Therapeutic role of exosomes and conditioned medium in keloid and hypertrophic scar and possible mechanisms

Pathogenesis, attenuation, and treatment strategies for keloid management

Keloid is an outcome of abnormal cellular response in the wound healing process with excessive fibroblast and collagen deposition in the dermal layer of the skin. It is characterized by a scar showing fibrous outgrowth that grows beyond the original boundaries of the wound. Thus, it is cosmetically and functionally disturbing to the patient. Keloidal development depends on various patient and environmental factors, possibly initiating abnormal wound healing. Due to abnormal wound healing, various aberrant cellular responses are observed during keloid development, like delayed inflammatory response, increased growth factors, varied cytokine level, decreased apoptosis, increased angiogenesis, and imbalanced proteinases. Bacteria and the immune system also play a role in keloid development. Advancements like single-cell RNA sequencing and transcriptomics studies have led to a better understanding of pathogenesis. In line with the complex pathogenesis, the later part of the review covers a detailed analysis of various treatment options employed for keloid, which includes silicone-based topical therapy, drug-based therapy, invasive approach (surgery), and minimally invasive therapies (radiation, laser therapy, and cryotherapy). The advantages and limitations of individual and combination therapies are also discussed. Keloids tend to re-occur after treatment; hence, follow-up is very important, making keloid treatment a complex procedure. Novel therapeutics in keloid have advantages like better efficacy of drugs, less pain, self-administration, and fewer side effects. A few nanotherapeutics advancements, such as microneedles, nanoparticles, liposomes, and exosomes, are discussed in the review.

Exploring the dermatological applications of human mesenchymal stem cell secretome: a comprehensive review

INTRODUCTION

Mesenchymal stem cell (MSC)-derived conditioned media is emerging as a promising alternative to stem cell therapy, owing to its abundant content of growth factors and cytokines.

OBJECTIVE

This review evaluates the clinical applications of MSC-conditioned media in improving scars, promoting wound healing, stimulating hair growth, and rejuvenating the skin.

MATERIALS AND METHODS

A thorough search of relevant databases was performed to identify studies meeting the inclusion criteria. From an initial pool of 75 articles, 16 studies published up to 2024 were selected based on their relevance, focus, and alignment with the research objectives.

RESULTS

Among the 17 selected studies, 5 examined the role of conditioned media in skin rejuvenation, 3 investigated its effects on hair growth, 5 assessed its efficacy in scar treatment, 2 assessed its efficacy in Inflammatory Dermatologic Disease and 2 explored its role in wound healing. All studies reported favorable outcomes, demonstrating significant improvements in scars, hair regrowth, and skin rejuvenation with the application of conditioned media.

CONCLUSION

This review underscores the potential of MSC-derived conditioned media in dermatology. Several studies also highlighted its enhanced therapeutic effects when combined with adjunctive treatments, such as laser therapy and microneedling, showcasing improved outcomes in dermatological care.

Effects of exosomes from human dental pulp stem cells on the biological behavior of human fibroblasts

The aim of this study was to investigate the effect of dental pulp stem cell-derived exosomes (DPSCs-Exos) on the biological behaviour of fibroblasts, particularly on keloid fibroblasts (KFs) and normal skin fibroblasts (NFs), with a view to providing new insights into cellular regenerative medicine. We obtained DPSCs-Exos by ultracentrifugation and co-cultured it with KFs and NFs. We detected its effect on cell proliferation using the CCK-8 assay; cell migration ability by cell scratch and Transwell assays; extracellular matrix synthesis using the hydroxyproline content assay; the expression levels of genes associated with fibrosis by PCR assay; and the expression levels of proteins related to fibrosis in the cells using the Western Blot method. DPSCs-Exos was able to be taken up by fibroblasts after addition to the culture medium and affected the biological behavior of NFs and KFs. DPSCs-Exos promoted the proliferation of NFs, inhibited the migration and extracellular matrix synthesis of KFs. In addition, DPSCs-Exos was able to inhibit the expression of fibrosis-related genes and proteins in KFs. This study highlights the role of DPSCs-Exos in regulating the biological behaviour of fibroblasts, providing new insights for future applications in the field of cell-free regenerative medicine.

Exosomes for Aesthetic Dermatology: A Comprehensive Literature Review and Update

BACKGROUND

Exosomes are nanoscale vesicles derived from various cell types and tissues that have many potential applications, generating great interest from researchers. One particularly intriguing application of exosomes is their use as a direct therapeutic for aesthetic indications. Several studies and case reports have explored the impact of exosomes for numerous cosmetic concerns but a consensus on the outcomes of these studies has not been established.

AIMS

In this review, we summarize the proposed mechanism of action, application, and efficacy of treatments with exosomes for alopecia and hair rejuvenation, facial rejuvenation, hyperpigmentation, and scarring.

METHODS

We conducted a comprehensive literature review on the use of exosomes for the treatment of alopecia and hair rejuvenation, facial rejuvenation, hyperpigmentation, and scarring. Additionally, several practical clinical cases where exosomes were applied for these indications were included.

RESULTS

The general consensus from the literature review showed that the early evidence supports the efficacy of exosomes for the treatment of alopecia, facial rejuvenation, hyperpigmentation, and scarring. The clinical cases included demonstrated promising improvements in the patients that received treatment. Several limitations regarding the lack of standardization in the production and application of exosomes may limit their current use until more studies are conducted.

CONCLUSIONS

Exosomes may serve as a potentially beneficial therapeutic option for several aesthetic dermatologic indications but further investigation is required to fully characterize the scope of their application.

Localized Administration of Mesenchymal Stem Cell-Derived Exosomes for the Treatment of Refractory Perianal Fistula in Patients With Crohn's Disease: A Phase II Clinical Trial

BACKGROUND

Crohn's disease perianal fistulas are often resistant to standard anti-tumor necrosis factor-α therapies. Mesenchymal stem cell-derived exosomes are extracellular vesicles with highly potent anti-inflammatory effects, and the previous phase of this study demonstrated their safety in the treatment of refractory perianal fistulas.

OBJECTIVE

To evaluate the efficacy of mesenchymal stem cell-derived exosomes for the treatment of refractory perianal fistulas.

DESIGN

Nonrandomized, nonblinded single-center phase II clinical trial.

SETTINGS

Tertiary university hospital.

PATIENTS

Twenty-three patients were enrolled, 20 of whom completed the study. Refractory perianal fistula was defined as resistance to at least 1 course of treatment with anti-tumor necrosis factor-α therapy.

INTERVENTIONS

After clinical assessment and MRI, the patients received general anesthesia, and 5 mL of exosome solution was injected directly into the fistula tracts. The injections were repeated 3 times at 2-month intervals, and patients were followed monthly for 6 months after the last injection. Tissue samples from the tracts were obtained before each injection and subjected to immunohistopathological assessment. MRI data were obtained before and 6 months after the last injection.

MAIN OUTCOME MEASURES

The primary outcome of this study was fistula tract closure on clinical examination and MRI. The secondary outcome was an improvement in the discharge from the tracts.

RESULTS

Fistula tracts were fully closed in 12 patients (60%). Four patients showed clinical improvement, with some tracts remaining open, and 4 patients were completely resistant to treatment. A total of 43 fistula tracts were treated during the trial, 30 of which (69.7%) showed complete closure. Histopathological analysis revealed substantial reductions in local inflammation and signs of enhanced tissue regeneration. Immunohistochemical analysis of CD68, CD20, and CD31 reaffirmed these results.

CONCLUSIONS

Mesenchymal stem cell-derived exosomes are safe and effective for treating refractory perianal fistulas in patients with Crohn's disease. See Video Abstract .

ADMINISTRACIN LOCALIZADA DE EXOSOMAS DERIVADOS DE CLULAS MADRE MESENQUIMALES PARA EL TRATAMIENTO DE LA FSTULA PERIANAL REFRACTARIA EN PACIENTES CON ENFERMEDAD DE CROHN ENSAYO CLNICO DE FASE II

ANTECEDENTES:Las fístulas perianales de la enfermedad de Crohn a menudo son resistentes a las terapias anti-TNF-α estándares. Los exosomas derivados de células madre mesenquimales (MSC) son vesículas extracelulares que tienen efectos antiinflamatorios muy potentes, y la fase anterior de este estudio demostró su seguridad en el tratamiento de fístulas perianales refractarias.OBJETIVO:Evaluar la eficacia de los exosomas derivados de MSC para el tratamiento de fístulas perianales refractarias.DISEÑO:Ensayo clínico de fase II, no aleatorizado y no ciego, unicéntrico.LUGARES:Hospital universitario terciario.PACIENTES:Se inscribieron veintitrés pacientes, 20 de los cuales completaron el estudio. La fístula perianal refractaria se definió como la resistencia a al menos un ciclo de tratamiento con terapia anti-TNF-α.INTERVENCIONES:Después de la evaluación clínica y la resonancia magnética, los pacientes fueron sometidos a anestesia general y se inyectaron 5 ml de solución de exosoma directamente en los trayectos de la fístula. Las inyecciones se repitieron tres veces a intervalos de 2 meses y los pacientes fueron seguidos mensualmente durante 6 meses después de la última inyección. Se obtuvieron muestras de tejido de los tractos antes de cada inyección y se sometieron a evaluación inmunohistopatológica. Los datos de imágenes de resonancia magnética se obtuvieron antes y seis meses después de la última inyección.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario de este estudio fue el cierre del trayecto de la fístula en el examen clínico y la imagen de resonancia magnética. El resultado secundario fue una mejora en la descarga de los tractos.RESULTADOS:Los trayectos de la fístula se cerraron completamente en 12 (60%) de los pacientes. Cuatro pacientes mostraron mejoría clínica, algunos tractos permanecieron abiertos y cuatro pacientes fueron completamente resistentes al tratamiento. Durante el ensayo se trataron un total de 43 trayectos fistulosos, 30 (69,7%) de los cuales mostraron un cierre completo. El análisis histopatológico reveló reducciones sustanciales en la inflamación local y signos de una mayor regeneración tisular. El análisis inmunohistoquímico del grupo de diferenciación 68, 20 y 31 reafirmó estos resultados.CONCLUSIONES:Los exosomas derivados de MSC son seguros y eficaces para el tratamiento de fístulas perianales refractarias en pacientes con enfermedad de Crohn. (Traducción-Dr. Aurian Garcia Gonzalez ).

The Usefulness of Exosomes in Accelerating Healing and Preventing Complications in Behçet's Disease: A Case Report

Behçet's disease (BD) is a systemic auto-inflammatory vasculitis. The clinical pictures of BD involve the skin and mucosal membranes such as oral and genital ulcers, ocular lesions, cardiovascular, gastrointestinal, muscular, nervous systems, and joints. A 38-year-old woman was repeatedly suffering from oral, genital, and ocular lesions, wound dehiscence after any surgical procedure, and joint pain. She has a family history where multiple relatives were affected by BD. The patient had an abdominoplasty two years ago with delayed wound healing and keloid formation. The patient presented with an asymmetrical labia majora with multiple lumps after fat transfer, multiple vaginal cysts, and a chronic Bartholin's cyst for three years. She consulted surgeons to correct the deformity and for cyst excision, but there was a great risk of keloid formation, dehiscence, and infections. This was a challenge for her surgery. The patient was on colchicine and corticosteroids. BD affects multiple systems, most commonly the healing of the skin and the mucous membranes. This causes difficulties in deciding to undergo surgery because of the risks. The diversity of the manifestations of BD requires a spectrum of pre-surgical adjustments in inflammatory markers, medication doses, and improving general patient conditions. Furthermore, the intra-operative and post-operative use of the recent regenerative medicine methods might provide the best surgical healing outcomes in these groups of patients. This is most challenging with BD but can be achieved regardless.

The mechanism of TGF-β mediating BRD4/STAT3 signaling pathway to promote fibroblast proliferation and thus promote keloid progression

The purpose of this study was to investigate the effect of TGF-β on keloid and its molecular mechanism in fibroblasts.

METHODS

The difference between normal tissue and keloid tissue can be detected using HE staining. Fibroblasts were treated with TGF-β, and then treated with the BRD4 inhibitor JQ1 and the STAT3 activator Colivelin TFA. Western blot was used to measure the relative protein expression of TGF-β, BRD4, p-STAT3, p-EZH2, C-myc, KLF2, KLF4, α-SMA, and Collagen-I. Immunofluorescence staining was used to measure the relative fluorescence intensity of BRD4, p-STAT3, α-SMA, and Collagen-I. Cell proliferation ability was evaluated by CCK-8 assay and colony formation assay.

RESULTS

The expression of TGF-β and BRD4 was significantly higher in keloid tissue compared to normal tissue. TGF-β mediated the BRD4/STAT3 signaling pathway to inhibit p-EZH2 and promote the expression of C-myc, KLF2, KLF4, α-SMA, and Collagen-I. Additionally, TGF-β mediated the BRD4/STAT3 signaling pathway to enhance fibroblast proliferation.

CONCLUSION

TGF-β mediates the BRD4/STAT3 signaling pathway to promote fibroblast proliferation and contribute to the progression of keloid.

Effects, methods and limits of the cryopreservation on mesenchymal stem cells

Mesenchymal stem cells (MSCs) are a type of cell capable of regulating the immune system, as well as exhibiting self-renewal and multi-lineage differentiation potential. Mesenchymal stem cells have emerged as an essential source of seed cells for therapeutic cell therapy. It is crucial to cryopreserve MSCs in liquid nitrogen prior to clinical application while preserving their functionality. Furthermore, efficient cryopreservation greatly enhances MSCs' potential in a range of biological domains. Nevertheless, there are several limits on the MSC cryopreservation methods now in use, necessitating thorough biosafety assessments before utilizing cryopreserved MSCs. Therefore, in order to improve the effectiveness of cryopreserved MSCs in clinical stem cell treatment procedures, new technological techniques must be developed immediately. The study offers an exhaustive analysis of the state-of-the-art MSC cryopreservation techniques, their effects on MSCs, and the difficulties encountered when using cryopreserved MSCs in clinical applications.

New challenges in scar therapy: the novel scar therapy strategies based on nanotechnology

The pathological mechanism of pathological scar is highly complex, encompassing the abnormalities of diverse cytokines, signaling pathways and regulatory factors. To discover more preferable scar treatment options, a variety of distinct approaches have been utilized clinically. Nevertheless, these treatments possess certain side effects and are inclined to relapse. Presently, pathological scar treatment remains a clinical conundrum, and there is an urgent demand for treatment methods that are safe, less traumatic and have lower recurrence rates. New drug delivery systems, novel therapeutic drugs and therapy strategies can enable drugs to permeate the skin effectively, decrease side effects, enhance drug efficacy and even achieve pain-free self-administration. Currently, novel nanotechnologies such as nanomicroneedles, photodynamics mediated by novel photosensitizers, bioelectrical stimulation and 3D printed dressings have been developed for the effective treatment of pathological scars. Additionally, innovative nanoscale fillers, including nano-fat and engineered exosomes, can serve as novel therapeutic agents for the efficient treatment of pathological scars. The intervention of nanomaterials can enhance drug absorption, stabilize and safeguard the active ingredients of drugs, delay or control drug release and enhance bioavailability. This article reviews these new treatment strategies for scar to explore novel approaches for efficient and safe for keloid treatment.

The Effects of Mesenchymal Stem Cells-Derived Exosomes on Metabolic Reprogramming in Scar Formation and Wound Healing

Pathological scarring results from aberrant cutaneous wound healing due to the overactivation of biological behaviors of human skin fibroblasts, characterized by local inordinate inflammation, excessive extracellular matrix and collagen deposition. Yet, its underlying pathogenesis opinions vary, which could be caused by increased local mechanical tension, enhanced and continuous inflammation, gene mutation, as well as cellular metabolic disorder, etc. Metabolic reprogramming is the process by which the metabolic pattern of cells undergoes a systematic adjustment and transformation to adapt to the changes of the external environment and meet the needs of their growth and differentiation. Therefore, the abnormality of metabolic reprogramming in cells within wounds and scars attaches great importance to scar formation. Mesenchymal stem cells-derived exosomes (MSC-Exo) are the extracellular vesicles that play an important role in tissue repair, cancer treatment as well as immune and metabolic regulation. However, there is not a systematic work to detail the relevant studies. Herein, we gave a comprehensive summary of the existing research on three main metabolisms, including glycometabolism, lipid metabolism and amino acid metabolism, and MSC-Exo regulating metabolic reprogramming in wound healing and scar formation for further research reference.

Insights into the role of adipose-derived stem cells and secretome: potential biology and clinical applications in hypertrophic scarring

Scar tissue is the inevitable result of repairing human skin after it has been subjected to external destructive stimuli. It leads to localized damage to the appearance of the skin, accompanied by symptoms such as itching and pain, which reduces the quality of life of the patient and causes serious medical burdens. With the continuous development of economy and society, there is an increasing demand for beauty. People are looking forward to a safer and more effective method to eliminate pathological scarring. In recent years, adipose-derived stem cells (ADSCs) have received increasing attention from researchers. It can effectively improve pathological scarring by mediating inflammation, regulating fibroblast proliferation and activation, and vascular reconstruction. This review focuses on the pathophysiological mechanisms of hypertrophic scarring, summarizing the therapeutic effects of in vitro, in vivo, and clinical studies on the therapeutic effects of ADSCs in the field of hypertrophic scarring prevention and treatment, the latest application techniques, such as cell-free therapies utilizing ADSCs, and discussing the advantages and limitations of ADSCs. Through this review, we hope to further understand the characterization of ADSC and clarify the effectiveness of its application in hypertrophic scarring treatment, so as to provide clinical guidance.

Hydrogel Loaded with Components for Therapeutic Applications in Hypertrophic Scars and Keloids

Hypertrophic scars and keloids are common fibroproliferative diseases following injury. Patients with pathologic scars suffer from impaired quality of life and psychological health due to appearance disfiguration, itch, pain, and movement disorders. Recently, the advancement of hydrogels in biomedical fields has brought a variety of novel materials, methods and therapeutic targets for treating hypertrophic scars and keloids, which exhibit broad prospects. This review has summarized current research on hydrogels and loaded components used in preventing and treating hypertrophic scars and keloids. These hydrogels attenuate keloid and hypertrophic scar formation and progression by loading organic chemicals, drugs, or bioactive molecules (such as growth factors, genes, proteins/peptides, and stem cells/exosomes). Among them, smart hydrogels (a very promising method for loading many types of bioactive components) are currently favoured by researchers. In addition, combining hydrogels and current therapy (such as laser or radiation therapy, etc.) could improve the treatment of hypertrophic scars and keloids. Then, the difficulties and limitations of the current research and possible suggestions for improvement are listed. Moreover, we also propose novel strategies for facilitating the construction of target multifunctional hydrogels in the future.