Therapeutic Applications of Extracellular Vesicles for Myocardial Repair

Research advances in the therapy of metabolic syndrome

Metabolic syndrome refers to the pathological state of metabolic disorder of protein, fat, carbohydrate, and other substances in the human body. It is a syndrome composed of a group of complex metabolic disorders, whose pathogenesis includes multiple genetic and acquired entities falling under the category of insulin resistance and chronic low-grade inflammationand. It is a risk factor for increased prevalence and mortality from diabetes and cardiovascular disease. Cardiovascular diseases are the predominant cause of morbidity and mortality globally, thus it is imperative to investigate the impact of metabolic syndrome on alleviating this substantial disease burden. Despite the increasing number of scientists dedicating themselves to researching metabolic syndrome in recent decades, numerous aspects of this condition remain incompletely understood, leaving many questions unanswered. In this review, we present an epidemiological analysis of MetS, explore both traditional and novel pathogenesis, examine the pathophysiological repercussions of metabolic syndrome, summarize research advances, and elucidate the mechanisms underlying corresponding treatment approaches.

Oncoprotein-induced transcript 3 protein-enriched extracellular vesicles promotes NLRP3 ubiquitination to alleviate acute lung injury after cardiac surgery

Acute lung injury (ALI) including acute respiratory distress syndrome (ARDS) is a major complication and increase the mortality of patients with cardiac surgery. We previously found that the protein cargoes enriched in circulating extracellular vesicles (EVs) are closely associated with cardiopulmonary disease. We aimed to evaluate the implication of EVs on cardiac surgery-associated ALI/ARDS. The correlations between "oncoprotein-induced transcript 3 protein (OIT3) positive" circulating EVs and postoperative ARDS were assessed. The effects of OIT3-overexpressed EVs on the cardiopulmonary bypass (CPB) -induced ALI in vivo and inflammation of human bronchial epithelial cells (BEAS-2B) were detected. OIT3 enriched in circulating EVs is reduced after cardiac surgery with CPB, especially with postoperative ARDS. The "OIT3 positive" EVs negatively correlate with lung edema, hypoxemia and CPB time. The OIT3-overexpressed EVs can be absorbed by pulmonary epithelial cells and OIT3 transferred by EVs triggered K48- and K63-linked polyubiquitination to inactivate NOD-like receptor protein 3 (NLRP3) inflammasome, and restrains pro-inflammatory cytokines releasing and immune cells infiltration in lung tissues, contributing to the alleviation of CPB-induced ALI. Overexpression of OIT3 in human bronchial epithelial cells have similar results. OIT3 promotes the E3 ligase Cbl proto-oncogene B associated with NLRP3 to induce the ubiquitination of NLRP3. Immunofluorescence tests reveal that OIT3 is reduced in the generation from the liver sinusoids endothelial cells (LSECs) and secretion in liver-derived EVs after CPB. In conclusion, OIT3 enriched in EVs is a promising biomarker of postoperative ARDS and a therapeutic target for ALI after cardiac surgery.

Immunometabolism, extracellular vesicles and cardiac injury

Recent evidence from our lab and others suggests that metabolic reprogramming of immune cells drives changes in immune cell phenotypes along the inflammatory-to-reparative spectrum and plays a critical role in mediating the inflammatory responses to cardiac injury (e.g. hypertension, myocardial infarction). However, the factors that drive metabolic reprogramming in immune cells are not fully understood. Extracellular vesicles (EVs) are recognized for their ability to transfer cargo such as microRNAs from remote sites to influence cardiac remodeling. Furthermore, conditions such as obesity and metabolic syndrome, which are implicated in the majority of cardiovascular disease (CVD) cases, can skew production of EVs toward pro-inflammatory phenotypes. In this mini-review, we discuss the mechanisms by which EVs may influence immune cell metabolism during cardiac injury and factors associated with obesity and the metabolic syndrome that can disrupt normal EV function. We also discuss potential sources of cardio-protective and anti-inflammatory EVs, such as brown adipose tissue. Finally, we discuss implications for future therapeutics.

The role of small extracellular vesicle-miRNAs in endometriosis

Endometriosis is defined by the presence of extrauterine endometrial-like tissue, which can cause pain and infertility in 10% of reproductive-age women. To date, the pathogenesis is poorly understood resulting in significant diagnostic delays and poor therapeutic outcomes in many women. Small extracellular vesicles (sEVs) (<200 nm) are cell-derived vesicles containing molecules that can influence gene expression and behaviour in target cells. One such cargo are microRNAs (miRNAs), which are short, non-coding RNAs mostly 19-25 nucleotides in length that regulate post-transcriptional gene expression. This mini-review focuses on the role of sEV-miRNAs, which are conceivably better biomarkers for endometriosis than free miRNAs, which reflect the true pathophysiological state in the body, as sEV-encapsulated miRNAs are protected from degradation compared to free miRNA and provide direct cell-to-cell communication via sEV surface proteins. sEV-miRNAs have been implicated in the immunomodulation of macrophages, the proliferation, migration and invasion of endometrial cells, and angiogenesis, all hallmarks of endometriosis. The diagnostic potential of sEV-miRNA was investigated in one study that reported the sensitivity and specificity of two sEV-miRNAs (hsa-miR-22-3p and hsa-miR-320a-3p) in distinguishing endometriosis from non-endometriosis cases. Only three studies have explored the therapeutic potential of sEV-miRNAs in vivo in mice-two looked into the role of sEV-hsa-miR-214-3p in decreasing fibrosis, and one investigated sEV-hsa-miR-30c-5p in suppressing the invasive and migratory potential of endometriotic lesions. While early results are encouraging, studies need to further address the potential influence of factors such as the menstrual cycle as well as the location and extent of endometriotic lesions on miRNA expression in sEVs. Given these findings, and extrapolating from other conditions such as cancer, diabetes, and pre-eclampsia, sEV-miRNAs could present an attractive and urgently needed future diagnostic and therapeutic target for millions of women suffering from endometriosis. However, research in this area is hampered by lack of adherence to the International Society for Extracellular Vesicles 2018 guideline in separating and characterising sEVs, as well as the World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonisation Project protocols.

Stem cells and extracellular vesicles to improve preclinical orofacial soft tissue healing

Orofacial soft tissue wounds caused by surgery for congenital defects, trauma, or disease frequently occur leading to complications affecting patients' quality of life. Scarring and fibrosis prevent proper skin, mucosa and muscle regeneration during wound repair. This may hamper maxillofacial growth and speech development. To promote the regeneration of injured orofacial soft tissue and attenuate scarring and fibrosis, intraoral and extraoral stem cells have been studied for their properties of facilitating maintenance and repair processes. In addition, the administration of stem cell-derived extracellular vesicles (EVs) may prevent fibrosis and promote the regeneration of orofacial soft tissues. Applying stem cells and EVs to treat orofacial defects forms a challenging but promising strategy to optimize treatment. This review provides an overview of the putative pitfalls, promises and the future of stem cells and EV therapy, focused on orofacial soft tissue regeneration.

Charting the Path: Navigating Embryonic Development to Potentially Safeguard against Congenital Heart Defects

Congenital heart diseases (CHDs) are structural or functional defects present at birth due to improper heart development. Current therapeutic approaches to treating severe CHDs are primarily palliative surgical interventions during the peri- or prenatal stages, when the heart has fully developed from faulty embryogenesis. However, earlier interventions during embryonic development have the potential for better outcomes, as demonstrated by fetal cardiac interventions performed in utero, which have shown improved neonatal and prenatal survival rates, as well as reduced lifelong morbidity. Extensive research on heart development has identified key steps, cellular players, and the intricate network of signaling pathways and transcription factors governing cardiogenesis. Additionally, some reports have indicated that certain adverse genetic and environmental conditions leading to heart malformations and embryonic death may be amendable through the activation of alternative mechanisms. This review first highlights key molecular and cellular processes involved in heart development. Subsequently, it explores the potential for future therapeutic strategies, targeting early embryonic stages, to prevent CHDs, through the delivery of biomolecules or exosomes to compensate for faulty cardiogenic mechanisms. Implementing such non-surgical interventions during early gestation may offer a prophylactic approach toward reducing the occurrence and severity of CHDs.

Stem cells derived exosomes and biomaterials to modulate autophagy and mend broken hearts

Autophagy maintains cellular homeostasis and plays a crucial role in managing pathological conditions including ischemic myocardial injury leading to heart failure (HF). Despite treatments, no intervention can replace lost cardiomyocytes. Stem cell therapy offers potential for post-myocardial infarction repair but struggles with poor cell retention due to immune rejection. In the search for effective therapies, stem cell-derived extracellular vesicles (EVs), especially exosomes, have emerged as promising tools. These tiny bioactive molecule carriers play vital roles in intercellular communication and tissue engineering. They offer numerous therapeutic benefits including modulating immune responses, promoting tissue repair, and boosting angiogenesis. Additionally, biomaterials provide a conducive 3D microenvironment for cell, exosome, and biomolecule delivery, and enhance heart muscle strength, making it a comprehensive cardiac repair strategy. In this regard, the current review delves into the intricate application of extracellular vesicles (EVs) and biomaterials for managing autophagy in the heart muscle during cardiac injury. Central to our investigation is the exploration of how these elements interact within the context of cardiac repair and regeneration. Additionally, this review also casts light on the formidable challenges that plague this field, such as the issues of safety, efficacy, controlled delivery, and acceptance of these therapeutic strategies for effective clinical translation. Addressing these challenges is crucial for unlocking the full therapeutic potential of EV and biomaterial-based therapies and ensuring their successful translation from bench to bedside.

The Therapeutic Potential of Multipotent Mesenchymal Stromal Cell-Derived Extracellular Vesicles in Endometrial Regeneration

Disruption of endometrial regeneration, fibrosis formation, and intrauterine adhesions underlie the development of "thin" endometrium and/or Asherman's syndrome (AS) and are a common cause of infertility and a high risk for adverse obstetric outcomes. The methods used (surgical adhesiolysis, anti-adhesive agents, and hormonal therapy) do not allow restoration of the regenerative properties of the endometrium. The experience gained today with cell therapy using multipotent mesenchymal stromal cells (MMSCs) proves their high regenerative and proliferative properties in tissue damage. Their contribution to regenerative processes is still poorly understood. One of these mechanisms is based on the paracrine effects of MMSCs associated with the stimulation of cells of the microenvironment by secreting extracellular vesicles (EVs) into the extracellular space. EVs, whose source is MMSCs, are able to stimulate progenitor cells and stem cells in damaged tissues and exert cytoprotective, antiapoptotic, and angiogenic effects. This review described the regulatory mechanisms of endometrial regeneration, pathological conditions associated with a decrease in endometrial regeneration, and it presented the available data from studies on the effect of MMSCs and their EVs on endometrial repair processes, and the involvement of EVs in human reproductive processes at the level of implantation and embryogenesis.

Theranostic extracellular vesicles: a concise review of current imaging technologies and labeling strategies

Extracellular vesicles (EVs), or exosomes, are naturally occurring nano- and micro-sized membrane vesicles playing an essential role in cell-to-cell communication. There is a recent increasing interest in harnessing the therapeutic potential of these natural nanoparticles to develop cell-free regenerative medicine and manufacture highly biocompatible and targeted drug and gene delivery vectors, amongst other applications. In the context of developing novel and effective EV-based therapy, imaging tools are of paramount importance as they can be used to not only elucidate the underlying mechanisms but also provide the basis for optimization and clinical translation. In this review, recent efforts and knowledge advances on EV-based therapies have been briefly introduced, followed by an outline of currently available labeling strategies by which EVs can be conjugated with various imaging agents and/or therapeutic drugs and genes. A comprehensive review of prevailing EV imaging technologies is then presented along with examples and applications, with emphasis on imaging probes and agents, corresponding labeling methods, and the pros and cons of each imaging modality. Finally, the potential of theranostic EVs as a powerful new weapon in the arsenal of regenerative medicine and nanomedicine is summarized and envisioned.

The Role of Extracellular Vesicles in Colorectal Cancer

Extracellular vesicles (EVs) are a class of spherical vesicles that are produced by active secretion of cells and encapsulated by phospholipid bilayers. In recent years, numerous studies have shown that EVs play pivotal roles in the regulation of intercellular communication between colorectal cancer (CRC) cells and target cells, and can regulate the proliferation, metastasis, and infiltration of tumor cells by regulating the microenvironment of tumor cells. EVs carry specific molecular substances in source CRC cells and are expected to serve as new molecular markers for the detection of cancers. This review highlights the current state of research and progress of potentially incorporating EVs in the diagnosis and treatment of CRC.

Myocardial injury: where inflammation and autophagy meet

Autophagy is a highly conserved bulk degradation mechanism that degrades damaged organelles, aged proteins and intracellular contents to maintain the homeostasis of the intracellular microenvironment. Activation of autophagy can be observed during myocardial injury, during which inflammatory responses are strongly triggered. Autophagy can inhibit the inflammatory response and regulate the inflammatory microenvironment by removing invading pathogens and damaged mitochondria. In addition, autophagy may enhance the clearance of apoptotic and necrotic cells to promote the repair of damaged tissue. In this paper, we briefly review the role of autophagy in different cell types in the inflammatory microenvironment of myocardial injury and discuss the molecular mechanism of autophagy in regulating the inflammatory response in a series of myocardial injury conditions, including myocardial ischemia, ischemia/reperfusion injury and sepsis cardiomyopathy.

Immunity: Psoriasis comorbid with atherosclerosis

Psoriasis is an immune-mediated, persistent inflammatory disease with a genetic predisposition, and the involvement of multiple organs in psoriasis remains indicative of systemic disease. Atherosclerosis (AS) is a common complication of patients with severe or prolonged psoriasis. The specific pathogenesis of psoriasis is still unclear. Current studies suggest that psoriasis is a polygenic genetic disease with the interaction of multiple factors such as heredity and environment. Keratinocytes are proliferated through immune-mediated inflammatory pathway, which leads to cell activation, infiltration of dermis cells and release of inflammatory factors. Activation of inflammatory cells and pro-inflammatory factors play an important role in the progression of psoriasis and atherosclerosis. Studies have found that there is a close relationship between psoriasis and atherosclerosis, and systemic inflammation may be the common feature of psoriasis and AS. This paper attempts to explore the possibility of the relationship between psoriasis and atherosclerotic comorbidities from the aspects of potential epidemiology and immune mechanism, in order to provide some reference for the subsequent scientific research.

Extracellular Vesicles in Multiple Myeloma-Cracking the Code to a Better Understanding of the Disease

Multiple myeloma (MM) is a plasma cell-derived malignancy that stands for around 1.5% of newly discovered cancer cases. Despite constantly improving treatment methods, the disease is incurable with over 13,000 deaths in the US and over 30,000 in Europe. Recent studies suggest that extracellular vesicles (EVs) might play a significant role in the pathogenesis and evolution of MM. Further investigation of their role could prove to be beneficial in establishing new therapies and hence, improve the prognosis of MM patients. What is more, EVs might serve as novel markers in diagnosing and monitoring the disease. Great advancements concerning the position of EVs in the pathophysiology of MM have recently been shown in research and in this review, we would like to delve into the still expanding state of knowledge.

Current Perspectives on Adult Mesenchymal Stromal Cell-Derived Extracellular Vesicles: Biological Features and Clinical Indications

Extracellular vesicles (EVs) constitute one of the main mechanisms by which cells communicate with the surrounding tissue or at distance. Vesicle secretion is featured by most cell types, and adult mesenchymal stromal cells (MSCs) of different tissue origins have shown the ability to produce them. In recent years, several reports disclosed the molecular composition and suggested clinical indications for EVs derived from adult MSCs. The parental cells were already known for their roles in different disease settings in regulating inflammation, immune modulation, or transdifferentiation to promote cell repopulation. Interestingly, most reports also suggested that part of the properties of parental cells were maintained by isolated EV populations. This review analyzes the recent development in the field of cell-free therapies, focusing on several adult tissues as a source of MSC-derived EVs and the available clinical data from in vivo models.

Bioengineering Extracellular Vesicles for the Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVD) remain one of the leading causes of mortality worldwide. Despite recent advances in diagnosis and interventions, there is still a crucial need for new multifaceted therapeutics that can address the complicated pathophysiological mechanisms driving CVD. Extracellular vesicles (EVs) are nanovesicles that are secreted by all types of cells to transport molecular cargo and regulate intracellular communication. EVs represent a growing field of nanotheranostics that can be leveraged as diagnostic biomarkers for the early detection of CVD and as targeted drug delivery vesicles to promote cardiovascular repair and recovery. Though a promising tool for CVD therapy, the clinical application of EVs is limited by the inherent challenges in EV isolation, standardization, and delivery. Hence, this review will present the therapeutic potential of EVs and introduce bioengineering strategies that augment their natural functions in CVD.

Islet-1 Mesenchymal Stem Cells-Derived Exosome-Incorporated Angiogenin-1 Hydrogel for Enhanced Acute Myocardial Infarction Therapy

Although stem cell-derived exosomes have been recognized as new candidates for cell-free treatment in myocardial infarction (MI), the challenge to improve the exosome retention in ischemic tissue remains. Our previous research indicated that islet-1(ISL1) overexpression enhances the paracrine function of mesenchymal stem cells (MSCs) and promotes angiogenesis in a model of MI. In this study, genetically engineered ISL1-MSC-derived exosomes (ISL1-MSCs-Exo) were collected, and the contents were analyzed by exosomal RNA sequencing. Next, we investigated if ISL1-MSCs-Exo could exert therapeutic effects and their incorporation into a new angiogenin-1 hydrogel (Ang-1 gel) could boost the retention of exosomes and further enhance their protective effects. Our results demonstrated that ISL1-MSCs-Exo could play a therapeutic role in vitro and in vivo, which might be due to changed exosomal contents. Ang-1 gel increased the retention and enhanced the anti-apoptosis, proliferation, and angiogenic capacity of ISL1-MSCs-Exo in endothelial cells. Echocardiography revealed that Ang-1 gel significantly augment the therapeutic effects of ISL1-MSCs-Exo for MI. The main mechanism might result from increased retention of ISL1-MSCs-Exo, herein enhanced pro-angiogenetic effects in an ischemic heart. Taken together, our findings indicated that ISL1-MSCs-Exo had endothelium-protective and pro-angiogenic abilities alone and Ang-1 gel could notably retain ISL1-MSCs-Exo at ischemic sites, which improved the survival and angiogenesis of endothelial cells and accelerated the recovery of MI. These results not only shed light on the therapeutic mechanism of ISL1-MSCs-Exo incorporated with Ang-1 gel but also offer a promising therapeutic option for ischemic disease.

Extracellular vesicles in pancreatic cancer immune escape: Emerging roles and mechanisms

Pancreatic cancer (PC) is the most lethal malignancy worldwide due to its delayed diagnosis and limited treatment options. Despite great progress in clinical trials of immunotherapies for various cancers, their effectiveness in PC is very low, indicating that immune evasion is still a major obstacle to immunotherapy in PC. However, the mechanism of immune escape in PC is not fully understood, which substantially restricts the development of immunotherapy. As an important component of intercellular communication networks, extracellular vesicles (EVs) have attracted increasing attention in relation to immune escape. This review aims to provide a better understanding of the roles of EVs in tumor immune escape and the potential to expand their application in cancer immunotherapy. The relationship between PC and the tumor immune microenvironment is briefly introduced. Then, the mechanism by which EVs are involved in immune regulation is summarized, and the latest progress in determining the role of EVs in regulating PC immune escape is highlighted.

Protective role of small extracellular vesicles derived from HUVECs treated with AGEs in diabetic vascular calcification

The pathogenesis of vascular calcification in diabetic patients remains elusive. As an effective information transmitter, small extracellular vesicles (sEVs) carry abundant microRNAs (miRNAs) that regulate the physiological and pathological states of recipient cells. In the present study, significant up-regulation of miR-126-5p was observed in sEVs isolated from human umbilical vein endothelial cells (HUVECs) stimulated with advanced glycation end-products (A-EC/sEVs). Intriguingly, these sEVs suppressed the osteogenic differentiation of vascular smooth muscle cells (VSMCs) by targeting BMPR1B, which encodes the receptor for BMP, thereby blocking the smad1/5/9 signalling pathway. In addition, knocking down miR-126-5p in HUVECs significantly diminished the anti-calcification effect of A-EC/sEVs in a mouse model of type 2 diabetes. Overall, miR-126-5p is highly enriched in sEVs derived from AGEs stimulated HUVECs and can target BMPR1B to negatively regulate the trans-differentiation of VSMCs both in vitro and in vivo.

Aptamer-Functionalized Iron-Based Metal–Organic Frameworks (MOFs) for Synergistic Cascade Cancer Chemotherapy and Chemodynamic Therapy

Hypoxia-activated prodrugs (HAPs) with selective toxicity in tumor hypoxic microenvironments are a new strategy for tumor treatment with fewer side effects. Nonetheless, the deficiency of tumor tissue enrichment and tumor hypoxia greatly affect the therapeutic effect of HAPs. Herein, we design an active targeted drug delivery system driven by AS1411 aptamer to improve the tumor tissue enrichment of HAPs. The drug delivery system, called TPZ@Apt-MOF (TA-MOF), uses iron-based MOF as a carrier, surface-modified nucleolin aptamer AS1411, and the internal loaded hypoxia activation prodrug TPZ. Compared with naked MOF, the AS1411-modified MOF showed a better tumor targeting effect both in vitro and in vivo. MOF is driven by GSH to degrade within the tumor, producing Fe2+, and releasing the cargo. This process leads to a high consumption of the tumor protective agent GSH. Then, the Fenton reaction mediated by Fe2+ not only consumes the intracellular oxygen but also increases the intracellular production of highly toxic superoxide anions. This enhances the toxicity and therapeutic effect of TPZ. This study provides a new therapeutic strategy for cancer treatment.

Engineered extracellular vesicles as intelligent nanosystems for next-generation nanomedicine

Extracellular vesicles (EVs), as natural carriers of bioactive cargo, have a unique micro/nanostructure, bioactive composition, and characteristic morphology, as well as fascinating physical, chemical and biochemical features, which have shown promising application in the treatment of a wide range of diseases. However, native EVs have limitations such as lack of or inefficient cell targeting, on-demand delivery, and therapeutic feedback. Recently, EVs have been engineered to contain an intelligent core, enabling them to (i) actively target sites of disease, (ii) respond to endogenous and/or exogenous signals, and (iii) provide treatment feedback for optimal function in the host. These advances pave the way for next-generation nanomedicine and offer promise for a revolution in drug delivery. Here, we summarise recent research on intelligent EVs and discuss the use of "intelligent core" based EV systems for the treatment of disease. We provide a critique about the construction and properties of intelligent EVs, and challenges in their commercialization. We compare the therapeutic potential of intelligent EVs to traditional nanomedicine and highlight key advantages for their clinical application. Collectively, this review aims to provide a new insight into the design of next-generation EV-based theranostic platforms for disease treatment.

Mesenchymal Stromal/Stem Cells and Their Extracellular Vesicles Application in Acute and Chronic Inflammatory Liver Diseases: Emphasizing on the Anti-Fibrotic and Immunomodulatory Mechanisms

Various factors, including viral and bacterial infections, autoimmune responses, diabetes, drugs, alcohol abuse, and fat deposition, can damage liver tissue and impair its function. These factors affect the liver tissue and lead to acute and chronic liver damage, and if left untreated, can eventually lead to cirrhosis, fibrosis, and liver carcinoma. The main treatment for these disorders is liver transplantation. Still, given the few tissue donors, problems with tissue rejection, immunosuppression caused by medications taken while receiving tissue, and the high cost of transplantation, liver transplantation have been limited. Therefore, finding alternative treatments that do not have the mentioned problems is significant. Cell therapy is one of the treatments that has received a lot of attention today. Hepatocytes and mesenchymal stromal/stem cells (MSCs) are used in many patients to treat liver-related diseases. In the meantime, the use of mesenchymal stem cells has been studied more than other cells due to their favourable characteristics and has reduced the need for liver transplantation. These cells increase the regeneration and repair of liver tissue through various mechanisms, including migration to the site of liver injury, differentiation into liver cells, production of extracellular vesicles (EVs), secretion of various growth factors, and regulation of the immune system. Notably, cell therapy is not entirely excellent and has problems such as cell rejection, undesirable differentiation, accumulation in unwanted locations, and potential tumorigenesis. Therefore, the application of MSCs derived EVs, including exosomes, can help treat liver disease and prevent its progression. Exosomes can prevent apoptosis and induce proliferation by transferring different cargos to the target cell. In addition, these vesicles have been shown to transport hepatocyte growth factor (HGF) and can promote the hepatocytes'(one of the most important cells in the liver parenchyma) growths.

Designer Functional Nanomedicine for Myocardial Repair by Regulating the Inflammatory Microenvironment

Acute myocardial infarction is a major global health problem, and the repair of damaged myocardium is still a major challenge. Myocardial injury triggers an inflammatory response: immune cells infiltrate into the myocardium while activating myofibroblasts and vascular endothelial cells, promoting tissue repair and scar formation. Fragments released by cardiomyocytes become endogenous “danger signals”, which are recognized by cardiac pattern recognition receptors, activate resident cardiac immune cells, release thrombin factors and inflammatory mediators, and trigger severe inflammatory responses. Inflammatory signaling plays an important role in the dilation and fibrosis remodeling of the infarcted heart, and is a key event driving the pathogenesis of post-infarct heart failure. At present, there is no effective way to reverse the inflammatory microenvironment in injured myocardium, so it is urgent to find new therapeutic and diagnostic strategies. Nanomedicine, the application of nanoparticles for the prevention, treatment, and imaging of disease, has produced a number of promising applications. This review discusses the treatment and challenges of myocardial injury and describes the advantages of functional nanoparticles in regulating the myocardial inflammatory microenvironment and overcoming side effects. In addition, the role of inflammatory signals in regulating the repair and remodeling of infarcted hearts is discussed, and specific therapeutic targets are identified to provide new therapeutic ideas for the treatment of myocardial injury.