Application of ADSCs and their Exosomes in Scar Prevention

Hypoxia-regulated miR-103-3p/FGF2 axis in adipose-derived stem cells promotes angiogenesis by vascular endothelial cells during ischemic tissue repair

BACKGROUND

Identifying factors mediating adipose-derived stem cells (ADSCs)-induced endothelial cell angiogenesis in hypoxic skin flap tissue is critical for reconstruction. While the paracrine action of VEGF by adipose-derived stem cells (ADSCs) is established in promoting endothelial cell angiogenesis, the role of FGF2 and its regulatory mechanisms in ADSCs paracrine secretion remains unclear.

METHODS

We induced hypoxia and examined the expression level of FGF2 in ADSCs using ELISA, qRT-PCR, and western blotting. Proliferation of ADSCs under hypoxia was assessed using a CCK-8 assay. Co-culture experiments of hypoxia-induced ADSCs with vascular endothelial cells were conducted, and migration and tube formation abilities were evaluated through wound healing assays, transwell cell migration, and tube formation experiments.

RESULTS

Hypoxia treatment induced significant upregulation of FGF2 expression in ADSCs, along with enhanced cell proliferation. Co-culture of hypoxia-induced ADSCs with vascular endothelial cells showed increased migration and tube formation abilities of endothelial cells. Knockdown of FGF2 inhibited these processes, while overexpression of miR-103-3p mimics in ADSCs suppressed endothelial cell migration and tube formation. FGF2 is a direct target of miR-103-3p in ADSCs. miR-103-3p/FGF2 axis regulates ADSCs on the biological activity of co-cultured vascular endothelial cells. Moreover, in the ischemic skin flap nude mouse model, ADSCs injection showed increased blood vessel formation and reduced flap necrosis, with the most significant improvement observed with ADSCs of miR-103-3p inhibitor overexpressed.

CONCLUSION

Hypoxia induces paracrine secretion of FGF2 from ADSCs, which enhances endothelial cell angiogenesis. FGF2 expression is regulated by miR-103-3p in ADSCs. The miR-103-3p/FGF2 axis induces endothelial cell migration and angiogenesis and finally modulates ischemic skin flap repair in nude mice in vivo.

Glutamate molecular structure and protein affect the inhibition of breast cancer cell metastasis: Cell-derived exosomes inhibitory effects through the MAPK signaling pathway

The aim of this study was to investigate the inhibitory effect of glutamate molecular structure and protein on breast cancer cell metastasis and the potential inhibitory mechanism of cell-derived exosomes via MAPK signaling pathway. Breast cancer cell lines with high metastatic potential were selected by in vitro cell culture technique. The effects of specific inhibitors of glutamic acid on the proliferation and metastasis of breast cancer cells were studied. Changes in protein expression profiles were analyzed by proteomics techniques to identify key proteins associated with breast cancer metastasis. Breast cancer cells were treated with inhibitors of the MAPK signaling pathway to evaluate their effect on cell metastasis and compare with exosome treatment. The results showed that the specific inhibitors of glutamate molecular structure could significantly inhibit the proliferation and metastasis of breast cancer cells. Proteomic analysis revealed several down-regulated proteins that are closely related to breast cancer metastasis.

The Role of Exosomes in Medical Dermatology: Literature Review and Update

BACKGROUND

Exosomes are extracellular vesicles, composed of a phospholipid bilayer, that are primarily derived from stem cells. The contents of exosomes can be incorporated into the tissue in which they are introduced, which presents a unique therapeutic option.

AIMS

Exosomes have been investigated as a treatment for a number of medical ailments, but the literature supporting these indications is inconclusive. In addition, much of the study on exosomes and their uses has been recently completed. Thus, this review summarizes the efficacy and implications of exosomes in the treatment of different dermatologic conditions.

METHODS

A literature review surrounding the use of exosomes for multiple medical dermatological conditions was conducted. Additionally, we present numerous practical cases in which patients had been treated with exosomes.

RESULTS

Overall, the success of exosomes in treating medical dermatologic conditions demonstrated varying efficacy in the literature, but the preliminary evidence is generally positive. The patient cases also showed satisfactory clinical outcomes but further studies and cases will be necessary to fully characterize the efficacy of exosomes and the ideal modalities for their application, including formulation, mode of distribution, and frequency of treatment.

CONCLUSIONS

Exosomes may serve as an effective treatment option for wound healing, reconstruction of skin flaps, radiation dermatitis, acne vulgaris, psoriasis, atopic dermatitis, allergic contact dermatitis, lichen simplex chronicus, vulvar lichen sclerosis, systemic sclerosis, systemic lupus erythematosus, and vitiligo although additional studies are needed to confirm their efficacy and safety.

Radial Egg White Hydrogel Releasing Extracellular Vesicles for Cell Fate Guidance and Accelerated Diabetic Skin Regeneration

Topology and bioactive molecules are crucial for stimulating cellular and tissue functions. To regulate the chronic wound microenvironment, mono-assembly technology is employed to fabricate a radial egg white hydrogel loaded with lyophilized adipose tissue-extracellular vesicles (radial EWH@L-EVs). The radial architecture not only significantly modified the gene expression of functional cells, but also achieved directional and controlled release kinetics of L-EVs. Through the synergy of topographical and inherent bioactive cues, radial EWH@L-EVs effectively reduced intracellular oxidative stress and promoted the polarization of macrophages toward an anti-inflammatory phenotype during the inflammatory phase. Afterward, radial EWH@L-EVs facilitated the centripetal migration and proliferation of fibroblasts and endothelial cells as the wound transitioned to the proliferative phase. During the latter remodeling phase, radial EWH@L-EVs accelerated the regeneration of granulation tissue, angiogenesis, and collagen deposition, thereby promoting the reorganization chronic wound. Compared with the gold standard collagen scaffold, radial EWH@L-EVs actively accommodated the microenvironment via various functions throughout all stages of diabetic wound healing. This can be attributed to the orientation of topological structures and bioactive molecules, which should be considered of utmost importance in tissue engineering.

Inhibition of Small Extracellular Vesicles by GW4869 Does not Disrupt the Paracrine Regulation of Adipose-Derived Mesenchymal Stem Cells Over Keloid Fibroblasts

BACKGROUND

Keloid, scar caused by atypical wound repair, represents a significant difficulty for specialists in plastic surgery and dermatology. Adipose-derived mesenchymal stem cells (ADSCs) can regulate fibrotic phenotypes of keloid fibroblasts (KFs) in a paracrine fashion, but whether small extracellular vesicles (SEVs) are the key functional carrier in ADSC paracrine regulation of KFs remains unknown. This study aims to explore whether the regulatory effects of conditioned medium (CM) obtained from ADSCs on KFs can be impaired by decreased SEV content in the ADSC-CM.

METHODS

Clinical specimens were utilized to extract keloid fibroblasts (KFs), normal fibroblasts (NFs), and adipose-derived stem cells (ADSCs). Fibroblasts were cultured with CM obtained from ADSCs untreated or treated with the sphingomyelinase inhibitor GW4869. The features of SEVs derived from ADSC-CM were characterized, and fibroblast proliferation, migration, apoptosis, and expression of ECM proteins were analyzed.

RESULTS

The sphingomyelinase inhibitor GW4869 successfully reduced the SEV content in ADSC-CM, and both control ADSC-CM and ADSC-CM with reduced SEV content significantly inhibited KF proliferation, migration, and α-SMA synthesis but not KF apoptosis, whereas only NF proliferation was inhibited by ADSC-CM. The reduced SEV content only affected the inhibition of KF proliferation induced by ADSC-CM.

CONCLUSION

ADSC-CM inhibits various fibrotic phenotypes of KFs, but decreasing the SEV content in ADSC-CM did not significantly alter the antifibrotic effects of ADSC-CM. Thus, SEVs may not be the key mediator of ADSCs paracrine regulation of KFs.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors . www.springer.com/00266 .

Exosome-based cell therapy for diabetic foot ulcers: Present and prospect

Diabetic foot ulcers (DFUs) represent a serious complication of diabetes with high incidence, requiring intensive treatment, prolonged hospitalization, and high costs. It poses a severe threat to the patient's life, resulting in substantial burdens on patient and healthcare system. However, the therapy of DFUs remains challenging. Therefore, exploring cell-free therapies for DFUs is both critical and urgent. Exosomes, as crucial mediators of intercellular communication, have been demonstrated potentially effective in anti-inflammation, angiogenesis, cell proliferation and migration, and collagen deposition. These functions have been proven beneficial in all stages of diabetic wound healing. This review aims to summarize the role and mechanisms of exosomes from diverse cellular sources in diabetic wound healing research. In addition, we elaborate on the challenges for clinical application, discuss the advantages of membrane vesicles as exosome mimics in wound healing, and present the therapeutic potential of exosomes and their mimetic vesicles for future clinical applications.

Advantages and disadvantages of various hydrogel scaffold types: A research to improve the clinical conversion rate of loaded MSCs-Exos hydrogel scaffolds

Mesenchymal stem cell-derived exosomes(MSCs-Exos) offer promising therapeutic potential for a wide range of tissues and organs such as bone/cartilage, nerves, skin, fat, and endocrine organs. In comparison to the application of mesenchymal stem cells (MSCs), MSCs-Exos address critical challenges related to rejection reactions and ethical concerns, positioning themselves as a promising cell-free therapy. As exosomes are extracellular vesicles, their effective delivery necessitates the use of carriers. Consequently, the selection of hydrogel materials as scaffolds for exosome delivery has become a focal point of contemporary research. The diversity of hydrogel scaffolds, which can take various forms such as injectable types, dressings, microneedles, and capsules, leads to differing choices among researchers for treating diseases within the same domain. This variability in hydrogel materials poses challenges for the translation of findings into clinical practice. The review highlights the potential of hydrogel-loaded exosomes in different fields and introduces the advantages and disadvantages of different forms of hydrogel applications. It aims to provide a multifunctional and highly recognized hydrogel scaffold option for tissue regeneration at specific sites, improve clinical translation efficiency, and benefit the majority of patients.

Chitosan-based self-healing hydrogel dressing for wound healing

Skin has strong self-regenerative capacity, while severe skin defects do not heal without appropriate treatment. Therefore, in order to cover the wound sites and hasten the healing process, wound dressings are required. Hydrogels have emerged as one of the most promising candidates for wound dressings because of their hydrated and porous molecular structure. Chitosan (CS) with biocompatibility, oxygen permeability, hemostatic and antimicrobial properties is beneficial for wound treatment and it can generate self-healing hydrogels through reversible crosslinks, from dynamic covalent bonding, such as Schiff base bonds, boronate esters, and acylhydrazone bonds, to physical interactions like hydrogen bonding, electrostatic interaction, ionic bonding, metal-coordination, host-guest interactions, and hydrophobic interaction. Therefore, various chitosan-based self-healing hydrogel dressings have been prepared in recent years to cope with increasingly complex wound conditions. This review's objective is to provide comprehensive information on the self-healing mechanism of chitosan-based hydrogel wound dressings, discuss their advanced functions including antibacterial, conductive, anti-inflammatory, anti-oxidant, stimulus-responsive, hemostatic/adhesive and controlled release properties, further introduce their applications in the promotion of wound healing in two categories: acute and chronic (infected, burn and diabetic) wounds, and finally discuss the future perspective of chitosan-based self-healing hydrogel dressings for wound healing.

Autologous Fat Grafting-A Panacea for Scar Tissue Therapy?

Scars may represent more than a cosmetic concern for patients; they may impose functional limitations and are frequently associated with the sensation of itching or pain, thus impacting both psychological and physical well-being. From an aesthetic perspective, scars display variances in color, thickness, texture, contour, and their homogeneity, while the functional aspect encompasses considerations of functionality, pliability, and sensory perception. Scars located in critical anatomic areas have the potential to induce profound impairments, including contracture-related mobility restrictions, thereby significantly impacting daily functioning and the quality of life. Conventional approaches to scar management may suffice to a certain extent, yet there are cases where tailored interventions are warranted. Autologous fat grafting emerges as a promising therapeutic avenue in such instances. Fundamental mechanisms underlying scar formation include chronic inflammation, fibrogenesis and dysregulated wound healing, among other contributing factors. These mechanisms can potentially be alleviated through the application of adipose-derived stem cells, which represent the principal cellular component utilized in the process of lipofilling. Adipose-derived stem cells possess the capacity to secrete proangiogenic factors such as fibroblast growth factor, vascular endothelial growth factor and hepatocyte growth factor, as well as neurotrophic factors, such as brain-derived neurotrophic factors. Moreover, they exhibit multipotency, remodel the extracellular matrix, act in a paracrine manner, and exert immunomodulatory effects through cytokine secretion. These molecular processes contribute to neoangiogenesis, the alleviation of chronic inflammation, and the promotion of a conducive milieu for wound healing. Beyond the obvious benefit in restoring volume, the adipose-derived stem cells and their regenerative capacities facilitate a reduction in pain, pruritus, and fibrosis. This review elucidates the regenerative potential of autologous fat grafting and its beneficial and promising effects on both functional and aesthetic outcomes when applied to scar tissue.

Potential Consequences of the Use of Adipose-Derived Stem Cells in the Treatment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) ranks as the most prevalent of primary liver cancers and stands as the third leading cause of cancer-related deaths. Early-stage HCC can be effectively managed with available treatment modalities ranging from invasive techniques, such as liver resection and thermoablation, to systemic therapies primarily employing tyrosine kinase inhibitors. Unfortunately, these interventions take a significant toll on the body, either through physical trauma or the adverse effects of pharmacotherapy. Consequently, there is an understandable drive to develop novel HCC therapies. Adipose-derived stem cells (ADSCs) are a promising therapeutic tool. Their facile extraction process, coupled with the distinctive immunomodulatory capabilities of their secretome, make them an intriguing subject for investigation in both oncology and regenerative medicine. The factors they produce are both enzymes affecting the extracellular matrix (specifically, metalloproteinases and their inhibitors) as well as cytokines and growth factors affecting cell proliferation and invasiveness. So far, the interactions observed with various cancer cell types have not led to clear conclusions. The evidence shows both inhibitory and stimulatory effects on tumor growth. Notably, these effects appear to be dependent on the tumor type, prompting speculation regarding their potential inhibitory impact on HCC. This review briefly synthesizes findings from preclinical and clinical studies examining the effects of ADSCs on cancers, with a specific focus on HCC, and emphasizes the need for further research.

The Mechanisms of Adipose Stem Cell-Derived Exosomes Promote Wound Healing and Regeneration

Chronic wound healing is a class of diseases influenced by multiple complex factors, causing severe psychological and physiological impact on patients. It is an intractable clinical challenge and its possible mechanisms are not yet clear. It has been proven that adipose stem cell-derived exosomes (ADSC-Exos) can promote wound healing and inhibit scar formation by regulating inflammation, promoting cell proliferation, migration, and angiogenesis, regulating matrix remodeling, which provides a new approach for wound healing through biological treatment. This review focuses on the mechanism, treatment, and administration methods of ADSC-Exos in wound healing, providing a comprehensive understanding the mechanisms of ADSC-Exos on wound healing. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Effect of Age on the Regenerative Potential of Adipose Stem-cell-derived Apoptotic Extracellular Vesicles in Rat Skin Wound Healing

Introduction: Skin, being the body's largest organ, is susceptible to injuries. Despite the adoption of common treatments such as debridement, wound dressing, and infection control measures for skin injuries, the outcomes remain unsatisfactory, especially in diabetic patients or elderly patients. The use of adipose stem cell-derived apoptotic extracellular vesicles (apoEVs-ASCs) has been shown great therapeutic potential in wound repair. The effect of the donor age on the biological properties and functions of apoEVs-ASCs has not been reported. Methods: In this study, we isolated apoEVs-ASCs from young and aged rats. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) were applied for the characteristics of apoEVs-ASCs. For aged and young apoEVs-ASCs groups, the proliferative and migration abilities in vitro, and wound healing function in vivo were contrastively evaluated and quantified for statistical analysis. Results: Our results showed that both young and aged apoEVs-ASCs induced skin healing and reduced scar formation. In addition, young apoEVs-ASCs had significantly higher proliferation, migration of fibroblasts and endothelial cells, and increased neo-angiogenesis ability, when compared with that of aged apoEVs-ASCs. Conclusion: Young apoEVs-ASCs should be employed for wound repair, which is associated with its superior promoting effect on wound healing.

miR-125b-5p delivered by adipose-derived stem cell exosomes alleviates hypertrophic scarring by suppressing Smad2

Background

Hypertrophic scarring is the most serious and unmet challenge following burn and trauma injury and often leads to pain, itching and even loss of function. However, the demand for ideal scar prevention and treatment is difficult to satisfy. We aimed to discover the effects and mechanisms of adipose-derived stem cell (ADSC) exosomes in hypertrophic scarring.

Methods

ADSC exosomes were isolated from the culture supernatant of ADSCs and identified by nanoparticle tracking analysis, transmission electron microscopy and western blotting. The effect of ADSC exosomes on wound healing and scar formation was detected by the wound model of BALB/c mice. We isolated myofibroblasts from hypertrophic scar tissue and detected the cell viability, proliferation and migration of myofibroblasts. In addition, collagen formation and fibrosis-related molecules were also detected. To further disclose the mechanism of ADSC exosomes on fibrosis in myofibroblasts, we detected the expression of Smad2 in hypertrophic scar tissue and normal skin and the regulatory mechanism of ADSC exosomes on Smad2. Injection of bleomycin was performed in male BALB/c mice to establish an in vivo fibrosis model while ADSC exosomes were administered to observe their protective effect. The tissue injury of mice was observed via hematoxylin and eosin and Masson staining and related testing.

Results

In this study, we found that ADSC exosomes could not only speed up wound healing and improve healing quality but also prevent scar formation. ADSC exosomes inhibited expression of fibrosis-related molecules such as α-smooth muscle actin, collagen I (COL1) and COL3 and inhibited the transdifferentiation of myofibroblasts. In addition, we verified that Smad2 is highly expressed in both hypertrophic scar tissue and hypertrophic fibroblasts, while ADSC exosomes downregulated the expression of Smad2 in hypertrophic fibroblasts. Further regulatory mechanism analysis revealed that microRNA-125b-5p (miR-125b-5p) is highly expressed in ADSC exosomes and binds to the 3' untranslated region of Smad2, thus inhibiting its expression. In vivo experiments also revealed that ADSC exosomes could alleviate bleomycin-induced skin fibrosis and downregulate the expression of Smad2.

Conclusions

We found that ADSC exosomes could alleviate hypertrophic scars via the suppression of Smad2 by the specific delivery of miR-125b-5p.

Adipose-derived stem cells derived decellularized extracellular matrix enabled skin regeneration and remodeling

The tissues or organs derived decellularized extracellular matrix carry immunogenicity and the risk of pathogen transmission, resulting in limited therapeutic effects. The cell derived dECM cultured in vitro can address these potential risks, but its impact on wound remodeling is still unclear. This study aimed to explore the role of decellularized extracellular matrix (dECM) extracted from adipose derived stem cells (ADSCs) in skin regeneration. Methods: ADSCs were extracted from human adipose tissue. Then we cultivated adipose-derived stem cell cells and decellularized ADSC-dECM for freeze-drying. Western blot (WB), enzyme-linked immunosorbent assay (ELISA) and mass spectrometry (MS) were conducted to analyzed the main protein components in ADSC-dECM. The cell counting assay (CCK-8) and scratch assay were used to explore the effects of different concentrations of ADSC-dECM on the proliferation and migration of human keratinocytes cells (HaCaT), human umbilical vein endothelia cells (HUVEC) and human fibroblasts (HFB), respectively. Moreover, we designed a novel ADSC-dECM-CMC patch which used carboxymethylcellulose (CMC) to load with ADSC-dECM; and we further investigated its effect on a mouse full thickness skin wound model. Results: ADSC-dECM was obtained after decellularization of in vitro cultured human ADSCs. Western blot, ELISA and mass spectrometry results showed that ADSC-dECM contained various bioactive molecules, including collagen, elastin, laminin, and various growth factors. CCK-8 and scratch assay showed that ADSC-dECM treatment could significantly promote the proliferation and migration of HaCaT, human umbilical vein endothelia cells, and human fibroblasts, respectively. To evaluate the therapeutic effect on wound healing in vivo, we developed a novel ADSC-dECM-CMC patch and transplanted it into a mouse full-thickness skin wound model. And we found that ADSC-dECM-CMC patch treatment significantly accelerated the wound closure with time. Further histology and immunohistochemistry indicated that ADSC-dECM-CMC patch could promote tissue regeneration, as confirmed via enhanced angiogenesis and high cell proliferative activity. Conclusion: In this study, we developed a novel ADSC-dECM-CMC patch containing multiple bioactive molecules and exhibiting good biocompatibility for skin reconstruction and regeneration. This patch provides a new approach for the use of adipose stem cells in skin tissue engineering.

Autologous nanofat harvested from donor site of full-thickness skin or skin flap grafting for the treatment of early postburn scarring: a case series

Introduction

Postburn scarring often presents a specific reconstructive challenge from both functional and cosmetic perspectives. The purpose of this study was to investigate whether autologous nanofat harvested from the donor site of full skin or a skin flap can be reused for the treatment of early postburn scaring.

Methods

From July 2018 to April 2022, patients with early postburn scarring underwent scar reconstruction surgery with full-thickness skin or a skin flap for a contour deformity and/or scar contracture, and autologous nanofat grafting was performed during the same operation. The Vancouver Scar Score (VSS) and the itch and pain scores were evaluated at the preoperation time point as well as at 2-3 weeks and 3-months postoperation. A comparison was made among the same patients at different time points.

Results

A total of 17 patients, aged from 18 months to 62 years old were included in this analysis. The VSS was reduced from 10.00 ± 2.12 to 7.41 ± 1.277 at the 2-3-week postoperation time point, and to 5.53 ± 1.37 at the 3-month postoperation time point. The pain and itch score were reduced from 4.65 ± 1.37 and 6.35 ± 1.27, to 3.70 ± 1.10 and 4.94 ± 1.30 at the 2-3-week postoperation time point, and to 3.00 ± 1.28 and 3.94 ± 0.97 at the 3-month postoperation time point respectively. The VSS and pain and itch scores showed a statistically significant reduction (P < 0.05) at the 2-3-week and 3-month postoperative follow-ups compared with the preoperation time point.

Conclusion

Autologous nanofat grafting from donor sites of full thickness skin or skin flap may be a promising treatment for an early postburn scaring as it promotes scar softening, improves itching and pain within the scar. However, this is a small case series with only 17 patients. Further conclusions need to be drawn through expanded samples for randomized controlled clinical trials.

Lay Summary

Hypertrophic scarring is the most common complication after partial thickness burn injury, and the complex pathogenesis and prolonged dynamic process render treatments only marginally effective. In the past few decades, with the technological advances of liposuction and fat grafting, nanofat grafting has been used in a variety of surgical fields, including wound healing, scleroderma, facial rejuvenation, and neuralgia. However, the role of nanofat grafting is not well documented in the prevention and treatment of early postburn scarring. Full-thickness skin grafting or skin flap transplantation is the most common method for the reconstruction of a hypertrophic scaring until now. In the current study, we harvested subcutaneous fat during the preparation of the full-thickness skin or skin flap, prepared nanofat and injected it in the scar located at a nonsurgical site. Comparison of the pre- and postoperation scores for scar color, scar thickness, scar stiffness, and scar regularity showed that the postoperation scores were decreased significantly and that there was a significant improvement in scar pigmentation and thickness as well astheaesthetic outcome after treatment. Most importantly, reductions in the scores for pain and itching could be assessed objectively. It seems that the nanofat grafting is a potential method for prevention and treatment for early postburn scaring.

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

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

Mesenchymal stem cell-based therapy for autoimmune-related fibrotic skin diseases-systemic sclerosis and sclerodermatous graft-versus-host disease

BACKGROUND

Systemic sclerosis (SSc) and sclerodermatous graft-versus-host disease (Scl-GVHD)-characterized by similar developmental fibrosis, vascular abnormalities, and innate and adaptive immune response, resulting in severe skin fibrosis at the late stage-are chronic autoimmune diseases of connective tissue. The significant immune system dysfunction, distinguishing autoimmune-related fibrosis from mere skin fibrosis, should be a particular focus of treating autoimmune-related fibrosis. Recent research shows that innovative mesenchymal stem cell (MSC)-based therapy, with the capacities of immune regulation, inflammation suppression, oxidation inhibition, and fibrosis restraint, shows great promise in overcoming the disease.

MAIN BODY

This review of recent studies aims to summarize the therapeutic effect and theoretical mechanisms of MSC-based therapy in treating autoimmune-related fibrotic skin diseases, SSc and Scl-GVHD, providing novel insights and references for further clinical applications. It is noteworthy that the efficacy of MSCs is not reliant on their migration into the skin. Working on the immune system, MSCs can inhibit the chemotaxis and infiltration of immune cells to the skin by down-regulating the expression of skin chemokines and chemokine receptors and reducing the inflammatory and pro-fibrotic mediators. ​Furthermore, to reduce levels of oxidative stress, MSCs may improve vascular abnormalities, and enhance the antioxidant defenses through inducible nitric oxide synthase, thioredoxin 1, as well as other mediators. The oxidative stress environment does not weaken MSCs and may even strengthen certain functions. Regarding fibrosis, MSCs primarily target the transforming growth factor-β signaling pathway to inhibit fibroblast activation. Here, miRNAs may play a critical role in ECM remodeling. Clinical studies have demonstrated the safety of these approaches, though outcomes have varied, possibly owing to the heterogeneity of MSCs, the disorders themselves, and other factors. Nevertheless, the research clearly reveals the immense potential of MSCs in treating autoimmune-related fibrotic skin diseases.

CONCLUSION

The application of MSCs presents a promising approach for treating autoimmune-related fibrotic skin diseases: SSc and Scl-GVHD. Therapies involving MSCs and MSC extracellular vesicles have been found to operate through three primary mechanisms: rebalancing the immune and inflammatory disorders, resisting oxidant stress, and inhibiting overactivated fibrosis (including fibroblast activation and ECM remodeling). However, the effectiveness of these interventions requires further validation through extensive clinical investigations, particularly randomized control trials and phase III/IV clinical trials. Additionally, the hypothetical mechanism underlying these therapies could be elucidated through further research.

Human Wound and Its Burden: Updated 2022 Compendium of Estimates

Significance: Chronic wounds affect 10.5 million (up 2.3 million from the 2014 update) of U.S. Medicare beneficiaries. Chronic wounds impact the quality of life of nearly 2.5% of the total population of the United States. This fraction is larger in the elderly. These wounds can lead to a range of complications and health care costs. Given the aging population, the continued threat of diabetes and obesity worldwide, and the persistent problem of infection, it is expected that chronic wounds will continue to be a substantial clinical, social, and economic challenge. Disparities in the prevalence and management of chronic wounds exist, with underserved communities and marginalized populations often facing greater challenges in accessing quality wound care. These disparities exacerbate the public health burden. Recent Advances: U.S. Centers for Medicare and Medicaid Services had proposed revision of its local coverage determination limiting the use of skin substitute grafts/cellular and/or tissue-based products for the treatment of diabetic foot ulcers and venous leg ulcers in the U.S. Medicare population. In response to the comment phase, this proposal has been put on hold. The U.S. Food and Drug Administration (FDA) has renewed its focus on addressing nonhealing chronic wounds and has outlined efforts to address identified barriers to product development for nonhealing chronic wounds. The new approach places emphasis on engaging key wound healing stakeholders, including academia, professional associations, patient groups, reimbursement organizations, and industry. Finally, recent advances demonstrating that wounds closed by current FDA definition of wound closure may remain functionally open because of deficiencies in restoration of barrier function warrant revisiting the wound closure endpoint. Such "closed" wounds that are functionally open, also known as invisible wounds, are likely to be associated with high wound recurrence. Future Directions: Addressing the public health problem of chronic wounds will require a multifaceted approach that includes prevention, improved wound care management, and addressing the underlying risk factors.

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

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

OPG gene-modified adipose-derived stem cells improve bone formation around implants in osteoporotic rat maxillae

Background

Osteoporosis is a significant barrier to the use of dental implants in the elderly for the treatment of tooth defects. Adipose derived stem cells (ADSCs) have demonstrated extensive potential for tissue repair and regeneration. The present study aimed to investigate the effectiveness of ADSCs engineered to express high levels of osteoprotegerin (OPG) for the treatment of bone loss in implant dentistry caused by estrogen deficiency.

Methods

A rat model of osteoporosis was established through double oophorectomy, and the rats were treated by gene modified cells Adv-OPG-ADSCs. The effects of the treatment on maxilla tissue changes were evaluated using HE staining and micro-CT. Additionally, ALP and TRAP staining were used to assess osteoblast and osteoclast alterations. Finally, the changes in related osteoblast and osteoclast indicators were measured by RT-qPCR, Western blot, and ELISA.

Results

The successfully generated high-OPG-expressing ADSCs led to increase of cell viability, proliferation, and osteoblast differentiation. Treatment with Adv-OPG-ADSCs significantly ameliorated maxillary morphology, trabecular volume reduction, and bone mineral density decline in the model of estrogen-deficient maxillary implant dentistry. Furthermore, the treatment was beneficial to promoting the generation of osteoblasts and inhibiting the generation of osteoclast. Adv-OPG-ADSCs increased OPG, ALP, OCN, and Runx-2 expressions in the maxilla while suppressing RANKL expression, and also increased the concentration of COL I and PINP, as well as decreased the concentration of CTX-1.

Conclusion

Adv-OPG-ADSCs promote the formation of osteoblasts and inhibit the generation of osteoclasts, thereby inhibiting bone absorption, facilitating bone formation, and promoting the repair of maxillary bone after dental implantation in the presence of osteoporosis-related complications, especially in the setting of estrogen deficiency, providing scientific basis for the application of Adv-OPG-ADSCs in the treatment of implant related osteoporosis.

Substrate stiffness can affect the crosstalk between adipose derived mesenchymal stem cells and macrophages in bone tissue engineering

Purpose: This study aimed to explore the effect of biomaterials with different stiffness on Adipose Derived Mesenchymal Stem Cells (ADSC)-macrophage crosstalk in bone tissue engineering and its role in bone repair. Methods: Biomaterials with Young's modulus of 64 and 0.2 kPa were selected, and the crosstalk between ADSCs and macrophages was investigated by means of conditioned medium treatment and cell co-culture, respectively. Polymerase chain reaction (PCR) and flow cytometry were used to evaluate the polarization of macrophages. Alkaline phosphatase (ALP) and alizarin red staining (ARS) solutions were used to evaluate the osteogenic differentiation of ADSCs. Transwell assay was used to evaluate the chemotaxis of ADSCs and macrophages. Moreover, mass spectrometry proteomics was used to analyze the secreted protein profile of ADSCs of different substrates and macrophages in different polarization states. Results: On exploring the influence of biomaterials on macrophages from ADSCs on different substrates, we found that CD163 and CD206 expression levels in macrophages were significantly higher in the 64-kPa group than in the 0.2-kPa group in conditioned medium treatment and cell co-culture. Flow cytometry showed that more cells became CD163+ or CD206+ cells in the 64-kPa group under conditioned medium treatment or cell co-culture. The Transwell assay showed that more macrophages migrated to the lower chamber in the 64-kPa group. The proteomic analysis found that ADSCs in the 64-kPa group secreted more immunomodulatory proteins, such as LBP and RBP4, to improve the repair microenvironment. On exploring the influence of biomaterials on ADSCs from macrophages in different polarization states, we found that ALP and ARS levels in ADSCs were significantly higher in the M2 group than in the other three groups (NC, M0, and M1 groups) in both conditioned medium treatment and cell co-culture. The Transwell assay showed that more ADSCs migrated to the lower chamber in the M2 group. The proteomic analysis found that M2 macrophages secreted more extracellular remodeling proteins, such as LRP1, to promote bone repair. Conclusion: In bone tissue engineering, the stiffness of repair biomaterials can affect the crosstalk between ADSCs and macrophages, thereby regulating local repair immunity and affecting bone repair.

Extracellular Vesicles Derived from Mesenchymal Stem Cells Promote Wound Healing and Skin Regeneration by Modulating Multiple Cellular Changes: A Brief Review

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) are biologically active substances secreted by MSCs into the extracellular matrix that play an immunomodulatory role in skin damage repair. To investigate the mechanism of MSC-EVs in reducing inflammation, promoting angiogenesis, promoting the proliferation and migration of epithelial cells and fibroblasts, and extracellular matrix remodeling during wound healing, we focused on the effects of EVs on multiple cell types at various stages of skin injury. A literature review was conducted to explore related research on the influence of MSC-EVs on the types of cells involved in wound healing. MSC-EVs show a strong regulatory ability on immune cells involved in the regulation of inflammation, including macrophages, neutrophils, and T cells, and other cells involved in tissue proliferation and remodeling, such as fibroblasts, keratinocytes, and endothelial cells, during wound healing in in vitro and in vivo experiments, which substantially promoted the understanding of wound healing in the field of trauma medicine. MSC-EVs have potential applications in combating poor skin wound healing. Elucidating the mechanism of action of EVs in the wound-healing process would greatly advance the understanding of therapeutic wound healing.

Characteristics of Serum Exosomes after Burn Injury and Dermal Fibroblast Regulation by Exosomes In Vitro

(1) Background: Exosomes (EXOs) have been considered a new target thought to be involved in and treat wound healing. More research is needed to fully understand EXO characteristics and the mechanisms of EXO-mediated wound healing, especially wound healing after burn injury. (2) Methods: All EXOs were isolated from 85 serum samples of 29 burn patients and 13 healthy individuals. We characterized the EXOs for morphology and density, serum concentration, protein level, marker expression, size distribution, and cytokine content. After a confirmation of EXO uptake by dermal fibroblasts, we also explored the functional regulation of primary human normal skin and hypertrophic scar fibroblast cell lines by the EXOs in vitro, including cell proliferation and apoptosis. (3) Results: EXOs dynamically changed their morphology, density, size, and cytokine level during wound healing in burn patients, which were correlated with burn severity and the stages of wound healing. EXOs both from burn patients and healthy individuals stimulated dermal fibroblast proliferation and apoptosis. (4) Conclusions: EXO features may be important signals that influence wound healing after burn injury; however, to understand the mechanisms by which EXOs regulates the fibroblasts in healing wounds, further studies will be required.

Lipoaspirate fluid derived factors and extracellular vesicles accelerate wound healing in a rat burn model

Background: The regenerative capabilities of derivatives derived from the fat layer of lipoaspirate have been demonstrated. However, the large volume of lipoaspirate fluid has not attracted extensive attention in clinical applications. In this study, we aimed to isolate the factors and extracellular vesicles from human lipoaspirate fluid and evaluate their potential therapeutic efficacy. Methods: Lipoaspirate fluid derived factors and extracellular vesicles (LF-FVs) were prepared from human lipoaspirate and characterized by nanoparticle tracking analysis, size-exclusion chromatography and adipokine antibody arrays. The therapeutic potential of LF-FVs was evaluated on fibroblasts in vitro and rat burn model in vivo. Wound healing process was recorded on days 2, 4, 8, 10, 12 and 16 post-treatment. The scar formation was analyzed by histology, immunofluorescent staining and scar-related gene expression at day 35 post-treatment. Results: The results of nanoparticle tracking analysis and size-exclusion chromatography indicated that LF-FVs were enriched with proteins and extracellular vesicles. Specific adipokines (adiponectin and IGF-1) were detected in LF-FVs. In vitro, LF-FVs augmented the proliferation and migration of fibroblasts in a dose-dependent manner. In vivo, the results showed that LF-FVs significantly accelerated burn wound healing. Moreover, LF-FVs improved the quality of wound healing, including regenerating cutaneous appendages (hair follicles and sebaceous glands) and decreasing scar formation in the healed skin. Conclusion: LF-FVs were successfully prepared from lipoaspirate liquid, which were cell-free and enriched with extracellular vesicles. Additionally, they were found to improve wound healing in a rat burn model, suggesting that LF-FVs could be potentially used for wound regeneration in clinical settings.

miR-125b-5p in adipose derived stem cells exosome alleviates pulmonary microvascular endothelial cells ferroptosis via Keap1/Nrf2/GPX4 in sepsis lung injury

BACKGROUND

Sepsis is a fatal disease with a high rate of morbidity and mortality, during which acute lung injury is the earliest and most serious complication. Injury of pulmonary microvascular endothelial cells (PMVECs) induced by excessive inflammation plays an important role in sepsis acute lung injury. This study is meant to explore the protective effect and mechanism of ADSCs exosomes on excessive inflammation PMVECs injury.

RESULTS

We successfully isolated ADSCs exosomes, the characteristic of which were confirmed. ADSCs exosomes reduced excessive inflammatory response induced ROS accumulation and cell injury in PMVECs. Besides, ADSCs exosomes inhibited excessive inflammatory response induced ferroptosis while upregulated expression of GPX4 in PMVECs. And further GPX4 inhibition experiments revealed that ADSCs exosomes alleviated inflammatory response induced ferroptosis via upregulating GPX4. Meanwhile, ADSCs exosomes could increase the expression and nucleus translocation of Nrf2, while decrease the expression of Keap1. miRNA analysis and further inhibition experiments verified that specific delivery of miR-125b-5p by ADSCs exosomes inhibited Keap1 and alleviated ferroptosis. In CLP induced sepsis model, ADSCs exosomes could relieve the lung tissue injury and reduced the death rate. Besides, ADSCs exosomes alleviated oxidative stress injury and ferroptosis of lung tissue, while remarkably increase expression of Nrf2 and GPX4.

CONCLUSION

Collectively, we illustrated a novel potentially therapeutic mechanism that miR-125b-5p in ADSCs exosomes could alleviate the inflammation induced PMVECs ferroptosis in sepsis induced acute lung injury via regulating Keap1/Nrf2/GPX4 expression, hence improve the acute lung injury in sepsis.

Mesenchymal Stem Cell Derived Extracellular Vesicles: Promising Nanomedicine for Cutaneous Wound Treatment

A skin wound represents a rupture caused by external damage or the existence of underlying pathological conditions. Sometimes, skin wound healing processes may place a heavy burden on patients, families, and society. Wound healing processes mainly consist of several continuous, dynamic, but overlapping stages, namely, the coagulation stage, inflammation stage, proliferation stage, and remodeling stage. Bacterial infection, excessive inflammation, impaired angiogenesis, and scar formation constitute the four significant factors impeding the recovery efficacy of skin wounds. This encourages scientists to develop multifunctional nanomedicines to meet challenging needs. As we know, mesenchymal stem cells (MSCs) have been widely explored for wound repair owing to their unique capability for self-renewal and multipotency. However, problems including immune concerns and legal restrictions should be properly resolved before MSC-based therapeutics are safely and widely used in clinics. Besides, maintaining the high viability/proliferation capability of MSCs during administration processes and therapy procedures is also one of the biggest technical bottlenecks. Extracellular vesicles (EVs) are cell-derived nanovesicles, that not only possess the basic characteristics and functions of their corresponding maternal cells but also contain several outstanding advantages including abundant sources, excellent biocompatibility, and convenient administration routes. Furthermore, the membrane surface and cavity are easy to flexibly modify to meet versatile application needs. Recently, MSC-derived EVs have emerged as promising therapeutics for skin wound repair. However, current reviews are too broad and rarely focused on the specific roles of EVs in the different stages of wound recovery. Therefore, it is quite necessary to demonstrate the significance of stem cell-derived EVs in promoting wound healing from several specific aspects. Here, this review primarily tries to provide critical comments on current advances in EVs derived from MSCs for wound repair, particularly elaborating on their impressive roles in effectively eliminating infections, inhibiting inflammation, promoting angiogenesis, and reducing scar formation. Last but not least, current limitations and future prospects of EVs derived from MSCs in the areas of wound repair are also objectively analyzed.

Small extracellular vesicles from mesenchymal stem cells: A potential Weapon for chronic non-healing wound treatment

Chronic non-healing wounds have posed a severe threat to patients mentally and physically. Behavior dysregulation of remaining cells at wound sites is recognized as the chief culprit to destroy healing process and hinders wound healing. Therefore, regulating and restoring normal cellular behavior is the core of chronic non-healing wound treatment. In recent years, the therapy with mesenchymal stem cells (MSCs) has become a promising option for chronic wound healing and the efficacy has increasingly been attributed to their exocrine functions. Small extracellular vesicles derived from MSCs (MSC-sEVs) are reported to benefit almost all stages of wound healing by regulating the cellular behavior to participate in the process of inflammatory response, angiogenesis, re-epithelization, and scarless healing. Here, we describe the characteristics of MSC-sEVs and discuss their therapeutic potential in chronic wound treatment. Additionally, we also provide an overview of the application avenues of MSC-sEVs in wound treatment. Finally, we summarize strategies for large-scale production and engineering of MSC-sEVs. This review may possibly provide meaningful guidance for chronic wound treatment with MSC-sEVs.

Therapeutic potential of adipose tissue-derivatives in modern dermatology

Stem cell-mediated therapies in combination with biomaterial and growth factor-based approaches in regenerative medicine are rapidly evolving with increasing application beyond the dermatologic field. Adipose-derived stem cells (ADSCs) are the more frequently used adult stem cells due to their abundance and easy access. In the case of volumetric defects, adipose tissue can take the shape of defects, restoring the volume and enhancing the regeneration of receiving tissue. When regenerative purposes prevail on volume restoration, the stromal vascular fraction (SVF) rich in staminal cells, purified mesenchymal stem cells (MSCs) or their cell-free derivatives grafting are favoured. The therapeutic efficacy of acellular approaches is explained by the fact that a significant part of the natural propensity of stem cells to repair damaged tissue is ascribable to their secretory activity that combines mitogenic factors, cytokines, chemokines and extracellular matrix components. Therefore, the secretome's ability to modulate multiple targets simultaneously demonstrated preclinical and clinical efficacy in reversing pathological mechanisms of complex conditions such atopic dermatitis (AD), vitiligo, psoriasis, acne and Lichen sclerosus (LS), non-resolving wounds and alopecia. This review analysing both in vivo and in vitro models gives an overview of the clinical relevance of adipose tissue-derivatives such as autologous fat graft, stromal vascular fraction, purified stem cells and secretome for skin disorders application. Finally, we highlighted the major disease-specific limitations and the future perspective in this field.

Exosomes from Adipose Stem Cells Promote Diabetic Wound Healing through the eHSP90/LRP1/AKT Axis

Oxidative damage is a critical cause of diabetic wounds. Exosomes from various stem cells could promote wound repair. Here, we investigated the potential mechanism by which exosomes from adipose-derived stem cells (ADSC-EXOs) promote diabetic wound healing through the modulation of oxidative stress. We found that ADSC-EXOs could promote proliferation, migration, and angiogenesis in keratinocytes, fibroblasts, and endothelial cells. Furthermore, ADSC-EXOs reduced the reactive oxygen species (ROS) levels in these cells and protected them against hypoxic and oxidative stress damage. Finally, the local injection of ADSC-EXOs at wound sites significantly increased collagen deposition and neovascularization while reducing ROS levels and cell death; thus, it led to accelerated diabetic wound closure. The mechanism underlying ADSC-EXO functions involved heat-shock protein 90 (HSP90) expressed on the cell surface; these functions could be inhibited by an anti-HSP90 antibody. Exosomal HSP90 could bind to the low-density lipoprotein receptor-related protein 1 (LRP1) receptor on the recipient cell membrane, leading to activation of the downstream AKT signaling pathway. Knockdown of LRP1 and inhibition of the AKT signaling pathway by LY294002 in fibroblasts was sufficient to impair the beneficial effect of ADSC-EXOs. In summary, ADSC-EXOs significantly accelerated diabetic wound closure through an exosomal HSP90/LRP1/AKT signaling pathway.

Adipose-Derived Stem Cell Exosomes Inhibit Hypertrophic Scaring Formation by Regulating Th17/Treg Cell Balance

Aiming to reveal the role of ADCS-Exos in secretion of inflammatory factors, Th17 and regulatory T (Treg) cell differentiation from naïve CD4+ T cells in hypertrophic scaring formation and maturation is explored. ELISA, qRT-PCR, and immunoblotting are performed to assay the local inflammatory factors IL-6, IL-10, IL-17A, and TNF-α, and transcriptional factors of RORϒt and Foxp3, in scaring tissue from patients and mice wound models treated with or without ADCS-Exos. Immunohistochemistry staining and immunoblotting are conducted to assay the extracellular matrix (ECM) deposition in vitro and in vivo. The results show that IL-6, IL-10, IL-17A, TNF-α, RORϒt, and Foxp3 are increased on mRNA and protein levels in hypertrophic scaring compared with atrophic scaring and normal skin. Naïve CD4⁺ T cells treated with ADCS-Exos in vitro can produce significantly less IL-6, IL-17A, TNF-α, and RORϒt and more IL-10 and Foxp3 on mRNA and protein levels. In addition, mice in ADSC-Exos-treated group demonstrate less collagen deposition; decreased IL-17A, TNF-α, and RORϒt; and increased IL-10 and Foxp3 production.

Clinical application of a double-modified sulfated bacterial cellulose scaffold material loaded with FGFR2-modified adipose-derived stem cells in urethral reconstruction

BACKGROUND

Urethral stricture and reconstruction are one of the thorny difficult problems in the field of urology. The continuous development of tissue engineering and biomaterials has given new therapeutic thinking to this problem. Bacterial cellulose (BC) is an excellent biomaterial due to its accessibility and strong plasticity. Moreover, adipose-derived stem cells (ADSCs) could enhance their wound healing ability through directional modification.

METHODS

First, we used physical drilling and sulfonation in this study to make BC more conducive to cell attachment and degradation. We tested the relevant mechanical properties of these materials. After that, we attached Fibroblast Growth Factor Receptor 2 (FGFR2)-modified ADSCs to the material to construct a urethra for tissue engineering. Afterward, we verified this finding in the male New Zealand rabbit model and carried out immunohistochemical and imaging examinations 1 and 3 months after the operation. At the same time, we detected the potential biological function of FGFR2 by bioinformatics and a cytokine chip.

RESULTS

The results show that the composite has excellent repairability and that this ability is correlated with angiogenesis. The new composite in this study provides new insight and therapeutic methods for urethral reconstruction. The preliminary mechanism showed that FGFR2 could promote angiogenesis and tissue repair by promoting the secretion of Vascular Endothelial Growth Factor A (VEGFA) from ADSCs.

CONCLUSIONS

Double-modified sulfonated bacterial cellulose scaffolds combined with FGFR2-modified ADSCs provide new sight and treatments for patients with urethral strictures.

Identification of Angiogenic Cargoes in Human Fibroblasts-Derived Extracellular Vesicles and Induction of Wound Healing

A complete redevelopment of the skin remains a challenge in the management of acute and chronic wounds. Recently, the application of extracellular vesicles (EVs) for soft tissue wound healing has received much attention. As fibroblasts are fundamental cells for soft tissues and skin, we investigate the proangiogenic factors in human normal fibroblast-derived EVs (hNF-EVs) and their effects on wound healing. Normal fibroblasts were isolated from human skin tissues and characterized by immunofluorescence (IF) and Western blotting (WB). hNF-EVs were isolated by ultracentrifugation and characterized using transmission electron microscopy and WB. The proangiogenic cargos in hNF-EVs were identified by a TaqMan assay and a protein array. Other in vitro assays, including internalization assays, cell counting kit-8 analysis, scratch wound assays, WBs, and tube formation assays were conducted to assess the effects of hNF-EVs on fibroblasts and endothelial cells. A novel scaffold-free noninvasive delivery of hNF-EVs with or without fibrin glue was applied onto full-thickness skin wounds in mice. The wound healing therapeutical effect of hNF-EVs was assessed by calculating the rate of wound closure and through histological analysis. Isolated hNF was confirmed by verifying the expression of the fibroblast markers vimentin, αSMA, Hsp70, and S100A4. Isolated hNF-EVs showed intact EVs with round morphology, enriched in CD81 and CD63, and devoid of the cell markers GM130, Calnexin, and Cytochrome C. Our TaqMan assay showed that hNF-EVs were enriched in miR130a and miR210, and protein arrays showed enriched levels of the proangiogenic proteins’ vascular endothelial growth factor (VEGF)-D and CXCL8. Next, we found that the internalization of hNF-EVs into hNF increased the proliferation and migration of hNF, in addition to increasing the expression of bFGF, MMP2, and αSMA. The internalization of hNF-EVs into the endothelial cells increased their proliferation and tube formation. A scaffold-free noninvasive delivery of hNF-EVs with or without fibrin glue accelerated the wound healing rate in full-thickness skin wounds in mice, and the treatments increased the cellular density, deposition, and maturation of collagens in the wounds. Moreover, the scaffold-free noninvasive delivery of hNF-EVs with or without fibrin glue increased the VEGF and CD31 expression in the wounds, indicating that hNF-EVs have an angiogenic ability to achieve complete skin regeneration. These findings open up for new treatment strategies to be developed for wound healing. Further, we offer a new approach to the efficient, scaffold-free noninvasive delivery of hNF-EVs to wounds.