Therapeutic potential of exosomes from adipose-derived stem cells in chronic wound healing

Harnessing the power of stem cell-derived exosomes: a rejuvenating therapeutic for skin and regenerative medicine

Exosomes are small extracellular vesicles produced by most cell types and contain proteins, lipids, and nucleic acids (non-coding RNAs, mRNA, and DNA) that can be released by donor cells to influence the function of recipient cells. Skin photoaging is the premature aging of skin structures caused by prolonged exposure to ultraviolet (UV), as demonstrated by depigmentation, roughness, rhytides, elastosis, and precancerous alterations. Exosomes are associated with aging processes such as oxidative damage, inflammation, and senescence. Exosomes' anti-aging properties have been linked to various in vitro and preclinical investigations. There are still several unanswered questions about the use of MSC exosomes for skin rejuvenation, despite encouraging results. Uncertainty surrounds the precise processes by which exosomes stimulate the creation of collagen, skin tissue via a variety of mechanisms, including reduced matrix metalloproteinase (MMP) expression, increased collagen and elastin production, and modulation of intracellular signaling pathways and intercellular communication. These findings suggest the therapeutic potential of exosomes in skin aging. This review provides information on the molecular mechanisms and consequences of exosome anti-aging.

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

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

The Transfer of USP25 by Exosomes of Adipose Tissue-Derived Mesenchymal Stem Cells Ameliorates Diabetic Nephropathy Through Stabilizing SMAD7 Expression

Adipose tissue-derived mesenchymal stem cells (ADSCs) are identified to be potential therapeutic candidates for diabetic nephropathy (DN) through secreting exosomes (Exos). Ubiquitin-specific protease 25 (USP25) has been reported to be involved in DN-induced renal injury. Herein, this study aimed to investigate whether ADSCs affected DN progression by Exo transfer of USP25. High glucose (HG)-induced mouse podocytes were used to mimic DN-induced injury for in vitro viability, inflammation, and apoptosis analyses. The db/db mice of DN were established for renal injury and function analysis in vivo. The deubiquitination effect of USP25 was analyzed by cellular ubiquitination and immunoprecipitation assays. ADSCs reversed HG-induced apoptosis and inflammation in podocytes, and these effects were achieved by Exo-mediated transfer of USP25. Mechanistically, USP25 interacted with SMAD7 protein and elevated its expression in podocytes via inducing SMAD7 deubiquitination. USP25 transferred via ADSC-Exos abolished HG-induced apoptosis and inflammation in podocytes by elevating SMAD7 protein levels. In vivo assay also confirmed that ADSC-Exo attenuated Type 2 Diabetes Mellitus-induced kidney injury and podocyte apoptosis and inflammation by releasing USP25. ADSCs attenuated T2DM-induced kidney injury, podocyte apoptosis, and inflammation via elevating SMAD7 stabilization through exosome transfer of USP25.

Nanomanaging Chronic Wounds with Targeted Exosome Therapeutics

Chronic wounds pose a significant healthcare challenge, impacting millions of patients worldwide and burdening healthcare systems substantially. These wounds often occur as comorbidities and are prone to infections. Such infections hinder the healing process, complicating clinical management and proving recalcitrant to therapy. The environment within the wound itself poses challenges such as lack of oxygen, restricted blood flow, oxidative stress, ongoing inflammation, and bacterial presence. Traditional systemic treatment for such chronic peripheral wounds may not be effective due to inadequate blood supply, resulting in unintended side effects. Furthermore, topical applications are often impervious to persistent biofilm infections. A growing clinical concern is the lack of effective therapeutic modalities for treating chronic wounds. Additionally, the chemically harsh wound microenvironment can reduce the effectiveness of treatments, highlighting the need for drug delivery systems that can deliver therapies precisely where needed with optimal dosages. Compared to cell-based therapies, exosome-based therapies offer distinct advantages as a cell-free approach for chronic wound treatment. Exosomes are of endosomal origin and enable cell-to-cell communications, and they possess benefits, including biocompatibility and decreased immunogenicity, making them ideal vehicles for efficient targeting and minimizing off-target damage. However, exosomes are rapidly cleared from the body, making it difficult to maintain optimal therapeutic concentrations at wound sites. The hydrogel-based approach and development of biocompatible scaffolds for exosome-based therapies can be beneficial for sustained release and prolong the presence of these therapeutic exosomes at chronic wound sites. Engineered exosomes have been shown to possess stability and effectiveness in promoting wound healing compared to their unmodified counterparts. Significant progress has been made in this field, but further research is essential to unlock their clinical potential. This review seeks to explore the benefits and opportunities of exosome-based therapies in chronic wounds, ensuring sustained efficacy and precise delivery despite the obstacles posed by the wound environment.

Different exosomes are loaded in hydrogels for the application in the field of tissue repair

Exosomes are double-membrane vesicular nanoparticles in the category of extracellular vesicles, ranging in size from 30 to 150 nm, and are released from cells through a specific multi-step exocytosis process. Exosomes have emerged as promising tools for tissue repair due to their ability to transfer bioactive molecules that promote cell proliferation, differentiation, and tissue regeneration. However, the therapeutic application of exosomes is hindered by their rapid clearance from the body and limited retention at the injury site. To overcome these challenges, hydrogels, known for their high biocompatibility and porous structure, have been explored as carriers for exosomes. Hydrogels can provide a controlled release mechanism, prolonging the retention time of exosomes at targeted tissues, thus enhancing their therapeutic efficacy. This review focuses on the combination of different exosomes with hydrogels in the context of tissue repair. We first introduce the sources and functions of exosomes, particularly those from mesenchymal stem cells, and their roles in regenerative medicine. We then examine various types of hydrogels, highlighting their ability to load and release exosomes. Several strategies for encapsulating exosomes in hydrogels are discussed, including the impact of hydrogel composition and structure on exosome delivery efficiency. Finally, we review the applications of exosomes-loaded hydrogels in the repair of different tissues, such as skin, bone, cartilage, and nerve, and explore the challenges and future directions in this field. The combination of exosomes with hydrogels offers significant promise for advancing tissue repair strategies and regenerative therapies.

Porcine pericardial decellularized matrix bilayer patch containing adipose stem cell-derived exosomes for the treatment of diabetic wounds

Chronic hard-to-heal wounds pose a significant threat to patients' health and quality of life, and their clinical management remains a challenge. Adipose-derived stem cell exosomes (ADSC-exos) have shown promising results in promoting diabetic wound healing. However, effectively enhancing the retention of exosomes in wounds for treatment remains a key issue that needs to be addressed. There is a pressing need to develop new materials or methods to improve the bioavailability of exosomes. Porcine pericardium, an extracellular matrix-rich tissue, is easily obtainable and widely available. Decellularized porcine pericardium removes cellular components while retaining an extracellular matrix that supports cellular growth, making it an ideal raw material for preparing wound dressings. In this study, we developed porcine pericardial decellularized matrix bilayer patches loaded with ADSC-exos, which were transplanted into diabetic mouse skin wounds. Histological and immunohistochemical analyses revealed that these bilayer matrix patches accelerate wound healing by promoting granulation tissue formation, re-epithelialization, stimulating vascularization, and enhancing collagen production. In terms of the underlying biological mechanism, we found that decellularized extracellular matrix bilayer patches loaded with ADSC-exos enhanced the proliferation and migration of human dermal fibroblasts (HDFs) and HaCaT cells in vitro, and promoted tube formation in human umbilical vein endothelial cells (HUVECs). This research demonstrated that the porcine pericardial decellularized matrix is well-suited for exosome delivery and that these bilayer patches hold great potential in promoting diabetic wound healing, providing evidence to support the future clinical application of ADSC-exos.

Stem Cells as a Novel Source for Regenerative Medicinal Applications in Alzheimer's Disease: An Update

Alzheimer's Disease (AD) is a progressive neurodegenerative disorder characterized by loss of the neurons, excessive accumulation of misfolded Aβ and Tau proteins, and degeneration of neural synapses, primarily occurring in the neocortex and the hippocampus regions of the brain. AD Progression is marked by cognitive deterioration, memory decline, disorientation, and loss of problem-solving skills, as well as language. Due to limited comprehension of the factors contributing to AD and its severity due to neuronal loss, even today, the medications approved by the U.S. Food and Drug Administration (FDA) are not precisely efficient and curative. Stem cells possess great potential in aiding AD due to their self-renewal, proliferation, and differentiation properties. Stem cell therapy can aid by replacing the lost neurons, enhancing neurogenesis, and providing an enriched environment to the pre-existing neural cells. Stem cell therapy has provided us with promising results in regard to the animal AD models, and even pre-clinical studies have shown rather positive results. Cell replacement therapies are potential curative means to treat AD, and there are a number of undergoing human clinical trials to make Stem Cell therapy accessible for AD patients. In this review, we aim to discuss the AD pathophysiology and varied stem cell types and their application.

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

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

A Brief History of Cell Culture: From Harrison to Organs-on-a-Chip

This comprehensive overview of the historical milestones in cell culture underscores key breakthroughs that have shaped the field over time. It begins with Wilhelm Roux's seminal experiments in the 1880s, followed by the pioneering efforts of Ross Granville Harrison, who initiated groundbreaking experiments that fundamentally shaped the landscape of cell culture in the early 20th century. Carrel's influential contributions, notably the immortalization of chicken heart cells, have marked a significant advancement in cell culture techniques. Subsequently, Johannes Holtfreter, Aron Moscona, and Joseph Leighton introduced methodological innovations in three-dimensional (3D) cell culture, initiated by Alexis Carrel, laying the groundwork for future consolidation and expansion of the use of 3D cell culture in different areas of biomedical sciences. The advent of induced pluripotent stem cells by Takahashi and Yamanaka in 2006 was revolutionary, enabling the reprogramming of differentiated cells into a pluripotent state. Since then, recent innovations have included spheroids, organoids, and organ-on-a-chip technologies, aiming to mimic the structure and function of tissues and organs in vitro, pushing the boundaries of biological modeling and disease understanding. In this review, we overview the history of cell culture shedding light on the main discoveries, pitfalls and hurdles that were overcome during the transition from 2D to 3D cell culture techniques. Finally, we discussed the future directions for cell culture research that may accelerate the development of more effective and personalized treatments.

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.

HucMSC extracellular vesicles increasing SATB 1 to activate the Wnt/β-catenin pathway in 6-OHDA-induced Parkinson's disease model

Parkinson's disease (PD) is a degenerative disorder of the nervous system characterized by the loss of dopaminergic neurons and damage of neurons in the substantia nigra (SN) and striatum, resulting in impaired motor functions. This study aims to investigate how extracellular vesicles (EVs) derived from human umbilical cord mesenchymal stem cells (HucMSC) regulate Special AT-rich sequence-binding protein-1 (SATB 1) and influence Wnt/β-catenin pathway and autophagy in PD model. The PD model was induced by damaging SH-SY5Y cells and mice using 6-OHDA. According to the study, administering EVs every other day for 14 days improved the motor behavior of 6-OHDA-induced PD mice and reduced neuronal damage, including dopaminergic neurons. Treatment with EVs for 12 hours increased the viability of 6-OHDA-induced SH-SY5Y cells. The upregulation of SATB 1 expression with EV treatment resulted in the activation of the Wnt/β-catenin pathway in PD model and led to overexpression of β-catenin. Meanwhile, the expression of LC3 II was decreased, indicating alterations in autophagy. In conclusion, EVs could mitigate neuronal damage in the 6-OHDA-induced PD model by upregulating SATB 1 and activating Wnt/β-catenin pathway while also regulating autophagy. Further studies on the potential therapeutic applications of EVs for PD could offer new insights and strategies.

Application of exosomes for the regeneration of skin wounds: Principles, recent applications and limitations

In the medical field, wound healing poses significant challenges due to its complexity and time-consuming nature. Cell-free wound repair, notably the utilization of exosomes (EXOs), has made significant progress in recent years. Urine, saliva, umbilical cord, blood, mesenchymal stem cells and breast milk cells can be used to extract and purify EXOs, which are Nano-sized lipid bilayer vesicles. Besides their relatively little toxicity, non-specific immunogenicity and excellent biocompatibility, EXOs also contain bioactive molecules such as proteins, lipids, microRNAs (miRNAs), and messenger RNAs (mRNAs). Their bioactive compounds have anti-inflammatory properties and can speed up wound healing. Various medicinal agents can also be contained within the EXOs. This review briefly provides new information on the different aspects of EXOs and evaluate the application of EXOs as a promising therapy in the regeneration of skin wounds in recent pre-clinical and clinical studies.

Exosomes Reshape the Osteoarthritic Defect: Emerging Potential in Regenerative Medicine-A Review

Osteoarthritis (OA) is a joint disorder caused by wear and tear of the cartilage that cushions the joints. It is a progressive condition that can cause significant pain and disability. Currently, there is no cure for OA, though there are treatments available to manage symptoms and slow the progression of the disease. A chondral defect is a common and devastating lesion that is challenging to treat due to its avascular and aneural nature. However, there are conventional therapies available, ranging from microfracture to cell-based therapy. Anyhow, its efficiency in cartilage defects is limited due to unclear cell viability. Exosomes have emerged as a potent therapeutic tool for chondral defects because they are a complicated complex containing cargo of proteins, DNA, and RNA as well as the ability to target cells due to their phospholipidic composition and the altering exosomal contents that boost regeneration potential. Exosomes are used in a variety of applications, including tissue healing and anti-inflammatory therapy. As in recent years, biomaterials-based bio fabrication has gained popularity among the many printable polymer-based hydrogels, tissue-specific decellularized extracellular matrix might boost the effects rather than an extracellular matrix imitating environment, a short note has been discussed. Exosomes are believed to be the greatest alternative option for current cell-based therapy, and future progress in exosome-based therapy could have a greater influence in the field of orthopaedics. The review focuses extensively on the insights of exosome use and scientific breakthroughs centered OA.

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.

Hypoxic Preconditioned ADSC Exosomes Enhance Vaginal Wound Healing via Accelerated Keratinocyte Proliferation and Migration Through AKT/HIF‑1α Axis Activation

Purpose

Accelerating wound healing is a main consideration in surgery. The three stages of wound healing are inflammatory response, tissue repair and cell proliferation. Much research has focused on epidermal cell proliferation and migration because this is an essential step in wound healing.

Methods and Results

The current study discovered that exosomes from Adipose-derived stem cell (ADSC) following hypoxic preconditioning (HExo) have a greater promotional effect on vaginal wound healing. Protein kinase B (AKT)/hypoxia-inducible factor 1-alpha (HIF-1α) play an important role in HExo-mediated HaCaT cell migration and proliferation. The promotional effect of HExo on rat wound healing was reversed by both, HIF‑1α and AKT inhibition. Phosphorylation of AKT (p-AKT) or HIF‑1α suppression reversed the protective effect of HExo on vaginal wound healing.

Conclusion

Taken together, our study found that hypoxic preconditioning of adipose MSC exosomes enhances vaginal wound healing via accelerated keratinocyte proliferation and migration through AKT/HIF‑1α axis activation.

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

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

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 .

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

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

Harnessing the potential of mesenchymal stem cells-derived exosomes in degenerative diseases

Mesenchymal stem cells (MSCs) have gained attention as a promising therapeutic approach in both preclinical and clinical osteoarthritis (OA) settings. Various joint cell types, such as chondrocytes, synovial fibroblasts, osteoblasts, and tenocytes, can produce and release extracellular vesicles (EVs), which subsequently influence the biological activities of recipient cells. Recently, extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) have shown the potential to modulate various physiological and pathological processes through the modulation of cellular differentiation, immune responses, and tissue repair. This review explores the roles and therapeutic potential of MSC-EVs in OA and rheumatoid arthritis, cardiovascular disease, age-related macular degeneration, Alzheimer's disease, and other degenerative diseases. Notably, we provide a comprehensive summary of exosome biogenesis, microRNA composition, mechanisms of intercellular transfer, and their evolving role in the highlight of exosome-based treatments in both preclinical and clinical avenues.

Clinical Applications of Adipose-Derived Stem Cell (ADSC) Exosomes in Tissue Regeneration

Adipose-derived stem cells (ADSCs) are mesenchymal stem cells with a great potential for self-renewal and differentiation. Exosomes derived from ADSCs (ADSC-exos) can imitate their functions, carrying cargoes of bioactive molecules that may affect specific cellular targets and signaling processes. Recent evidence has shown that ADSC-exos can mediate tissue regeneration through the regulation of the inflammatory response, enhancement of cell proliferation, and induction of angiogenesis. At the same time, they may promote wound healing as well as the remodeling of the extracellular matrix. In combination with scaffolds, they present the future of cell-free therapies and promising adjuncts to reconstructive surgery with diverse tissue-specific functions and minimal adverse effects. In this review, we address the main characteristics and functional properties of ADSC-exos in tissue regeneration and explore their most recent clinical application in wound healing, musculoskeletal regeneration, dermatology, and plastic surgery as well as in tissue engineering.

Exosomes in renal cell carcinoma: challenges and opportunities

Renal cell carcinoma (RCC) is the most common type of kidney cancer that accounts for approximately 2-3% of adult malignancies. Among the primary treatment methods for this type of cancer are surgery and targeted treatment. Still, due to less than optimal effectiveness, there are problems such as advanced distant metastasis, delayed diagnosis, and drug resistance that continue to plague patients. In recent years, therapeutic advances have increased life expectancy and effective treatment in renal cell carcinoma patients. One of these methods is the use of stem cells. Although the therapeutic effects of stem cells, especially mesenchymal stem cells, are still impressive, today, extracellular vesicles (EVs) as carrying molecules and various mediators in intercellular communications, having a central role in tumorigenesis, metastasis, immune evasion, and drug response, and on the other hand, due to its low immunogenicity and strong regulatory properties of the immune system, has received much attention from researchers and doctors. Despite the increasing interest in exosomes as the most versatile type of EVs, the heterogeneity of their efficacy presents challenges and, on the other hand, exciting opportunities for diagnostic and clinical interventions.In the upcoming article, we will review the various aspects of exosomes' effects in the prevention, treatment, and progress of renal cell carcinoma and also ways to optimize them to strengthen their positive sides.

Exosomes from adipose-derived stem cells restore fibroblast function and accelerate diabetic wound healing

Background

Diabetes is common yet challenging chronic disease, that affects a wide range of people around the world. Complex cellular environments around diabetic wounds tend to damage the function of effector cells, including vascular endothelial cells (VECs), fibroblasts and epithelial cells. This study aims to analyze the differences between diabetic wounds and normal skin as well as whether adipose-derived stem cell (ADSC) exosome could promote healing of diabetic wound.

Methods

Human diabetic wounds and normal skin were collected and stained with HE, Masson, CD31 and 8-hydroxy-2 deoxyguanosine immunohistochemical staining. RNA-seq data were collected for further bioinformatics analysis. ADSC exosomes were isolated and identified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and western blotting. The effect of ADSC exosomes on diabetic wound healing was assessed on full thickness wounds in mice. To further verify the regulative impact of ADSCs exosomes in high glucose treated fibroblasts, we isolated fibroblasts from normal skin tissue and measured the cell viability, apoptosis rate, proliferation and migration of fibroblasts. In addition, collagen formation and fibrosis-related molecules were also detected. To further disclose the mechanism of ADSC exosomes on the function of high glucose treated fibroblasts, we detected the expression of apoptosis related molecules including BCL2, Bax, and cleaved caspase-3.

Results

Histological observation indicated that perilesional skin tissues from diabetic patients showed structural disorder, less collagen disposition and increased injury compared with normal skin. Bioinformatics analysis showed that the levels of inflammatory and collagen synthesis related molecules, as well as oxidative stress and apoptosis related molecules, were significantly changed. Furthermore, we found that ADSC exosomes could not only speed up diabetic wound healing, but could also improve healing quality. ADSC exosomes restored high glucose induced damage to cell viability, migration and proliferation activity, as well as fibrosis-related molecules such as SMA, collagen 1 and collagen 3. In addition, we verified that ADSC exosomes downregulated high glucose induced increased apoptosis rate in fibroblast and the protein expression of Bax as well as cleaved caspases 3.

Conclusions

This study indicated that ADSC exosomes alleviated high glucose induced damage to fibroblasts and accelerate diabetic wound healing by inhibiting Bax/caspase 3.

The Evolution of Current Concept of the Reconstructive Ladder in Plastic Surgery: The Emerging Role of Translational Medicine

Plastic surgeons have used the reconstructive ladder for many decades as a standard directory for complex trauma reconstruction with the goal of repairing body structures and restoring functionality. This consists of different surgical maneuvers, such as secondary intention and direct tissue closure, as well as more complex methods such as local tissue transfer and free flap. The reconstructive ladder represents widely known options achievable for tissue reconstruction and wound closure that puts at the bottom rung the simplest methods of reconstruction and strengthens the complexity by moving upward. Regenerative medicine and surgery constitute a quickly spreading area of translational research that can be employed by minimally invasive surgical strategies, with the aim of regenerating cells and tissues in vivo in order to reestablish normal function through the intrinsic potential of cells, in combination with biomaterials and appropriate biochemical stimuli. These translational procedures have the aim of creating an appropriate microenvironment capable of supporting the physiological cellular function to generate the desired cells or tissues and to generate parenchymal, stromal, and vascular components on demand, and above all to produce intelligent materials capable of determining the fate of cells. Smart technologies have been grown that give extra "rungs" on the classic reconstructive ladder to integrate a more holistic, patient-based approach with improved outcomes. This commentary presents the evolution of the traditional concept of the reconstructive ladder in the field of plastic surgery into a new course with the aim of achieving excellent results for soft tissue reconstruction by applying innovative technologies and biologically active molecules for a wide range of surgical diseases.

Looking into the Skin in Health and Disease: From Microscopy Imaging Techniques to Molecular Analysis

The skin is a complex organ that includes a wide variety of tissue types with different embryological origins [...].

Birt-Hogg-Dubé Syndrome: A Rare Genodermatosis Presenting as Skin Papillomas

The authors present a rare case of Birt-Hogg-Dubé (BHD) syndrome that presented primarily as an aesthetic case. Previous providers failed to accurately diagnose BHD, despite the patient's history of pneumothoraces. This female patient complained of numerous recurrent, small skin-colored growths on the face and neck and patchy hypopigmentation from the multiple treatments she had to undergo for her "bumpy skin." She also suffered 4 spontaneous pneumothoraces. Following histopathologic and genetic testing, the patient was diagnosed with BHD. Computed tomography and ultrasound scans revealed multiple cysts in both lungs and an angiomyolipoma in both kidneys. This patient had undergone a variety of treatments to aesthetically remove and heal her skin bumps from several healthcare providers, all of whom had misdiagnosed her condition.

Level of Evidence 5

Hypoxia activates the PI3K/AKT/HIF-1α pathway to promote the anti-inflammatory effect of adipose mesenchymal stem cells

This study aimed to investigate the effect of hypoxia on the anti-inflammatory effect of adipose-derived mesenchymal stem cells (AMSCs) in vitro and its possible mechanism. AMSCs were cultured in vitro in a hypoxic environment with 3% O₂, and a normoxic (21% O₂) environment was used as the control. The cells were identified by in vitro adipogenic and osteogenic differentiation and cell surface antigen detection, and the cell viability were detected. The effect of hypoxic AMSCs on macrophage inflammation was analyzed by co-culture. The results showed that under hypoxia, AMSCs had better viability, significantly downregulated the expression of inflammatory factors, alleviated macrophage inflammation, and activated the PI3K/AKT/HIF-1α pathway.

Exosomes from bacteria (Streptococcus parauberis) challenged olive flounder (Paralichthys olivaceus): Isolation, molecular characterization, wound healing, and regeneration activities

Exosomes are a group of extracellular vesicles carrying membrane proteins, lipids, RNAs, and, cytosolic proteins, which play key role in intercellular communication and homeostasis. This study describes the isolation, physicochemical, morphological and molecular characterization, toxicity, wound healing, and regeneration properties of plasma derived exosomes from naive (phosphate-buffered saline [PBS]-injected; PBS-Exo) and Streptococcus parauberis-challenged (Sp-Exo) olive flounder (Paralichthys olivaceus). The average diameters of PBS-Exo and Sp-Exo were 120.5 ± 6.1 and 113.1 ± 9.3 nm, respectively, and they presented unique cup shape morphologies. Both exosomes exhibited classical tetraspanin surface markers (CD81, CD9, and CD63) and were enriched with acetylcholinesterase. High-throughput miRNA profiling revealed differentially expressed miRNAs (log₂ fold change ≥1; P < 0.05), including 14 known and 22 novel miRNAs, in Sp-Exo. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that the target genes of the miRNAs contribute towards various physiological and immunological functions, including wound healing and fin regeneration. Sp-Exo exhibited a rapid wound healing (cell migration) capacity in human fibroblast cells, and its mRNA and protein expression patterns corroborated its activity. Higher larval fin regeneration was more prevalent in Sp-Exo than in PBS-Exo, which further confirmed its functional significance. Our study provides the first basic physiochemical, morphometric, molecular (miRNA profiling), and wound healing evidences of Sp-Exo in olive flounder and highlights important miRNA cargoes in exosomes that may be potential therapeutic candidates in wound healing.

Obesity and Wound Healing: Focus on Mesenchymal Stem Cells

Chronic wounds represent nowadays a major challenge for both clinicians and researchers in the regenerative setting. Obesity represents one of the major comorbidities in patients affected by chronic ulcers and therefore diverse studies aimed at assessing possible links between these two morbid conditions are currently ongoing. In particular, adipose tissue has recently been described as having metabolic and endocrine functions rather than serving as a mere fat storage deposit. In this setting, adipose-derived stem cells, a peculiar subset of mesenchymal stromal/stem cells (MSCs) located in adipose tissue, have been demonstrated to possess regenerative and immunological functions with a key role in regulating both adipocyte function and skin regeneration. The aim of the present review is to give an overview of the most recent findings on wound healing, with a special focus on adipose tissue biology and obesity.

[Research advances of adipose stem cell matrix gel in promoting wound healing]

In recent years, with the problem of aging population in China being prominant, the number of patients with chronic wounds such as diabetic foot, pressure ulcer, and vascular ulcer is increasing. Those diseases seriously affect the life quality of patients and increase the economy and care burden of the patients' family, which have been one of the most urgent clinical problems. Many researches have confirmed that adipose stem cells can effectively promote wound healing, while exogenous protease is needed, and there are ethical and many other problems, which limit the clinical application of adipose stem cells. Adipose stem cell matrix gel is a gel-like mixture of biologically active extracellular matrix and stromal vascular fragment obtained from adipose tissue by the principle of fluid whirlpool and flocculation precipitation. It contains rich adipose stem cells, hematopoietic stem cells, endothelial progenitor cells, and macrophages, etc. The preparation method of adipose stem cell matrix gel is simple and the preparation time is short, which is convenient for clinical application. Many studies at home and abroad showed that adipose stem cell matrix gel can effectively promote wound healing by regulating inflammatory reaction, promoting microvascular reconstruction and collagen synthesis. Therefore, this paper summarized the preparation of adipose stem cell matrix gel, the mechanism and problems of the matrix gel in promoting wound repair, in order to provide new methods and ideas for the treatment of chronic refractory wounds in clinic.