Exosomes from human adipose-derived mesenchymal stromal/stem cells accelerate angiogenesis in wound healing: implication of the EGR-1/lncRNA-SENCR/DKC1/VEGF-A axis

In Vitro Assessment of Chitosan-PEG Hydrogels Enriched with MSCs-Exosomes for Enhancing Wound Healing

Regenerating skin tissue remains a major challenge in medical science, especially due to the risk of scarring and prolonged healing, which becomes even more complicated in people with diabetes. Recent advancements have led to the creation of therapeutic dressings incorporating drug-delivery systems to tackle these issues. Exosomes (Exos) derived from mesenchymal stem cells (MSCs) have gained significant attention for mediating therapy without directly using cells, thanks to their natural anti-inflammatory and tissue repair properties mirroring those of MSCs. In this study, an advanced wound dressing combines chitosan (CS) and polyethylene glycol (PEG) hydrogel with adipose MSCs-derived Exos (ADMSCs-Exos). This composite, formed using a straightforward blending technique, is engineered to improve the healing process of severe skin injuries by steadily releasing Exos as the hydrogel degrades. The in vitro studies demonstrate that this hydrogel-exosome dressing greatly enhances endothelial cell migration, reduces oxidative stress, and promotes angiogenesis, crucial for effective wound healing. Additionally, real time-polymerase chain reaction (RT-PCR) analysis revealed significant upregulation of key genes involved in these processes, supporting the therapeutic potential of the hydrogel-Exo combination. These findings emphasize the potential of this hydrogel-Exos combination as an innovative and promising solution for advanced wound care.

Mesenchymal Stem Cell-Derived Exosomes: A Promising Therapeutic Strategy for Age-Related Diseases

The global increase in the aging population has led to a concurrent rise in the incidence of age-related diseases, posing substantial challenges to healthcare systems and affecting the well-being of the elderly. Identifying and securing effective treatments has become an urgent priority. In this context, mesenchymal stem cell-derived exosomes (MSC-Exos) have emerged as a promising and innovative modality in the field of anti-aging medicine, offering a multifaceted therapeutic approach. MSC-Exos demonstrate significant potential due to their immunomodulatory and anti-inflammatory properties, their ability to inhibit oxidative stress, and their reparative effects on senescent tissues. These attributes make them valuable in combating a range of conditions associated with aging, such as cardiovascular diseases, neurodegeneration, skin aging, and osteoarthritis. The integration of exosomes with membrane-penetrating peptides introduces a novel strategy for the delivery of biomolecules, surmounting traditional cellular barriers and enhancing therapeutic efficacy. This review provides a comprehensive synthesis of the current understanding of MSC-Exos, underscoring their role as a novel and potent therapeutic strategy against the intricate challenges of age-related diseases.

Non-coding RNAs in adipose-derived stem cell exosomes: Mechanisms, therapeutic potential, and challenges in wound healing

The treatment of complex wounds presents a significant clinical challenge due to the limited availability of standardized therapeutic options. Adipose-derived stem cell exosomes (ADSC-Exos) are promising for their capabilities to enhance angiogenesis, mitigate oxidative stress, modulate inflammatory pathways, support skin cell regeneration, and promote epithelialization. These exosomes deliver non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs, which facilitate collagen remodeling, reduce scar formation, and expedite wound healing. This study reviews the mechanisms, therapeutic roles, and challenges of non-coding RNA-loaded ADSC-Exos in wound healing and identifies critical directions for future research. It aims to provide insights for researchers into the potential mechanisms and clinical applications of ADSC-Exos non-coding RNAs in wound healing.

Small extracellular vesicles: the origins, current status, future prospects, and applications

Small extracellular vesicles (sEVs) are membrane-bound vesicles with a size of less than 200 nm, released by cells. Due to their relatively small molecular weight and ability to participate in intercellular communication, sEVs can serve not only as carriers of biomarkers for disease diagnosis but also as effective drug delivery agents. Furthermore, these vesicles are involved in regulating the onset and progression of various diseases, reflecting the physiological and functional states of cells. This paper introduces the classification of extracellular vesicles, with a focus on the extraction and identification of sEVs and their significant role in repair, diagnosis, and intercellular communication. Additionally, the paper addresses the engineering modification of sEVs to provide a reference for enhanced understanding and application.

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.

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 exosomal lncRNAs derived from stem cells in wound healing: focusing on mesenchymal stem cells

The self-renewal ability and multipotency of stem cells give them great potential for use in wound healing. Stem cell-derived exosomes, owing to their close biological resemblance to their parent cells, offer a more efficient, safer, and economical approach for facilitating cellular communication and interactions within different environments. This potential makes them particularly valuable in the treatment of both acute and chronic wounds, such as lacerations, burns, and diabetic ulcers. Long non-coding RNAs (lncRNAs) enclosed in exosomes, as one of the leading actors of these extracellular microvesicles, through interaction with miRNAs and regulation of various signaling pathways involved in inflammation, angiogenesis, cell proliferation, and migration, could heal the wounds. Exosome-derived lncRNAs from stem cells facilitate extracellular matrix remodeling through interaction between macrophages and fibroblasts. Moreover, alongside regulating the expression of inflammatory cytokines, controlling reactive oxygen species levels, and enhancing autophagic activity, they also modulate immune responses to support wound healing. Regulating the expression of genes and signaling pathways related to angiogenesis, by increasing blood supply and accelerating the delivery of essential substances to the wound environment, is another effect exosomal lncRNAs derived from stem cells for wound healing. These lncRNAs can also enhance skin wound healing by regulating homeostasis, increasing the proliferation and differentiation of cells involved in the wound-healing process, and enhancing fibroblast viability and migration to the injury site. Ultimately, exosome-derived lncRNAs from stem cells offer valuable and novel insights into the molecular mechanisms underlying improved wound healing. They can pave the way for potential therapeutic strategies, fostering further research for a better future. Meanwhile, exosomes derived from mesenchymal stem cells, due to their exceptional regenerative properties, as well as the lncRNAs derived from these exosomes, have emerged as one of the innovative tools in wound healing. This review article aims to narrate the cellular and molecular roles of exosome-derived lncRNAs from stem cells in enhancing wound healing with a focus on mesenchymal stem cells.

The role of lncRNA in the differentiation of adipose-derived stem cells: from functions to mechanism

Adipose-derived stem cells (ADSCs) have become one of the best seed cells widely studied and concerned in tissue engineering because of their rich sources and excellent multi-directional differentiation ability, which are expected to play a practical application role in tissue defect, osteoporosis, plastic surgery, and other fields. However, the differentiation direction of ADSCs is regulated by complex factors. Long non-coding RNAs (lncRNAs) are RNA molecules longer than 500 nucleotides that do not encode proteins and can act as signaling RNAs in response to intracellular and extracellular stimuli. Recently, accumulating evidence has revealed that lncRNAs could regulate the cell cycle and differentiation direction of ADSCs through various mechanisms, including histone modification, binding to RNA-binding proteins, and regulating the expression of miRNAs. Therefore, enriching and elucidating its mechanism of action as well as targeting lncRNAs to regulate ADSCs differentiation have potential prospects in tissue regeneration applications such as bone, blood vessels, and adipose. In this review, we summarize the role and mechanism of lncRNAs and its complexes in the multi-directional differentiation of ADSCs and discuss some potential approaches that can exert therapeutic effects on tissue defects by modulating the expression level of lncRNAs in ADSCs. Our work might provide some new research directions for the clinical applications of tissue engineering.

Exosomes derived from minor salivary gland mesenchymal stem cells: a promising novel exosome exhibiting pro-angiogenic and wound healing effects similar to those of adipose-derived stem cell exosomes

BACKGROUNDS

Minor salivary gland mesenchymal stem cells (MSGMSCs) can be easily extracted and have a broad range of sources. Applying exosomes to wounds is a highly promising method for promoting wound healing. Exosomes derived from different stem cell types have been proven to enhance wound healing, with adipose-derived stem cell (ADSC)-derived exosomes being the most extensively researched. Considering that MSGMSCs have advantages such as easier extraction compared to ADSCs, MSGMSCs should also be a very promising type of stem cell in exosome therapy. However, whether MSGMSC-derived exosomes (MSGMSC-exos) can promote wound healing and how they compare to ADSC-derived exosomes (ADSC-exos) in the wound healing process remain unclear.

MATERIALS

The effects of MSGMSC-exos and ADSC-exos on angiogenesis in wound healing were investigated in vitro using CCK-8, scratch assays, and tube formation assays. Subsequently, the promotion of wound healing by MSGMSC-exos and ADSC-exos was evaluated in vivo using a full-thickness wound defect model in mice. Immunohistochemistry was used to verify the effects of MSGMSC-exos and ADSC-exos on promoting collagen deposition, angiogenesis, and cell proliferation in the wound. Immunofluorescence staining was performed to investigate the role of MSGMSC-exos and ADSC-exos in modulating the inflammatory response in the wound. Furthermore, proteomic sequencing was conducted to investigate the functional similarities and differences between the proteomes of MSGMSC-exos and ADSC-exos, with key protein contents verified by ELISA.

RESULTS

MSGMSC-exos exhibited similar effects as ADSC-exos in promoting the migration, proliferation, and tube formation of human umbilical vein endothelial cells (HUVECs) in vitro, with a comparable dose-dependent effect. In vivo experiments confirmed that MSGMSC-exos have similar wound healing-promoting functions as ADSC-exos. MSGMSC-exos promoted the neovascularization and maturation of blood vessels in vivo at a level comparable to ADSC-exos. Despite MSGMSC-exos showing less collagen deposition than ADSC-exos, they exhibited stronger anti-scar formation and anti-inflammatory effects. Proteomic analysis revealed that the proteins promoting wound healing in both MSGMSC-exos and ADSC-exos were relatively conserved, with ITGB1 identified as a critical protein for angiogenesis. Further differential analysis revealed that the functions specifically enriched in MSGMSC-exos and ADSC-exos reflected the functions of their source tissue.

CONCLUSIONS

Our study confirms that MSGMSC-exos exhibit highly similar wound healing and angiogenesis-promoting functions compared to ADSC-exos, and the proteins involved in promoting wound healing in both are relatively conserved. Moreover, MSGMSC-exos show stronger anti-scar formation and anti-inflammatory effects than ADSC-exos. This suggests that MSGMSCs are a promising stem cell source with broad applications in wound healing treatment.

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.

NORAD accelerates skin wound healing through extracellular vesicle transfer from hypoxic adipose derived stem cells: miR-524-5p pathway and Pumilio protein mechanism

Skin wound healing is a multifaceted biological process that encompasses a variety of cell types and intricate signaling pathways. Recent research has uncovered that exosomes derived from adipose stem cells, commonly referred to as ADSC exosomes, play a crucial role in facilitating the healing process. Moreover, it has been demonstrated that an anoxic, or low-oxygen, environment significantly enhances the effectiveness of these exosomes in promoting skin repair. The primary objective of this study was to investigate the underlying mechanisms through which ADSC exosomes contribute to Skin wound healing, particularly by regulating the long non-coding RNA known as NORAD under hypoxic conditions. A significant focus of our research was to examine the interplay between the microRNA miR-524-5p and the Pumilio protein, as we aimed to understand how these molecular interactions might influence the overall healing process. In this study, ADSC exosomes were extracted by simulating hypoxia in vitro and their effects on the proliferation and migration of skin fibroblasts (FB) were evaluated. The expression levels of NORAD, miR-524-5p and Pumilio were analyzed by fluorescence quantitative PCR. Pumilio protein was silenced by siRNA technique to evaluate its role in ADSC exosome-mediated wound healing. The experimental results showed that under hypoxia conditions, NORAD levels in ADSC exosomes increased significantly and could effectively regulate the expression of miR-524-5p. After Pumilio protein silencing, the proliferation and migration ability of fibroblasts were significantly reduced, indicating that Pumilio protein played a role in the process of wound healing. By inhibiting miR-524-5p, the expression of Pumilio protein was restored, further confirming its regulatory mechanism.

The Angiogenic Repertoire of Stem Cell Extracellular Vesicles: Demystifying the Molecular Underpinnings for Wound Healing Applications

Stem cells-derived extracellular vesicles (SC-EVs) have emerged as promising therapeutic agents for wound repair, recapitulating the biological effects of parent cells while mitigating immunogenic and tumorigenic risks. These EVs orchestrate wound healing processes, notably through modulating angiogenesis-a critical event in tissue revascularization and regeneration. This study provides a comprehensive overview of the multifaceted mechanisms underpinning the pro-angiogenic capacity of EVs from various stem cell sources within the wound microenvironment. By elucidating the molecular intricacies governing their angiogenic prowess, we aim to unravel the mechanistic repertoire underlying their remarkable potential to accelerate wound healing. Additionally, methods to enhance the angiogenic effects of SC-EVs, current limitations, and future perspectives are highlighted, emphasizing the significant potential of this rapidly advancing field in revolutionizing wound healing strategies.

Research progress and application prospect of adipose-derived stem cell secretome in diabetes foot ulcers healing

Diabetic foot ulcers (DFUs) are chronic wounds and one of the most common complications of diabetes, imposing significant physical and mental burdens on patients due to their poor prognosis and treatment efficacy. Adipose-derived stem cells (ADSCs) have been proven to promote wound healing, with studies increasingly attributing these beneficial effects to their paracrine actions. Consequently, research on ADSC secretome as a novel and promising alternative for DFU treatment has been extensively conducted. This article provides a comprehensive review of the mechanisms underlying refractory DFU wounds, the secretome of ADSCs, and its role in promoting wound healing in diabetes foot ulcers. And the review aims to provide reliable evidence for the clinical application of ADSC secretome in the treatment of refractory DFU wounds.

The Myofibroblast Fate of Therapeutic Mesenchymal Stromal Cells: Regeneration, Repair, or Despair?

Mesenchymal stromal cells (MSCs) can be isolated from various tissues of healthy or patient donors to be retransplanted in cell therapies. Because the number of MSCs obtained from biopsies is typically too low for direct clinical application, MSC expansion in cell culture is required. However, ex vivo amplification often reduces the desired MSC regenerative potential and enhances undesired traits, such as activation into fibrogenic myofibroblasts. Transiently activated myofibroblasts restore tissue integrity after organ injury by producing and contracting extracellular matrix into scar tissue. In contrast, persistent myofibroblasts cause excessive scarring-called fibrosis-that destroys organ function. In this review, we focus on the relevance and molecular mechanisms of myofibroblast activation upon contact with stiff cell culture plastic or recipient scar tissue, such as hypertrophic scars of large skin burns. We discuss cell mechanoperception mechanisms such as integrins and stretch-activated channels, mechanotransduction through the contractile actin cytoskeleton, and conversion of mechanical signals into transcriptional programs via mechanosensitive co-transcription factors, such as YAP, TAZ, and MRTF. We further elaborate how prolonged mechanical stress can create persistent myofibroblast memory by direct mechanotransduction to the nucleus that can evoke lasting epigenetic modifications at the DNA level, such as histone methylation and acetylation. We conclude by projecting how cell culture mechanics can be modulated to generate MSCs, which epigenetically protected against myofibroblast activation and transport desired regeneration potential to the recipient tissue environment in clinical therapies.

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.

circ-Amotl1 in extracellular vesicles derived from ADSCs improves wound healing by upregulating SPARC translation

Aim

This study aims to explore the mechanism of circ- AMOT-like protein 1 (Amotl1) in extracellular vesicles (Evs) derived from adipose-derived stromal cells (ADSCs) regulating SPARC translation in wound healing process.

Methods

The morphology, wound healing rate of the wounds and Ki67 positive rate in mouse wound healing models were assessed by H&E staining and immunohistochemistry (IHC). The binding of IGF2BP2 and SPARC was verified by RNA pull-down. Adipose-derived stromal cells (ADSCs) were isolated and verified. The Evs from ADSCs (ADSC-Evs) were analyzed.

Results

Overexpression of SPARC can promote the wound healing process in mouse models. IGF2BP2 can elevate SPARC expression to promote the proliferation and migration of HSFs. circ-Amotl1 in ADSC-Evs can increase SPARC expression by binding IGF2BP2 to promote the proliferation and migration of HSFs.

Conclusion

ADSC-Evs derived circ-Amotl1 can bind IGF2BP2 to increase SPARC expression and further promote wound healing process.

Roles of long non-coding RNAs in angiogenesis-related diseases: Focusing on non-neoplastic aspects

Angiogenesis is a key process in organ and tissue morphogenesis, as well as growth during human development, and is coordinated by pro- and anti-angiogenic factors. When this balance is affected, the related physiological and pathological changes lead to disease. Long non-coding RNAs (lncRNAs) are an important class of non-coding RNAs that do not encode proteins, but play a dynamic role in regulating gene expression. LncRNAs have been reported to be extensively involved in angiogenesis, particularly tumor angiogenesis. The non-tumor aspects have received relatively little attention and summary, but there is a broad space for research and exploration on lncRNA-targeted angiogenesis in this area. In this review, we focus on lncRNAs in angiogenesis-related diseases other than tumors, such as atherosclerosis, myocardial infarction, stroke, diabetic complications, hypertension, osteoporosis, dermatosis, as well as, endocrine, neurological, and other systemic disorders. Moreover, multiple cell types have been implicated in lncRNA-targeted angiogenesis, but only endothelial cells have attracted widespread attention. Thus, we explore the roles of other cells. Finally, we summarize the potential research directions in the area of lncRNAs and angiogenesis that can be undertaken by combining cutting-edge technology and interdisciplinary research, which will provide new insights into the involvement of lncRNAs in angiogenesis-related diseases.

Probing the links: Long non-coding RNAs and NF-κB signalling in atherosclerosis

Atherosclerosis is a chronic inflammatory disease that involves the accumulation of lipids and immune cells in the arterial wall. NF-kB signaling is a key regulator of inflammation and is known to play a critical role in atherosclerosis. Recent studies have shown that lncRNAs can regulate NF-kB and contribute to the development and progression of atherosclerosis. Preliminary findings reveal significant alterations in the expression of specific lncRNAs in atherosclerotic lesions compared to healthy arterial tissue. Experimental evidence suggests that these dysregulated lncRNAs can influence the NF-kB pathway. By unravelling the crosstalk between lncRNAs and NF-kB signaling, this review aims to enhance our understanding of the molecular mechanisms underlying atherosclerosis. Identifying novel therapeutic targets and diagnostic markers may lead to developing interventions and management strategies for this prevalent cardiovascular disease. This review summarizes the current knowledge on the role of lncRNAs in NF-kB signaling in atherosclerosis and highlights their potential as therapeutic targets for this disease.

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.

Adipokines in atherosclerosis: unraveling complex roles

Adipokines are biologically active factors secreted by adipose tissue that act on local and distant tissues through autocrine, paracrine, and endocrine mechanisms. However, adipokines are believed to be involved in an increased risk of atherosclerosis. Classical adipokines include leptin, adiponectin, and ceramide, while newly identified adipokines include visceral adipose tissue-derived serpin, omentin, and asprosin. New evidence suggests that adipokines can play an essential role in atherosclerosis progression and regression. Here, we summarize the complex roles of various adipokines in atherosclerosis lesions. Representative protective adipokines include adiponectin and neuregulin 4; deteriorating adipokines include leptin, resistin, thrombospondin-1, and C1q/tumor necrosis factor-related protein 5; and adipokines with dual protective and deteriorating effects include C1q/tumor necrosis factor-related protein 1 and C1q/tumor necrosis factor-related protein 3; and adipose tissue-derived bioactive materials include sphingosine-1-phosphate, ceramide, and adipose tissue-derived exosomes. However, the role of a newly discovered adipokine, asprosin, in atherosclerosis remains unclear. This article reviews progress in the research on the effects of adipokines in atherosclerosis and how they may be regulated to halt its progression.

Advancements and Insights in Exosome-Based Therapies for Wound Healing: A Comprehensive Systematic Review (2018-June 2023)

Exosomes have shown promising potential as a therapeutic approach for wound healing. Nevertheless, the translation from experimental studies to commercially available treatments is still lacking. To assess the current state of research in this field, a systematic review was performed involving studies conducted and published over the past five years. A PubMed search was performed for English-language, full-text available papers published from 2018 to June 2023, focusing on exosomes derived from mammalian sources and their application in wound healing, particularly those involving in vivo assays. Out of 531 results, 148 papers were selected for analysis. The findings revealed that exosome-based treatments improve wound healing by increasing angiogenesis, reepithelization, collagen deposition, and decreasing scar formation. Furthermore, there was significant variability in terms of cell sources and types, biomaterials, and administration routes under investigation, indicating the need for further research in this field. Additionally, a comparative examination encompassing diverse cellular origins, types, administration pathways, or biomaterials is imperative. Furthermore, the predominance of rodent-based animal models raises concerns, as there have been limited advancements towards more complex in vivo models and scale-up assays. These constraints underscore the substantial efforts that remain necessary before attaining commercially viable and extensively applicable therapeutic approaches using exosomes.

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.

Natural exosome-like nanoparticles derived from ancient medicinal insect Periplaneta americana L. as a novel diabetic wound healing accelerator

Along with the recognized therapeutic outcomes of regenerative medicine, extracellular vesicles and their exosome subsets have become an alternative option for wound healing. Periplaneta americana L. (PA), an ancient and traditional medicinal insect, has been around for 300 million years, and displays magic formidable vitality and environmental adaptive ability. The linkage between intrinsic amputation regeneration feature and the acknowledged wound healing medicinal benefit of PA has never been revealed. Herein, inspired by the ability of exosomes to participate in the interkingdom communication, we explored whether this effect was ascribed to PA derived exosome-like nanoparticles (PA-ELNs). PA-ELNs were extracted by differential velocity centrifugation approach and characterized by DLS, NTA and TEM. Their cargoes were analyzed by LC-MS/MS proteomics and small RNA-seq analysis. The wound healing activity was verified in vivo and in vitro. PA-ELNs with a concentration of 2.33x10⁹±6.35x10⁷ particles/mL exhibited a lipid bilayer-bound membrane structure with an average size of 104.7 nm. Furthermore, the miRNA cargoes in PA-ELNs participate in some wound healing related signal pathways such as TGF-beta, mTOR, and autophagy. As expected, the in vitro tests indicated that PA-ELNs were apt to be internalized in HUVECs, L929 and RAW 264.7 cells and contributed to cell proliferation and migration. Most importantly, we demonstrated that the topical administration of PA-ELNs could remarkably accelerate wound healing in a diabetic mouse model, and was involved in anti-inflammatory, re-epithelialization and autophagy regulation. This study provides clear evidence for the first time that PA-ELNs, as diabetic wound healing accelerators, are the "bioactive code" of this ancient medicinal insect.

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.

Intravenous Infusion of Exosomes Derived from Human Adipose Tissue-Derived Stem Cells Promotes Angiogenesis and Muscle Regeneration: An Observational Study in a Murine Acute Limb Ischemia Model

INTRODUCTION

Recent studies have demonstrated that adipose tissue-derived stem cell (ADSC) transplantation could promote neoangiogenesis in various ischemic diseases. However, as whole cells, ADSCs have some disadvantages, such as shipping and storage issues, high costs, and controversies related to the fates of grafted cells in the recipients. Therefore, this study aimed to investigate the effects of intravenously infused exosomes purified from human ADSCs on ischemic disease in a murine hindlimb ischemia model.

METHODS

ADSCs were cultured in exosome-free medium for 48 h before the conditioned medium was collected for exosome isolation by ultracentrifugation. The murine ischemic hindlimb models were created by cutting and burning the hindlimb arteries. Exosomes were intravenously infused into murine models (ADSC-Exo group), with phosphate-buffered saline (PBS) used as a placebo (PBS group). Treatment efficacy was determined using a murine mobility assay (frequency of pedaling in water per 10 s), peripheral blood oxygen saturation (SpO₂ index), and the recovery of vascular circulation by trypan blue staining. The formation of blood vessels was shown by X-ray. Expression levels of genes related to angiogenesis and muscle tissue repair were quantified by quantitative reverse-transcription polymerase chain reaction. Finally, H&E staining was used to determine the histological structure of muscle in the treatment and placebo groups.

RESULTS

The rates of acute limb ischemia in the PBS and ADSC-Exo injection groups were 66% (9/16 mice) and 43% (6/14 mice), respectively. The mobility of the limbs 28 days after surgery was significantly different between the ADSC-Exo treatment group (41 ± 1 times/10 s) and the PBS group (24 ± 1 times/10 s; n = 3; p < 0.05). Peripheral blood oxygen saturation 21 days after treatment was 83.83% ± 2.02% in the PBS group and 83% ± 1.73% in the ADSC-Exo treatment group, and the difference was not statistically significant (n = 3, p > 0.05). On day 7 after treatment, the time required to stain the toes after trypan blue injection was 20.67 ± 12.5 s and 85 ± 7.09 s in the ADSC-Exo and PBS groups, respectively (n = 3, p < 0.05). On day 3 after the operation, the expression of genes promoting angiogenesis and muscle remodeling, such as Flk1, Vwf, Ang1, Tgfb1, Myod, and Myf5, was increased 4-8 times in the ADSC-Exo group compared with the PBS group. No mice in either group died during the experimental period.

CONCLUSIONS

These results revealed that intravenous infusion of human ADSC-derived exosomes is a safe and effective method to treat ischemic disease, especially hindlimb ischemia, by promoting angiogenesis and muscle regeneration.

Integrated printed BDNF-stimulated HUCMSCs-derived exosomes/collagen/chitosan biological scaffolds with 3D printing technology promoted the remodelling of neural networks after traumatic brain injury

The restoration of nerve dysfunction after traumatic brain injury (TBI) faces huge challenges due to the limited self-regenerative abilities of nerve tissues. In situ inductive recovery can be achieved utilizing biological scaffolds combined with endogenous human umbilical cord mesenchymal stem cells (HUCMSCs)-derived exosomes (MExos). In this study, brain-derived neurotrophic factor-stimulated HUCMSCs-derived exosomes (BMExos) were composited with collagen/chitosan by 3D printing technology. 3D-printed collagen/chitosan/BMExos (3D-CC-BMExos) scaffolds have excellent mechanical properties and biocompatibility. Subsequently, in vivo experiments showed that 3D-CC-BMExos therapy could improve the recovery of neuromotor function and cognitive function in a TBI model in rats. Consistent with the behavioural recovery, the results of histomorphological tests showed that 3D-CC-BMExos therapy could facilitate the remodelling of neural networks, such as improving the regeneration of nerve fibres, synaptic connections and myelin sheaths, in lesions after TBI.