriCord graft has exhibited a safe profile and notable immunomodulatory properties. Nevertheless, further research is required to fully unlock its potential as a platform for managing inflammatory-related pathologies. FUNDING: This work was supported in part by grants from MICINN (SAF2017-84324-C2-1-R); Instituto de Salud Carlos III (ICI19/00039 and Red RICORS-TERAV RD21/0017/0022, and CIBER Cardiovascular CB16/11/00403) as a part of the Plan Nacional de I + D + I, and co-funded by ISCIII-Subdirección General de Evaluación y el Fondo Europeo de Desarrollo Regional (FEDER) and AGAUR (2021-SGR-01437).

La proteína meteorin-like se asocia a un perfil de mayor riesgo y predice un peor pronóstico en pacientes con IAMCEST / Meteorin-like protein is associated with a higher risk profile and predicts a worse outcome in patients with STEMI

Introducción y objetivos: La proteína meteorin-like (Metrnl) es una citocina implicada en la atenuación de la inflamación asociada a mal pronóstico en la insuficiencia cardiaca. En este estudio se evalúan los niveles circulantes de Metrnl y su valor pronóstico en el infarto agudo de miocardio con elevación del segmento ST (IAMCEST).Métodos: Se incluyó a pacientes con IAMCEST tratados con angioplastia primaria. Se determinaron los niveles de Metrnl en sangre periférica a las 12 horas del inicio de los síntomas. El criterio de evaluación primario fue muerte por cualquier causa o infarto de miocardio no mortal a 3 años.Resultados: Se estudiaron 381 pacientes (edad media 61 años, 21% mujeres, 8% clase Killip III/IV). Los niveles de Metrnl se asociaron con la edad, los factores de riesgo cardiovascular y la extensión de la enfermedad coronaria, pero también con complicaciones del infarto, especialmente insuficiencia cardíaca y shock cardiogénico. En la regresión multivariante de Cox Metrnl fue un predictor independiente del criterio de evaluación combinado (HR = 1,86; IC95%, 1,23-2,81; p=0,003). Además, los pacientes en el tercil más alto (> 491,6 pg/ml) presentaron mayor riesgo que en los terciles inferiores (HR = 3,24; IC95%, 1,92-5,44; p <0,001), incluso después de ajustar por edad, diabetes, paro cardíaco, clase Killip-Kimball III/IV, fracción de eyección y aclaramiento de creatinina (HR = 1,90; IC95%, 1,10-3,29; p=0,021).Conclusiones: En los pacientes con IAMCEST, los niveles circulantes de Metrnl se asocian con las complicaciones durante la fase aguda y predicen de forma independiente un peor pronóstico.(AU)

Introduction and objectives: Meteorin-like protein (Metrnl) is a cytokine involved in the attenuation of inflammation. In patients with heart failure, high levels of this biomarker are associated with a worse outcome. In this study, we evaluated the circulating levels and prognostic value of Metrnl in patients with ST-segment elevation myocardial infarction (STEMI).Methods: We enrolled STEMI patients undergoing primary percutaneous coronary intervention. Circulating Metrnl levels were measured in peripheral blood 12hours after symptom onset. The primary endpoint was a composite of all-cause mortality or nonfatal myocardial infarction (MI) at 3 years.Results: We studied 381 patients (mean age 61 years, 21% female, 8% Killip class III/IV). Metrnl levels were associated with age, cardiovascular risk factors and the extent of coronary artery disease, as well as with STEMI complications, particularly heart failure and cardiogenic shock. Multivariable Cox regression analysis revealed that Metrnl independently predicted all-cause death or nonfatal MI at 3 years (HR, 1.86; 95%CI, 1.23-2.81; P=.003). Moreover, patients in the highest tertile (> 491.6 pg/mL) were at higher risk for the composite endpoint than those in the lowest tertiles (HR, 3.24; 95%CI, 1.92-5.44; P <.001), even after adjustment by age, diabetes mellitus, cardiac arrest, Killip-Kimball III/IV class, left ventricular ejection fraction, and creatinine clearance (HR, 1.90; 95%CI, 1.10-3.29; P=.021).Conclusions: Circulating Metrnl levels are associated with complications during the acute phase of STEMI and independently predict a worse outcome in these patients.(AU)

Soluble mutant huntingtin drives early human pathogenesis in Huntington's disease.

Huntington's disease (HD) is an incurable inherited brain disorder characterised by massive degeneration of striatal neurons, which correlates with abnormal accumulation of misfolded mutant huntingtin (mHTT) protein. Research on HD has been hampered by the inability to study early dysfunction and progressive degeneration of human striatal neurons in vivo. To investigate human pathogenesis in a physiologically relevant context, we transplanted human pluripotent stem cell-derived neural progenitor cells (hNPCs) from control and HD patients into the striatum of new-born mice. Most hNPCs differentiated into striatal neurons that projected to their target areas and established synaptic connexions within the host basal ganglia circuitry. Remarkably, HD human striatal neurons first developed soluble forms of mHTT, which primarily targeted endoplasmic reticulum, mitochondria and nuclear membrane to cause structural alterations. Furthermore, HD human cells secreted extracellular vesicles containing mHTT monomers and oligomers, which were internalised by non-mutated mouse striatal neurons triggering cell death. We conclude that interaction of mHTT soluble forms with key cellular organelles initially drives disease progression in HD patients and their transmission through exosomes contributes to spread the disease in a non-cell autonomous manner.

Meteorin-like protein is associated with a higher risk profile and predicts a worse outcome in patients with STEMI.

INTRODUCTION AND OBJECTIVES: Meteorin-like protein (Metrnl) is a cytokine involved in the attenuation of inflammation. In patients with heart failure, high levels of this biomarker are associated with a worse outcome. In this study, we evaluated the circulating levels and prognostic value of Metrnl in patients with ST-segment elevation myocardial infarction (STEMI). METHODS: We enrolled STEMI patients undergoing primary percutaneous coronary intervention. Circulating Metrnl levels were measured in peripheral blood 12hours after symptom onset. The primary endpoint was a composite of all-cause mortality or nonfatal myocardial infarction (MI) at 3 years. RESULTS: We studied 381 patients (mean age 61 years, 21% female, 8% Killip class III/IV). Metrnl levels were associated with age, cardiovascular risk factors and the extent of coronary artery disease, as well as with STEMI complications, particularly heart failure and cardiogenic shock. Multivariable Cox regression analysis revealed that Metrnl independently predicted all-cause death or nonfatal MI at 3 years (HR, 1.86; 95%CI, 1.23-2.81; P=.003). Moreover, patients in the highest tertile (> 491.6 pg/mL) were at higher risk for the composite endpoint than those in the lowest tertiles (HR, 3.24; 95%CI, 1.92-5.44; P <.001), even after adjustment by age, diabetes mellitus, cardiac arrest, Killip-Kimball III/IV class, left ventricular ejection fraction, and creatinine clearance (HR, 1.90; 95%CI, 1.10-3.29; P=.021). CONCLUSIONS: Circulating Metrnl levels are associated with complications during the acute phase of STEMI and independently predict a worse outcome in these patients.

Preclinical scenario of targeting myocardial fibrosis with chimeric antigen receptor (CAR) immunotherapy.

Fibrosis is present in an important proportion of myocardial disorders. Injury activates cardiac fibroblasts, which deposit excess extracellular matrix, increasing tissue stiffness, impairing cardiac function, and leading to heart failure. Clinical therapies that directly target excessive fibrosis are limited, and more effective treatments are needed. Immunotherapy based on chimeric antigen receptor (CAR) T cells is a novel technique that redirects T lymphocytes toward specific antigens to eliminate the target cells. It is currently used in haematological cancers but has demonstrated efficacy in mouse models of hypertensive cardiac fibrosis, with activated fibroblasts as the target cells. CAR T cell therapy is associated with significant toxicities, but CAR natural killer cells can overcome efficacy and safety limitations. The use of CAR immunotherapy offers a potential alternative to current therapies for fibrosis reduction and restoration of cardiac function in patients with myocardial fibrosis.

Electrophysiological effects of adipose graft transposition procedure (AGTP) on the post-myocardial infarction scar: A multimodal characterization of arrhythmogenic substrate.

Objective: To assess the arrhythmic safety profile of the adipose graft transposition procedure (AGTP) and its electrophysiological effects on post-myocardial infarction (MI) scar. Background: Myocardial repair is a promising treatment for patients with MI. The AGTP is a cardiac reparative therapy that reduces infarct size and improves cardiac function. The impact of AGTP on arrhythmogenesis has not been addressed. Methods: MI was induced in 20 swine. Contrast-enhanced magnetic resonance (ce-MRI), electrophysiological study (EPS), and left-ventricular endocardial high-density mapping were performed 15 days post-MI. Animals were randomized 1:1 to AGTP or sham-surgery group and monitored with ECG-Holter. Repeat EPS, endocardial mapping, and ce-MRI were performed 30 days post-intervention. Myocardial SERCA2, Connexin-43 (Cx43), Ryanodine receptor-2 (RyR2), and cardiac troponin-I (cTnI) gene and protein expression were evaluated. Results: The AGTP group showed a significant reduction of the total infarct scar, border zone and dense scar mass by ce-MRI (p = 0.04), and a decreased total scar and border zone area in bipolar voltage mapping (p < 0.001). AGTP treatment significantly reduced the area of very-slow conduction velocity (<0.2 m/s) (p = 0.002), the number of deceleration zones (p = 0.029), and the area of fractionated electrograms (p = 0.005). No differences were detected in number of induced or spontaneous ventricular arrhythmias at EPS and Holter-monitoring. SERCA2, Cx43, and RyR2 gene expression were decreased in the infarct core of AGTP-treated animals (p = 0.021, p = 0.018, p = 0.051, respectively). Conclusion: AGTP is a safe reparative therapy in terms of arrhythmic risk and provides additional protective effect against adverse electrophysiological remodeling in ischemic heart disease.

N-Glycans in Immortalized Mesenchymal Stromal Cell-Derived Extracellular Vesicles Are Critical for EV-Cell Interaction and Functional Activation of Endothelial Cells.

Mesenchymal stromal cell-derived extracellular vesicles (MSC-EV) are widely considered as a cell-free therapeutic alternative to MSC cell administration, due to their immunomodulatory and regenerative properties. However, the interaction mechanisms between EV and target cells are not fully understood. The surface glycans could be key players in EV-cell communication, being specific molecular recognition patterns that are still little explored. In this study, we focused on the role of N-glycosylation of MSC-EV as mediators of MSC-EV and endothelial cells' interaction for subsequent EV uptake and the induction of cell migration and angiogenesis. For that, EV from immortalized Wharton's Jelly MSC (iWJ-MSC-EV) were isolated by size exclusion chromatography (SEC) and treated with the glycosidase PNGase-F in order to remove wild-type N-glycans. Then, CFSE-labelled iWJ-MSC-EV were tested in the context of in vitro capture, agarose-spot migration and matrigel-based tube formation assays, using HUVEC. As a result, we found that the N-glycosylation in iWJ-MSC-EV is critical for interaction with HUVEC cells. iWJ-MSC-EV were captured by HUVEC, stimulating their tube-like formation ability and promoting their recruitment. Conversely, the removal of N-glycans through PNGase-F treatment reduced all of these functional activities induced by native iWJ-MSC-EV. Finally, comparative lectin arrays of iWJ-MSC-EV and PNGase-F-treated iWJ-MSC-EV found marked differences in the surface glycosylation pattern, particularly in N-acetylglucosamine, mannose, and fucose-binding lectins. Taken together, our results highlight the importance of N-glycans in MSC-EV to permit EV-cell interactions and associated functions.

Acellular cardiac scaffolds enriched with MSC-derived extracellular vesicles limit ventricular remodelling and exert local and systemic immunomodulation in a myocardial infarction porcine model.

Rationale: Extracellular vesicles (EVs) from mesenchymal stromal cell (MSC) are a potential therapy for cardiac healing after myocardial infarction (MI). Nevertheless, neither their efficient administration nor therapeutic mechanisms are fully elucidated. Here, we evaluate the preclinical efficacy of a tissue engineering approach to locally deliver porcine cardiac adipose tissue MSC-EV (cATMSC-EV) in an acute MI pig model. Methods: After MI by permanent ligation of the coronary artery, pigs (n = 24) were randomized to Untreated or treated groups with a decellularised pericardial scaffold filled with peptide hydrogel and cATMSC-EV purified by size exclusion chromatography (EV-Treated group) or buffer (Control group), placed over the post-infarcted myocardium. Results: After 30 days, cardiac MRI showed an improved cardiac function in EV-Treated animals, with significantly higher right ventricle ejection fraction (+20.8% in EV-Treated; p = 0.026), and less ventricle dilatation, indicating less myocardial remodelling. Scar size was reduced, with less fibrosis in the distal myocardium (-42.6% Col I in EV-Treated vs Untreated; p = 0.03), a 2-fold increase in vascular density (EV-Treated; p = 0.019) and less CCL2 transcription in the infarct core. EV-treated animals had less macrophage infiltration in the infarct core (-31.7% of CD163+ cells/field in EV-Treated; p = 0.026), but 5.8 times more expressing anti-inflammatory CD73 (p = 0.015). Systemically, locally delivered cATMSC-EV also triggered a systemic effect, doubling the circulating IL-1ra (p = 0.01), and reducing the PBMC rush 2d post-MI, the TNFα and GM-CSF levels at 30d post-MI, and modulating the CD73+ and CCR2+ monocyte populations, related to immunomodulation and fibrosis modulation. Conclusions: These results highlight the potential of cATMSC-EV in modulating hallmarks of ischemic injury for cardiac repair after MI.

Circulating virome and inflammatory proteome in patients with ST-elevation myocardial infarction and primary ventricular fibrillation.

Primary ventricular fibrillation (PVF) is a life-threatening complication of ST-segment elevation myocardial infarction (STEMI). It is unclear what roles viral infection and/or systemic inflammation may play as underlying triggers of PVF, as a second hit in the context of acute ischaemia. Here we aimed to evaluate whether the circulating virome and inflammatory proteome were associated with PVF development in patients with STEMI. Blood samples were obtained from non-PVF and PVF STEMI patients at the time of primary PCI, and from non-STEMI healthy controls. The virome profile was analysed using VirCapSeq-VERT (Virome Capture Sequencing Platform for Vertebrate Viruses), a sequencing platform targeting viral taxa of 342,438 representative sequences, spanning all virus sequence records. The inflammatory proteome was explored with the Olink inflammation panel, using the Proximity Extension Assay technology. After analysing all viral taxa known to infect vertebrates, including humans, we found that non-PVF and PVF patients only significantly differed in the frequencies of viruses in the Gamma-herpesvirinae and Anelloviridae families. In particular, most showed a significantly higher relative frequency in non-PVF STEMI controls. Analysis of systemic inflammation revealed no significant differences between the inflammatory profiles of non-PVF and PVF STEMI patients. Inflammatory proteins associated with cell adhesion, chemotaxis, cellular response to cytokine stimulus, and cell activation proteins involved in immune response (IL6, IL8 CXCL-11, CCL-11, MCP3, MCP4, and ENRAGE) were significantly higher in STEMI patients than non-STEMI controls. CDCP1 and IL18-R1 were significantly higher in PVF patients compared to healthy subjects, but not compared to non-PVF patients. The circulating virome and systemic inflammation were not associated with increased risk of PVF development in acute STEMI. Accordingly, novel strategies are needed to elucidate putative triggers of PVF in the setting of acute ischaemia, in order to reduce STEMI-driven sudden death burden.

Commonly used methods for extracellular vesicles' enrichment: Implications in downstream analyses and use.

Extracellular vesicles (EVs) are becoming promising tools for clinical application, either as sources of disease-specific molecular signatures for the unraveling of disease pathophysiology and establishment of novel biomarkers, or as platforms for cell-free nanotherapy. Yet, an unsolved issue is to define standardized techniques for EV isolation allowing data comparison across laboratories worldwide. Considering the difficulties to find this necessary consensus, it has to be stressed out that the outcome of the downstream analysis might be deeply biased by the isolation method, among other variables. Thus, it is crucial that the researcher is aware of the strengths and weaknesses of each method keeping their intended use in mind, and to sufficiently report the methodology details for the results to be comparable and solid. This review aims to present the most widely used EV isolation methods, from the initial differential ultracentrifugation (dUC) to newest approaches.

Mechanisms governing the therapeutic effect of mesenchymal stromal cell-derived extracellular vesicles: A scoping review of preclinical evidence.

Compelling evidence supports the therapeutic benefit of extracellular vesicles (EVs). EVs are nanostructures with a lipid bilayer membrane that are secreted by multiple cells, including mesenchymal stromal cells (MSCs), as means of cellular communication. MSC-EVs, resembling their MSC origin, carry protected immunomodulatory and pro-regenerative cargoes to targeted neighboring or distant cells and tissues. Though treatments focused on MSC-EVs have emerged as greatly versatile approaches to modulate multiple inflammatory-related conditions, crucial concerns, including the possibility of increasing therapeutic outcomes by pre-conditioning parental MSCs or engineering derived EVs and clarification of the most relevant mechanisms of action, remain. Here, we summarize the large amount of preclinical research surrounding the modulation of beneficial effects by MSC-EVs.

Porcine iPSC Generation: Testing Different Protocols to a Successful Application.

Stem cell therapy has an unparalleled potential to treat blood cancers, cardiovascular diseases and neurodegenerative conditions, among others. However, stem cell therapeutics must overcome multiple requirements before reaching clinical trials, including large animal safety and efficacy studies. In cardiovascular diseases swine models are the most widely adopted due to its great translational potential to humans. In this chapter, we will describe several protocols to induce iPSC dedifferentiation in swine fibroblasts, as well as conditioning treatments that may help in the reprogramming process.

Clinical translation of mesenchymal stromal cell extracellular vesicles: Considerations on scientific rationale and production requisites.

The present paper is a commentary to 'Identification and characterization of hADSC-derived exosome proteins from different isolation methods' (Huang et al. 2021; 10.1111/jcmm.16775). Given the enthusiasm for the potential of mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs), some considerations deserve attention as they move through successive stages of research and application into humans. We herein remark the prerequisite of generating that evidence ensuring a high consistency in safety, composition and biological activity of the intended MSC-EV preparations, and the suitability of disparate isolation techniques to produce efficacious EV preparations and fulfil requirements for standardized clinical-grade biomanufacturing.

Deep Learning Analyses to Delineate the Molecular Remodeling Process after Myocardial Infarction.

Specific proteins and processes have been identified in post-myocardial infarction (MI) pathological remodeling, but a comprehensive understanding of the complete molecular evolution is lacking. We generated microarray data from swine heart biopsies at baseline and 6, 30, and 45 days after infarction to feed machine-learning algorithms. We cross-validated the results using available clinical and experimental information. MI progression was accompanied by the regulation of adipogenesis, fatty acid metabolism, and epithelial-mesenchymal transition. The infarct core region was enriched in processes related to muscle contraction and membrane depolarization. Angiogenesis was among the first morphogenic responses detected as being sustained over time, but other processes suggesting post-ischemic recapitulation of embryogenic processes were also observed. Finally, protein-triggering analysis established the key genes mediating each process at each time point, as well as the complete adverse remodeling response. We modeled the behaviors of these genes, generating a description of the integrative mechanism of action for MI progression. This mechanistic analysis overlapped at different time points; the common pathways between the source proteins and cardiac remodeling involved IGF1R, RAF1, KPCA, JUN, and PTN11 as modulators. Thus, our data delineate a structured and comprehensive picture of the molecular remodeling process, identify new potential biomarkers or therapeutic targets, and establish therapeutic windows during disease progression.

Wharton's Jelly Mesenchymal Stromal Cells and Derived Extracellular Vesicles as Post-Myocardial Infarction Therapeutic Toolkit: An Experienced View.

Outstanding progress has been achieved in developing therapeutic options for reasonably alleviating symptoms and prolonging the lifespan of patients suffering from myocardial infarction (MI). Current treatments, however, only partially address the functional recovery of post-infarcted myocardium, which is in fact the major goal for effective primary care. In this context, we largely investigated novel cell and TE tissue engineering therapeutic approaches for cardiac repair, particularly using multipotent mesenchymal stromal cells (MSC) and natural extracellular matrices, from pre-clinical studies to clinical application. A further step in this field is offered by MSC-derived extracellular vesicles (EV), which are naturally released nanosized lipid bilayer-delimited particles with a key role in cell-to-cell communication. Herein, in this review, we further describe and discuss the rationale, outcomes and challenges of our evidence-based therapy approaches using Wharton's jelly MSC and derived EV in post-MI management.

Local administration of porcine immunomodulatory, chemotactic and angiogenic extracellular vesicles using engineered cardiac scaffolds for myocardial infarction.

The administration of extracellular vesicles (EV) from mesenchymal stromal cells (MSC) is a promising cell-free nanotherapy for tissue repair after myocardial infarction (MI). However, the optimal EV delivery strategy remains undetermined. Here, we designed a novel MSC-EV delivery, using 3D scaffolds engineered from decellularised cardiac tissue as a cell-free product for cardiac repair. EV from porcine cardiac adipose tissue-derived MSC (cATMSC) were purified by size exclusion chromatography (SEC), functionally analysed and loaded to scaffolds. cATMSC-EV markedly reduced polyclonal proliferation and pro-inflammatory cytokines production (IFNγ, TNFα, IL12p40) of allogeneic PBMC. Moreover, cATMSC-EV recruited outgrowth endothelial cells (OEC) and allogeneic MSC, and promoted angiogenesis. Fluorescently labelled cATMSC-EV were mixed with peptide hydrogel, and were successfully retained in decellularised scaffolds. Then, cATMSC-EV-embedded pericardial scaffolds were administered in vivo over the ischemic myocardium in a pig model of MI. Six days from implantation, the engineered scaffold efficiently integrated into the post-infarcted myocardium. cATMSC-EV were detected within the construct and MI core, and promoted an increase in vascular density and reduction in macrophage and T cell infiltration within the damaged myocardium. The confined administration of multifunctional MSC-EV within an engineered pericardial scaffold ensures local EV dosage and release, and generates a vascularised bioactive niche for cell recruitment, engraftment and modulation of short-term post-ischemic inflammation.