The functions and clinical application potential of exosomes derived from adipose mesenchymal stem cells: a comprehensive review

Mechanical properties of blood exosomes and lipoproteins after the rat whole blood irradiation with X-rays in vitro explored by atomic force microscopy

Blood is a two-component system with two levels of hierarchy: the macrosystem of blood formed elements and the dispersed system of blood nanoparticles. Biological nanoparticles are the key participants in communication between the irradiated and non-irradiated cells and inducers of the non-targeted effects of ionizing radiation. The work aimed at studying by atomic force microscopy the structural, mechanical, and electrical properties of exosomes and lipoproteins (LDL/VLDL) isolated from rat blood after its exposure to X-rays in vitro.

MATERIALS AND METHODS

The whole blood of Wistar rats fed with a high-fat diet was irradiated with X-rays (1 and 100 Gy) in vitro. The structural and mechanical properties (the elastic modulus and nonspecific adhesion force) of exosome and lipoprotein isolates from the blood by ultracentrifugation method were studied using Bruker Bioscope Resolve atomic force microscope in PF QNM mode, their electric properties (the zeta-potential) was measured by electrophoretic mobility.

RESULTS

Lipoproteins isolated from non-irradiated blood were softer (Me(LQ; UQ): 7.8(4.9;12.1) MPa) compared to blood nanoparticles of its exosome fraction (34.8(22.6;44.9) MPa) containing both exosomes and non-membrane nanoparticles. X-ray blood irradiation with a dose of 1 Gy significantly weakened the elastic properties of lipoproteins. Exposure of the blood to 100 Gy X-rays made lipoproteins stiffer and their nonspecific adhesive properties stronger. The radiation effects on the mechanical parameters of exosomes and non-membrane nanoparticles in exosome fractions differed. The significant radiation-induced change in electric properties of the studied nanoparticles was detected only for lipoproteins in the blood irradiated with 1 Gy X-rays. The low-dose radiation-induced changes in zeta-potential and increase in lipoprotein size with the appearance of a soft thick surface layer indicate the formation of the modified lipoproteins covered with a corona from macromolecules of irradiated blood.

CONCLUSION

Our data obtained using the nanomechanical mapping mode of AFM are the first evidence of the significant radiation-induced changes in the structural and mechanical properties of the dispersed system of blood nanoparticles after the X-ray irradiation of the blood.

Therapeutic potential of adipose-derived stem cell extracellular vesicles: from inflammation regulation to tissue repair

Inflammation is a key pathological feature of many diseases, disrupting normal tissue structure and resulting in irreversible damage. Despite the need for effective inflammation control, current treatments, including stem cell therapies, remain insufficient. Recently, extracellular vesicles secreted by adipose-derived stem cells (ADSC-EVs) have garnered attention for their significant anti-inflammatory properties. As carriers of bioactive substances, these vesicles have demonstrated potent capabilities in modulating inflammation and promoting tissue repair in conditions such as rheumatoid arthritis, osteoarthritis, diabetes, cardiovascular diseases, stroke, and wound healing. Consequently, ADSC-EVs are emerging as promising alternatives to conventional ADSC-based therapies, offering advantages such as reduced risk of immune rejection, enhanced stability, and ease of storage and handling. However, the specific mechanisms by which ADSC-EVs regulate inflammation under pathological conditions are not fully understood. This review discusses the role of ADSC-EVs in inflammation control, their impact on disease prognosis, and their potential to promote tissue repair. Additionally, it provides insights into future clinical research focused on ADSC-EV therapies for inflammatory diseases, which overcome some limitations associated with cell-based therapies.

Transfer of miR-877-3p via extracellular vesicles derived from dental pulp stem cells attenuates neuronal apoptosis and facilitates early neurological functional recovery after cerebral ischemia-reperfusion injury through the Bclaf1/P53 signaling pathway

Cerebral ischemia-reperfusion injury (I/RI) is one of the principal pathogenic factors in the poor prognosis of ischemic stroke, for which current therapeutic options to enhance neurological recovery are notably insufficient. Dental pulp stem cell-derived extracellular vesicles (DPSC-EVs) have promising prospects in stroke treatment and the specific underlying mechanisms have yet to be fully elucidated. The present study observed that DPSC-EVs ameliorated the degree of cerebral edema and infarct volume by reducing the apoptosis of neurons. Furthermore, the miRNA sequencing and functional enrichment analysis identified that miR-877-3p as a key component in DPSC-EVs, contributing to neuroprotection and anti-apoptotic effects. Following target prediction and dual-luciferase assay indicated that miR-877-3p interacted with Bcl-2-associated transcription factor (Bclaf1) to play a function. The miR-877-3p inhibitor or Bclaf1 overexpression reversed the neuroprotective effects of DPSC-EVs. The findings reveal a novel therapeutic pathway where miR-877-3p, transferred via DPSC-EVs, confers neuroprotection against cerebral I/RI, highlighting its potential in promoting neuronal survival and recovery post-ischemia.

Engineered Mesenchymal Stromal Cell Exosomes-Loaded Microneedles Improve Corneal Healing after Chemical Injury

Corneal alkali burns represent a prevalent ophthalmic emergency with the potential to induce blindness. The main contributing mechanisms include excessive inflammation and delayed wound healing. Existing clinical therapies have limitations, promoting the exploration of alternative methods that offer improved efficacy and reduced side effects. Adipose-derived stem cell-exosome (ADSC-Exo) has the potential to sustain immune homeostasis and facilitate tissue regeneration. Nevertheless, natural ADSC-Exo lacks disease specificity and exhibits limited bioavailability on the ocular surface. In this study, we conjugated antitumor necrosis factor-α antibodies (aT) to the surface of ADSC-Exo using matrix metalloproteinase-cleavable peptide chains to create engineered aT-Exo with synergistic effects. In both in vivo and in vitro assessments, aT-Exo demonstrated superior efficacy in mitigating corneal injuries compared to aT alone, unmodified exosomes, or aT simply mixed with exosomes. The cleavable conjugation of aT-Exo notably enhanced wound healing and alleviated inflammation more effectively. Simultaneously, we developed poly(vinyl alcohol) microneedles (MNs) for precise and sustained exosome delivery. The in vivo results showcased the superior therapeutic efficiency of MNs compared with conventional topical administration and subconjunctival injection. Therefore, the bioactive nanodrugs-loaded MNs treatment presents a promising strategy for addressing ocular surface diseases.

Mesenchymal stem cell therapy for Alzheimer's disease: A novel therapeutic approach for neurodegenerative diseases

Alzheimer's disease (AD) is one of the most progressive and prevalent types of neurodegenerative diseases in the aging population (aged >65 years) and is considered a major factor for dementia, affecting 55 million people worldwide. In the current scenario, drug-based therapies have been employed for the treatment of Alzheimer's disease but are only able to provide symptomatic relief to patients rather than a permanent solution from Alzheimer's. Recent advancements in stem cell research unlock new horizons for developing effective and highly potential therapeutic approaches due to their self-renewal, self-replicating, regenerative, and high differentiation capabilities. Stem cells come in multiple lineages such as embryonic, neural, and induced pluripotent, among others. Among different kinds of stem cells, mesenchymal stem cells are the most investigated for Alzheimer's treatment due to their multipotent nature, low immunogenicity, ability to penetrate the blood-brain barrier, and low risk of tumorigenesis, immune & inflammatory modulation, etc. They have been seen to substantially promote neurogenesis, synaptogenesis by secreting neurotrophic growth factors, as well as in ameliorating the Aβ and tau-mediated toxicity. This review covers the pathophysiology of AD, new medications, and therapies. Further, it will focus on the advancements and benefits of Mesenchymal Stem Cell therapies, their administration methods, clinical trials concerning AD progression, along with their future prospective.

Adipose Tissue Dysfunction and the Role of Adipocyte-Derived Extracellular Vesicles in Obesity and Metabolic Syndrome

Obesity is a major public health issue that is associated with metabolic diseases including diabetes mellitus type 2 and metabolic syndrome. This pathology leads to detrimental cardiovascular health and secondary effects, such as lipotoxicity, inflammation, and oxidative stress. Recently, extracellular vesicles (EVs) have been highlighted as novel players participating in human physiology and pathophysiology. In obesity, adipose tissue is related to the active shedding of adipocyte-derived extracellular vesicles (AdEVs). The current review explores and highlights the role of AdEVs and their cargo in obesity and metabolic syndrome. AdEVs are proposed to play an important role in obesity and its comorbidities. AdEVs are biological nanoparticles mainly shed by visceral and subcutaneous adipose tissue, acting in physiological and pathophysiological conditions, and also carrying different cargo biomolecules, such as RNA, microRNA (miRNA), proteins, and lipids, among others. RNA and miRNA have local and systemic effects affecting gene expression in target cell types via paracrine and endocrine actions. State of the art analyses identified some miRNAs, such as miR-222, miR-23b, miR-4429, miR-148b, and miR-4269, that could potentially affect cell pathways involved in obesity-related comorbidities, such as chronic inflammation and fibrosis. Similarly, AdEVs-proteins (RBP4, perilipin-A, FABP, mimecan, TGFBI) and AdEVs-lipids (sphingolipids) have been linked to the obesity pathophysiology. The current knowledge about AdEVs along with further research would support and reveal novel pathways, potential biomarkers, and therapeutic options in obesity.

Exosome-shuttled miR-150-5p from LPS-preconditioned mesenchymal stem cells down-regulate PI3K/Akt/mTOR pathway via Irs1 to enhance M2 macrophage polarization and confer protection against sepsis

Rationale

Sepsis is a life-threatening organ dysfunction and lack of effective measures in the current. Exosomes from mesenchymal stem cells (MSCs) reported to alleviate inflammation during sepsis, and the preconditioning of MSCs could enhance their paracrine potential. Therefore, this study investigated whether exosomes secreted by lipopolysaccharide (LPS)-pretreated MSCs exert superior antiseptic effects, and explored the underlying molecular mechanisms.

Methods

Exosomes were isolated and characterized from the supernatants of MSCs. The therapeutic efficacy of normal exosomes (Exo) and LPS-pretreated exosomes (LPS-Exo) were evaluated in terms of survival rates, inflammatory response, and organ damage in an LPS-induced sepsis model. Macrophages were stimulated with LPS and treated with Exo or LPS-Exo to confirm the results of the in vivo studies, and to explain the potential mechanisms.

Results

LPS-Exo were shown to inhibit aberrant pro-inflammatory cytokines, prevent organ damages, and improve survival rates of the septic mice to a greater extent than Exo. In vitro, LPS-Exo significantly promoted the M2 polarization of macrophages exposed to inflammation. miRNA sequencing and qRT-PCR analysis identified the remarkable expression of miR-150-5p in LPS-Exo compared to that in Exo, and exosomal miR-150-5p was transferred into recipient macrophages and mediated macrophage polarization. Further investigation demonstrated that miR-150-5p targets Irs1 in recipient macrophages and subsequently modulates macrophage plasticity by down-regulating the PI3K/Akt/mTOR pathway.

Conclusion

The current findings highly suggest that exosomes derived from LPS pre-conditioned MSCs represent a promising cell-free therapeutic method and highlight miR-150-5p as a novel molecular target for regulating immune hyperactivation during sepsis.

Adipose-Derived Stem Cell Exosomes Facilitate Diabetic Wound Healing: Mechanisms and Potential Applications

Wound healing in diabetic patients is frequently hampered. Adipose-derived stem cell exosomes (ADSC-eoxs), serving as a crucial mode of intercellular communication, exhibit promising therapeutic roles in facilitating wound healing. This review aims to comprehensively outline the molecular mechanisms through which ADSC-eoxs enhance diabetic wound healing. We emphasize the biologically active molecules released by these exosomes and their involvement in signaling pathways associated with inflammation modulation, cellular proliferation, vascular neogenesis, and other pertinent processes. Additionally, the clinical application prospects of the reported ADSC-eoxs are also deliberated. A thorough understanding of these molecular mechanisms and potential applications is anticipated to furnish a theoretical groundwork for combating diabetic wound healing.

Recent advances in the use of extracellular vesicles from adipose-derived stem cells for regenerative medical therapeutics

Adipose-derived stem cells (ADSCs) are a subset of mesenchymal stem cells (MSCs) isolated from adipose tissue. They possess remarkable properties, including multipotency, self-renewal, and easy clinical availability. ADSCs are also capable of promoting tissue regeneration through the secretion of various cytokines, factors, and extracellular vesicles (EVs). ADSC-derived EVs (ADSC-EVs) act as intercellular signaling mediators that encapsulate a range of biomolecules. These EVs have been found to mediate the therapeutic activities of donor cells by promoting the proliferation and migration of effector cells, facilitating angiogenesis, modulating immunity, and performing other specific functions in different tissues. Compared to the donor cells themselves, ADSC-EVs offer advantages such as fewer safety concerns and more convenient transportation and storage for clinical application. As a result, these EVs have received significant attention as cell-free therapeutic agents with potential future application in regenerative medicine. In this review, we focus on recent research progress regarding regenerative medical use of ADSC-EVs across various medical conditions, including wound healing, chronic limb ischemia, angiogenesis, myocardial infarction, diabetic nephropathy, fat graft survival, bone regeneration, cartilage regeneration, tendinopathy and tendon healing, peripheral nerve regeneration, and acute lung injury, among others. We also discuss the underlying mechanisms responsible for inducing these therapeutic effects. We believe that deciphering the biological properties, therapeutic effects, and underlying mechanisms associated with ADSC-EVs will provide a foundation for developing a novel therapeutic approach in regenerative medicine.

Keratinocyte-derived small extracellular vesicles delay diabetic wound healing by triggering fibroblasts autophagy

Keratinocyte and fibroblast dysfunctions contribute to delayed healing of diabetic wounds. Small extracellular vesicles (sEV) are key mediators of intercellular communication and are involved in the pathogenesis of several diseases. Recent findings suggest that sEV derived from high-glucose-treated keratinocyte (HaCaT-HG-sEV) can transport LINC01435 to inhibit tube formation and migration of HUVECs, thereby delaying wound healing. This study aimed to elucidate sEV-related communication mechanisms between keratinocytes and fibroblasts during diabetic wound healing. HaCaT-HG-sEV treatment and LINC01435 overexpression significantly decreased fibroblast collagen level and migration ability but significantly increased fibroblast autophagy. However, treatment with an autophagy inhibitor suppressed LINC01435 overexpression-induced decrease in collagen levels in fibroblasts. In diabetic mice, HaCaT-HG-sEV treatment decreased collagen levels and increased the expression of the autophagy-related proteins Beclin-1 and LC3 at the wound site, thereby delaying wound healing. Conclusively, LINC01435 in keratinocyte-derived sEV activates fibroblast autophagy and reduces fibroblast collagen synthesis, leading to impaired diabetic wound healing.

Insight into the Functional Dynamics and Challenges of Exosomes in Pharmaceutical Innovation and Precision Medicine

Of all the numerous nanosized extracellular vesicles released by a cell, the endosomal-originated exosomes are increasingly recognized as potential therapeutics, owing to their inherent stability, low immunogenicity, and targeted delivery capabilities. This review critically evaluates the transformative potential of exosome-based modalities across pharmaceutical and precision medicine landscapes. Because of their precise targeted biomolecular cargo delivery, exosomes are posited as ideal candidates in drug delivery, enhancing regenerative medicine strategies, and advancing diagnostic technologies. Despite the significant market growth projections of exosome therapy, its utilization is encumbered by substantial scientific and regulatory challenges. These include the lack of universally accepted protocols for exosome isolation and the complexities associated with navigating the regulatory environment, particularly the guidelines set forth by the U.S. Food and Drug Administration (FDA). This review presents a comprehensive overview of current research trajectories aimed at addressing these impediments and discusses prospective advancements that could substantiate the clinical translation of exosomal therapies. By providing a comprehensive analysis of both the capabilities and hurdles inherent to exosome therapeutic applications, this article aims to inform and direct future research paradigms, thereby fostering the integration of exosomal systems into mainstream clinical practice.

Autophagy, a double-edged sword for oral tissue regeneration

BACKGROUND

Oral health is of fundamental importance to maintain systemic health in humans. Stem cell-based oral tissue regeneration is a promising strategy to achieve the recovery of impaired oral tissue. As a highly conserved process of lysosomal degradation, autophagy induction regulates stem cell function physiologically and pathologically. Autophagy activation can serve as a cytoprotective mechanism in stressful environments, while insufficient or over-activation may also lead to cell function dysregulation and cell death.

AIM OF REVIEW

This review focuses on the effects of autophagy on stem cell function and oral tissue regeneration, with particular emphasis on diverse roles of autophagy in different oral tissues, including periodontal tissue, bone tissue, dentin pulp tissue, oral mucosa, salivary gland, maxillofacial muscle, temporomandibular joint, etc. Additionally, this review introduces the molecular mechanisms involved in autophagy during the regeneration of different parts of oral tissue, and how autophagy can be regulated by small molecule drugs, biomaterials, exosomes/RNAs or other specific treatments. Finally, this review discusses new perspectives for autophagy manipulation and oral tissue regeneration.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Overall, this review emphasizes the contribution of autophagy to oral tissue regeneration and highlights the possible approaches for regulating autophagy to promote the regeneration of human oral tissue.

TSG6-Exo@CS/GP Attenuates Endometrium Fibrosis by Inhibiting Macrophage Activation in a Murine IUA Model

Intrauterine adhesion (IUA) is characterized by the formation of fibrous scar tissue within the uterine cavity, which significantly impacts female reproductive health and even leads to infertility. Unfortunately, severe cases of IUA currently lack effective treatments. This study presents a novel approach that utilizes tumor necrosis factor-(TNF) stimulated gene 6 (TSG6)-modified exosomes (Exos) in conjunction with an injectable thermosensitive hydrogel (CS/GP) to mitigate the occurrence of IUA by reducing endometrium fibrosis in a mouse IUA model. This study demonstrate that TSG6-modified Exos effectively inhibits the activation of inflammatory M1-like macrophages during the initial stages of inflammation and maintains the balance of macrophage phenotypes (M1/M2) during the repair phase. Moreover, TSG6 inhibits the interaction between macrophages and endometrial stromal fibroblasts, thereby preventing the activation of stromal fibroblasts into myofibroblasts. Furthermore, this research indicates that CS/GP facilitates the sustained release of TSG6-modified Exos, leading to a significant reduction in both the manifestations of IUA and the extent of endometrium fibrosis. Collectively, through the successful construction of CS/GP loaded with TSG6-modified Exos, a reduction in the occurrence and progression of IUA is achieved by mitigating endometrium fibrosis. Consequently, this approach holds promise for the treatment of IUA.

Biological scaffold as potential platforms for stem cells: Current development and applications in wound healing

Wound repair is a complex challenge for both clinical practitioners and researchers. Conventional approaches for wound repair have several limitations. Stem cell-based therapy has emerged as a novel strategy to address this issue, exhibiting significant potential for enhancing wound healing rates, improving wound quality, and promoting skin regeneration. However, the use of stem cells in skin regeneration presents several challenges. Recently, stem cells and biomaterials have been identified as crucial components of the wound-healing process. Combination therapy involving the development of biocompatible scaffolds, accompanying cells, multiple biological factors, and structures resembling the natural extracellular matrix (ECM) has gained considerable attention. Biological scaffolds encompass a range of biomaterials that serve as platforms for seeding stem cells, providing them with an environment conducive to growth, similar to that of the ECM. These scaffolds facilitate the delivery and application of stem cells for tissue regeneration and wound healing. This article provides a comprehensive review of the current developments and applications of biological scaffolds for stem cells in wound healing, emphasizing their capacity to facilitate stem cell adhesion, proliferation, differentiation, and paracrine functions. Additionally, we identify the pivotal characteristics of the scaffolds that contribute to enhanced cellular activity.

Exosomes Secreted by Wharton's Jelly-Derived Mesenchymal Stem Cells Promote the Ability of Cell Proliferation and Migration for Keratinocyte

Mesenchymal stem cells (MSCs) isolated from Wharton's jelly (WJ-MSCs) and adipose tissue (AD-MSCs) are alternative sources for bone marrow-derived MSCs. Owing to their multiple functions in angiogenesis, immune modulation, proliferation, migration, and nerve regeneration, MSC-derived exosomes can be applied in "cell-free cell therapy". Here, we investigated the functional protein components between the exosomes from WJ-MSCs and AD-MSCs to explain their distinct functions. Proteins of WJ-MSC and AD-MSC exosomes were collected and compared based on iTRAQ gel-free proteomics data. Results: In total, 1695 proteins were detected in exosomes. Of these, 315 were more abundant (>1.25-fold) in AD-MSC exosomes and 362 kept higher levels in WJ-MSC exosomes, including fibrinogen proteins. Pathway enrichment analysis suggested that WJ-MSC exosomes had higher potential for wound healing than AD-MSC exosomes. Therefore, we treated keratinocyte cells with exosomes and the recombinant protein of fibrinogen beta chain (FGB). It turned out that WJ-MSC exosomes better promoted keratinocyte growth and migration than AD-MSC exosomes. In addition, FGB treatment had similar results to WJ-MSC exosomes. The fact that WJ-MSC exosomes promoted keratinocyte growth and migration better than AD-MSC exosomes can be explained by their higher FGB abundance. Exploring the various components of AD-MSC and WJ-MSC exosomes can aid in their different clinical applications.

Stem Cell-Derived Exosomes: An Advanced Horizon to Cancer Regenerative Medicine

Cancer research has made significant progress in recent years, and extracellular vesicles (EVs) based cancer investigation reveals several facts about cancer. Exosomes are a subpopulation of EVs. In the present decade, exosomes is mostly highlighted for cancer theranostic research. Tumor cell derived exosomes (TEXs) promote cancer but there are multiple sources of exosomes that can be used as cancer therapeutic agents (plant exosomes, stem cell-derived exosomes, modified or synthetic exosomes). Stem cells based regenerative medicine faces numerous challenges, such as promote tumor development, cellular reprogramming etc., and therefore addressing these complications becomes essential. Stem cell-derived exosomes serves as an answer to these problems and offers a better solution. Global research indicates that stem cell-derived exosomes also play a dual role in the cellular system by either inhibiting or promoting cancer. Modified exosomes which are genetically engineered exosomes or surface modified exosomes to increase the efficacy of the therapeutic properties can also be considered to target the above concerns. However, the difficulties associated with the exosomes include variations in exosomes heterogenity, isolation protocols, large scale production, etc., and these have to be managed effectively. In this review, we explore exosomes biogenesis, multiple stem cell-derived exosome sources, drug delivery, modified stem cells exosomes, clinical trial of stem cells exosomes, and the related challenges in this domain and future orientation. This article may encourage researchers to explore stem cell-derived exosomes and develop an effective and affordable cancer therapeutic solution.

Therapeutic potential of ADSC-EV-derived lncRNA DLEU2: A novel molecular pathway in alleviating sepsis-induced lung injury via the miR-106a-5p/LXN axis

This study investigates the molecular mechanisms by which extracellular vesicles (EVs) derived from adipose-derived mesenchymal stem cells (ADSCs) promote M2 polarization of macrophages and thus reduce lung injury caused by sepsis. High-throughput sequencing was used to identify differentially expressed genes related to long non-coding RNA (lncRNA) in ADSC-derived EVs (ADSC-EVs) in sepsis lung tissue. Weighted gene co-expression network analysis (WGCNA) was employed to predict the downstream target genes of the lncRNA DLEU2. The RNAInter database predicted miRNAs that interact with DLEU2 and LXN. Functional and pathway enrichment analyses were performed using GO and KEGG analysis. A mouse model of sepsis was established, and treatment with a placebo or ADSC-EVs was administered, followed by RT-qPCR analysis. ADSC-EVs were isolated and identified. In vitro cell experiments were conducted using the mouse lung epithelial cell line MLE-12, mouse macrophage cell line RAW264.7, and mouse lung epithelial cell line (LEPC). ADSC-EVs were co-cultured with RAW264.7 and MLE-12/LEPC cells to study the regulatory mechanism of the lncRNA DLEU2. Cell viability, proliferation, and apoptosis of lung injury cells were assessed using CCK-8, EdU, and flow cytometry. ELISA was used to measure the levels of inflammatory cytokines in the sepsis mouse model, flow cytometry was performed to determine the number of M1 and M2 macrophages, lung tissue pathology was evaluated by H&E staining, and immunohistochemistry was conducted to examine the expression of proliferation- and apoptosis-related proteins. High-throughput sequencing and bioinformatics analysis revealed enrichment of the lncRNA DLEU2 in ADSC-EVs in sepsis lung tissue. Animal and in vitro cell experiments showed increased expression of the lncRNA DLEU2 in sepsis lung tissue after treatment with ADSC-EVs. Furthermore, ADSC-EVs were found to transfer the lncRNA DLEU2 to macrophages, promoting M2 polarization, reducing inflammation response in lung injury cells, and enhancing their viability, proliferation, and apoptosis inhibition. Further functional experiments indicated that lncRNA DLEU2 promotes M2 polarization of macrophages by regulating miR-106a-5p/LXN, thereby enhancing the viability and proliferation of lung injury cells and inhibiting apoptosis. Overexpression of miR-106a-5p could reverse the biological effects of ADSC-EVs-DLEU2 on MLE-12 and LEPC in vitro cell models. Lastly, in vivo animal experiments confirmed that ADSC-EVs-DLEU2 promotes high expression of LXN by inhibiting the expression of miR-106a-5p, further facilitating M2 macrophage polarization and reducing lung edema, thus alleviating sepsis-induced lung injury. lncRNA DLEU2 in ADSC-EVs may promote M2 polarization of macrophages and enhance the viability and proliferation of lung injury cells while inhibiting inflammation and apoptosis reactions, thus ameliorating sepsis-induced lung injury in a mechanism involving the regulation of the miR-106a-5p/LXN axis.

The implications of exosomes in psoriasis: disease: emerging as new diagnostic markers and therapeutic targets

As the largest human organ, the skin is continuously exposed to various external and internal triggers that affect body homeostasis. Psoriasis is a persistent inflammatory skin condition that has a major bearing on patients' physiological functioning as well as their mental well-being. It is an autoimmune disorder and has been the focus of extensive research efforts in recent years. Cells secrete exosomes into the environment surrounding them, which comprises a lipid bilayer. The movement of cellular components like microRNAs, mRNAs, DNA, lipids, metabolites, and cell-surface proteins is mediated by exosomes. Exosomes are crucial for inducing communication between cells. There has been extensive study of exosomes, both preclinical and clinical, looking at their potential role in autoimmune diseases. Besides the role that they play in the body's basic processes, exosomes are also considered an increasingly essential part as diagnostic and therapeutic agents. In the following article, we conduct a literature review of current studies related to molecular and structural aspects of exosomes. We emphasis on the function of exosomes in pathogenesis, as well as the possibility of their usage in medicinal applications and as biomarkers.

Enhanced Therapeutic Potential of Hybrid Exosomes Loaded with Paclitaxel for Cancer Therapy

The advancement of exosome studies has positioned engineered exosomes as crucial biomaterials for the development of advanced drug delivery systems. This study focuses on developing a hybrid exosome system by fusing mesenchymal stem cells (MSCs) exosomes with folate-targeted liposomes. The aim was to improve the drug loading capacity and target modification of exosome nanocarriers for delivering the first-line chemotherapy drug paclitaxel (PTX) and its effectiveness was assessed through cellular uptake studies to evaluate its ability to deliver drugs to tumor cells in vitro. Additionally, in vivo experiments were conducted using a CT26 tumor-bearing mouse model to assess the therapeutic efficacy of hybrid exosomes loaded with PTX (ELP). Cellular uptake studies demonstrated that ELP exhibited superior drug delivery capabilities to tumor cells in vitro. Moreover, in vivo experiments revealed that ELP significantly suppressed tumor growth in the CT26 tumor-bearing mouse model. Notably, for the first time, we examined the tumor microenvironment following intratumoral administration of ELP. We observed that ELP treatment activated CD4+ and CD8+ T cells, reduced the expression of M2 type tumor-associated macrophages (TAMs), polarized TAMs towards the M1 type, and decreased regulatory T cells (Tregs). Our research highlights the considerable therapeutic efficacy of ELP and its promising potential for future application in cancer therapy. The development of hybrid exosomes presents an innovative approach to enhance drug delivery and modulate the tumor microenvironment, offering exciting prospects for effective cancer treatment strategies.

Human adipose tissue-derived stem cell extracellular vesicles attenuate ocular hypertension-induced retinal ganglion cell damage by inhibiting microglia- TLR4/MAPK/NF-κB proinflammatory cascade signaling

Microglia-mediated neuroinflammatory responses are recognized as a predominant factor during high intraocular pressure (IOP)-induced retinal and optic nerve injury along with potential therapeutic targets for the disease. Our previous research indicated that mesenchymal stem cell (MSC) treatment could reduce high IOP-induced neuroinflammatory responses through the TLR4 pathway in a rat model without apparent cell replacement and differentiation, suggesting that the anti-neuroinflammatory properties of MSCs are potentially mediated by paracrine signaling. This study aimed to evaluate the anti-neuroinflammatory effect of human adipose tissue-derived extracellular vesicles (ADSC-EVs) in microbead-induced ocular hypertension (OHT) animals and to explore the underlying mechanism since extracellular vesicles (EVs) are the primary transporters for cell secretory action. The anti-neuroinflammatory effect of ADSC-EVs on LPS-stimulated BV-2 cells in vitro and OHT-induced retinal and optic nerve injury in vivo was investigated. According to the in vitro research, ADSC-EV treatment reduced LPS-induced microglial activation and the TLR4/NF-κB proinflammatory cascade response axis in BV-2 cells, such as CD68, iNOS, TNF-α, IL-6, and IL-1β, TLR4, p-38 MAPK, NF-κB. According to the in vivo data, intravitreal injection of ADSC-EVs promoted RGC survival and function, reduced microglial activation, microglial-derived neuroinflammatory responses, and TLR4/MAPK/NF-κB proinflammatory cascade response axis in the OHT mice. Our findings provide preliminary evidence for the RGC protective and microglia-associated neuroinflammatory reduction effects of ADSC-EVs by inhibiting the TLR4/MAPK/NF-κB proinflammatory cascade response in OHT mice, indicating the therapeutic potential ADSC-EVs or adjunctive therapy for glaucoma.

Engineered exosomes and composite biomaterials for tissue regeneration

Exosomes, which are small vesicles enclosed by a lipid bilayer and released by many cell types, are widely dispersed and have garnered increased attention in the field of regenerative medicine due to their ability to serve as indicators of diseases and agents with therapeutic potential. Exosomes play a crucial role in mediating intercellular communication through the transfer of many biomolecules, including proteins, lipids, RNA, and other molecular constituents, between cells. The targeted transport of proteins and nucleic acids to specific cells has the potential to enhance or impair specific biological functions. Exosomes have many applications, and they can be used alone or in combination with other therapeutic approaches. The examination of the unique attributes and many functions of these factors has emerged as a prominent field of study in the realm of biomedical research. This manuscript summarizes the origins and properties of exosomes, including their structural, biological, physical, and chemical aspects. This paper offers a complete examination of recent progress in tissue repair and regenerative medicine, emphasizing the possible implications of these methods in forthcoming tissue regeneration attempts.

ADSC-Exos enhance functional recovery after spinal cord injury by inhibiting ferroptosis and promoting the survival and function of endothelial cells through the NRF2/SLC7A11/GPX4 pathway

BACKGROUND

Spinal cord injury (SCI) is a devastating disease that causes major motor, sensory and autonomic dysfunctions. Currently, there is a lack of effective treatment. In this study, we aimed to investigate the potential mechanisms of Exosomes from adipose-derived stem cells (ADSC-Exos) in reducing ferroptosis and promoting angiogenesis after spinal cord injury.

METHODS

We isolated ADSC-Exos, the characteristics of which were confirmed. In vitro, we tested the potential of ADSC-Exos to promote the survival and function of human brain microvascular endothelial cells (HBMECs) and analyzed the ferroptosis of HBMECs. In vivo, we established rat models of SCI and locally injected ADSC-Exos to verify their efficacy.

RESULTS

ADSC-Exos can reduce reactive oxygen species (ROS) accumulation and cell damage induced by an excessive inflammatory response in HBMECs. ADSC-Exos inhibit ferroptosis induced by excessive inflammation and upregulate the expression of glutathione peroxidase 4(GPX4) in HBMECs. It can also effectively promote proliferation, migration, and vessel-like structure formation. In vitro, ADSC-Exos improved behavioral function after SCI and increased the number and density of blood vessels around the damaged spinal cord. Moreover, we found that ADSC-Exos could increase nuclear factor erythroid-2-related factor 2(NRF2) expression and nuclear translocation, thereby affecting the expression of solute carrier family 7 member 11(SLC7A11) and GPX4, and the NRF2 inhibitor ML385 could reverse the above changes.

CONCLUSION

Our results suggest that ADSC-Exos may inhibit ferroptosis and promote the recovery of vascular and neural functions after SCI through the NRF2/SLC7A11/GPX4 pathway. This may be a potential therapeutic mechanism for spinal cord injury.

Skin boosters: Definitions and varied classifications

BACKGROUND

The concept of "skin boosters" has evolved, marking a shift from traditional uses of hyaluronic acid (HA) fillers primarily for augmenting skin volume to a more diverse application aimed at improving dermal conditions. Restylane Vital and other HA fillers have been repurposed to combat skin aging and wrinkles by delivering HA directly to the dermis.

OBJECTIVES

This review aims to define the term "skin booster" and to discuss the various components that constitute skin boosters. It seeks to provide a comprehensive overview of the different ingredients used in skin boosters, their roles, and their impact on enhancing dermal conditions.

METHODS

A comprehensive review was conducted, focusing on representative skin booster ingredients. The approach involved analyzing the different elements used in skin boosters and their specific roles in enhancing dermal improvement.

RESULTS

The findings indicate that skin boosters, encompassing a range of ingredients, are effective in improving the condition of the skin's dermis. The review identifies key ingredients in skin boosters and their specific benefits, including hydration, elasticity improvement, and wrinkle reduction.

CONCLUSIONS

Skin boosters represent a significant development in dermatological treatments, offering diverse benefits beyond traditional HA fillers. This review provides valuable insights into the constituents of skin boosters and their effectiveness, aiding readers in making informed decisions about these treatments. The potential of skin boosters in dermatological practice is considerable, warranting further research and application.

Ameliorating impaired cardiac function in myocardial infarction using exosome-loaded gallic-acid-containing polyurethane scaffolds

Myocardial infarction (MI) can be tackled by implanting cardiac patches which provide mechanical support to the heart. However, most tissue-engineered scaffolds face difficulty in attenuating oxidative stress, maintaining mechanical stability, and regenerating damaged cardiomyocytes. Here, we fabricated elastic cryogels using polyurethane modified with antioxidant gallic acid in its backbone (PUGA) and further coated them with decellularized extracellular matrix (dECM) to improve adhesiveness, biocompatibility and hemocompatibility. The scaffold was functionalized with exosomes (EXO) isolated from adipose-derived stem cells having regenerative potential. PUGA-dECM + EXO was tested in a rat model with induced MI where echocardiography after 8 weeks of implantation showed significant recovery in treatment group. Histological analysis revealed a decrease in fibrosis after application of patch and promotion of angiogenesis with reduced oxidative stress was shown by immunostaining. Expression of cardiac tissue contractile function marker was also observed in treatment groups. Thus, the proposed biomaterial has a promising application to be utilized as a patch for cardiac regeneration. More detailed studies with larger animal species are needed for using these observations for specific applications.

Bone marrow mesenchymal stem cell-derived exosomes promote osteoblast proliferation, migration and inhibit apoptosis by regulating KLF3-AS1/miR-338-3p

AIM

This study aimed to investigate the effect and mechanism of bone marrow mesenchymal stem cell-derived exosomes on osteoblast function.

METHODS

The expression of KLF3-AS1 and miR-338-3p in serum of fracture patients was detected by qRT-PCR. Exosomes from BMSCs were isolated by ultrafast centrifugation. MC3T3-E1 cells were cultured in vitro as experimental cells. Intracellular gene expression was regulated by transfection of si-KLF3-AS1 or miR-338-3p inhibitors. MTT assay, Transwell assay and flow cytometry were used to evaluate cell viability, migration, and apoptosis. The luciferase reporter gene was used to verify the targeting relationship between KLF3-AS1 and miR-338-3p. Bioinformatics analysis was used to identify the basic functions and possible enrichment pathways of miR-338-3p target genes.

RESULTS

The expressions of KLF3-AS1 and miR-338-3p in the serum of fracture patients were down-regulated and up-regulated, respectively. The expression of KLF3-AS1 was increased in MC3T3-E1 cells cultured with BMSCs-Exo, while the viability and migration ability of MC3T3-E1 cells were enhanced, and the apoptosis ability was weakened. Further analysis revealed miR-338-3p was the target gene of KLF3-AS1. The expression of miR-338-3p was downregulated in MC3T3-E1 cells cultured with BMSCs-Exo. Inhibition of miR-338-3p in MC3T3-E1 cells enhanced the viability and migration ability of MC3T3-E1 cells when cultured with BMSCs-Exo, while suppressing apoptosis. Bioinformatics analysis demonstrated that the target genes of miR-338-3p were predominantly localized at the axon's initiation site, involved in biological processes such as development and growth regulation, and mainly enriched in MAPK and ErbB signaling pathways.

CONCLUSION

In vitro, BMSCs-Exo exhibits the capacity to enhance proliferation and migration while inhibiting apoptosis of MC3T3-E1 cells, potentially achieved through modulation of KLF3-AS1 and miR-338-3p expression in MC3T3-E1 cells.

Understanding exosomes: Part 2-Emerging leaders in regenerative medicine

Exosomes are the smallest subset of extracellular signaling vesicles secreted by most cells with the ability to communicate with other tissues and cell types over long distances. Their use in regenerative medicine has gained tremendous momentum recently due to their ability to be utilized as therapeutic options for a wide array of diseases/conditions. Over 5000 publications are currently being published yearly on this topic, and this number is only expected to dramatically increase as novel therapeutic strategies continue to be developed. Today exosomes have been applied in numerous contexts including neurodegenerative disorders (Alzheimer's disease, central nervous system, depression, multiple sclerosis, Parkinson's disease, post-traumatic stress disorders, traumatic brain injury, peripheral nerve injury), damaged organs (heart, kidney, liver, stroke, myocardial infarctions, myocardial infarctions, ovaries), degenerative processes (atherosclerosis, diabetes, hematology disorders, musculoskeletal degeneration, osteoradionecrosis, respiratory disease), infectious diseases (COVID-19, hepatitis), regenerative procedures (antiaging, bone regeneration, cartilage/joint regeneration, osteoarthritis, cutaneous wounds, dental regeneration, dermatology/skin regeneration, erectile dysfunction, hair regrowth, intervertebral disc repair, spinal cord injury, vascular regeneration), and cancer therapy (breast, colorectal, gastric cancer and osteosarcomas), immune function (allergy, autoimmune disorders, immune regulation, inflammatory diseases, lupus, rheumatoid arthritis). This scoping review is a first of its kind aimed at summarizing the extensive regenerative potential of exosomes over a broad range of diseases and disorders.

Combination of stem cells and nerve guide conduit for the treatment of peripheral nerve injury: A meta-analysis

INTRODUCTION/AIMS

Many small-sized, single-center preclinical studies have investigated the benefits of introducing stem cells into the interior of nerve conduit. The aims of this meta-analysis are to review and contrast the effects of various types of stem cells in in vivo models used to reconstruct peripheral nerve injuries (PNIs) and to assess the reliability and stability of the available evidence.

METHODS

A systematic search was conducted using Cochrane Library, Embase, PubMed, and Web of Science to identify studies conducted from January 1, 2000, to September 21, 2022, and investigate stem cell therapy in peripheral nerve reconstruction animal models. Studies that met the relevant criteria were deemed eligible for this meta-analysis.

RESULTS

Fifty-five preclinical studies with a total of 1234 animals were incorporated. Stem cells demonstrated a positive impact on peripheral nerve regeneration at different follow-up times in the forest plots of five outcome indicators: compound muscle action potential (CMAP) amplitude, latency, muscle mass ratio, nerve conduction velocity, and sciatic functional index (SFI). In most comparisons, stem cell groups showed substantial differences compared with the control groups. The superior performance of adipose-derived stem cells (ADSCs) in terms of SFI, CMAP amplitude, and latency (p < .001) was identified.

DISCUSSION

The findings consistently demonstrated a favorable outcome in the reconstruction process when utilizing different groups of stem cells, as opposed to control groups where stem cells were not employed.

Advances in mesenchymal stem cells therapy for tendinopathies

Tendinopathies are chronic diseases of an unknown etiology and associated with inflammation. Mesenchymal stem cells (MSCs) have emerged as a viable therapeutic option to combat the pathological progression of tendinopathies, not only because of their potential for multidirectional differentiation and self-renewal, but also their excellent immunomodulatory properties. The immunomodulatory effects of MSCs are increasingly being recognized as playing a crucial role in the treatment of tendinopathies, with MSCs being pivotal in regulating the inflammatory microenvironment by modulating the immune response, ultimately contributing to improved tissue repair. This review will discuss the current knowledge regarding the application of MSCs in tendinopathy treatments through the modulation of the immune response.

Exosomes Derived from Human Adipose Mesenchymal Stem Cells Inhibits Fibrosis and Treats Oral Submucous Fibrosis via the miR-181a-5p/Smad2 Axis

BACKGROUND

Oral submucous fibrosis (OSF) is a chronic disease with carcinogenic tendency that poses a non-negligible threat to human health. Exosomes derived from human adipose mesenchymal stem cells (ADSC-Exo) reduces visceral and cutaneous fibroses, but their role in OSF has received little attention. The aim of this study was to investigate the effects of ADSC-Exo on OSF and elucidate the mechanism.

METHODS

In brief, ADSCs were extracted from adipose tissues and subjected to flow cytometry and induction culture. Fibroblasts were isolated from human buccal mucosa and subjected to immunofluorescence. Myofibroblasts were obtained from fibroblasts induced by arecoline and identified. Immunofluorescence assay confirmed that myofibroblasts could take up ADSC-Exo. The effects of ADSC-Exo on the proliferative and migratory capacities of myofibroblasts were examined using the Cell Counting Kit-8 and scratch assay. Real-time quantitative polymerase chain reaction (qPCR) was performed to evaluate mothers against decapentaplegic homolog 2 (Smad2), Smad3, Smad7, collagen type 1 (Col1), Col3, alpha smooth muscle actin (α-SMA), fibronectin, and vimentin. Western blotting was performed to detect phospho (p)-Smad2, Smad2, p-Smad2/3, Smad2/3, Smad7, Col1, Col3, α-SMA, fibronectin, and vimentin. Furthermore, the dual-luciferase reporter assay was performed to prove that miR-181a-5p in ADSC-Exo directly inhibited the expression of Smad2 mRNA to regulate the transforming growth factor beta (TGF-β) pathway. We also performed qPCR and western blotting to verify the results.

RESULTS

ADSC-Exo could promote the proliferation and migration of myofibroblasts, reduce the expressions of p-smad2, Smad2, p-smad2/3, Smad2/3, Col1, αSMA, fibronectin, and vimentin and elevated the levels of Smad7 and Col3. In addition, miR-181a-5p was highly expressed in ADSC-Exo and bound to the 3'-untranslated region of Smad2. ADSC-Exo enriched with miR-181a-5p reduced collagen production in myofibroblasts and modulated the TGF-β pathway.

CONCLUSIONS

ADSC-Exo promoted the proliferative and migratory capacities of myofibroblasts and inhibited collagen deposition and trans-differentiation of myofibroblasts in vitro. miR-181a-5p in exosomes targets Smad2 to regulate the TGF-β pathway in myofibroblasts. ADSC-Exo perform antifibrotic actions through the miR-181a-5p/Smad2 axis and may be a promising clinical treatment for OSF.

Delivery of microRNA-423-5p by exosome from adipose-derived stem/stromal cells inhibits DVL3 to potentiate autologous fat graft survival through adipogenesis and inflammatory response

Autologous fat grafting represents a reconstructive technique but is limited by unstable graft retention. Based on existing reports and bioinformatics prediction, we hypothesized that delivering exosomes from human adipose-derived stem/stromal cells (hADSC-Exo) would increase fat graft survival and further explore the mechanism. hADSC-Exo were extracted and identified. An autologous fat grafting model was established using donor and recipient mice, followed by hADSC-Exo treatment. hADSC-Exo promoted the retention of autologous fat grafts in mice, along with increased adipocyte activity, angiogenesis, and decreased inflammation in grafts. Moreover, hADSC-Exo potentiated the adipose differentiation of 3T3-L1 cells, enhanced the angiogenic and migratory capacity of human umbilical vein endothelial cells, and inhibited the inflammation and viability of RAW 264.7 cells. The therapeutic effect of hADSC-Exo on fat grafting was associated with the delivery of microRNA (miR)-423-5p. Deletion of miR-423-5p in Exo impaired the function of hADSC-Exo on fat retention. miR-423-5p bound to DVL3 to suppress DVL3 expression, and DVL3 deletion promoted adipose differentiation of 3T3-L1 cells. In conclusion, our findings further widen the theoretical basis of the clinical application of hADSC-Exo in autologous fat grafts.

Treatment with Exosomes Derived from Mesenchymal Stem Cells: A New Window of Healing Science in Regenerative Medicine

Many studies have been conducted on the potential applications of mesenchymal stem cells (MSCs) over recent years due to their growing importance in regenerative medicine. Exosomes are considered cargos capable of transporting proteins, peptides, lipids, mRNAs, and growth factors. MSCsderived exosomes are also involved in the prevention or treatment of a variety of diseases, including cardiovascular diseases, neurological diseases, skin disorders, lung diseases, osteoarthritis, damaged tissue repair, and other diseases. This review attempted to summarize the importance of employing MSCs in regenerative medicine by gathering and evaluating information from current literature. The role of MSCs and the potential applications of MSCs-derived exosomes have also been discussed.

Adipose Tissue-Derived Extracellular Vesicles: A Promising Biomarker and Therapeutic Strategy for Metabolic Disorders

Adipose tissue plays an important role in systemic energy metabolism, and its dysfunction can lead to severe metabolic disorders. Various cells in adipose tissue communicate with each other to maintain metabolic homeostasis. Extracellular vesicles (EVs) are recognized as novel medium for remote intercellular communication by transferring various bioactive molecules from parental cells to distant target cells. Increasing evidence suggests that the endocrine functions of adipose tissue and even the metabolic homeostasis are largely affected by different cell-derived EVs, such as insulin signaling, lipolysis, and metabolically triggered inflammation regulations. Here, we provide an overview focused on the role of EVs released by different cell types of adipose tissue in metabolic diseases and their possible molecular mechanisms and highlight the potential applications of EVs as biomarkers and therapeutic targets. Moreover, the current EVs-based therapeutic strategies have also been discussed. This trial is registered with NCT05475418.

Recent advances of exosomes in soft tissue injuries in sports medicine: A critical review on biological and biomaterial applications

Sports medicine is generally associated with soft tissue injuries including muscle injuries, meniscus and ligament injuries, tendon ruptures, tendinopathy, rotator cuff tears, and tendon-bone healing during injuries. Tendon and ligament injuries are the most common sport injuries accounting for 30-40% of all injuries. Therapies for tendon injuries can be divided into surgical and non-surgical methods. Surgical methods mainly depend on the operative procedures, the surgeons and postoperative interventions. In non-surgical methods, cell therapy with stem cells and cell-free therapy with secretome of stem cell origin are current directions. Exosomes are the main paracrine factors of mesenchymal stem cells (MSCs) containing biological components such as proteins, nucleic acids and lipids. Compared with MSCs, MSC-exosomes (MSC-exos) possess the capacity to escape phagocytosis and achieve long-term circulation. In addition, the functions of exosomes from various cell sources in soft tissue injuries in sports medicine have been gradually revealed in recent years. Along with the biological and biomaterial advances in exosomes, exosomes can be designed as drug carriers with biomaterials and exosome research is providing promising contributions in cell biology. Exosomes with biomaterial have the potential of becoming one of the novel therapeutic modalities in regenerative researches. This review summarizes the derives of exosomes in soft tissue regeneration and focuses on the biological and biomaterial mechanism and advances in exosomal therapy in soft tissue injuries.

Enhancing Functional Recovery after Segmental Nerve Defect Using Nerve Allograft Treated with Plasma-Derived Exosome

BACKGROUND

Nerve injuries can result in detrimental functional outcomes. Currently, autologous nerve graft offers the best outcome for segmental peripheral nerve injury. Allografts are alternatives, but do not have comparable results. This study evaluated whether plasma-derived exosome can improve nerve regeneration and functional recovery when combined with decellularized nerve allografts.

METHODS

The effect of exosomes on Schwann cell proliferation and migration were evaluated. A rat model of sciatic nerve repair was used to evaluate the effect on nerve regeneration and functional recovery. A fibrin sealant was used as the scaffold for exosome. Eighty-four Lewis rats were divided into autograft, allograft, and allograft with exosome groups. Gene expression of nerve regeneration factors was analyzed on postoperative day 7. At 12 and 16 weeks, rats were subjected to maximum isometric tetanic force and compound muscle action potential. Nerve specimens were then analyzed by means of histology and immunohistochemistry.

RESULTS

Exosomes were readily taken up by Schwann cells that resulted in improved Schwann cell viability and migration. The treated allograft group had functional recovery (compound muscle action potential, isometric tetanic force) comparable to that of the autograft group. Similar results were observed in gene expression analysis of nerve regenerating factors. Histologic analysis showed no statistically significant differences between treated allograft and autograft groups in terms of axonal density, fascicular area, and myelin sheath thickness.

CONCLUSIONS

Plasma-derived exosome treatment of decellularized nerve allograft may provide comparable clinical outcomes to that of an autograft. This can be a promising strategy in the future as an alternative for segmental peripheral nerve repair.

CLINICAL RELEVANCE STATEMENT

Off-the-shelf exosomes may improve recovery in nerve allografts.

Adipose stem cells in tissue regeneration and repair: From bench to bedside

ADSCs are a large number of mesenchymal stem cells in Adipose tissue, which can be applied to tissue engineering. ADSCs have the potential of multi-directional differentiation, and can differentiate into bone tissue, cardiac tissue, urothelial cells, skin tissue, etc. Compared with other mesenchymal stem cells, ADSCs have a multitude of promising advantages, such as abundant number, accessibility in cell culture, stable function, and less immune rejection. There are two main methods to use ADSCs for tissue repair and regeneration. One is to implant the "ADSCs-scaffold composite" into the injured site to promote tissue regeneration. The other is cell-free therapy: using ADSC-exos or ADSC-CM alone to release a large number of miRNAs, cytokines and other bioactive substances to promote tissue regeneration. The tissue regeneration potential of ADSCs is regulated by a variety of cytokines, signaling molecules, and external environment. The differentiation of ADSCs into different tissues is also induced by growth factors, ions, hormones, scaffold materials, physical stimulation, and other factors. The specific mechanisms are complex, and most of the signaling pathways need to be further explored. This article reviews and summarizes the mechanism and clinical application of ADSCs in tissue injury repair so far, and puts forward further problems that need to be solved in this field, hoping to provide directions for further research in this field.

Mechanisms and Optimization Strategies of Paracrine Exosomes from Mesenchymal Stem Cells in Ischemic Heart Disease

The morbidity and mortality of myocardial infarction (MI) are increasing worldwide. Mesenchymal stem cells (MSCs) are multipotent stem cells with self-renewal and differentiation capabilities that are essential in tissue healing and regenerative medicine. However, the low implantation and survival rates of transplanted cells hinder the widespread clinical use of stem cells. Exosomes are naturally occurring nanovesicles that are secreted by cells and promote the repair of cardiac function by transporting noncoding RNA and protein. In recent years, MSC-derived exosomes have been promising cell-free treatment tools for improving cardiac function and reversing cardiac remodeling. This review describes the biological properties and therapeutic potential of exosomes and summarizes some engineering approaches for exosomes optimization to enhance the targeting and therapeutic efficacy of exosomes in MI.

Crucial Factors Influencing the Involvement of Odontogenic Exosomes in Dental Pulp Regeneration

Recent progress in exosome based studies has revealed that they possess several advantages over cells, including "cell-free" properties, low immunogenicity and ethical controversy, high biological safety and effective action. These characteristics confer exosomes significant advantages that allow them to overcome the limitations associated with traditional "cell therapy" by circumventing the issues of immune rejection, scarcity of donor cells, heterogeneity, and ethical concerns. Identification of a complete and effective radical treatment for irreversible pulpal disease, a common clinical problem, continues to pose challenges. Although traditional root canal therapy remains the primary clinical treatment, it does not fully restore the physiological functions of pulp. Although stem cell transplantation appears to be a relatively viable treatment strategy for pulp disease, issues such as cell heterogeneity and poor regeneration effects remain problematic. Dental pulp regeneration strategies based on "cell-free" exosome therapies explored by numerous studies appear to have shown significant advantages. In particular, exosomes derived from odontogenic stem cells have demonstrated considerable potential in tooth tissue regeneration engineering, and continue to exhibit superior therapeutic effects compared to non-odontogenic stem cell-derived exosomes. However, only a few studies have comprehensively summarised their research results, particularly regarding the critical factors involved in the process. Therefore, in this study, our purpose was to review the effects exerted by odontogenic exosomes on pulp regeneration and to analyse and discus crucial factors related to this process, thereby providing scholars with a feasible and manageable new concept with respect to regeneration schemes.

Umbilical cord mesenchymal stromal cell-derived extracellular vesicles lack the potency to immunomodulate human monocyte-derived macrophages in vitro

Mesenchymal stromal cells (MSCs) have been reported to display efficacy in a variety of preclinical models, but without long-term engraftment, suggesting a role for secreted factors, such as MSC-derived extracellular vesicles (EVs). MSCs are known to elicit immunomodulatory effects, an important aspect of which is their ability to affect macrophage phenotype. However, it is not clear if these effects are mediated by MSC-derived EVs, or other factors secreted by the MSCs. Here, we use flow cytometry to assess the effects of human umbilical cord (hUC) MSC-derived EVs on the expression of pro-inflammatory (CD80) and anti-inflammatory (CD163) surface markers in human monocyte-derived macrophages (hMDMs). hUC-MSC-derived EVs did not change the surface marker expression of the hMDMs. In contrast, when hMDMs were co-incubated with hUC-MSCs in indirect co-cultures, changes were observed in the expression of CD14, CD80 and CD163, particularly in M1 macrophages, suggesting that soluble factors are necessary to elicit a shift in phenotype. However, even though EVs did not alter the surface marker expression of macrophages, they promoted angiogenesis and phagocytic capacity increased proportionally to increases in EV concentration. Taken together, these results suggest that hUC-MSC-derived EVs are not sufficient to alter macrophage phenotype and that additional MSC-derived factors are needed.

Adipose Mesenchymal Stem Cell Derived Exosomes Promote Keratinocytes and Fibroblasts Embedded in Collagen/Platelet-Rich Plasma Scaffold and Accelerate Wound Healing

Engineered skin substitutes derived from human skin significantly reduce inflammatory reactions mediated by foreign/artificial materials and are consequently easier to use for clinical application. Type I collagen is a main component of the extracellular matrix during wound healing and has excellent biocompatibility, and platelet-rich plasma can be used as the initiator of the healing cascade. Adipose mesenchymal stem cell derived exosomes are crucial for tissue repair and play key roles in enhancing cell regeneration, promoting angiogenesis, regulating inflammation, and remodeling extracellular matrix. Herein, Type I collagen and platelet-rich plasma, which provide natural supports for keratinocyte and fibroblast adhesion, migration, and proliferation, are mixed to form a stable 3D scaffold. Adipose mesenchymal stem cell derived exosomes are added to the scaffold to improve the performance of the engineered skin. The physicochemical properties of this cellular scaffold are analyzed, and the repair effect is evaluated in a full-thickness skin defect mouse model. The cellular scaffold reduces the level of inflammation and promotes cell proliferation and angiogenesis to accelerate wound healing. Proteomic analysis shows that exosomes exhibit excellent anti-inflammatory and proangiogenic effects in collagen/platelet-rich plasma scaffolds. The proposed method provides a new therapeutic strategy and theoretical basis for tissue regeneration and wound repair.

Application of Adipose-Tissue Derived Products for Burn Wound Healing

Burn injuries are a significant global health concern, leading to high morbidity and mortality. Deep burn injuries often result in delayed healing and scar formation, necessitating effective treatment options. Regenerative medicine, particularly cell therapy using adipose-derived stem cells (ASCs), has emerged as a promising approach to improving burn wound healing and reducing scarring. Both in vitro and preclinical studies have demonstrated the efficacy of ASCs and the stromal vascular fraction (SVF) in addressing burn wounds. The application of ASCs for burn healing has been studied in various forms, including autologous or allogeneic cells delivered in suspension or within scaffolds in animal burn models. Additionally, ASC-derived non-cellular components, such as conditioned media or exosomes have shown promise. Injection of ASCs and SVF at burn sites have been demonstrated to enhance wound healing by reducing inflammation and promoting angiogenesis, epithelialization, and granulation tissue formation through their paracrine secretome. This review discusses the applications of adipose tissue derivatives in burn injury treatment, encompassing ASC transplantation, as well as the utilization of non-cellular components utilization for therapeutic benefits. The application of ASCs in burn healing in the future will require addressing donor variability, safety, and efficacy for successful clinical application.

Recent Advances of Using Exosomes as Diagnostic Markers and Targeting Carriers for Cardiovascular Disease

Cardiovascular diseases (CVDs) are the leading cause of human death worldwide. Exosomes act as endogenous biological vectors; they possess advantages of low immunogenicity and low safety risks, also providing tissue selectivity, including the inherent targeting the to heart. Therefore, exosomes not only have been applied as biomarkers for diagnosis and therapeutic outcome confirmation but also showed potential as drug carriers for cardiovascular targeting delivery. This review aims to summarize the progress and challenges of exosomes as novel biomarkers, especially many novel exosomal noncoding RNAs (ncRNAs), and also provides an overview of the improved targeting functions of exosomes by unique engineered approaches, the latest developed administration methods, and the therapeutic effects of exosomes used as the biocarriers of medications for cardiovascular disease treatment. Also, the possible therapeutic mechanisms and the potentials for transferring exosomes to the clinic for CVD treatment are discussed. The advances, in vivo and in vitro applications, modifications, mechanisms, and challenges summarized in this review will provide a general understanding of this promising strategy for CVD treatment.

EXOSOMAL CIRCVMA21 DERIVED FROM ADIPOSE-DERIVED STEM CELLS ALLEVIATES SEPSIS-INDUCED ACUTE KIDNEY INJURY BY TARGETING MIR-16-5P

ABSTRACT

Background: Exosome from adipose-derived stem cells (ADSCs-Exo) has been shown to inhibit the progression of human diseases, including sepsis-related acute kidney injury (AKI). CircVMA21 is considered to be an important regulator for sepsis-related AKI. However, whether ADSCs-Exo affected sepsis-induced AKI by delivering circVMA21 is not clear. Methods: Adipose-derived stem cells were identified by alizarin red staining, oil red O staining, and flow cytometry. Exosome from adipose-derived stem cells was authenticated by transmission electron microscopy, nanoparticle tracking analysis, western blot analysis, and immunofluorescence assay. Cell apoptosis was assessed by flow cytometry, and inflammation cytokine levels were determined by ELISA. Lactate production was assessed using Lactate Acid Content Assay Kit. The expression levels of aerobic glycolysis-related markers, circVMA21 and miR-16-5p, was evaluated by quantitative real time-polymerase chain reaction. Dual-luciferase reporter assay and RIP assay were employed to detect RNA interaction. Animal experiments were used to evaluate the role of ADSCs-Exo on renal function and cell injury in LPS-induced AKI mice model. Results: Exosome from adipose-derived stem cells inhibited LPS-induced HK-2 cell apoptosis, inflammation, and aerobic glycolysis. Knockdown of exosomal circVMA21 derived from ADSCs enhanced HK-2 cell injury induced by LPS. In terms of mechanism, circVMA21 could serve as sponge for miR-16-5p. Besides, miR-16-5p inhibitor reversed the promotion effect of Exo-sh-circVMA21 on LPS-induced cell injury. In addition, ADSCs-Exo protected LPS-induced AKI in mice by increasing circVMA21 expression and decreasing miR-16-5p expression. Conclusion: Exosomal circVMA21 derived by ADSCs relieved LPS-induced AKI through targeting miR-16-5p, which provided a potential molecular target for treating sepsis-related AKI.

The functions and clinical application potential of exosomes derived from mesenchymal stem cells on wound repair: a review of recent research advances

Wound repair is a complex problem for both clinical practitioners and scientific investigators. Conventional approaches to wound repair have been associated with several limitations, including prolonged treatment duration, high treatment expenses, and significant economic and psychological strain on patients. Consequently, there is a pressing demand for more efficacious and secure treatment modalities to enhance the existing treatment landscapes. In the field of wound repair, cell-free therapy, particularly the use of mesenchymal stem cell-derived exosomes (MSC-Exos), has made notable advancements in recent years. Exosomes, which are small lipid bilayer vesicles discharged by MSCs, harbor bioactive constituents such as proteins, lipids, microRNA (miRNA), and messenger RNA (mRNA). These constituents facilitate material transfer and information exchange between the cells, thereby regulating their biological functions. This article presents a comprehensive survey of the function and mechanisms of MSC-Exos in the context of wound healing, emphasizing their beneficial impact on each phase of the process, including the regulation of the immune response, inhibition of inflammation, promotion of angiogenesis, advancement of cell proliferation and migration, and reduction of scar formation.

Application of stem cells in regeneration medicine

Regeneration is a complex process affected by many elements independent or combined, including inflammation, proliferation, and tissue remodeling. Stem cells is a class of primitive cells with the potentiality of differentiation, regenerate with self-replication, multidirectional differentiation, and immunomodulatory functions. Stem cells and their cytokines not only inextricably linked to the regeneration of ectodermal and skin tissues, but also can be used for the treatment of a variety of chronic wounds. Stem cells can produce exosomes in a paracrine manner. Stem cell exosomes play an important role in tissue regeneration, repair, and accelerated wound healing, the biological properties of which are similar with stem cells, while stem cell exosomes are safer and more effective. Skin and bone tissues are critical organs in the body, which are essential for sustaining life activities. The weak repairing ability leads a pronounced impact on the quality of life of patients, which could be alleviated by stem cell exosomes treatment. However, there are obstacles that stem cells and stem cells exosomes trough skin for improved bioavailability. This paper summarizes the applications and mechanisms of stem cells and stem cells exosomes for skin and bone healing. We also propose new ways of utilizing stem cells and their exosomes through different nanoformulations, liposomes and nanoliposomes, polymer micelles, microspheres, hydrogels, and scaffold microneedles, to improve their use in tissue healing and regeneration.

Mechanisms and applications of adipose-derived stem cell-extracellular vesicles in the inflammation of wound healing

Wound healing is a sophisticated process consisting of serial phases with overlaps, including hemostasis, inflammation, proliferation, and remodeling. The inflammation response is an early response that plays a crucial role in eliminating microbes and clearing damaged cell debris. However, in some pathological circumstances, such as diabetes mellitus, ischemia, trauma, deep burn, etc., abnormal inflammation can cause impaired wound healing. Adipose-derived stem cells (ADSCs) belong to the mesenchymal stem cell (MSC) family and exhibit prospective applications in tissue regeneration and dermatological repairs. ADSC-secreted extracellular vesicles (ADSC-EVs) mimic the functions of ADSCs without the concerns of cell survival, immune response, or ethical issues. Studies have revealed that ADSC-EVs can inhibit abnormal inflammation responses and accelerate wound healing through various mechanisms. Moreover, some studies explored modifications in the cargo components of ADSC-EVs to enhance their therapeutic efficacy. Given the increasing studies focusing on the potential of ADSC-EVs in wound healing, how they interfere with different phases of this process has been investigated in pieces. In this review, we summarized all up-to-date evidence to map a clearer picture of the underlying mechanisms of ADSC-EVs in inflammation response. The applications of ADSC-EVs aiming at inflammation in the healing process were also reviewed to provide therapeutic strategies for future investigators.

Novel Technologies for Exosome and Exosome-like Nanovesicle Procurement and Enhancement

Exosomes are extracellular nanovesicles commonly produced by mammalian cells that in recent years have risen as a novel strategy for drug delivery systems and cancer therapy because of their innate specificity and high bioavailability. However, there are limitations that undermine their potential. Among them is the lack of mass production capacity with the current available sources and the failure to reach the intended therapeutic effect because of their insufficient uptake or their rapid clearance once administered. This review aims to show the current advances in overcoming these limitations by presenting, firstly, reported strategies to improve exosome and exosome-like nanovesicle extraction from possible novel eukaryotic sources, including animals, plants, and protozoa; and secondly, alternative modification methods that functionalize exosomes by conferring them higher targeting capacity and protection from organism defenses, which results in an increase in the attachment of ligands and cellular uptake of inorganic materials. However, even when these strategies might address some of the obstacles in their procurement and therapeutic use, there are still several aspects that need to be addressed, so several perspectives of the matter are also presented and analyzed throughout this work.

Photo-crosslinked adhesive hydrogel loaded with extracellular vesicles promoting hemostasis and liver regeneration

Hepatectomy is an effective surgical method for the treatment of liver diseases, but intraoperative bleeding and postoperative liver function recovery are still key issues. This study aims to develop a composite hydrogel dressing with excellent hemostatic properties, biocompatibility, and ability to promote liver cell regeneration. The modified gelatin matrix (GelMA, 10%) was mixed with equal volumes of sodium alginate-dopamine (Alg-DA) at concentrations of 0.5%, 1%, and 2%. Then a cross-linking agent (0.1%) was added to prepare different composite hydrogels under UV light, named GelMA/Alg-DA-0.5, GelMA/Alg-DA-1 and GelMA/Alg-DA-2, respectively. All the prepared hydrogel has a porous structure with a porosity greater than 65%, and could be stabilized in a gel state after being cross-linked by ultraviolet light. Physicochemical characterization showed that the elastic modulus, water absorption, adhesion, and compressibility of the composite hydrogels were improved with increasing Alg-DA content. Furthermore, the prepared hydrogel exhibits in vitro degradability, excellent biocompatibility, and good hemostatic function. Among all tested groups, the group of GelMA/Alg-DA-1 hydrogel performed the best. To further enhance its application potential in the field of liver regeneration, adipose-derived mesenchymal stem cell exosomes (AD-MSC-Exo) were loaded into GelMA/Alg-DA-1 hydrogel. Under the same conditions, GelMA/Alg-DA-1/Exo promoted cell proliferation and migration more effectively than hydrogels without extracellular vesicles. In conclusion, the prepared GelMA/Alg-DA-1 composite hydrogel loaded with AD-MSC-Exo has great application potential in liver wound hemostasis and liver regeneration.

Study on the Promotion of hADSCs Migration and Chemotaxis by SDF-1

PURPOSE

The purpose of this study was to investigate the chemotaxis effect of stromal cell-derived factor-1 (SDF-1) on human adipose-derived stem cells (hADSCs).

METHODS

A lentivirus vector with the enhanced green fluorescent protein gene was constructed and transfected to hADSCs. A control group and an SDF-1 induction group were set to estimate the efficacy of SDF-1 in promoting hADSCs chemotaxis and migration.

RESULTS

After 7 days of infection with hADSCs by enhanced green fluorescent protein lentivirus, the positive rate of fluorescence expression detected by flow cytometry was 100%. After the addition of SDF-1 induction, the invasion ability of hADSCs was enhanced.

CONCLUSIONS

SDF-1 can promote hADSCs migration and chemotaxis, which may play a role in stem cell transplantation.

Stem cell-derived exosomes: emerging therapeutic opportunities for wound healing

Wound healing is a dynamic and highly sequential process involving a series of overlapping spatial and temporal phases, including hemostasis, inflammation, proliferation, and tissue remodeling. Mesenchymal stem cells (MSCs) are multipotent stem cells with self-renewal, multidirectional differentiation potential, and paracrine regulation. Exosomes are subcellular vesicular components 30-150 nm in size and are novel carriers of intercellular communication in regulating the biological behaviors of skin cells. Compared to MSCs, MSC-derived exosomes (MSC-exos) possess lower immunogenicity, easy storage, and highly effective biological activity. MSC-exos, mainly derived from adipose-derived stem cells (ADSCs), bone marrow-derived MSCs (BMSCs), human umbilical cord MSCs (hUC-MSCs), and other stem cell types, play a role in shaping the activity of fibroblasts, keratinocytes, immune cells, and endothelial cells in diabetic wounds, inflammatory wound repair, and even wound-related keloid formation. Therefore, this study focuses on the specific roles and mechanisms of different MSC-exos in wound healing, as well as the current limitations and various perspectives. Deciphering the biological properties of MSC-exos is crucial to providing a promising cell-free therapeutic tool for wound healing and cutaneous regeneration.

Effects of stem cell-derived exosome therapy on erectile dysfunction: a systematic review and meta-analysis of preclinical studies

Introduction

Erectile dysfunction (ED) is a common disease among elderly men, and novel therapy methods are needed for drug-refractory ED. As an extracellular vesicle, stem cell-derived exosomes displayed erectile function improvement in rat ED models in some preclinical studies. However, the therapeutic efficacy has not been comprehensively evaluated.

Aim

To study the therapeutic effects of stem cell-derived exosomes on ED in preclinical studies and to investigate the potential mechanisms responsible for the efficacy.

Methods

The systematic literature search was conducted in Web of Science, PubMed, and Embase to retrieve studies utilizing stem cell-derived exosomes for ED treatment. We extracted data of intracavernous pressure/mean artery pressure (ICP/MAP), and cavernosum structural changes in rat ED models before and after stem cell-derived exosome therapy. RevMan 5.3 was used to perform meta-analyses of ICP/MAP and cavernosum microstructural changes. Publication bias was assessed with the Egger test and funnel plot by Stata 15.0 (StataCorp).

Main Outcome Measures

Outcomes included ICP/MAP, smooth muscle, and endothelial markers-such as the ratio of smooth muscle to collagen and the expression of α-SMA (alpha smooth muscle actin), CD31 (cluster of differentiation 31), nNOS and eNOS (neuronal and endothelial nitric oxide synthase), TGF-β1 (transforming growth factor β1), and caspase 3 protein-to evaluate erectile function and microstructural changes. Forest plots of effect sizes were performed.

Results

Of 146 studies retrieved, 11 studies were eligible. Pooled analysis showed that stem cell-derived exosomes ameliorated damaged ICP/MAP (standardized mean difference, 3.68; 95% CI, 2.64-4.72; P < .001) and structural changes, including the ratio of smooth muscle to collagen and the expression of α-SMA, CD31, nNOS, eNOS, TGF-β1, and caspase 3 protein. Subgroup analysis indicated that exosome type and ED model type made no difference to curative effects.

Conclusion

This meta-analysis suggests the therapeutic efficacy of stem cell-derived exosomes for ED. Exosomes may restore erectile function by optimizing cavernosum microstructures.