Exosomes released from human induced pluripotent stem cells-derived MSCs facilitate cutaneous wound healing by promoting collagen synthesis and angiogenesis

An Adipose-Derived Stem Cell Exosome Sheet Promotes Oral Mucosal Wound Healing

Objective: Oral mucosal wound healing is not completely understood, and effective therapies are lacking. This study explores the potential of an adipose-derived stem cell (ADSC) exosome sheet in enhancing intraoral wound healing in rats. Approach: An ADSC exosome sheet derived from Tisseel and rat adipose tissue (ADSC-exo) was applied to 16 rats with 6 mm full-thickness mucosal hard palate wounds. Eight wounds received ADSC-exo with a superficial occlusive dressing (ADSC-exo group), and eight received only an occlusive dressing (control group). Wound closure was monitored on days 0, 2, 4, 7, and 10, with dressings changed every 2 days. On day 10, rats were sacrificed, and wounds (n = 8 per group) were collected for immunohistochemical analysis. In vitro, four ADSC-exosome concentrations (0, 4.5 × 1011, 9 × 1011, and 18 × 1011 exosomes/mL; n = 4 per group) were applied to rat oral mucosal fibroblasts to assess migration speed. Results: ADSC-exo accelerated wound closure (18% ± 5% vs. 35% ± 9% of initial wound area; p = 0.002) and fibroblast migration (for 18 × 1011 exosomes/mL at 24 h: 29.7% ± 3% vs. 62.2% ± 4% of initial gap area; p < 0.0001) compared with the control. ADSC-exo promoted reepithelialization (87% ± 14% vs. 21% ± 6%; p < 0.0001), proliferation (34 ± 12 vs. 18 ± 7 Ki67+/high-power field [HPF]; p = 0.004), and neovascularization (28 ± 9 vs. 11 ± 5 CD31+/HPF; p = 0.0002) while reducing inflammation (4 ± 1 vs. 13 ± 9 CD68+/HPF; p < 0.0001) and increasing M2 macrophages (9.2 ± 2 vs. 4.2 ± 3 CD163+/HPF; p = 0.0008). ADSC-exo increased Transforming Growth Factor beta 1 (TGF-β1) (1.3 ± 0.3 vs. 0.9 ± 0.2; p = 0.006), Smad3 (0.9 ± 0.02 vs. 0.7 ± 0.1; p = 0.006), and collagen I (1.5 ± 0.9 vs. 0.5 ± 0.3; p = 0.005) while downregulating caspase-3 (0.7 ± 0.3 vs. 1.1 ± 0.2; p = 0.003) and Bax (0.9 ± 0.2 vs. 1.4 ± 0.1; p < 0.0001). Innovation: This is the first study to demonstrate the pro-wound healing effects of an ADSC exosome sheet on intraoral wounds. This paves the way for future research and clinical applications of ADSC exosomes in mucosal wound healing. Conclusions: Application of an ADSC-exo to rat mucosal wounds significantly improved wound healing. Mechanistically, these effects may be linked to upregulated activity of the TGF-β/Smad pathway.

Mesenchymal Stem Cell-Derived Exosomes Hold Promise in the Treatment of Diabetic Foot Ulcers

Diabetic foot ulcers (DFU) represent one of the most common side effects of diabetes, significantly impacting patients' quality of life and imposing considerable financial burdens on families and society at large. Despite advancements in therapies targeting lower limb revascularization and various medications and dressings, outcomes for patients with severe lesions remain limited. A recent breakthrough in DFU treatment stems from the development of mesenchymal stem cells (MSCs). MSCs have shown promising results in treating various diseases and skin wounds due to their ability for multidirectional differentiation and immunomodulation. Recent studies highlight that MSCs primarily repair tissue through their paracrine activities, with exosomes playing a crucial role as the main biologically active components. These exosomes transport proteins, mRNA, DNA, and other substances, facilitating DFU treatment through immunomodulation, antioxidant effects, angiogenesis promotion, endothelial cell migration and proliferation, and collagen remodeling. Mesenchymal stem cell-derived exosomes (MSC-Exo) not only deliver comparable therapeutic effects to MSCs but also mitigate adverse reactions like immune rejection associated with MSCs transplantation. This article provides an overview of DFU pathophysiology and explores the mechanisms and research progress of MSC-Exo in DFU therapy.

The role of exosomes derived from various sources in facilitating the healing of chronic refractory wounds

Chronic refractory wounds (CRWs) represent a common and challenging issue in clinical practice, including diabetic foot ulcers, pressure ulcers, venous ulcers, and arterial ulcers. These wounds significantly impact patients' quality of life and may lead to severe consequences such as amputation. Their treatment requires a comprehensive consideration of both the patient's overall physical condition and the local wound situation. The major challenges in treatment include complex pathogenesis, a long treatment cycle, a high recurrence rate, and heavy economic pressure on the patients. Exosomes represent an emerging therapeutic modality with characteristics such as low immunogenicity, good biostability, and high targeting efficiency in the treatment of diseases. Exosomes derived from different sources exhibit heterogeneity, demonstrating their respective advantages and unique properties in treatment. This article delves into the potential applications and mechanisms of action of exosomes from various sources in the treatment of CRWs, aiming to provide new perspectives and ideas for the management of such wounds.

Extracellular vesicles: innovative cell-free solutions for wound repair

Chronic non-healing wounds are often associated with conditions such as diabetes and peripheral vascular disease, pose significant medical and socioeconomic challenges. Cell-based therapies have shown promise in promoting wound healing but have major drawbacks such as immunogenicity and tumor formation. As a result, recent research has shifted to the potential of extracellular vesicles (EVs) derived from these cells. EVs are nanosized lipid bilayer vesicles, naturally produced by all cell types, which facilitate intercellular communication and carry bioactive molecules, offering advantages such as low immunogenicity, negligible toxicity and the potential to be re-engineered. Recent evidence recognizes that during wound healing EVs are released from a wide range of cells including immune cells, skin cells, epithelial cells and platelets and they actively participate in wound repair. This review comprehensively summarizes the latest research on the function of EVs from endogenous cell types during the different phases of wound healing, thereby presenting interesting therapeutic targets. Additionally, it gives a critical overview of the current status of mesenchymal stem cell-derived EVs in wound treatment highlighting their tremendous therapeutic potential as a non-cellular of-the-shelf alternative in wound care.

Application of stem cell-derived exosomes in anterior segment eye diseases: A comprehensive update review

Mesenchymal stem cell (MSC) therapy has emerged as a promising approach for addressing various eye-related conditions. Yet, its clinical application faces challenges due to issues such as limited biocompatibility and difficulties in effectively delivering treatment to specific ocular tissues. Recent studies have shifted attention towards MSC-derived exosomes, which share similar regenerative, reparative, and immunomodulatory capabilities with their origin cells. This review delves into the latest research on the use of MSC-derived exosomes for treating anterior segment diseases of the eye. It explores the exosomes' composition, biological functions, and the methods used for their isolation, as well as their roles in disease progression, diagnosis, and therapy. The review critically assesses the therapeutic advantages and mechanisms of action of MSC-derived exosomes in treating conditions like dry eye disease, Sjogren's syndrome, keratoconus, corneal lesions, and corneal allograft rejection. Additionally, it discusses the obstacles and future prospects of employing MSC-derived exosomes as innovative therapies for anterior segment eye diseases. This comprehensive overview underscores the significant potential of MSC-derived exosomes in transforming the treatment paradigm for anterior segment eye disorders, while also highlighting the necessity for further research to enhance their clinical application.

Cell origin and microenvironment: The players of differentiation capacity in human mesenchymal stem cells

Mesenchymal stem cells (MSCs) have several important properties that make them desirable for regenerative medicine. These properties include immunomodulatory ability, growth factor production, and differentiation into various cell types. Despite extensive research and promising results in clinical trials, our understanding of MSC biology, their mechanism of action, and their targeted and routine use in clinics is limited. Differentiation of human MSCs (hMSCs) is a complex process influenced by various elements such as growth factors, pharmaceutical compounds, microRNAs, 3D scaffolds, and mechanical and electrical stimulation. Research has shown that different culture conditions can affect the differentiation potential of hMSCs obtained from multiple fetal and adult sources. Additionally, it seems that what affects the differentiation capacities of these cells is their secretory characteristics, which are influenced by the origin of the cells and the local microenvironment where the cells are located. The review can provide insights into the microenvironment-based mechanisms involved in MSC differentiation, which can be valuable for future therapeutic applications.

Mesenchymal stem cells-derived small extracellular vesicles and apoptotic extracellular vesicles for wound healing and skin regeneration: a systematic review and meta-analysis of preclinical studies

BACKGROUND

Studies examining the therapeutic potential of Mesenchymal stem cells-derived extracellular vesicles (MSC-EVs) in wound healing and skin regeneration have progressed rapidly. Prior to considering clinical translation, a systematic and comprehensive understanding of these experimental details and the overall impact of MSC-EVs on skin regeneration is necessary.

METHODS

83 studies were identified in Web of Science, Embase, and PubMed that satisfied a set of prespecified inclusion criteria. A random effects meta-analysis was conducted for wound closure rate, scar width, blood vessel density and collagen deposition.

CONCLUSIONS

Our findings demonstrate clear potential of MSC-EVs to be developed as therapy for wound healing and skin regeneration both in diabetic and non-diabetic animal models. Moreover, subgroup analyses demonstrated that apoptotic small extracellular vesicles (ApoSEVs) showed better efficacy than apoptotic bodies (ApoBDs) and small extracellular vesicles (sEVs) in wound closure outcome and collagen deposition, while sEVs displayed better than ApoEVs in revascularization. Among frequently used routes of administration, subcutaneous injection displayed a greater improvement to wound closure, collagen deposition and revascularization as compared to dressing/covering. Among easier-access source of MSCs, ADSCs demonstrated the best effect in wound closure rate and collagen deposition, as compared, BMMSCs displayed better in revascularization. Additionally, high heterogeneity observed in collection conditions, separation methods, storage methods, modifications, treatment dose, administration route, and frequency of MSC-EVs underscores the urgent need for standardization in these areas, prior to clinical translation.

PROTOCOL REGISTRATION

PROSPERO CRD42024499172.

Exosomes Derived from Metformin-Pretreated BMSCs Accelerate Diabetic Wound Repair by Promoting Angiogenesis Via the LINC-PINT/miR-139-3p/FOXC2 Axis

Chronic trauma is a prevalent and significant complication of diabetes. Mesenchymal stem cell(MSC)-derived exosomes (Exos) have been reported to accelerate the healing of chronic diabetic wounds. MSCs pretreated with chemical or biological factors were reported to enhance the biological activity of MSC-derived exosomes. Hence, this study investigated the role of exosomes derived from bone marrow mesenchymal stem cells (BMSCs) pretreated with metformin (MET) on diabetic wound healing. The results showed that MET-Exos promoted endothelial cell migration, tube formation, and angiogenesis, leading to accelerated wound healing in diabetic mice. Mechanistically, MET-Exos upregulated LINC-PINT, which, through competitive binding to miR-139-3p, activated FOXC2, a key regulator of angiogenesis. These data reveal that MET-Exos might promote revascularization and wound healing through the LINC-PINT/miR-139-3p/FOXC2 axis, showing its potential as a therapeutic modality for diabetic wounds.

From Plant Based Therapy to Plant-Derived Vesicle-Like Nanoparticles for Cancer Treatment: Past, Present and Future

Cancer stands as a formidable malady profoundly impacting human health. Throughout history, plant-based therapies have remained pivotal in the arsenal against cancer, evolving alongside the epochs. Presently, challenges such as the arduous extraction of active components and potential safety concerns impede the progression of plant-based anticancer therapies. The isolation of plant-derived vesicle-like nanoparticles (PDVLNs), a kind of lipid bilayer capsules isolated from plants, has brought plant-based anticancer therapy into a novel realm and has led to decades of research on PDVLNs. Accumulating evidence indicates that PDVLNs can deliver plant-derived active substances to human cells and regulate cellular functions. Regulating immunity, inducing cell cycle arrest, and promoting apoptosis in cancer cells are the most commonly reported mechanisms of PDVLNs in tumor suppression. Low immunogenicity and lack of tumorigenicity make PDVLNs a good platform for drug delivery. The molecules within the PDVLNs are all from source plants, so the selection of source plants is crucial. In recent years, there has been a clear trend that the source plants have changed from vegetables or fruits to medicinal plants. This review highlights the mechanisms of medicinal plant-based cancer therapies to identify candidate source plants. More importantly, the current research on PDVLN-based cancer therapy and the applications of PDVLNs for drug delivery are systematically discussed.

Exosomes derived from adipose mesenchymal stem cells promote corneal injury repair and inhibit the formation of scars by anti-apoptosis

In the corneal wound healing process, epithelial cell re-epithelialization and migration are the critical first steps following an injury. As the disease progresses, orderly regeneration of corneal stromal collagen and mild corneal stromal fibrosis are vital for corneal function reconstruction. Exosomes derived from adipose-derived mesenchymal stem cells (ADSCs-Exos) have emerged as a promising therapy due to their anti-oxidant, anti-apoptosis, and tissue repair properties. In this study, we successfully isolated exosomes via differential centrifugation and verified their effective extraction through transmission electron microscopy and nanoparticle tracking analysis. In vitro, ADSCs-Exos increased corneal epithelial cell migration by 20 % and reduced oxidative damage by 50 %. In addition, ADSCs-Exos demonstrated remarkable wound healing properties in corneal tissue. This effect was attributed to their ability to inhibit apoptosis of corneal stroma cells by upregulating Bax and downregulating Bcl2, reducing the Bax/Bcl2 protein expression ratio from 1 to 0.45. This decrease may subsequently inhibit α-SMA expression, thereby preventing corneal scarring. Overall, this research has elucidated the effects and potential targets of ADSCs-Exos in promoting corneal wound repair, offering a novel and promising approach for treating corneal injuries.

Exploring the ncRNA landscape in exosomes: Insights into wound healing mechanisms and therapeutic applications

Exosomal non-coding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, have emerged as crucial modulators in cellular signaling, influencing wound healing processes. Stem cell-derived exosomes, which serve as vehicles for these ncRNAs, show remarkable therapeutic potential due to their ability to modulate wound healing stages, from initial inflammation to collagen formation. These ncRNAs act as molecular signals, regulating gene expression and protein synthesis necessary for cellular responses in healing. Wound healing is a complex, staged process involving inflammation, hemostasis, fibroblast proliferation, angiogenesis, and tissue remodeling. Stem cell-derived exosomal ncRNAs enhance these stages by reducing excessive inflammation, promoting anti-inflammatory responses, guiding fibroblast and keratinocyte maturation, enhancing vascularization, and ensuring organized collagen deposition. Their molecular cargo, particularly ncRNAs, specifically targets pathways to aid chronic wound repair and support scarless regeneration. This review delves into the unique composition and signaling roles of Stem cell-derived exosomes and ncRNAs, highlighting their impact across wound healing stages and their potential as innovative therapeutics. Understanding the interaction between exosomal ncRNAs and cellular signaling pathways opens new avenues in regenerative medicine, positioning Stem cell-derived exosomes and their ncRNAs as promising molecular-level interventions in wound healing.

Therapeutic potential of exosomes derived from human endometrial mesenchymal stem cells for heart tissue regeneration after myocardial infarction

Myocardial infarction (MI) is the most common cardiovascular disease (CVD) and the leading cause of mortality worldwide. Recent advancements have identified human endometrial mesenchymal stem cells (hEnMSCs) as a promising candidate for heart regeneration, however, challenges associated with cell-based therapies have shifted focus toward cell-free treatments (CFTs), such as exosome therapy, which show considerable promise for myocardial tissue regeneration. MI was induced in male Wistar rats by occluding the left anterior descending (LAD) coronary artery. The hEnMSCs-derived exosomes (hEnMSCs-EXOs) were encapsulated in injectable fibrin gel inside the cardiac tissue. The encapsulated hEnMSC-EXOs were administered, and their effects on myocardial regeneration, angiogenesis, and heart function were monitored for 30 days post-MI. The treatments were evaluated through histological analysis, echocardiographic parameters of left ventricular internal dimension at end-diastole (LVIDD) and end-systole (LVID), left ventricular end-diastole volume (LVEDV), left ventricular end-systole volume (LVESV), and left ventricular ejection fraction (LVEF) and molecular studies. Histological findings demonstrated significant fibrosis and left ventricular remodeling following MI. Treatment with fibrin gel-encapsulated hEnMSCs-EXOs substantially reduced fibrosis, enhanced angiogenesis, and prevented heart remodeling, leading to improved cardiac function. Notably, 30 days after encapsulated hEnMSCs-EXOs were delivered corresponded with a less inflammatory microenvironment, supporting cardiomyocyte retention in ischemic tissue. This study highlights the potential of encapsulated hEnMSCs-EXOs in fibrin gel as a novel therapeutic strategy for ischemic myocardium repair post-MI. The findings underscore the importance of biomaterials in advancing stem cell-based therapies and lay a foundation for clinical applications to mitigate heart injury following MI.

Effect of adipose-derived stem cells exosomes cross-linked chitosan-αβ-glycerophosphate thermosensitive hydrogel on deep burn wounds

BACKGROUND

Burn wound management is challenging, and while mesenchymal stem cell-derived exosomes show therapeutic potential, optimal delivery methods are unclear.

AIM

To study chitosan (CS)-αβ-glycerophosphate (CS-αβ-GP) hydrogel crosslinked with adipose-derived stem cell exosomes (ASC-Exos) for healing deep burn injuries.

METHODS

Rats with deep burn injuries were divided into the CS + ASCs-Exos group, the ASCs-Exos group, the CS group, and the control group. The healing rates on days 4, 7, and 14 after treatment were analyzed using ImageJ software. On day 14, the tissues were stained with hematoxylin and eosin staining, Masson’s trichrome staining, and immunohistochemical analysis to evaluate tumor necrosis factor α, interleukin-6 (IL-6), IL-1α, IL-10, transforming growth factor β, and epidermal growth factor. The mRNA levels of IL-1α, CD86, C-C motif chemokine ligand 22, and CD163 were evaluated through quantitative polymerase chain reaction.

RESULTS

The CS + ASC-Exos group exhibited enhanced healing, reduced lymphocyte infiltration, blood vessels, and muscle fiber distribution. Increased IL-10, transforming growth factor β, and epidermal growth factor and decreased tumor necrosis factor α, IL-1α, and IL-6 expression were observed. Quantitative polymerase chain reaction revealed reduced IL-1α and CD86 and increased C-C motif chemokine ligand 22 and CD163 expression. Protein analysis showed downregulation of phosphorylated inhibitor of kappa Balpha and P65 in the nuclear factor κB (NF-κB) pathway. ASC-Exos crosslinked with CS-αβ-GP hydrogel demonstrates superior effects in anti-inflammation, wound healing promotion, and promotion of M1 macrophage transformation to M2 macrophage by blocking the NF-κB pathway compared to ASC-Exos alone.

CONCLUSION

Our research demonstrates that the ASC-Exos cross-linked CS-αβ-GP hydrogel represents an advanced therapeutic approach for treating deep burn wounds. It has anti-inflammatory effects, promotes wound healing, and facilitates the transition of M1 macrophages to M2 macrophages by blocking the NF-κB pathway.

Functional transfer of integrin co-receptor CD98hc by small extracellular vesicles improves wound healing in vivo

Extracellular vesicles (EVs) mediate intercellular communication. EVs are composed of a lipid bilayer and contain cytosolic proteins and RNAs. Studies highlight EVs striking functions in cell-cell crosstalk. Here, we found that small EVs can transfer functional signaling molecules through their lipid bilayer and participate in skin homeostasis. We identified a transmembrane protein CD98hc (a.k.a. SLC3A2), an integrin co-receptor (Itgb1 and Itgb3), implicated in epidermis homeostasis via its capacity in regulating extracellular matrix, as an important mediator of EV-based intercellular communication in vivo. We first demonstrated that healthy dermal fibroblasts produced and secreted EVs bearing characteristic of exosome-like small EVs (sEVs). We show that CD98hc, Itgb1 co-receptor, is present at the surface of sEVs, transferred and stabilized at the plasma membrane. The transferred complex is functional on recipient cells both in vitro and in vivo. Indeed, treatment with sEVs from WT, but not KO cells rescued migratory defects observed either in CD98hc KO dermal fibroblasts or in keratinocytes in vitro. Furthermore, injection of sEVs at the margins of wound in impaired wound healing mouse models (epidermal CD98hc KO mice exhibiting healing defect and elderly mice) improved wound closure in vivo. CD98hc complex transferred from sEVs remained stabilized at least 7 days after injection. Thus, our findings reveal that in vivo treatment with sEVs containing integrin co-receptor CD98hc could improve multiple skin afflictions.

Exosome laden sprayable thermo-sensitive polysaccharide-based hydrogel for enhanced burn wound healing

Severe burns pose significant threats to patient well-being, characterized by pain, inflammation, bacterial infection, and extended recovery periods. While exosome-loaded hydrogels have demonstrated considerable promise in wound healing, current formulations often fall short of achieving optimal therapeutic efficacy for burn wounds due to challenges related to their adaptability to wound shape and limited anti-bacterial capabilities. In this study a novel exosome laden sprayable thermosensitive polysaccharide-based hydrogel (ADA-aPF127@LL18/Exo) comprising alginate dialdehyde (ADA) and aminated Pluronic F127 (aPF127) was fabricated via Schiff base reaction. ADA-aPF127@LL18/Exo exhibited sustained release of exosome and enhanced antibacterial efficacy. Furthermore, the biological assessments displayed excellent biocompatibility and enhanced in vitro cell proliferation and migration. In a deep partial thickness burn model, ADA-aPF127@LL18/Exo significantly augmented wound healing processes by accelerating epithelialization, promoting granulation tissue formation and collagen deposition, inducing hair follicle regeneration, effectively mitigating inflammatory responses, and facilitating enhanced neovascularization. In conclusion, ADA-aPF127@LL18/Exo represents a highly promising therapeutic dressing for the treatment of deep burns, exhibiting multifaceted properties conducive to efficient wound management.

Bone Marrow Mesenchymal Stem Cells-Derived Exosomes Inhibit Apoptosis of Pulmonary Microvascular Endothelial Cells in COPD Mice Through miR-30b/Wnt5a Pathway

Background

Bone marrow mesenchymal stem cells (BMSCs)-derived exosomes are rich in a variety of active substances, including microRNA (miR) and have shown powerful therapeutic effects to ameliorate cell injury and diseases. However, the role of BMSCs-derived exosomes on chronic obstructive pulmonary disease (COPD) has been poorly studied. In addition, pulmonary microvascular endothelial cells (PMVECs) apoptosis contributes to the onset of COPD. Inhibition of PMVECs apoptosis can reverse COPD changes. Therefore, the aim of this study was to explore the role of BMSCs-derived exosomes in the apoptosis of PMVECs in COPD and to investigate the potential mechanisms.

Methods

We isolated and characterized normal mouse BMSCs-derived exosomes and PMVECs. We performed miR sequencing of BMSCs-derived exosomes. We transfected PMVECs with the miR-30b mimic and Wnt5a overexpression plasmid to assess the underlying mechanisms. Cigarette smoke extract (CSE)-induced COPD mice were treated with exosomes and HBLV-mmu-miR-30b via intratracheal instillation. Finally, we determined the expression of miR-30b and Wnt5a in tissues from patients with COPD.

Results

BMSCs-derived exosomes could significantly reduce apoptosis of CSE-induced PMVECs and increase the expression of miR-30b (p<0.05). Based on miR sequencing, miR-30b was highly enriched in BMSCs-derived exosomes. The knockdown of miR-30b in BMSCs-derived exosomes could increase the apoptosis of CSE-induced PMVECs (p<0.05). miR-30b overexpression significantly reduced apoptosis and repressed Wnt5a protein expression in CSE-induced PMVECs (p<0.05). Furthermore, Wnt5a overexpression reversed the anti-apoptotic effect of miR-30b on CSE-induced PMVECs (p<0.05). In addition, compared with the COPD group, treatment with BMSCs-derived exosomes and miR-30b overexpression could alleviate emphysema changes, decrease the mean linear intercept and alveolar destructive index, reduce apoptosis, increase the expression of miR-30b, and decrease the expression of Wnt5a in lung tissue (p<0.05). Finally, miR-30b expression was decreased in patients with COPD, while Wnt5a expression was increased in these patients (p<0.05).

Conclusion

BMSCs-derived exosomes could improve the damage of COPD perhaps by delivering miR-30b. miR-30b could reduce apoptosis of CSE-induced PMVECs by targeting Wnt5a.

Exosomes and Exosome-Mimetics for Atopic Dermatitis Therapy

BACKGROUND

Exosomes and exosome mimetics are used as alternatives to cell therapy. They have shown potential in treating skin disorders by fortifying the skin barrier, mediating angiogenesis, and regulating the immune response while minimizing side effects. Currently, numerous studies have applied exosome therapy to treat atopic dermatitis (AD) caused by a weakened skin barrier and chronic inflammation. Research on exosomes and exosome mimetics represents a promising avenue for tissue regeneration, potentially paving the way for new therapeutic options. However, the efficacy of the therapy remains poorly understood. Also, the potential of exosome mimetics as alternatives to exosomes in skin therapy remains underexplored.

METHODS

Here, we reviewed the pathological features and current therapies of AD. Next, we reviewed the application of exosomes and exosome mimetics in regenerative medicine. Finally, we highlighted the therapeutic effects of exosomes based on their cell source and assessed whether exosome mimetics are viable alternatives.

RESULTS AND CONCLUSION

Exosome therapy may treat AD due to its skin regenerative properties, and exosome mimetics may offer an equally effective yet more efficient alternative. Research on exosomes and exosome mimetics represents a promising avenue for tissue regeneration, potentially paving the way for new therapeutic options.

Regenerative properties of bone marrow mesenchymal stem cell derived exosomes in rotator cuff tears

ABSTRCT

Rotator cuff injury (RCI), characterized by shoulder pain and restricted mobility, represents a subset of tendon-bone insertion injuries (TBI). In the majority of cases, surgical reconstruction of the affected tendons or ligaments is required to address the damage. However, numerous clinical failures have underscored the suboptimal outcomes associated with such procedures. Further investigations have revealed that these failures are largely attributable to delayed healing at the tendon-bone interface, excessive formation of vascularized scar tissue, and inadequate integration of tendon grafts within bone tunnels. As a result, the healing process of rotator cuff injuries faces significant challenges.Bone marrow-derived mesenchymal stem cell exosomes (BMSC-exos) have emerged as a prominent focus of research within the field of bioengineering, owing to their remarkable potential to regulate cellular proliferation and differentiation, modulate immune responses, and facilitate tissue repair and regeneration following cellular damage. In this review, we explore the anti-inflammatory, angiogenic, anti-scarring, and bone metabolism-modulating effects of BMSC-exos in the context of rotator cuff injury. Additionally, we address the limitations and ongoing challenges within current research, offering insights that could guide the clinical application of BMSC-exos in the treatment of rotator cuff injuries in the future.

Extracellular vesicles: essential agents in critical bone defect repair and therapeutic enhancement

Bone serves as a fundamental structural component in the body, playing pivotal roles in support, protection, mineral supply, and hormonal regulation. However, critical-sized bone injuries have become increasingly prevalent, necessitating extensive medical interventions due to limitations in the body's capacity for self-repair. Traditional approaches, such as autografts, allografts, and xenografts, have yielded unsatisfactory results. Stem cell therapy emerges as a promising avenue, but challenges like immune rejection and low cell survival rates hinder its widespread clinical implementation. Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) have garnered attention for their regenerative capabilities, which surpass those of MSCs themselves. EVs offer advantages such as reduced immunogenicity, enhanced stability, and simplified storage, positioning them as a promising tool in stem cell-based therapies. This review explores the potential of EV-based therapy in bone tissue regeneration, delving into their biological characteristics, communication mechanisms, and preclinical applications across various physiological and pathological conditions. The mechanisms underlying EV-mediated bone regeneration, including angiogenesis, osteoblast proliferation, mineralization, and immunomodulation, are elucidated. Preclinical studies demonstrate the efficacy of EVs in promoting bone repair and neovascularization, even in pathological conditions like osteoporosis. EVs hold promise as a potential alternative for regenerating bone tissue, particularly in the context of critical-sized bone defects, offering new avenues for effective bone defect repair and management.

The Effect of Adipose-Derived Stem Cell (ADSC)-Exos on the Healing of Autologous Skin Grafts in Miniature Pigs

The skin functions as the body's primary defense barrier; when compromised, it can lead to dehydration, infection, shock, or potentially life-threatening conditions. Miniature pigs exhibit skin characteristics and healing processes highly analogous to humans. Mesenchymal stem cells contribute to skin injury repair through a paracrine mechanism involving exosomes. This research examines whether adipose-derived MSC exosomes effectively enhance healing following autologous skin grafting in miniature pigs. It also compares the roles and distinctions of ADSCs and ADSC-Exos in inflammatory responses and tissue regeneration. This study found significantly reduced levels of oxidative stress products and pro-inflammatory factors, while antioxidant factors, anti-inflammatory factors, and pro-regenerative factors were elevated, and anti-regenerative factor levels decreased. Moreover, the expression levels of key markers-namely, PI3K, Akt, and mTOR-in the regeneration-associated signaling pathway were increased. The alterations in these indicators indicate that ADSC-Exos can regulate inflammatory responses and promote regeneration. This study provides a novel theoretical foundation for the implementation of acellular therapy in clinical settings.

The cell replacement therapeutic potential of human pluripotent stem cells

INTRODUCTION

The remarkable ability of human pluripotent stem cells (hPSCs) to differentiate into specialized cells of the human body emphasizes their immense potential in treating various diseases. Advances in hPSC technology are paving the way for personalized and allogeneic cell-based therapies. The first-in-human studies showed improved treatment of diseases with no adverse effects, which encouraged the industrial production of this type of medicine. To ensure the quality, safety and efficacy of hPSC-based products throughout their life cycle, it is important to monitor and control their clinical translation through good practices (GxP) regulations. Understanding these rules in advance will help ensure that the industrial development of hPSC-derived products for widespread clinical implementation is feasible and progresses rapidly.

AREAS COVERED

In this review, we discuss the key translational obstacles of hPSCs, outline the current hPSC-based clinical trials, and present a workflow for putative clinical hPSC-based products. Finally, we highlight some future therapeutic opportunities for hPSC-derivatives.

EXPERT OPINION

hPSC-based products continue to show promise for the treatment of a variety of diseases. While clinical trials support the relative safety and efficacy of hPSC-based products, further investigation is required to explore the clinical challenges and achieve exclusive regulations for hPSC-based cell therapies.

Exosomes: Historical Evolution and Emerging Roles in Dermatology

BACKGROUND

Exosomes are a nanoscale extracellular vesicles derived from different cell types that have been investigated for various clinical applications, including functioning as biomarkers and use as direct therapeutics. Given the role of exosomes in multiple pathophysiologic pathways and potential practical applications, they have garnered significant interest in the scientific community but much is still unknown about their development and use.

AIMS

This literature review covers the background, mechanisms of action, use as biomarkers, methods of application, and direct therapeutic applications of exosomes.

METHODS

A literature review on the background and uses of exosomes was conducted. Key articles describing the pathophysiologic pathways and applications of exosomes were summarized and described.

RESULTS

Exosomes impact several cellular pathways which allow them to function as biomarkers for malignancy and inflammatory dermatoses and may make them useful therapeutics for skin rejuvenation, hair loss, and wound repair. Limitations of exosomes include an incomplete understanding of their functions and impacts and a lack of standardization in their production and application.

CONCLUSIONS

Exosomes are a unique and novel cellular medium that offer promise as a diagnostic tool and therapy. While there are limitations to the uses of exosomes as well as our current understanding of them, further investigation may yield additional applications and a larger role in medicine for exosomes.

Novel Strategies for Angiogenesis in Tissue Injury: Therapeutic Effects of iPSCs-Derived Exosomes

Regeneration after tissue injury is a dynamic and complex process, and angiogenesis is necessary for normal physiological activities and tissue repair. Induced pluripotent stem cells are a new approach in regenerative medicine, which provides good model for the study of difficult-to-obtain human tissues, patient-specific therapy, and tissue repair. As an innovative cell-free therapeutic strategy, the main advantages of the treatment of induced pluripotent stem cells (iPSCs)-derived exosomes are low in tumorigenicity and immunogenicity, which become an important pathway for tissue injury. This review focuses on the mechanism of the angiogenic effect of iPSCs-derived exosomes on wound repair in tissue injury and their potential therapeutic targets, with a view to providing a theoretical basis for the use of iPSCs-derived exosomes in clinical therapy.

The Role of Mesenchymal Stem Cell-Derived Exosomes in Skin Regeneration, Tissue Repair, and the Regulation of Hair Follicle Growth

Skin regeneration, repair, and the promotion of hair growth are intricate and dynamic processes essential for preserving the overall health, functionality, and appearance of both skin and hair. These processes involve a coordinated interplay of cellular activities and molecular signaling pathways that ensure the maintenance and restoration of skin integrity and hair vitality. Recent advancements in regenerative medicine have underscored the significant role of mesenchymal stem cell (MSC)-derived exosomes as key mediators in these processes. Exosomes, emerging as a promising cell-free therapy in tissue engineering, hold substantial potential due to their ability to influence various biological functions. This review explores the mechanisms by which MSC-derived exosomes facilitate skin regeneration and repair, and hair growth, their therapeutic applications, and the future research directions in this emerging field.

Harnessing Mesenchymal Stromal Cells for Advanced Wound Healing: A Comprehensive Review of Mechanisms and Applications

Chronic wounds and injuries remain a substantial healthcare challenge, with significant burdens on patient quality of life and healthcare resources. Mesenchymal stromal cells (MSCs) present an innovative approach to enhance tissue repair and regeneration in the context of wound healing. The intrinsic presence of MSCs in skin tissue, combined with their roles in wound repair, ease of isolation, broad secretory profile, and low immunogenicity, makes them especially promising for treating chronic wounds. This review explores the current landscape of MSC application, focusing on preclinical and clinical data across chronic wounds, diabetic ulcers, burns, non-union bone fractures, lower extremity venous ulcers, pressure ulcers, and genetic skin conditions like epidermolysis bullosa. Special emphasis is given to the mechanisms through which MSCs exert their regenerative effects, underscoring their potential in advancing wound healing therapies and supporting the broader field of regenerative medicine.

Exosomes derived from umbilical cord mesenchymal stem cells promote healing of complex perianal fistulas in rats

BACKGROUND

Complex perianal fistulas, challenging to treat and prone to recurrence, often require surgical intervention that may cause fecal incontinence and lower quality of life due to large surgical wounds and potential sphincter damage. Human umbilical cord-derived MSCs (hUC-MSCs) and their exosomes (hUCMSCs-Exo) may promote wound healing.

METHODS

This study assessed the efficacy, mechanisms, and safety of these exosomes in treating complex perianal fistulas in SD rats. We established a rat model, divided rats with fistulas into the control and the exosome groups. We assessed treatment efficacy through ultrasound, clinical observations, and histopathological analysis. We also evaluated the activation of the HIF-1α/TGF-β/Smad signaling pathway via PCR and Western blot and assessed serological markers for HIF-1α and inflammatory indices through ELISA. We analyzed gut microbiota and the systemic metabolic environment via untargeted metabolomics.

RESULTS

The hUCMSCs-Exo effectively promoted healing of wound, regulated the immune balance enhanced collagen synthesis and angiogenesis in the perianal fistulas model of rats, and regulated the gut microbiota and metabolomic profiles. Results of PCR and Western blot analyses indicated that the exosomes activated HIF-1α/TGF-β/Smad signaling pathways. To the dosages tested, the 10ug/100ul concentration (medium dose) was found to be the most effective to the treatment of complex perianal fistulas.

CONCLUSIONS

The hUCMSCs-Exo significantly promoted the healing of wound in perianal fistulas of rats and demonstrated higher safety. The underlying mechanism facilitating the healing process was likely associated with the activation of the HIF-1α/TGF-β/Smad signaling pathway.

The Role of Extracellular Vesicles in the Development and Treatment of Psoriasis: Narrative Review

Psoriasis is a chronic inflammatory polygenic disease with significant impacts on skin and joints, leading to substantial treatment challenges and healthcare costs. The quest for novel therapeutic avenues has recently highlighted extracellular vesicles (EVs) due to their potential as biomarkers and therapeutic agents in autoimmune diseases, including psoriasis. EVs are nano-sized, lipid membrane-bound particles secreted by cells that have emerged as promising tools for targeted drug delivery, owing to their unique structure. This review delves into how EVs, either as mediators of cell communication or via their cargo (such as miRNA), directly participate in the pathology of psoriasis, influencing processes such as immune regulation, cell proliferation, and differentiation. Furthermore, this review explores the innovative application of EVs in psoriasis treatment, both as direct therapeutic agents and as vehicles for drug delivery, offering a novel approach to overcoming the current treatment limitations.

miR-21-5p Enriched Exosomes from Human Embryonic Stem Cells Promote Osteogenesis via YAP1 Modulation

Purpose

To investigate the osteogenic potential of human embryonic stem cell-derived exosomes (hESC-Exos) and their effects on the differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs).

Methods

hESC-Exos were isolated and characterized using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. hUCMSCs were cultured with hESC-Exos to assess osteogenic differentiation through alizarin red staining, quantitative PCR (qPCR), and Western blotting. miRNA profiling of hESC-Exos was performed using miRNA microarray analysis. In vivo bone regeneration was evaluated using an ovariectomized rat model with bone defects treated with exosome-loaded scaffolds.

Results

hESC-Exos significantly promoted the osteogenic differentiation of hUCMSCs, as evidenced by increased alizarin red staining and the upregulation of osteogenesis-related genes and proteins (ALP, RUNX2, OCN). miRNA analysis revealed that miR-21-5p is a key regulator that targets YAP1 and activates the Wnt/β-catenin signaling pathway. In vivo, hESC-Exos enhanced bone repair in ovariectomized rats, as demonstrated by increased bone mineral density and improved bone microarchitecture compared to those in controls.

Conclusion

hESC-Exos exhibit significant osteogenic potential by promoting the differentiation of hUCMSCs and enhancing bone regeneration in vivo. This study revealed that the miR-21-5p-YAP1/β-catenin axis is a critical pathway, suggesting that the use of hESC-Exos is a promising therapeutic strategy for bone regeneration and repair.

Extracellular derivatives for bone metabolism

BACKGROUND

Bone metabolism can maintain the normal homeostasis and function of bone tissue. Once the bone metabolism balance is broken, it will cause osteoporosis, osteoarthritis, bone defects, bone tumors, or other bone diseases. However, such orthopedic diseases still have many limitations in clinical treatment, such as drug restrictions, drug tolerance, drug side effects, and implant rejection.

AIM OF REVIEW

In complex bone therapy and bone regeneration, extracellular derivatives have become a promising research focus to solve the problems of bone metabolic diseases. These derivatives, which include components such as extracellular matrix, growth factors, and extracellular vesicles, have significant therapeutic potential. It has the advantages of good biocompatibility, low immune response, and dynamic demand for bone tissue. The purpose of this review is to provide a comprehensive perspective on extracellular derivatives for bone metabolism and elucidate the intrinsic properties and versatility of extracellular derivatives. Further discussion of them as innovative advanced orthopedic materials for improving the effectiveness of bone therapy and regeneration processes.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this review, we first listed the types and functions of three extracellular derivatives. Then, we discussed the effects of extracellular derivatives of different cell sources on bone metabolism. Subsequently, we collected applications of extracellular derivatives in the treatment of bone metabolic diseases and summarized the advantages and challenges of extracellular derivatives in clinical applications. Finally, we prospected the extracellular derivatives in novel orthopedic materials and clinical applications. We hope that the comprehensive understanding of extracellular derivatives in bone metabolism will provide new solutions to bone diseases.

Nature's carriers: leveraging extracellular vesicles for targeted drug delivery

With the rapid development of drug delivery systems, extracellular vesicles (EVs) have emerged as promising stars for improving targeting abilities and realizing effective delivery. Numerous studies have shown when compared to conventional strategies in targeted drug delivery (TDD), EVs-based strategies have several distinguished advantages besides targeting, such as participating in cell-to-cell communications and immune response, showing high biocompatibility and stability, penetrating through biological barriers, etc. In this review, we mainly focus on the mass production of EVs including the challenges and strategies for scaling up EVs production in a cost-effective and reproducible manner, the loading and active targeting methods, and examples of EVs as vehicles for TDD in consideration of potential safety and regulatory issues associated. We also conclude and discuss the rigor and reproducibility of EVs production, the current research status of the application of EVs-based strategies to targeted drug delivery, clinical conversion prospects, and existing chances and challenges.

Emerging technologies in regenerative medicine: The future of wound care and therapy

Wound healing, an intricate biological process, comprises orderly phases of simple biological processed including hemostasis, inflammation, angiogenesis, cell proliferation, and ECM remodeling. The regulation of the shift in these phases can be influenced by systemic or environmental conditions. Any untimely transitions between these phases can lead to chronic wounds and scarring, imposing a significant socio-economic burden on patients. Current treatment modalities are largely supportive in nature and primarily involve the prevention of infection and controlling inflammation. This often results in delayed healing and wound complications. Recent strides in regenerative medicine and tissue engineering offer innovative and patient-specific solutions. Mesenchymal stem cells (MSCs) and their secretome have gained specific prominence in this regard. Additionally, technologies like tissue nano-transfection enable in situ gene editing, a need-specific approach without the requirement of complex laboratory procedures. Innovating approaches like 3D bioprinting and ECM bioscaffolds also hold the potential to address wounds at the molecular and cellular levels. These regenerative approaches target common healing obstacles, such as hyper-inflammation thereby promoting self-recovery through crucial signaling pathway stimulation. The rationale of this review is to examine the benefits and limitations of both current and emerging technologies in wound care and to offer insights into potential advancements in the field. The shift towards such patient-centric therapies reflects a paradigmatic change in wound care strategies.

The Opportunities and Challenges of Mesenchymal Stem Cells-Derived Exosomes in Theranostics and Regenerative Medicine

Cell-secreted nanovesicles of endosomal origin, called exosomes, are vital for mediating intracellular communication. As local or distal transporters of intracellular cargo, they reflect the unique characteristics of secretory cells and establish cell-specific interactions via characteristic surface proteins and receptors. With the advent of rapid isolation, purification, and identification techniques, exosomes have become an attractive choice for disease diagnosis (exosomal content as biomarkers), cell-free therapy, and tissue regeneration. Mesenchymal stem cell (MSC)-derived exosomes (MSC-exosomes) display angiogenic, immune-modulatory, and other therapeutic effects crucial for cytoprotection, ischemic wound repair, myocardial regeneration, etc. The primary focus of this review is to highlight the widespread application of MSC-exosomes in therapeutics, theranostics, and tissue regeneration. After a brief introduction of exosome properties, biogenesis, isolation, and functions, recent studies on therapeutic and regenerative applications of MSC-exosomes are described, focusing on bone, cartilage, periodontal, cardiovascular, skin, and nerve regeneration. Finally, the review highlights the theranostic potential of exosomes followed by challenges, summary, and outlook.

Exosomes from mesenchymal stem cells: Potential applications in wound healing

Wound healing is a continuous and complex process regulated by multiple factors, which has become an intractable clinical burden. Mesenchymal stem cell-derived exosomes (MSC-exos) possess low immunogenicity, easy preservation, and potent bioactivity, which is a mirror to their parental cells MSC-exos are important tools for regulating the biological behaviors of wound healing-associated cells, including fibroblasts, keratinocytes, immune cells, and endothelial cells. MSC-exos accelerate the wound healing process at cellular and animal levels by modulating inflammatory responses, promoting collagen deposition and vascularization. MSC-exos accelerate wound healing at the cellular and animal levels by modulating inflammatory responses and promoting collagen deposition and vascularization. This review summarizes the roles and mechanisms of MSC-exos originating from various sources in promoting the healing efficacy of general wounds, diabetic wounds, burn wounds, and healing-related scars. It also discusses the limitations and perspectives of MSC-exos in wound healing, in terms of exosome acquisition, mechanistic complexity, and exosome potentiation modalities. A deeper understanding of the properties and functions of MSC-exos is beneficial to advance the therapeutic approaches for achieving optimal wound healing.

Amelioration of full-thickness cutaneous wound healing using stem cell exosome and zinc oxide nanoparticles in rats

Background

Wound healing is a complex procedure that requires the coordination of several factors, so this study aimed to assess the zinc oxide nanoparticles' regenerated effect and stem cell exosomes on full-thickness wounds in rats.

Methods

Seventy-two Wistar male rats were subjected to a full-thickness skin defect (20 mm2) on the dorsal surface of each rat between two shoulder joints. The rats were randomized into four groups (18/group) according to wound treatments. The wounds were irrigated with normal saline (Control group), or the wound's edges were subcutaneously injected daily with 0.3 ml of exosome (Exo-group), or 1 ml of zinc oxide nanoparticles (ZnO2-NPs group), or 0.3 ml of exosome in combined with 1 ml of zinc oxide nanoparticles (Exo/ZnO2-NPs group). On the 7th, 14th, and 21st days post-wounding, the weight of the rats, the wound healing breaking strength, the wound size, and the contraction percent were evaluated. Six rats in each group were euthanized at each time point for histopathological, immunohistochemical examination of collagen, the levels of alpha-smooth muscle actin (α-SMA), and epidermal growth factor receptor (EGFR). additionally, the gene expression analysis of the relative renal nuclear factor erythroid 2-related factor2 (Nrf2 mRNA), Transforming growth factor beta-1 (TGFβ1), fibroblast growth factor-7 (FGF7), Transforming growth factor beta-1 (TGFβ1), Lysyl oxidase (LOX), and Vascular endothelial growth factor (VEGF) were applied.

Results

The Exo-group exhibited a significant decrease in wound size and a significant increase in wound contraction compared with other groups. Histopathologically evaluation during the three intervals revealed that the Exo-group had the highest collagen deposition area with a significant reduction of the granulation tissue. Moreover, upregulated gene expression profiles of the growth factors genes at all time points post-wounding.

Discussion

The exosomes-treated group revealed superior wound healing and contraction, with minimal inflammatory signs, higher angiogenesis, and myofibroblasts, and associated with higher growth factor expression genes compared to the other groups.

Conclusions

Exosome-based therapy demonstrates potential as a treatment method to promote and accelerate wound healing by modulating angiogenesis, re-epithelialization, collagen deposition, and gene expression profiles.

The Potential Role of Exosomes in Ocular Surface and Lacrimal Gland Regeneration

PURPOSE

Dry eye disease (DED), a multifactorial disease of the lacrimal system, manifests itself in patients with various symptoms such as itching, inflammation, discomfort and visual impairment. In its most severe forms, it results in the breakdown of the vital tissues of lacrimal functional unit and carries the risk of vision loss. Despite the frequency of occurrence of the disease, there are no effective curative treatment options available to date. Treatment using stem cells and its secreted factors could be a promising approach in the regeneration of damaged tissues of ocular surface. The treatment using secreted factors as well as extracellular vesicles has been demonstrated beneficial effects in various ocular surface diseases. This review provides insights on the usage of stem cell derived exosomes as a promising therapy against LG dysfunction induced ADDE for ocular surface repair.

METHODS

In order to gain an overview of the existing research in this field, literature search was carried out using the PubMed, Medline, Scopus and Web of Science databases. This review is based on 164 publications until June 2024 and the literature search was carried out using the key words "exosomes", "lacrimal gland regeneration", "exosomes in lacrimal dysfunction".

RESULTS

The literature and studies till date suggest that exosomes and other secreted factors from stem cells have demonstrated beneficial effects on damaged ocular tissues in various ocular surface diseases. Exosomal cargo plays a crucial role in regenerating tissues by promoting homeostasis in the lacrimal system, which is often compromised in severe cases of dry eye disease. Exosome therapy shows promise as a regenerative therapy, potentially addressing the lack of effective curative treatments available for patients with dry eye disease.

CONCLUSION

Stem cell-derived exosomes represent a promising, innovative approach as a new treatment option for ADDE. By targeting lacrimal gland dysfunction and enhancing ocular surface repair, exosome therapy offers potential for significant advances in dry eye disease management. Future research is needed to refine the application of this therapy, optimize delivery methods, and fully understand its long-term efficacy in restoring ocular health.

Mesoporous bioactive glass-enhanced MSC-derived exosomes promote bone regeneration and immunomodulation in vitro and in vivo

BACKGROUND

Exosomes produced by mesenchymal stem cells (MSCs) have vascular generative properties and are considered new effective candidates for the treatment of bone defects as alternatives to cell therapy. Improving the pro-regenerative function and efficacy of exosomes has been a popular research topic in the field of orthopaedics.

METHODS

We prepared mesoporous bioactive glass (mBG) microspheres via the template method. The ionic products of mBGs used to treat MSCs were extracted, and the effects of exosomes secreted by MSCs on osteoblast (OB) and macrophage (MP) behaviour and bone defect repair were observed in vivo (Micro-CT, H&E, Masson, and immunofluorescence staining for BMP2, COL1, VEGF, CD31, CD163, and iNOS).

RESULTS

The mBG spheres were successfully prepared, and the Exo-mBG were isolated and extracted. Compared with those in the blank and Exo-Con groups, the proliferation and osteogenic differentiation of OBs in the Exo-mBG group were significantly greater. For example, on Day 7, OPN gene expression in the Ctrl-Exo group was 3.97 and 2.83 times greater than that in the blank and Exo-mBG groups, respectively. In a cranial defect rat model, Exo-mBG promoted bone tissue healing and angiogenesis, increased M2 macrophage polarisation and inhibited M1 macrophage polarisation, as verified by micro-CT, H&E staining, Masson staining and immunofluorescence staining. These effects may be due to the combination of a higher silicon concentration and a higher calcium-to-phosphorus ratio in the mBG ionic products.

CONCLUSION

This study provides insights for the application of exosomes in cell-free therapy and a new scientific basis and technical approach for the utilisation of MSC-derived exosomes in bone defect repair.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

Our study demonstrated that exosomes produced by mBG-stimulated MSCs have excellent in vitro and in vivo bone-enabling and immunomodulatory functions and provides insights into the use of exosomes in clinical cell-free therapies.

Generation of CRISPR/Cas9 modified human iPSC line with correction of heterozygous mutation in exon 6 of the CaSR gene

The calcium-sensing receptor (CaSR) gene encodes a cell membrane G protein-coupled receptor (GPCR) which has a key role in maintaining the extracellular Ca2+ homeostasis. We aimed at correcting the compound heterozygous mutation in the 6th [c.1656delA, p.I554SfsX73] and 7th [c.2217 T > A, p.C739X] exons of the CASR gene which the original patient-derived iPSC line had. The mutation is associated with neonatal severe primary hyperparathyroidism of the patient. We generated and characterized a CRISP/Cas9-edited hiPSC line with the restored sequence in the sixth exon of the CASR gene, bearing only heterozygous mutation in the 7th exon. The results showed that the new genetically modified cell line has karyotype without abnormalities, typical hiPSCs morphology, characteristic expression of pluripotency markers, and ability to develop into three germ layers, and differentiates in chondrogenic, adipogenic, osteogenic directions. This new cell line will complement the existing pool of CaSR-mutated cell lines, a valuable resource for in-depth understanding of neonatal severe primary hyperparathyroidism. This will allow further exploration of the application of pharmacological drugs in the context of personalized medicine to correct Ca-homeostasis disorders.

Exosomes Induce Crosstalk Between Multiple Types of Cells and Cardiac Fibroblasts: Therapeutic Potential for Remodeling After Myocardial Infarction

Recanalization therapy can significantly improve the prognosis of patients with acute myocardial infarction (AMI). However, infarction or reperfusion-induced cardiomyocyte death, immune cell infiltration, fibroblast proliferation, and scarring formation lead to cardiac remodeling and gradually progress to heart failure or arrhythmia, resulting in a high mortality rate. Due to the inability of cardiomyocytes to regenerate, the healing of infarcted myocardium mainly relies on the formation of scars. Cardiac fibroblasts, as the main effector cells involved in repair and scar formation, play a crucial role in maintaining the structural integrity of the heart after MI. Recent studies have revealed that exosome-mediated intercellular communication plays a huge role in myocardial repair and signaling transduction after myocardial infarction (MI). Exosomes can regulate the biological behavior of fibroblasts by activating or inhibiting the intracellular signaling pathways through their contents, which are derived from cardiomyocytes, immune cells, endothelial cells, mesenchymal cells, and others. Understanding the interactions between fibroblasts and other cell types during cardiac remodeling will be the key to breakthrough therapies. This review examines the role of exosomes from different sources in the repair process after MI injury, especially the impacts on fibroblasts during myocardial remodeling, and explores the use of exosomes in the treatment of myocardial remodeling after MI.

Enhancing bone regeneration and immunomodulation via gelatin methacryloyl hydrogel-encapsulated exosomes from osteogenic pre-differentiated mesenchymal stem cells

Mesenchymal stem cell-derived exosomes (MSC-Exos) have emerged as promising candidates for cell-free therapy in tissue regeneration. However, the native osteogenic and angiogenic capacities of MSC-Exos are often insufficient to repair critical-sized bone defects, and the underlying immune mechanisms remain elusive. Furthermore, achieving sustained delivery and stable activity of MSC-Exos at the defect site is essential for optimal therapeutic outcomes. Here, we extracted exosomes from osteogenically pre-differentiated human bone marrow mesenchymal stem cells (hBMSCs) by ultracentrifugation and encapsulated them in gelatin methacryloyl (GelMA) hydrogel to construct a composite scaffold. The resulting exosome-encapsulated hydrogel exhibited excellent mechanical properties and biocompatibility, facilitating sustained delivery of MSC-Exos. Osteogenic pre-differentiation significantly enhanced the osteogenic and angiogenic properties of MSC-Exos, promoting osteogenic differentiation of hBMSCs and angiogenesis of human umbilical vein endothelial cells (HUVECs). Furthermore, MSC-Exos induced polarization of Raw264.7 cells from a pro-inflammatory phenotype to an anti-inflammatory phenotype under simulated inflammatory conditions, thereby creating an immune microenvironment conducive to osteogenesis. RNA sequencing and bioinformatics analysis revealed that MSC-Exos activate the p53 pathway through targeted delivery of internal microRNAs and regulate macrophage polarization by reducing DNA oxidative damage. Our study highlights the potential of osteogenic exosome-encapsulated composite hydrogels for the development of cell-free scaffolds in bone tissue engineering.

Unveiling the Immunomodulatory and regenerative potential of iPSC-derived mesenchymal stromal cells and their extracellular vesicles

Induced pluripotent stem cell (iPSC)-derived mesenchymal stromal cells (iMSCs) offer a promising alternative to primary mesenchymal stromal cells (MSCs) and their derivatives, particularly extracellular vesicles (EVs), for use in advanced therapy medicinal products. In this study we evaluated the immunomodulatory and regenerative potential of iMSCs as well as iMSC-EVs, alongside primary human umbilical cord-derived mesenchymal stromal cells (hUCMSCs). Our findings demonstrate that iMSCs exhibit comparable abilities to hUCMSCs in regulating lymphocyte proliferation and inducing an anti-inflammatory phenotype in monocytes. We also observed decreased TNFα levels and increased IL-10 induction, indicating a potential mechanism for their immunomodulatory effects. Furthermore, iMSC-EVs also showed effective immunomodulation by inhibiting T cell proliferation and inducing macrophage polarization similar to their parental cells. Additionally, iMSC-EVs exhibited pro-regenerative potential akin to hUCMSC-EVs in in vitro scratch assays. Notably, priming iMSCs with pro-inflammatory cytokines significantly enhanced the immunomodulatory potential of iMSC-EVs. These results underscore the considerable promise of iMSCs and iMSCs-EVs as an alternate source for MSC-derived therapeutics, given their potent immunomodulatory and regenerative properties.

Global trends in the clinical utilization of exosomes in dermatology: a bibliometric analysis

The arena of exosomal research presents substantial emerging prospects for clinical dermatology applications. This investigation conducts a thorough analysis of the contemporary global research landscape regarding exosomes and their implications for dermatological applications over the preceding decade. Employing bibliometric methodologies, this study meticulously dissects the knowledge framework and identifies dynamic trends within this specialized field. Contemporary scholarly literature spanning the last decade was sourced from the Web of Science Core Collection (WoSCC) database. Subsequent to retrieval, both quantitative and visual analyses of the pertinent publications were performed utilizing the analytical software tools VOSviewer and Citespace. A comprehensive retrieval yielded 545 scholarly articles dated from January 1, 2014, to December 31, 2023. Leading the research forefront are institutions such as Shanghai Jiao Tong University, The Fourth Military Medical University, and Sun Yat-sen University. The most prolific contributors on a national scale are China, the United States, and South Korea. Among the authors, Zhang Bin, Zhang Wei, and Zhang Yan emerge as the most published, with Zhang Bin also achieving the distinction of being the most cited. The International Journal of Molecular Sciences leads in article publications, whereas Stem Cell Research & Therapy holds the pinnacle in citation rankings. Theranostics boasts the highest impact factor among the periodicals. Current research hotspots in this area include Adipose mesenchymal stem cell-derived exosomes(ADSC-Exos), diabetic skin wounds, cutaneous angiogenesis, and the combination of biomaterials and exosomes. This manuscript constitutes the inaugural comprehensive bibliometric analysis that delineates the prevailing research trends and advancements in the clinical application of exosomes in dermatology. These analyses illuminate the contemporary research focal points and trajectories, providing invaluable insights that will inform further exploration within this domain.

Exosomes in nanomedicine: a promising cell-free therapeutic intervention in burn wounds

Burn injuries are serious injuries that have a big impact on a person's health and can even cause death. Incurring severe burns can incite an immune response and inflammation within the body, alongside metabolic changes. It is of utmost importance to grasp the fact that the effects of the burn injury extend beyond the body, affecting the mind and overall well-being. Burn injuries cause long-lasting changes that need to be taken care of in order to improve their quality of life. The intricate process of skin regeneration at the site of a burn wound involves a complex and dynamic interplay among diverse cells, growth factors, nerves, and blood vessels. Exciting opportunities have arisen in the field of stem cells and regenerative medicine, allowing us to explore the development of cell-free-based alternatives that can aid in the treatment of burn injuries. These cell-free-based therapies have emerged as a promising facet within regenerative medicine. Exosomes, also referred to as naturally occurring nanoparticles, are small endosome-derived vesicles that facilitate the delivery of molecular cargo between the cells, thus allowing intercellular communication. The knowledge gained in this field has continued to support their therapeutic potential, particularly in the domains of wound healing and tissue regeneration. Notably, exosomes derived from mesenchymal stem cells (MSCs) can be safely administered in the system, which is then adeptly uptaken and internalized by fibroblasts/epithelial cells, subsequently accelerating essential processes such as migration, proliferation, and collagen synthesis. Furthermore, exosomes released by immune cells, specifically macrophages, possess the capability to modulate inflammation and effectively diminish it in adjacent cells. Exosomes also act as carriers when integrated with a scaffold, leading to scarless healing of cutaneous wounds. This comprehensive review examines the role of exosomes in burn wound healing and their potential utility in regeneration and repair.

Trinitroglycerin-loaded chitosan nanogels accelerate angiogenesis in wound healing process

Trinitroglycerin (TNG) with remarkable angiogenic, antibacterial, and antioxidative activity is a promising candidate to govern wound healing capacity. However, its clinical administration is limited due to associated complications and NO short half-life. In the current study, TNG-loaded chitosan nanogels (TNG-Ngs) were examined in-vitro and in-vivo to gain insight into their clinical application. We prepared TNG-Ngs and characterized their physiochemical properties. The potential of TNG-Ngs was assessed using biocompatibility, scratch assay, and a full-thickness skin wounds model, followed by histopathological and immunohistochemistry examinations. TNG-Ngs particle size 96 ± 18 and definite size distribution histogram. The loading capacity (LC) and encapsulation efficiency (EE) of prepared TNG-Ngs were 70.2 % and 2.1 %, respectively. The TNG-Ngs samples showed enhanced migration of HUVECs with no apparent cytotoxicity. The topical use of TNG-Ngs200 on the wounds revealed a complete wound closure ratio, skin component formation, less scar width, remarkable granulation tissue, promoted collagen deposition, and enhanced the relative mean density of α-SMA and CD31. TNG-Ngs accelerated wound healing by promoting collagen deposition and angiogenic activity, as well as reducing inflammation. The findings indicated that TNG-Ngs is expected to be well vascularized in the wound area and to be more effective in topical therapy.

Target specification and therapeutic potential of extracellular vesicles for regulating corneal angiogenesis, lymphangiogenesis, and nerve repair

Extracellular vesicles, including exosomes, are small extracellular vesicles that range in size from 30 nm to 10 μm in diameter and have specific membrane markers. They are naturally secreted and are present in various bodily fluids, including blood, urine, and saliva, and through the variety of their internal cargo, they contribute to both normal physiological and pathological processes. These processes include immune modulation, neuronal synapse formation, cell differentiation, cancer metastasis, angiogenesis, lymphangiogenesis, progression of infectious disease, and neurodegenerative disorders like Alzheimer's and Parkinson's disease. In recent years, interest has grown in the use of exosomes as a potential drug delivery system for various diseases and injuries. Importantly, exosomes originating from a patient's own cells exhibit minimal immunogenicity and possess remarkable stability along with inherent and adjustable targeting capabilities. This review explores the roles of exosomes in angiogenesis, lymphangiogenesis, and nerve repair with a specific emphasis on these processes within the cornea. Furthermore, it examines exosomes derived from specific cell types, discusses the advantages of exosome-based therapies in modulating these processes, and presents some of the most established methods for exosome isolation. Exosome-based treatments are emerging as potential minimally invasive and non-immunogenic therapies that modulate corneal angiogenesis and lymphangiogenesis, as well as enhance and accelerate endogenous corneal nerve repair.

Engineered mesenchymal stem cell-derived extracellular vesicles: kill tumors and protect organs

Solid tumors cause 90% of cancers and remain the primary cause of mortality. However, treating solid tumors presents significant challenges due to the complex tumor microenvironment and drug resistance, leading to inadequate treatment targeting and severe side effects. Surgery, radiotherapy, and chemotherapy Although it is an effective method for the treatment of solid tumors, it can lead to organ dysfunction and affect patient prognosis. Therefore, it is imperative to improve treatment precision and organ repair capabilities to manage solid tumors. Mesenchymal stem cell extracellular vesicles (MSC-EVs) have wide application prospects as a new agent for solid tumor therapy. Firstly, MSC-EVs is a derivative of MSCs. It has the function of promoting tissue regeneration by inducing dedifferentiation in surviving cells after injury. Additionally, MSC-EVs offer unique advantages in terms of safety, stability and penetrability, making them a promising extracellular therapeutic modality for solid tumor treatment. Finally, MSC-EVs are able to enhance therapeutic efficacy through engineering strategies. To sum up, this review takes MSC-EVs as its object. And then we discuss recent advancements and engineering strategies in the use of MSC-EVs for soid tumor suppression. This review aims to inspire researchers to devise a new method for effectively treat solid tumors.

Advancements in diabetic foot ulcer research: Focus on mesenchymal stem cells and their exosomes

Diabetes represents a widely acknowledged global public health concern. Diabetic foot ulcer (DFU) stands as one of the most severe complications of diabetes, its occurrence imposing a substantial economic burden on patients, profoundly impacting their quality of life. Despite the deepening comprehension regarding the pathophysiology and cellular as well as molecular responses of DFU, the current therapeutic arsenal falls short of efficacy, failing to offer a comprehensive remedy for deep-seated chronic wounds and microvascular occlusions. Conventional treatments merely afford symptomatic alleviation or retard the disease's advancement, devoid of the capacity to effectuate further restitution of compromised vasculature and nerves. An escalating body of research underscores the prominence of mesenchymal stem cells (MSCs) owing to their paracrine attributes and anti-inflammatory prowess, rendering them a focal point in the realm of chronic wound healing. Presently, MSCs have been validated as a highly promising cellular therapeutic approach for DFU, capable of effectuating cellular repair, epithelialization, granulation tissue formation, and neovascularization by means of targeted differentiation, angiogenesis promotion, immunomodulation, and paracrine activities, thereby fostering wound healing. The secretome of MSCs comprises cytokines, growth factors, chemokines, alongside exosomes harboring mRNA, proteins, and microRNAs, possessing immunomodulatory and regenerative properties. The present study provides a systematic exposition on the etiology of DFU and elucidates the intricate molecular mechanisms and diverse functionalities of MSCs in the context of DFU treatment, thereby furnishing pioneering perspectives aimed at harnessing the therapeutic potential of MSCs for DFU management and advancing wound healing processes.

Direct and cell-mediated EV-ECM interplay

Extracellular vesicles (EV) are a heterogeneous group of lipid particles excreted by cells. They play an important role in regeneration, development, inflammation, and cancer progression, together with the extracellular matrix (ECM), which they constantly interact with. In this review, we discuss direct and indirect interactions of EVs and the ECM and their impact on different physiological processes. The ECM affects the secretion of EVs, and the properties of the ECM and EVs modulate EVs' diffusion and adhesion. On the other hand, EVs can affect the ECM both directly through enzymes and indirectly through the modulation of the ECM synthesis and remodeling by cells. This review emphasizes recently discovered types of EVs bound to the ECM and isolated by enzymatic digestion, including matrix-bound nanovesicles (MBV) and tissue-derived EV (TiEV). In addition to the experimental studies, computer models of the EV-ECM-cell interactions, from all-atom models to quantitative pharmacology models aiming to improve our understanding of the interaction mechanisms, are also considered. STATEMENT OF SIGNIFICANCE: Application of extracellular vesicles in tissue engineering is an actively developing area. Vesicles not only affect cells themselves but also interact with the matrix and change it. The matrix also influences both cells and vesicles. In this review, different possible types of interactions between vesicles, matrix, and cells are discussed. Furthermore, the united EV-ECM system and its regulation through the cellular activity are presented.

In Situ Triggered Self-Contraction Bioactive Microgel Assembly Accelerates Diabetic Skin Wound Healing by Activating Mechanotransduction and Biochemical Pathway

Chronic nonhealing skin wounds, characterized by reduced tissue contractility and inhibited wound cell survival under hyperglycemia and hypoxia, present a significant challenge in diabetic care. Here, an advanced self-contraction bioactive core-shell microgel assembly with robust tissue-adhesion (SMART-EXO) is introduced to expedite diabetic wound healing. The SMART-EXO dressing exhibits strong, reversible adhesion to damaged tissue due to abundant hydrogen and dynamic coordination bonds. Additionally, the core-shell microgel components and dynamic coordination bonds provide moderate rigidity, customizable self-contraction, and an interlinked porous architecture. The triggered in situ self-contraction of the SMART-EXO dressing enables active, tunable wound contraction, activating mechanotransduction in the skin and promoting the optimal fibroblast-to-myofibroblast conversion, collagen synthesis, and angiogenesis. Concurrently, the triggered contraction of SMART-EXO facilitates efficient loading and on-demand release of bioactive exosomes, contributing to re-epithelialization and wound microenvironment regulation in diabetic mice. RNA-seq results reveal the activation of critical signaling pathways associated with mechanosensing and exosome regulation, highlighting the combined biomechanical and biochemical mechanisms. These findings underscore SMART-EXO as a versatile, adaptable solution to the complex challenges of diabetic wound care.

Placenta-derived mesenchymal stem cells promote diabetic wound healing via exosomal protein interaction networks

There is a lack of effective treatment options for diabetic refractory wounds, which presents a critical clinical issue that needs to be addressed urgently. Our research has demonstrated that human placenta-derived mesenchymal stem cells (plaMSCs) facilitate the migration and proliferation of HaCat cells, thereby enhancing diabetic wound healing primarily via the exosomes derived from plaMSCs (plaMSCs-Ex). Using label-free proteomics, plaMSCs and their exosomes were analysed for proteome taxonomic content in order to explore the underlying effective components mechanism of plaMSCs-Ex in diabetic wound healing. Differentially expressed proteins enriched in plaMSCs-Ex were identified and underwent bioinformatics analysis including GO annotation, KEGG pathway enrichment, gene set enrichment analysis (GSEA) and protein-protein interaction analysis (PPI). Results showed that the proteins enriched in plaMSCs-Ex are significantly involved in extracellular matrix organisation, epithelium morphogenesis, cell growth, adhesion, proliferation and angiogenesis. PPI analysis filtered 2 wound healing-related clusters characterised by hub proteins such as POSTN, FN1, SPARC, TIMP1, SERPINE1, LRP1 and multiple collagens. In brief, the exosomal proteins derived from plaMSCs reveal diverse functions of regeneration and tissue remodelling based on proteomics analysis and potentially play a role in diabetic wound healing.