Umbilical Cord-Derived Mesenchymal Stem Cell-Derived Exosomes Combined Pluronic F127 Hydrogel Promote Chronic Diabetic Wound Healing and Complete Skin Regeneration

Dual-functional gallium/chitosan/silk/umbilical cord mesenchymal stem cell exosome sponge scaffold for diabetic wound by angiogenesis and antibacteria

The treatment of diabetic wounds possessed significant challenges in clinical practice, which was accompanied with continuous infection, inflammation, and limited angiogenesis. Current wound dressings used for diabetic wound healing struggle to address these issues simultaneously. Therefore, Ga3+ was added to the chitosan/silk solution to confer potent antibacterial properties. Subsequently, umbilical cord mesenchymal stem cell exosomes (UCSC-Exo) were integrated into the gallium/chitosan/silk solution to enhance its angiogenesis-inducing activity. The mixture was lyophilized to prepare gallium/chitosan/silk/exosome sponge scaffolds (Ga/CSSF-Exo sponge scaffolds). The experiments of In vitro and in vivo demonstrated that Ga/CSSF-Exo sponge scaffolds exhibited sustained release of Ga3+ and bioactive exosomes, which effectively exerted continuous antibacterial effects and promoted angiogenesis. In diabetic rat wound models, Ga/CSSF-Exo sponge scaffolds facilitated angiogenesis, suppressed bacterial growth and inflammation, as well as promoted collagen deposition and re-epithelialization of wounds. Collectively, our findings suggested that Ga/CSSF-Exo held excellent potential for diabetic wound healing.

From stem cells to extracellular vesicles: a new horizon in tissue engineering and regenerative medicine

In the fields of tissue engineering and regenerative medicine, extracellular vesicles (EVs) have become viable therapeutic tools. EVs produced from stem cells promote tissue healing by regulating the immune system, enhancing cell proliferation and aiding remodeling processes. Recently, EV has gained significant attention from researchers due to its ability to treat various diseases. Unlike stem cells, stem cell-derived EVs show lower immunogenicity, are less able to overcome biological barriers, and have a higher safety profile. This makes the use of EVs derived from cell-free stem cells a promising alternative to whole-cell therapy. This review focuses on the biogenesis, isolation, and characterization of EVs and highlights their therapeutic potential for bone fracture healing, wound healing, and neuronal tissue repair and treatment of kidney and intestinal diseases. Additionally, this review discusses the potential of EVs for the treatment of cancer, COVID-19, and HIV. In summary, the use of EVs derived from stem cells offers a new horizon for applications in tissue engineering and regenerative medicine.

The Optimal Effective Dose of Adipose-Derived Stem Cell Exosomes in Wound Healing

INTRODUCTION

Although the effect of adipose-derived mesenchymal stem cell exosomes (ADSC-exos) on wound healing with different doses are shown in various studies, efficient and sufficient doses of ADSC-exos are still unknown. The study aimed to determine the optimal dose of ADSC-exos in wound healing.

METHODS

The 45 Sprague-Dawley rats were randomly divided into five groups, with seven animals in each. After dorsal circular defects were created, each wound was injected as follows: group 1: saline, group 2: 10 μg/mL of ADSC-exos, group 3: 100 μg/mL of ADSC-exos, group 4: 200 μg/mL of ADSC-exos, and group 5: 400 μg/mL of ADSC-exos. The effects of ADSC-exos on epithelization, angiogenesis, and collagen formation were analyzed macroscopically, histopathologically, and immunohistochemically on day 14.

RESULTS

A total of 200 μg/mL and 400 μg/mL ADSC-exos groups had higher epithelial tongue length, epithelial tongue area, and angiogenesis scores than the other groups. Although there was no statistical difference in fibrosis scores among groups, collagen fibers were becoming well-organized as the ADSC-exos doses increased. While the wound area was clinically smaller in the 200 μg/mL ADSC-exos group, there was no statistically significant difference among groups on day 14.

CONCLUSIONS

A total of 200 μg/mL of ADSC-exos was found to be the adequate and effective dose for re-epithelialization and angiogenesis in cutaneous wound healing. Moreover, the collagen density increased with a more regular pattern in the 200 μg/mL group, which can be important in scar regulation.

Desktop-Stereolithography 3D Printing of a Decellularized Extracellular Matrix/Mesenchymal Stem Cell Exosome Bioink for Vaginal Reconstruction

BACKGROUND

3D-printing is widely used in regenerative medicine and is expected to achieve vaginal morphological restoration and true functional reconstruction. Mesenchymal stem cells-derived exosomes (MSCs-Exos) were applyed in the regeneration of various tissues. The current study aimed to explore the effctive of MSCs-Exos in vaginal reconstruction.

METHODS

In this work, hydrogel was designed using decellularized extracellular matrix (dECM) and gelatin methacrylate (GelMA) and silk fibroin (SF). The biological scaffolds were constructed using desktop-stereolithography. The physicochemical properties of the hydrogels were evaluated; Some experiments have been conducted to evaluate exosomes' effect of promotion vaginal reconstruction and to explore the mechanism in this process.

RESULTS

It was observed that the sustained release property of exosomes in the hydrogel both in vitro and in vitro.The results revealed that 3D scaffold encapsulating exosomes expressed significant effects on the vascularization and musule regeneration of the regenerative vagina tissue. Also, MSCs-Exos strongly promoted vascularization in the vaginal reconstruction of rats, which may through the PI3K/AKT signaling pathway.

CONCLUSION

The use of exosome-hydrogel composites improved the epithelial regeneration of vaginal tissue, increased angiogenesis, and promoted smooth muscle tissue regeneration. 3D-printed, lumenal scaffold encapsulating exosomes might be used as a cell-free alternative treatment strategy for vaginal reconstruction.

Exosomes derived from cord blood Treg cells promote diabetic wound healing by targeting monocytes

Chronic nonhealing diabetic wounds are a critical clinical challenge. Regulatory T cells (Tregs) are immunosuppressive modulators affecting wound healing progression by controlling the inflammatory response. The current study attempted to investigate whether the exosomes derived from cord blood (CB) Tregs can accelerate the healing process. Exosomes were isolated from CB-Treg cultures using ultracentrifugation and validated with different specific markers of exosomes. The purified CB-Treg-derived exosomes were co-cultured with peripheral blood mononuclear cells (PBMCs) and CD14+ monocytes. The migration-promoting effect of CB-Treg-derived exosomes on fibroblasts and endothelial cells was investigated. We used thermosensitive Pluronic F-127 hydrogel (PF-127) loaded with CB-Treg-derived exosomes in a diabetic wound healing mouse model. CB-Treg-derived exosomes with 30-120 nm diameters revealed exosome-specific markers, such as TSG101, Alix, and CD63. CB-Treg-derived exosomes were mainly bound to the monocytes when co-cultured with PBMCs, and promoted monocyte polarization to the anti-inflammatory phenotype (M2) in vitro. CB-Treg-derived exosomes enhanced the migration of endothelial cells and fibroblasts. Furthermore, CB-Treg-derived exosomes treatment accelerated wound healing by downregulating inflammatory factor levels and upregulating the M2 macrophage ratio in vivo. Our findings indicated that CB-Treg-derived exosomes could be a promising cell-free therapeutic strategy for diabetic wound healing, partly by targeting monocytes.

Application of Mesenchymal Stem Cells and Exosome alone or Combination Therapy as a Treatment Strategy for Wound Healing

The process of wound healing consists of multiple phases, and any disruptions in these phases can lead to the wound becoming chronic and impose heavy financial and psychological costs on the patient and a huge economic burden on the country's healthcare system. Various treatments such as drugs, matrix and scaffolds, blood products, cell therapy, and a combination of these treatments are used for wound healing. The use of mesenchymal stem cells (MSCs) is one of these methods that have produced appropriate responses in the healing of patients' wounds. MSCs by secreting growth factors, cytokines, chemokines, and RNAs elicit changes in cell proliferation, migration, growth, signaling, immunomodulation, and wound re-epithelialization process, and as a result, accelerate wound closure and wound healing. These cells can be isolated from different body sources with different cell characteristics and used directly on the wound site or by injection. In addition, MSCs-derived exosomes have attracted growing attention due to circumventing concerns relating to the direct use of MSCs. To increase the performance of MSCs, they can be used together with other compounds such as platelets, matrices, or scaffolds. This study examined the functions of MSCs in wound healing, as well as the vesicles they secrete, cellular and molecular mechanisms, and combined treatments with MSCs for wound healing.

The Role of Hydrogel Biomaterials in the Intervention of Wound Healing and Skin Regeneration via Exosomes: A Systematic Review and Meta-Analysis of Preclinical Animal Studies

Significance: The combination of hydrogel biomaterials with exosomes to facilitate wound healing and skin regeneration is a promising approach. Recent Advances: Recent preclinical animal studies have focused on investigating the efficacy of hydrogel-based delivery systems for exosomes in promoting wound healing and skin regeneration. Critical Issues: Despite encouraging results, critical issues remain unresolved, such as optimizing hydrogel properties to enhance the efficacy of combined therapy with exosomes for wound and bridging the translational gap between preclinical and clinical applications. Future Directions: Future research endeavors should concentrate on refining hydrogel design to enhance exosome delivery efficacy, conducting rigorous clinical trials to assess the safety and efficacy of exosome-loaded hydrogels in human wound healing and skin regeneration, and exploring innovative strategies to maximize therapeutic outcomes.

The role of exosomes derived from stem cells in nerve regeneration: A contribution to neurological repair

Stem cell-derived exosomes have gained attention in regenerative medicine for their role in encouraging nerve regeneration and potential use in treating neurological diseases. These nanosized extracellular vesicles act as carriers of bioactive molecules, facilitating intercellular communication and enhancing the regenerative process in neural tissues. This comprehensive study explores the methods by which exosomes produced from various stem cells contribute to nerve healing, with a particular emphasis on their role in angiogenesis, inflammation, and cellular signaling pathways. By examining cutting-edge developments and exploring the potential of exosomes in delivering disease-specific miRNAs and proteins, we highlight their versatility in tailoring personalized therapeutic strategies. The findings presented here highlight the potential of stem cell-produced exosomes for use in neurological diseases therapy, establishing the door for future research into exosome-based neurotherapies.

Advances and clinical challenges of mesenchymal stem cell therapy

In recent years, cell therapy has provided desirable properties for promising new drugs. Mesenchymal stem cells are promising candidates for developing genetic engineering and drug delivery strategies due to their inherent properties, including immune regulation, homing ability and tumor tropism. The therapeutic potential of mesenchymal stem cells is being investigated for cancer therapy, inflammatory and fibrotic diseases, among others. Mesenchymal stem cells are attractive cellular carriers for synthetic nanoparticles for drug delivery due to their inherent homing ability. In this review, we comprehensively discuss the various genetic and non-genetic strategies of mesenchymal stem cells and their derivatives in drug delivery, tumor therapy, immune regulation, tissue regeneration and other fields. In addition, we discuss the current limitations of stem cell therapy and the challenges in clinical translation, aiming to identify important development areas and potential future directions.

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

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

Bioengineered mesenchymal stem cell-derived exosomes: emerging strategies for diabetic wound healing

Diabetic wounds are among the most common complications of diabetes mellitus and their healing process can be delayed due to persistent inflammatory reactions, bacterial infections, damaged vascularization and impaired cell proliferation, which casts a blight on patients'health and quality of life. Therefore, new strategies to accelerate diabetic wound healing are being positively explored. Exosomes derived from mesenchymal stem cells (MSC-Exos) can inherit the therapeutic and reparative abilities of stem cells and play a crucial role in diabetic wound healing. However, poor targeting, low concentrations of therapeutic molecules, easy removal from wounds and limited yield of MSC-Exos are challenging for clinical applications. Bioengineering techniques have recently gained attention for their ability to enhance the efficacy and yield of MSC-Exos. In this review, we summarise the role of MSC-Exos in diabetic wound healing and focus on three bioengineering strategies, namely, parental MSC-Exos engineering, direct MSC-Exos engineering and MSC-Exos combined with biomaterials. Furthermore, the application of bioengineered MSC-Exos in diabetic wound healing is reviewed. Finally, we discuss the future prospects of bioengineered MSC-Exos, providing new insights into the exploration of therapeutic strategies.

Lipid nanoparticle: advanced drug delivery systems for promotion of angiogenesis in diabetic wounds

Diabetic wound is one of the most challenge in healthcare, requiring innovative approaches to promote efficient healing. In recent years, lipid nanoparticle-based drug delivery systems have emerged as a promising strategy for enhancing diabetic wound repair by stimulating angiogenesis. These nanoparticles offer unique advantages, including improved drug stability, targeted delivery, and controlled release, making them promising in enhancing the formation of new blood vessels. In this review, we summarize the emerging advances in the utilization of lipid nanoparticles to deliver angiogenic agents and promote angiogenesis in diabetic wounds. Furthermore, we provide an in-depth exploration of key aspects, including the intricate design and fabrication of lipid nanoparticles, their underlying mechanisms of action, and a comprehensive overview of preclinical studies. Moreover, we address crucial considerations pertaining to safety and the translation of these innovative systems into clinical practice. By synthesizing and analyzing the available knowledge, our review offers valuable insights into the future prospects and challenges associated with utilizing the potential of lipid nanoparticle-based drug delivery systems for promoting robust angiogenesis in the intricate process of diabetic wound healing.

Cellular In Vitro Responses Induced by Human Mesenchymal Stem/Stromal Cell-Derived Extracellular Vesicles Obtained from Suspension Culture

Mesenchymal stem/stromal cells (MSCs) and their extracellular vesicles (MSC-EVs) have been described to have important roles in tissue regeneration, including tissue repair, control of inflammation, enhancing angiogenesis, and regulating extracellular matrix remodeling. MSC-EVs have many advantages for use in regeneration therapies such as facility for dosage, histocompatibility, and low immunogenicity, thus possessing a lower possibility of rejection. In this work, we address the potential activity of MSC-EVs isolated from adipose-derived MSCs (ADMSC-EVs) cultured on cross-linked dextran microcarriers, applied to test the scalability and reproducibility of EV production. Isolated ADMSC-EVs were added into cultured human dermal fibroblasts (NHDF-1), keratinocytes (HaCat), endothelial cells (HUVEC), and THP-1 cell-derived macrophages to evaluate cellular responses (i.e., cell proliferation, cell migration, angiogenesis induction, and macrophage phenotype-switching). ADMSC viability and phenotype were assessed during cell culture and isolated ADMSC-EVs were monitored by nanotracking particle analysis, electron microscopy, and immunophenotyping. We observed an enhancement of HaCat proliferation; NHDF-1 and HaCat migration; endothelial tube formation on HUVEC; and the expression of inflammatory cytokines in THP-1-derived macrophages. The increased expression of TGF-β and IL-1β was observed in M1 macrophages treated with higher doses of ADMSC-EVs. Hence, EVs from microcarrier-cultivated ADMSCs are shown to modulate cell behavior, being able to induce skin tissue related cells to migrate and proliferate as well as stimulate angiogenesis and cause balance between pro- and anti-inflammatory responses in macrophages. Based on these findings, we suggest that the isolation of EVs from ADMSC suspension cultures makes it possible to induce in vitro cellular responses of interest and obtain sufficient particle numbers for the development of in vivo concept tests for tissue regeneration studies.

Hydrogel Loaded with Extracellular Vesicles: An Emerging Strategy for Wound Healing

An increasing number of novel biomaterials have been applied in wound healing therapy. Creating beneficial environments and containing various bioactive molecules, hydrogel- and extracellular vesicle (EV)-based therapies have respectively emerged as effective approaches for wound healing. Moreover, the synergistic combination of these two components demonstrates more favorable outcomes in both chronic and acute wound healing. This review provides a comprehensive discussion and summary of the combined application of EVs and hydrogels to address the intricate scenario of wounds. The wound healing process and related biological mechanisms are outlined in the first section. Subsequently, the utilization of EV-loaded hydrogels during the wound healing process is evaluated and discussed. The moist environment created by hydrogels is conducive to wound tissue regeneration. Additionally, the continuous and controlled release of EVs from various origins could be achieved by hydrogel encapsulation. Finally, recent in vitro and in vivo studies reported on hydrogel dressings loaded with EVs are summarized and challenges and opportunities for the future clinical application of this therapeutic approach are outlined.

Exosome/antimicrobial peptide laden hydrogel wound dressings promote scarless wound healing through miR-21-5p-mediated multiple functions

Mesenchymal stem cell (MSC)-based therapy is an effective strategy for regenerative therapy. However, safety and ease of use are still issues to be overcome in clinical applications. Exosomes are naturally derived nanoparticles containing bioactive molecules, which serve as ideal cell-free therapeutic modalities. However, issues such as delivery, long-term preservation and activity maintenance of exosomes are other problems that limit their application. In this study, we proposed the use of rapid freeze-dry-thaw macroporous hydrogels for the encapsulation of HucMSC-derived exosomes (HucMSC-Exos) combined with an antimicrobial peptide coating. This exosome-encapsulated hyaluronic acid macroporous hydrogel HD-DP7/Exo can achieve long-term storage and transport by lyophilization and can be rapidly redissolved for treatment. After comprehensively comparing the therapeutic effects of HucMSC-Exos and HucMSC-loaded hydrogels, we found that HucMSC-Exos could also effectively regulate fibroblasts, vascular endothelial cells, and macrophages and inhibit myofibroblast-mediated fibrosis, thus promoting tissue regeneration and inhibiting scar formation in a mouse model of deep second-degree burn infection healing. These properties of lyophilized storage and whole-process-repair make HD-DP7/Exo have potential application value and application prospects.

Harnessing the potential of hydrogels for advanced therapeutic applications: current achievements and future directions

The applications of hydrogels have expanded significantly due to their versatile, highly tunable properties and breakthroughs in biomaterial technologies. In this review, we cover the major achievements and the potential of hydrogels in therapeutic applications, focusing primarily on two areas: emerging cell-based therapies and promising non-cell therapeutic modalities. Within the context of cell therapy, we discuss the capacity of hydrogels to overcome the existing translational challenges faced by mainstream cell therapy paradigms, provide a detailed discussion on the advantages and principal design considerations of hydrogels for boosting the efficacy of cell therapy, as well as list specific examples of their applications in different disease scenarios. We then explore the potential of hydrogels in drug delivery, physical intervention therapies, and other non-cell therapeutic areas (e.g., bioadhesives, artificial tissues, and biosensors), emphasizing their utility beyond mere delivery vehicles. Additionally, we complement our discussion on the latest progress and challenges in the clinical application of hydrogels and outline future research directions, particularly in terms of integration with advanced biomanufacturing technologies. This review aims to present a comprehensive view and critical insights into the design and selection of hydrogels for both cell therapy and non-cell therapies, tailored to meet the therapeutic requirements of diverse diseases and situations.

Repair Effect of Umbilical Cord Mesenchymal Stem Cells Embedded in Hydrogel on Mouse Insulinoma 6 Cells Injured by Streptozotocin

Umbilical cord mesenchymal stem cells (UC-MSCs) possess the capabilities of differentiation and immune modulation, which endow them with therapeutic potential in the treatment of type 2 diabetes mellitus (T2DM). In this study, to investigate the repair mechanism of UC-MSCs in hydrogel on pancreatic β-cells in diabetes, mouse insulinoma 6 (MIN-6) cells damaged by streptozotocin (STZ) in vitro were used in co-culture with UC-MSCs in hydrogel (UC-MSCs + hydrogel). It was found that UC-MSCs + hydrogel had a significant repair effect on injured MIN-6 cells, which was better than the use of UC-MSCs alone (without hydrogel). After repair, the expression of superoxide dismutase (SOD) and catalase (CAT) as well as the total antioxidant capacity (T-AOC) of the repaired MIN-6 cells were increased, effectively reducing the oxidative stress caused by STZ. In addition, UC-MSCs + hydrogel were able to curb the inflammatory response by promoting the expression of anti-inflammatory factor IL-10 and reducing inflammatory factor IL-1β. In addition, the expression of both nuclear antigen Ki67 for cell proliferation and insulin-related genes such as Pdx1 and MafA was increased in the repaired MIN-6 cells by UC-MSCs + hydrogel, suggesting that the repair effect promotes the proliferation of the injured MIN-6 cells. Compared with the use of UC-MSCs alone, UC-MSCs + hydrogel exhibit superior antioxidant stress resistance against injured MIN-6 cells, better proliferation effects and a longer survival time of UC-MSCs because the porous structure and hydrophilic properties of the hydrogel could affect the growth of cells and slow down their metabolic activities, resulting in a better repair effect on the injured MIN-6 cells.

Different origin-derived exosomes and their clinical advantages in cancer therapy

Exosomes, as a class of small extracellular vesicles closely related to the biological behavior of various types of tumors, are currently attracting research attention in cancer diagnosis and treatment. Regarding cancer diagnosis, the stability of their membrane structure and their wide distribution in body fluids render exosomes promising biomarkers. It is expected that exosome-based liquid biopsy will become an important tool for tumor diagnosis in the future. For cancer treatment, exosomes, as the "golden communicators" between cells, can be designed to deliver different drugs, aiming to achieve low-toxicity and low-immunogenicity targeted delivery. Signaling pathways related to exosome contents can also be used for safer and more effective immunotherapy against tumors. Exosomes are derived from a wide range of sources, and exhibit different biological characteristics as well as clinical application advantages in different cancer therapies. In this review, we analyzed the main sources of exosomes that have great potential and broad prospects in cancer diagnosis and therapy. Moreover, we compared their therapeutic advantages, providing new ideas for the clinical application of exosomes.

Umbilical cord mesenchymal stem cell exosomes alleviate necrotizing enterocolitis in neonatal mice by regulating intestinal epithelial cells autophagy

BACKGROUND

Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease that affects premature infants. Although mounting evidence supports the therapeutic effect of exosomes on NEC, the underlying mechanisms remain unclear.

AIM

To investigate the mechanisms underlying the regulation of inflammatory response and intestinal barrier function by umbilical cord mesenchymal stem cell (UCMSCs) exosomes, as well as their potential in alleviating NEC in neonatal mice.

METHODS

NEC was induced in 5-d-old C57BL/6 pups through hypoxia and gavage feeding of formula containing lipopolysaccharide (LPS), after which the mice received human UCMSC exosomes (hUCMSC-exos). The control mice were allowed to breastfeed with their dams. Ileal tissues were collected from the mice and analyzed by histopathology and immunoblotting. Colon tissues were collected from NEC neonates and analyzed by immunofluorescence. Molecular biology and cell culture approaches were employed to study the related mechanisms in intestinal epithelial cells.

RESULTS

We found that autophagy is overactivated in intestinal epithelial cells during NEC, resulting in reduced expression of tight junction proteins and an increased inflammatory response. The ability of hUCMSC-exos to ameliorate NEC in a mouse model was dependent on decreased intestinal autophagy. We also showed that hUCMSC-exos alleviate the inflammatory response and increase migration ability in intestinal epithelial cells induced by LPS.

CONCLUSION

These results contribute to a better understanding of the protective mechanisms of hUCMSC-exos against NEC and provide a new theoretical and experimental foundation for NEC treatment. These findings also enhance our understanding of the role of the autophagy mechanism in NEC, offering potential avenues for identifying new therapeutic targets.

Umbilical cord mesenchymal stem cell exosomes alleviate necrotizing enterocolitis in neonatal mice by regulating intestinal epithelial cells autophagy

BACKGROUND

Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease that affects premature infants. Although mounting evidence supports the therapeutic effect of exosomes on NEC, the underlying mechanisms remain unclear.

AIM

To investigate the mechanisms underlying the regulation of inflammatory response and intestinal barrier function by umbilical cord mesenchymal stem cell (UCMSCs) exosomes, as well as their potential in alleviating NEC in neonatal mice.

METHODS

NEC was induced in 5-d-old C57BL/6 pups through hypoxia and gavage feeding of formula containing lipopolysaccharide (LPS), after which the mice received human UCMSC exosomes (hUCMSC-exos). The control mice were allowed to breastfeed with their dams. Ileal tissues were collected from the mice and analyzed by histopathology and immunoblotting. Colon tissues were collected from NEC neonates and analyzed by immunofluorescence. Molecular biology and cell culture approaches were employed to study the related mechanisms in intestinal epithelial cells.

RESULTS

We found that autophagy is overactivated in intestinal epithelial cells during NEC, resulting in reduced expression of tight junction proteins and an increased inflammatory response. The ability of hUCMSC-exos to ameliorate NEC in a mouse model was dependent on decreased intestinal autophagy. We also showed that hUCMSC-exos alleviate the inflammatory response and increase migration ability in intestinal epithelial cells induced by LPS.

CONCLUSION

These results contribute to a better understanding of the protective mechanisms of hUCMSC-exos against NEC and provide a new theoretical and experimental foundation for NEC treatment. These findings also enhance our understanding of the role of the autophagy mechanism in NEC, offering potential avenues for identifying new therapeutic targets.

Pluronic F127 composite hydrogel for the repair of contraction suppressed full-thickness skin wounds in a rabbit model

Hydrogels are commonly used as carriers for cell delivery due to their similarities to the extracellular matrix. A contraction-suppressed full-thickness wound model was used to evaluate the therapeutic potential of Pluronic F127 (PF127) hydrogel loaded with adipose-derived stromal vascular fraction (AdSVF), mesenchymal stem cells (AdMSC), and conditioned media (AdMSC-CM) for the repair of wounds in a rabbit model. The experimental study was conducted on forty-eight healthy adult New Zealand white rabbits randomly divided into eight groups with six animals each and treated with AdSVF, AdMSC, and AdMSC-CM as an injectable or topical preparation. The healing potential of different adipose-derived cell-based and cell-free therapeutics was evaluated based on percentage wound healing, period of epithelialization, epidermal thickness, scar evaluation, histopathology analysis, histochemical evaluation, immunohistochemistry (collagen type I), and hydroxyproline assay by comparing with the positive and negative control. Collagen density analysis using different staining methods, immunohistochemistry, and hydroxyproline assay consistently showed that delivering AdMSC and AdMSC-CM in PF127 hydrogel enhanced epithelialization, collagen production, and organization, contributing to improved tissue strength and quality. Even though allogeneic AdSVF was found to promote wound healing in rabbits, it has a lower potential than AdMSC and AdMSC-CM. The wound healing potential of AdMSC and AdMSC-CM was enhanced when loaded in PF127 hydrogel and applied topically. Even though wounds treated with AdMSC outperformed AdMSC-CM, a significant difference in the healing quality was not observed in most instances, indicating almost similar therapeutic potential. The findings indicate that the wound healing potential of AdMSC and AdMSC-CM was enhanced when loaded in PF127 hydrogel and applied topically. These treatments promoted collagen production, tissue organization, and epidermal regeneration, ultimately improving overall healing outcomes.

A Big Prospect for Hydrogel Nano-System in Glioma

Patients diagnosed with glioma typically face a limited life expectancy (around 15 months on average), a bleak prognosis, and a high likelihood of recurrence. As such, glioma is recognized as a significant form of malignancy. Presently, the treatment options for glioma include traditional approaches such as surgery, chemotherapy, and radiotherapy. Regrettably, the efficacy of these treatments has been less than optimal. Nevertheless, a promising development in glioma treatment lies in the use of hydrogel nano-systems as sophisticated delivery systems. These nano-systems have demonstrated exceptional therapeutic effects in the treatment of glioma by various responsive ways, including temperature-response, pH-response, liposome-response, ROS-response, light-response, and enzyme-response. This study seeks to provide a comprehensive summary of both the therapeutic application of hydrogel nano-systems in managing glioma and the underlying immune action mechanisms.

A Novel Dehydrated Human Umbilical Cord Particulate Medical Device: Matrix Characterization, Performance, and Biocompatibility for the Management of Acute and Chronic Wounds

Chronic wounds present a significant socioeconomic burden forecasted to increase in prevalence and cost. Minimally manipulated human placental tissues have been increasingly employed and proven to be advantageous in the treatment of chronic wounds, showing improved clinical outcomes and cost-effectiveness. However, technological advances have been constrained by minimal manipulation and homologous use criteria. This study focuses on the characterization of a novel dehydrated human umbilical cord particulate (dHUCP) medical device, which offers a unique allogeneic technological advancement and the first human birth tissue device for wound management. Characterization analyses illustrated a complex extracellular matrix composition conserved in the dHUCP device compared to native umbilical cord, with abundant collagens and glycosaminoglycans imbibing an intricate porous scaffold. Dermal fibroblasts readily attached to the intact scaffold of the dHUCP device. Furthermore, the dHUCP device elicited a significant paracrine proliferative response in dermal fibroblasts, in contrast to fibrillar collagen, a prevalent wound device. Biocompatibility testing in a porcine full-thickness wound model showed resorption of the dHUCP device and normal granulation tissue maturation during healing. The dHUCP device is a promising advancement in wound management biomaterials, offering a unique combination of structural complexity adept for challenging wound topographies and a microenvironment supportive of tissue regeneration.

Preclinical and Clinical Studies on the Use of Extracellular Vesicles Derived from Mesenchymal Stem Cells in the Treatment of Chronic Wounds

To date, the widespread implementation of therapeutic strategies for the treatment of chronic wounds, including debridement, infection control, and the use of grafts and various dressings, has been time-consuming and accompanied by many challenges, with definite success not yet achieved. Extensive studies on mesenchymal stem cells (MSCs) have led to suggestions for their use in treating various diseases. Given the existing barriers to utilizing such cells and numerous pieces of evidence indicating the crucial role of the paracrine signaling system in treatments involving MSCs, extracellular vesicles (EVs) derived from these cells have garnered significant attention in treating chronic wounds in recent years. This review begins with a general overview of current methods for chronic wound treatment, followed by an exploration of EV structure, biogenesis, extraction methods, and characterization. Subsequently, utilizing databases such as Google Scholar, PubMed, and ScienceDirect, we have explored the latest findings regarding the role of EVs in the healing of chronic wounds, particularly diabetic and burn wounds. In this context, the role and mode of action of these nanoparticles in healing chronic wounds through mechanisms such as oxygen level elevation, oxidative stress damage reduction, angiogenesis promotion, macrophage polarization assistance, etc., as well as the use of EVs as carriers for engineered nucleic acids, have been investigated. The upcoming challenges in translating EV-based treatments for healing chronic wounds, along with possible approaches to address these challenges, are discussed. Additionally, clinical trial studies in this field are also covered.

Understanding molecular characteristics of extracellular vesicles derived from different types of mesenchymal stem cells for therapeutic translation

Mesenchymal stem cells (MSCs) have been studied for decades as candidates for cellular therapy, and their secretome, including secreted extracellular vesicles (EVs), has been identified to contribute significantly to regenerative and reparative functions. Emerging evidence has suggested that MSC-EVs alone, could be used as therapeutics that emulate the biological function of MSCs. However, just as with MSCs, MSC-EVs have been shown to vary in composition, depending on the tissue source of the MSCs as well as the protocols employed in culturing the MSCs and obtaining the EVs. Therefore, the importance of careful choice of cell sources and culture environments is receiving increasing attention. Many factors contribute to the therapeutic potential of MSC-EVs, including the source tissue, isolation technique, and culturing conditions. This review illustrates the molecular landscape of EVs derived from different types of MSC cells along with culture strategies. A thorough analysis of publicly available omic datasets was performed to advance the precision understanding of MSC-EVs with unique tissue source-dependent molecular characteristics. The tissue-specific protein and miRNA-driven Reactome ontology analysis was used to reveal distinct patterns of top Reactome ontology pathways across adipose, bone marrow, and umbilical MSC-EVs. Moreover, a meta-analysis assisted by an AI technique was used to analyze the published literature, providing insights into the therapeutic translation of MSC-EVs based on their source tissues.

Pluronic F127 hydrogel-loaded extracellular vesicles from adipose-derived mesenchymal stem cells promote tracheal cartilage regeneration via SCNN1B delivery

Extracellular vesicles (EVs) derived from adipose-derived mesenchymal stem cells (AMSC-EVs) have been highlighted as a cell-free therapy due to their regenerative capability to enhance tissue and organ regeneration. Herein, we aimed to examine the mechanism of PF127-hydrogel@AMSC-EVs in promoting tracheal cartilage defect repair. Based on bioinformatics methods, SCNN1B was identified as a key gene for the osteogenic differentiation of AMSCs induced by AMSC-EVs. EVs were isolated from rat AMSCs and then loaded onto thermo-sensitive PF-127 hydrogel to develop PF127-hydrogel@AMSC-EVs. It was established that PF127-hydrogel@AMSC-EVs could effectively deliver SCNN1B into AMSCs, where SCNN1B promoted AMSC osteogenic differentiation. The promotive effect was evidenced by enhanced ALP activity, extracellular matrix mineralization, and expression of s-glycosaminoglycan, RUNX2, OCN, collagen II, PERK, and ATF4. Furthermore, the in vivo experiments revealed that PF127-hydrogel@AMSC-SCNN1B-EVs stimulated tracheal cartilage regeneration in rats through PERK/ATF4 signaling axis activation. Therefore, PF127-hydrogel@AMSC-SCNN1B-EVs may be a novel cell-free biomaterial to facilitate tracheal cartilage regeneration and cartilage injury repair.

A multifunctional silk-hyaluronic acid self-healing hydrogel laden with alternatively activated macrophage-derived exosomes reshape microenvironment of diabetic wound and accelerate healing

The impairment of phenotype switching of pro-inflammatory M1 to pro-healing M2 macrophage induced by hyperglycemic microenvironment often elevates oxidative stress, impairs angiogenesis, and leads to chronic non-healing wounds in diabetic patients. Administration of M2 macrophage-derived exosomes (M2Exo) at wound site is known to polarize M1 to M2 macrophage and can accelerate wound healing by enhancing collagen deposition, angiogenesis, and re-epithelialization. In the present study, M2Exo were conjugated with oxidized hyaluronic acid and mixed with PEGylated silk fibroin to develop self-healing Exo-gel to achieve an efficient therapy for diabetic wounds. Exo-gel depicted porous networked morphology with self-healing and excellent water retention behaviour. Fibroblast cells treated with Exo-gel showed significant uptake of M2Exo that increased their proliferation and migration in vitro. Interestingly, in a diabetic wound model of wistar rats, Exo-gel treatment induced 75 % wound closure within 7 days with complete epithelial layer regeneration by modulating cytokine levels, stimulating fibroblast-keratinocyte interaction and migration, angiogenesis, and organized collagen deposition. Taken together, this study suggests that Exo-gel depict properties of an excellent wound healing matrix and can be used as a therapeutic alternative to treat chronic non-healing diabetic wounds.

The Therapeutic Potential of Human Umbilical Cord Mesenchymal Stromal Cells Derived Exosomes for Wound Healing: Harnessing Exosomes as a Cell-free Therapy

Wound healing is a complicated process that involves many different types of cells and signaling pathways. Mesenchymal stromal cells (MSCs) have shown great potential as a treatment to improve wound healing because they can modulate inflammation, promote the growth of new blood vessels, and stimulate the regeneration of tissue. Recent evidence indicates MSCs-derived extracellular vesicles known as exosomes may mediate many of the therapeutic effects of MSCs on wound healing. Exosomes contain bioactive molecules such as proteins, lipids, and RNAs that can be transferred to recipient cells to modulate cellular responses. This article reviews current evidence on the mechanisms and therapeutic effects of human umbilical cord MSCs (hUCMSCs)-derived exosomes on wound healing. In vitro and animal studies demonstrate that hUCMSC-derived exosomes promote fibroblast proliferation/migration, angiogenesis, and re-epithelialization while reducing inflammation and scar formation. These effects are mediated by exosomal transfer of cytokines, growth factors, and regulatory microRNAs that modulate signaling pathways involved in wound healing. Challenges remain in exosome isolation methods, optimizing targeting/retention, and translation to human studies. Nevertheless, hUCMSCs-derived exosomes show promise as a novel cell-free therapeutic approach to accelerate wound closure and improve healing outcomes. Further research is warranted to fully characterize hUCMSCs-exosomal mechanisms and explore their clinical potential for wound management.

Exosomes isolated from IMMUNEPOTENT CRP, a hemoderivative, to accelerate diabetic wound healing

The increasing risk of amputation due to diabetic foot ulcer calls for new therapeutic options; for that, we determined the role of IMMUNEPOTENT CRP (ICRP) and its parts in the wound healing process of superficial wounds in diabetic BALB/c mice. A potency test was performed to confirm the batch of ICRP, and then its parts were separated into pellets, supernatants, and exosomes, and another group of exosomes loaded with insulin was added. Viability and scratch healing were assessed in NIH-3T3, HUVEC, and HACAT cell lines. Diabetes was induced with streptozotocin, and wounds were made by dissecting the back skin. Treatments were topically applied, and closure was monitored; inflammatory cytokines in sera were also evaluated by flow cytometry, and histological analysis was performed by Masson's staining and immunohistochemistry for p-AKT, p-FOXO, p-P21, and p-TSC2. ICRP pellets and exosomes increased cellular viability, and exosomes and exosome-insulin accelerated scratch healing in vitro. Exosome-insulin releases insulin constantly over time in vitro. In vivo, treatments accelerated wound closure, and better performance was observed in pellet, exosome, and exosome-insulin treatments. Best collagen expression was induced by ICRP. P-AKT and p-FOXO were overexpressed in healing tissues. Inflammatory cytokines were downregulated by all treatments. In conclusion, IMMUNEPOTENT CRP components, especially exosomes, and the process of encapsulation of exosome-insulin accelerate diabetic wound healing and enhance cellular proliferation, collagen production, and inflammation modulation through the phosphorylation of components of the AKT pathway.

Hydrogel-based immunoregulation of macrophages for tissue repair and regeneration

The rational design of hydrogel materials to modulate the immune microenvironment has emerged as a pivotal approach in expediting tissue repair and regeneration. Within the immune microenvironment, an array of immune cells exists, with macrophages gaining prominence in the field of tissue repair and regeneration due to their roles in cytokine regulation to promote regeneration, maintain tissue homeostasis, and facilitate repair. Macrophages can be categorized into two types: classically activated M1 (pro-inflammatory) and alternatively activated M2 (anti-inflammatory and pro-repair). By regulating the physical and chemical properties of hydrogels, the phenotypic transformation and cell behavior of macrophages can be effectively controlled, thereby promoting tissue regeneration and repair. A full understanding of the interaction between hydrogels and macrophages can provide new ideas and methods for future tissue engineering and clinical treatment. Therefore, this paper reviews the effects of hydrogel components, hardness, pore size, and surface morphology on cell behaviors such as macrophage proliferation, migration, and phenotypic polarization, and explores the application of hydrogels based on macrophage immune regulation in skin, bone, cartilage, and nerve tissue repair. Finally, the challenges and future prospects of macrophage-based immunomodulatory hydrogels are discussed.

Resveratrol Promotes Diabetic Wound Healing by Inhibiting Notch Pathway

INTRODUCTION

Diabetic foot ulcer (DFU) is a severe complication that threatens the daily lives of patients with diabetes and represents a serious challenge to the global health system. Considering that impaired wound healing is the leading cause of DFU, exploring the mechanism of diabetic wound healing is beneficial for improving DFU treatment. Resveratrol (RES) is a native polyphenol with various pharmacological characteristics, and recent studies have indicated an accelerated function of RES in diabetic wound healing. As human dermal fibroblasts (HDFs) play a significant role in diabetic wound healing, this study aimed to elucidate the regulatory mechanism of RES in HDFs.

METHODS

To mimic diabetic wound healing in vitro, the HDFs were stimulated with high glucose (HG). Our findings revealed that RES reversed HG-induced suppression of HDF proliferation and migration caused by HG. RES inhibits the Notch signaling pathway. More importantly, we demonstrated that the activation of the Notch pathway abrogated the effects of RES on HG-induced HDFs.

RESULTS

In vivo assays also illustrated that RES contributed to wound healing in diabetic mice by blocking the Notch pathway.

CONCLUSIONS

In conclusion, RES improved diabetic wound healing by targeting the Notch pathway, which offers novel insights into DFU therapy.

Host-microbiota interactions in collagen-induced arthritis rats treated with human umbilical cord mesenchymal stem cell exosome and ginsenoside Rh2

Mesenchymal stem cell exosome (MSCs-exo) is a class of products secreted by mesenchymal stem cells (MSCs) that contain various biologically active substances. MSCs-exo is a promising alternative to MSCs due to their lower immunogenicity and lack of ethical constraints. Ginsenoside Rh2 (Rh2) is a hydrolyzed component of the primary active substance of ginsenosides. Rh2 has a variety of pharmacological functions, including anti-inflammatory, anti-tumor, and antioxidant. Studies have demonstrated that gut microbiota and metabolites are critical in developing rheumatoid arthritis (RA). In this study, we constructed a collagen-induced arthritis (CIA) model in rats. We used MSCs-exo combined with Rh2 to treat CIA rats. To observe the effect of MSCs-exo combined with Rh2 on joint inflammation, rat feces were collected for 16 rRNA amplicon sequencing and untargeted metabolomics analysis. The results showed that the arthritis index score and joint swelling of CIA rats treated with MSCs-exo in combination with Rh2 were significantly lower than those of the model and MSCs-exo alone groups. MSCs-exo and Rh2 significantly ameliorated the disturbed gut microbiota in CIA rats. The regulation of Candidatus_Saccharibacteria and Clostridium_XlVb regulation may be the most critical. Rh2 enhanced the therapeutic effect of MSCs-exo compared with the MSCs-exo -alone group. Furthermore, significant changes in gut metabolites were observed in the CIA rat group, and these differentially altered metabolites may act as messengers for host-microbiota interactions. These differential metabolites were enriched into relevant critical metabolic pathways, revealing possible pathways for host-microbiota interactions.

Advancing Tissue Damage Repair in Geriatric Diseases: Prospects of Combining Stem Cell-Derived Exosomes with Hydrogels

Geriatric diseases are a group of diseases with unique characteristics related to senility. With the rising trend of global aging, senile diseases now mainly include endocrine, cardiovascular, neurodegenerative, skeletal, and muscular diseases and cancer. Compared with younger populations, the structure and function of various cells, tissues and organs in the body of the elderly undergo a decline as they age, rendering them more susceptible to external factors and diseases, leading to serious tissue damage. Tissue damage presents a significant obstacle to the overall health and well-being of older adults, exerting a profound impact on their quality of life. Moreover, this phenomenon places an immense burden on families, society, and the healthcare system.In recent years, stem cell-derived exosomes have become a hot topic in tissue repair research. The combination of these exosomes with biomaterials allows for the preservation of their biological activity, leading to a significant improvement in their therapeutic efficacy. Among the numerous biomaterial options available, hydrogels stand out as promising candidates for loading exosomes, owing to their exceptional properties. Due to the lack of a comprehensive review on the subject matter, this review comprehensively summarizes the application and progress of combining stem cell-derived exosomes and hydrogels in promoting tissue damage repair in geriatric diseases. In addition, the challenges encountered in the field and potential prospects are presented for future advancements.

The Immunomodulatory effect of exosomes in diabetes: a novel and attractive therapeutic tool in diabetes therapy

Exosomes carry proteins, metabolites, nucleic acids and lipids from their parent cell of origin. They are derived from cells through exocytosis, are ingested by target cells, and can transfer biological signals between local or distant cells. Therefore, exosomes are often modified in reaction to pathological processes, including infection, cancer, cardiovascular diseases and in response to metabolic perturbations such as obesity and diabetes, all of which involve a significant inflammatory aspect. Here, we discuss how immune cell-derived exosomes origin from neutrophils, T lymphocytes, macrophages impact on the immune reprogramming of diabetes and the associated complications. Besides, exosomes derived from stem cells and their immunomodulatory properties and anti-inflammation effect in diabetes are also reviewed. Moreover, As an important addition to previous reviews, we describes promising directions involving engineered exosomes as well as current challenges of clinical applications in diabetic therapy. Further research on exosomes will explore their potential in translational medicine and provide new avenues for the development of effective clinical diagnostics and therapeutic strategies for immunoregulation of diabetes.

Narrative review on nanoparticles based on current evidence: therapeutic agents for diabetic foot infection

Diabetes's effects on wound healing present a major treatment challenge and increase the risk of amputation. When traditional therapies fail, new approaches must be investigated. With their submicron size and improved cellular internalisation, nanoparticles present a viable way to improve diabetic wound healing. They are attractive options because of their innate antibacterial qualities, biocompatibility, and biodegradability. Nanoparticles loaded with organic or inorganic compounds, or embedded in biomimetic matrices such as hydrogels, chitosan, and hyaluronic acid, exhibit excellent anti-inflammatory, antibacterial, and antioxidant properties. Drug delivery systems (DDSs)-more precisely, nanodrug delivery systems (NDDSs)-use the advantages of nanotechnology to get around some of the drawbacks of traditional DDSs. Recent developments show how expertly designed nanocarriers can carry a variety of chemicals, transforming the treatment of diabetic wounds. Biomaterials that deliver customised medications to the wound microenvironment demonstrate potential. Delivery techniques for nanomedicines become more potent than ever, overcoming conventional constraints. Therapeutics for diabetes-induced non-healing wounds are entering a revolutionary era thanks to precisely calibrated nanocarriers that effectively distribute chemicals. This review highlights the therapeutic potential of nanoparticles and outlines the multifunctional nanoparticles of the future that will be used for complete wound healing in diabetics. The investigation of novel nanodrug delivery systems has the potential to revolutionise diabetic wound therapy and provide hope for more efficient and focused therapeutic approaches.

HucMSC-Exo Induced N2 Polarization of Neutrophils: Implications for Angiogenesis and Tissue Restoration in Wound Healing

Background

Neutrophils rapidly accumulate in large numbers at sites of tissue damage, exhibiting not only their well-known bactericidal capabilities but also playing crucial roles in angiogenesis and tissue repair. While exosomes derived from human umbilical cord mesenchymal stem cells (HucMSC-Exo) have emerged as a promising therapeutic tool, their exact mechanisms of action remain partly elusive. We hypothesize that HucMSC-Exo treatment may modulate neutrophil phenotypes, thereby significantly influencing wound healing outcomes.

Methods

HucMSC-Exo were isolated via ultracentrifugation and subsequently administered through subcutaneous injection into full-thickness cutaneous wounds in mice. To determine the impact of host neutrophils on the healing effects of HucMSC-Exo in skin injuries, strategies including neutrophil depletion and adoptive transfer were employed. Flow cytometry was used to evaluate the proportion of N2 subtype neutrophils in both normal and diabetic wounds, and the effect of HucMSC-Exo on this proportion was assessed. Furthermore, the mitochondrial metabolic reprogramming driven by HucMSC-Exo during N2 polarization was investigated through JC1 staining, ATP quantification, fatty acid uptake assays, and assessment of FAO-related genes (Cpt1b, Acadm, and Acadl).

Results

Depleting host neutrophils strikingly dampened prohealing effect of HucMSC-Exo on skin injury, while adoptive transfer of bone marrow neutrophils rescued this process. During normal healing process, some neutrophils expressed N2 markers, in contrast, diabetic wounds exhibited a reduced expression of N2 markers. After treatment with HucMSC-Exo, most neutrophils increased the phosphorylation of STAT6, leading to mitochondrial metabolic reprogramming and thus acquired an N2 phenotype. These N2 neutrophils, polarized by HucMSC-Exo, boosted the release of proangiogenic factors, particularly BV8, a myeloid cell-derived proangiogenic factor, and induced angiogenesis thereby favoring tissue restoration.

Conclusion

This research uniquely demonstrates the identification of N2 neutrophils in skin injury and shows that HucMSC-Exo could skew neutrophils toward N2 phenotype, enhancing our insight into how cells react to HucMSC-Exo.

Enhancing Skin Injury Repair: Combined Application of PF-127 Hydrogel and hADSC-Exos Containing miR-148a-3p

The use of exosomes to relieve skin injuries has received considerable attention. The PluronicF-127 hydrogel (PF-127 hydrogel) is a novel biomaterial that can be used to carry biomolecules. This study sought to investigate the impact of exosomes originating from human mesenchymal stem cells (MSCs) developed from adipose tissue (hADSC-Exos) combined with a PF-127 hydrogel on tissue repair and explore the underlying mechanism using in vitro and in vivo experiments. miR-148a-3p is the most expressed microRNA (miRNA) in hADSC-Exos. We found that exosomes combined with the PF-127 hydrogel had a better efficacy than exosomes alone; moreover, miR-148a-3p knockdown lowered its efficacy. In vitro, we observed a significant increase in the tumor-like ability of HUVECs after exosome treatment, which was attenuated after miR-148a-3p knockdown. Furthermore, the effects of miR-148a-3p on hADSC-Exos were achieved through the prevention of PTEN and the triggering of phosphatidylinositol 3-kinase (PI3K)/Akt signaling. In conclusion, our results demonstrated that hADSC-Exos can promote angiogenesis and skin wound healing by delivering miR-148a-3p and have a better effect when combined with the PF-127 hydrogel, which may be an alternative strategy to promote wound healing.

Advancements in wound healing: integrating biomolecules, drug delivery carriers, and targeted therapeutics for enhanced tissue repair

Wound healing, a critical biological process vital for tissue restoration, has spurred a global market exceeding $15 billion for wound care products and $12 billion for scar treatment. Chronic wounds lead to delayed or impaired wound healing. Natural bioactive compounds, prized for minimal side effects, stand out as promising candidates for effective wound healing. In response, researchers are turning to nanotechnology, employing the encapsulation of these agents into drug delivery carriers. Drug delivery system will play a crucial role in enabling targeted delivery of therapeutic agents to promote tissue regeneration and address underlying issues such as inflammation, infection, and impaired angiogenesis in chronic wound healing. Drug delivery carriers offer distinct advantages, exhibiting a substantial ratio of surface area to volume and altered physical and chemical properties. These carriers facilitate sustained and controlled release, proving particularly advantageous for the extended process of wound healing, that typically comprise a diverse range of components, integrating both natural and synthetic polymers. Additionally, they often incorporate bioactive molecules. Despite their properties, including poor solubility, rapid degradation, and limited bioavailability, various natural bioactive agents face challenges in clinical applications. With a global research, emphasis on harnessing nanomaterial for wound healing application, this research overview engages advancing drug delivery technologies to augment the effectiveness of tissue regeneration using bioactive molecules. Recent progress in drug delivery has poised to enhance the therapeutic efficacy of natural compounds in wound healing applications.

Umbilical cord-derived mesenchymal stem cell secretome promotes skin regeneration and rejuvenation: From mechanism to therapeutics

How to effectively repair cutaneous wounds and promote skin rejuvenation has always been a challenging issue for clinical medicine and medical aesthetics. Current conventional medicines exhibit several drawbacks, including limited therapeutic effects, prolonged treatment periods, and high costs. As a novel cell-free therapy, the umbilical cord-derived mesenchymal stem cell (UCMSC) secretome may offer a promising approach for skin regeneration and rejuvenation. The UCMSC secretome is a collection of all proteins secreted by mesenchymal stem cells, including conditioned media, exosomes, and other substances. The UCMSC secretome has numerous abilities to accelerate acute wound healing, including high fibroblast and keratinocyte proliferative activity, pro-angiogenesis, anti-inflammation, anti-fibrosis, and anti-oxidative stress. Its impact on the four stages of wound healing is manifested by inducing the haemostasis phase, inhibiting the inflammation phase, promoting the proliferation phase, and regulating the remodelling phase. Furthermore, it is highly effective in the treatment of chronic wounds, alopecia, aging, and skin homeostasis disturbance. This review focuses on the clinical therapies and application prospects of the UCMSC secretome, encompassing its source, culture, separation, identification, storage, and pretreatment. Additionally, a discussion on the dosage, administration route, efficacy, and biosafety in the clinical situation is presented. This review aims to provide scientific support for the mechanistic investigation and clinical utilisation of the UCMSC secretome in wound healing and skin rejuvenation.

Extracellular vesicles produced by 3D cultured MSCs promote wound healing by regulating macrophage activation through ANXA1

The conundrum of wound healing has transformed into an imminent medical challenge. Presently, cell-free therapy centered around extracellular vesicles (EVs) has become a pivotal and promising research avenue. EVs generated from three-dimensional (3D) cell cultures have been previously established to possess enhanced tissue regeneration potential, although the underlying mechanisms remain elusive. In this study, we observed higher expression of annexin ANXA1 in 3D-cultured EVs. Remarkably, 3D-EVs with elevated ANXA1 expression demonstrated a more potent capacity to promote macrophage polarization from the M1 phenotype to the M2 phenotype. Concurrently, they exhibited superior abilities to enhance cell migration and tube formation, facilitating expedited wound healing in animal experiments. Conversely, the application of an ANXA1 inhibitor counteracted the positive effects of 3D-EVs. Taken together, our data validate that extracellular vesicles derived from 3D-cultured MSCs regulate macrophage polarization via ANXA1, thereby fostering wound healing.

Sanchi-mediated inactivation of IL1B accelerates wound healing through the NFκB pathway deficit

Context

Sanchi promotes wound healing by repressing fibroblast proliferation.

Objective

This study examined the effect of Sanchi on keratinocytes (KCs) and microvascular endothelial cells (MECs) and rats with skin injury.

Materials & methods

Hydrogels containing different concentrations of Sanchi extract were prepared to observe wound closure over 10 days. SD rats were divided into the control, Hydrogel, 5% Hydrogel, 10% Hydrogel, 10% Hydrogel + Ad5-NC, and 10% Hydrogel + Ad5-IL1B groups. KCs and MECs were induced with H2O2 for 24 h. Cell viability, apoptosis, and the levels of inflammation- and oxidative stress-related factors were examined. The effect of IL1B on wound healing was also evaluated.

Results

Compared to the Control group (83% ± 7.4%) or Hydrogel without Sanchi extract (84% ± 8.5%), Hydrogel with 5% (95% closure ± 4.0%) or 10% Sanchi extract (98% ± 1.7%) accelerated wound healing in rats and attenuated inflammation and oxidative stress. Hydrogels containing Sanchi extract increased collagen deposition and CD31 expression in tissues. H2O2 (100 μM) induced injury in KCs and MECs, whereas Sanchi rescued the viability of KCs and MECs. Sanchi inhibited cell inflammation and oxidative stress and decreased apoptosis. As Sanchi blocked the NFκB pathway via IL1B, IL1B mitigated the therapeutic effect of Sanchi.

Discussion and conclusion

Sanchi demonstrated therapeutic effects on wound healing in rats by promoting KCs and MECs activity. These findings provide valuable information for the clinical application of Sanchi, which needs to be validated in future clinical trials.

Proteomic characterization of hUC-MSC extracellular vesicles and evaluation of its therapeutic potential to treat Alzheimer's disease

In recent years, human umbilical cord mesenchymal stem cell (hUC-MSC) extracellular vesicles (EVs) have been used as a cell replacement therapy and have been shown to effectively overcome some of the disadvantages of cell therapy. However, the specific mechanism of action of EVs is still unclear, and there is no appropriate system for characterizing the differences in the molecular active substances of EVs produced by cells in different physiological states. We used a data-independent acquisition (DIA) quantitative proteomics method to identify and quantify the protein composition of two generations EVs from three different donors and analysed the function and possible mechanism of action of the proteins in EVs of hUC-MSCs via bioinformatics. By comparative proteomic analysis, we characterized the different passages EVs. Furthermore, we found that adaptor-related protein complex 2 subunit alpha 1 (AP2A1) and adaptor-related protein complex 2 subunit beta 1 (AP2B1) in hUC-MSC-derived EVs may play a significant role in the treatment of Alzheimer's disease (AD) by regulating the synaptic vesicle cycle signalling pathway. Our work provides a direction for batch-to-batch quality control of hUC-MSC-derived EVs and their application in AD treatment.

Identification and clinical validation of the role of anoikis-related genes in diabetic foot

This study aims to investigate the role of anoikis-related genes in diabetic foot (DF) by utilizing bioinformatics analysis to identify key genes associated with anoikis in DF. We selected the GEO datasets GSE7014, GSE80178 and GSE68183 for the extraction and analysis of differentially expressed anoikis-related genes (DE-ARGs). GO analysis and KEGG analysis indicated that DE-ARGs in DF were primarily enriched in apoptosis, positive regulation of MAPK cascade, anoikis, focal adhesion and the PI3K-Akt signalling pathway. Based on the LASSO and SVM-RFE algorithms, we identified six characteristic genes. ROC curve analysis revealed that these six characteristic genes had an area under the curve (AUC) greater than 0.7, indicating good diagnostic efficacy. Expression analysis in the validation set revealed downregulation of CALR in DF, consistent with the training set results. GSEA results demonstrated that CALR was mainly enriched in blood vessel morphogenesis, endothelial cell migration, ECM-receptor interaction and focal adhesion. The HPA database revealed that CALR was moderately enriched in endothelial cells, and CALR was found to interact with 63 protein-coding genes. Functional analysis with DAVID suggested that CALR and associated genes were enriched in the phagosome component. CALR shows promise as a potential marker for the development and treatment of DF.

Regulation of inflammation during wound healing: the function of mesenchymal stem cells and strategies for therapeutic enhancement

A wound takes a long time to heal and involves several steps. Following tissue injury, inflammation is the primary cause of tissue regeneration and repair processes. As a result, the pathophysiological processes involving skin damage, healing, and remodeling depend critically on the control of inflammation. The fact that it is a feasible target for improving the prognosis of wound healing has lately become clear. Mesenchymal stem cells (MSCs) are an innovative and effective therapeutic option for wound healing due to their immunomodulatory and paracrine properties. By controlling the inflammatory milieu of wounds through immunomodulation, transplanted MSCs have been shown to speed up the healing process. In addition to other immunomodulatory mechanisms, including handling neutrophil activity and modifying macrophage polarization, there may be modifications to the activation of T cells, natural killer (NK) cells, and dendritic cells (DCs). Furthermore, several studies have shown that pretreating MSCs improves their ability to modulate immunity. In this review, we summarize the existing knowledge about how MSCs influence local inflammation in wounds by influencing immunity to facilitate the healing process. We also provide an overview of MSCs optimizing techniques when used to treat wounds.

P407 hydrogel loaded with nitric oxide microbubbles promotes angiogenesis and functional improvement in testicular transplantation

Prepubertal male patients with cancer have decreased fertility after treatment, but there are currently no suitable means for fertility rescue. Testicular transplantation seems to be a promising treatment. The short-term insufficiency of blood supply after transplantation is the key problem that needs to be solved. In this research, nitric oxide (NO), a gas and small molecule transmitter with the effect of promoting angiogenesis, acted at the site of testicular transplantation. Herein, poloxamer-407 (P407) and lipid microbubble materials served as transport carriers for NO and helped NO to function at the transplant site. P407 hydrogel loaded with NO microbubbles (PNO) slowly released NO in vitro. The three-dimensional space of the hydrogel provided a stable environment for NO microbubbles, which is conducive to the continuous release of NO. In this study, 25% PNO (w/v) was selected, and the gelling temperature was 19.47 °C. The gelling efficiency was relatively high at body temperature. Rheological experiments showed that PNO, at this concentration, had stable mechanical properties. The results from in vivo experiments demonstrated that testicular grafts in the PNO group exhibited a notably accelerated blood flow recovery compared to the other groups. Additionally, the PNO group displayed a significant improvement in reproductive function recovery. In conclusion, PNO exhibited slow release of NO, and a small amount of NO promoted angiogenesis in testicular grafts and restored reproductive function.

Porous Collagen Sponge Loaded with Large Efficacy-Potentiated Exosome-Mimicking Nanovesicles for Diabetic Skin Wound Healing

Diabetic skin wounds are difficult to heal quickly due to insufficient angiogenesis and prolonged inflammation, which is an urgent clinical problem. To address this clinical problem, it becomes imperative to develop a dressing that can promote revascularization and reduce inflammation during diabetic skin healing. Herein, a multifunctional collagen dressing (CTM) was constructed by loading large efficacy-potentiated exosome-mimicking nanovesicles (L-Meseomes) into a porous collagen sponge with transglutaminase (TGase). L-Meseomes were constructed in previous research with the function of promoting cell proliferation, migration, and angiogenesis and inhibiting inflammation. CTM has a three-dimensional porous network structure with good biocompatibility, swelling properties, and degradability and could release L-Meseome slowly. In vitro experiments showed that CTM could promote the proliferation of fibroblasts and the polarization of macrophages to the anti-inflammatory phenotype. For in vivo experiments, on the 21st day after surgery, the wound healing rates of the control and CTM were 83.026 ± 4.17% and 93.12 ± 2.16%, respectively; the epidermal maturation and dermal differentiation scores in CTM were approximately four times that of the control group, and the skin epidermal thickness of the CTM group was approximately 20 μm, which was closest to that of normal rats. CTM could significantly improve wound healing in diabetic rats by promoting anti-inflammation, angiogenesis, epidermal recovery, and dermal collagen deposition. In summary, the multifunctional collagen dressing CTM could significantly promote the healing of diabetic skin wounds, which provides a new strategy for diabetic wound healing in the clinic.

Hydrogel-mediated extracellular vesicles for enhanced wound healing: the latest progress, and their prospects for 3D bioprinting

Extracellular vesicles have shown promising tissue recovery-promoting effects, making them increasingly sought-after for their therapeutic potential in wound treatment. However, traditional extracellular vesicle applications suffer from limitations such as rapid degradation and short maintenance during wound administration. To address these challenges, a growing body of research highlights the role of hydrogels as effective carriers for sustained extracellular vesicle release, thereby facilitating wound healing. The combination of extracellular vesicles with hydrogels and the development of 3D bioprinting create composite hydrogel systems boasting excellent mechanical properties and biological activity, presenting a novel approach to wound healing and skin dressing. This comprehensive review explores the remarkable mechanical properties of hydrogels, specifically suited for loading extracellular vesicles. We delve into the diverse sources of extracellular vesicles and hydrogels, analyzing their integration within composite hydrogel formulations for wound treatment. Different composite methods as well as 3D bioprinting, adapted to varying conditions and construction strategies, are examined for their roles in promoting wound healing. The results highlight the potential of extracellular vesicle-laden hydrogels as advanced therapeutic tools in the field of wound treatment, offering both mechanical support and bioactive functions. By providing an in-depth examination of the various roles that these composite hydrogels can play in wound healing, this review sheds light on the promising directions for further research and development. Finally, we address the challenges associated with the application of composite hydrogels, along with emerging trends of 3D bioprinting in this domain. The discussion covers issues such as scalability, regulatory considerations, and the translation of this technology into practical clinical settings. In conclusion, this review underlines the significant contributions of hydrogel-mediated extracellular vesicle therapy to the field of 3D bioprinting and wound healing and tissue regeneration. It serves as a valuable resource for researchers and practitioners alike, fostering a deeper understanding of the potential benefits, applications, and challenges involved in utilizing composite hydrogels for wound treatment.

Exosomes derived from BMSCs enhance diabetic wound healing through circ-Snhg11 delivery

BACKGROUND

Exosomes (Exos) generated from bone mesenchymal stem cells (BMSCs) are elucidated to enhance cutaneous wound healing in mice models of diabetes mellitus (DM). While underlying mechanisms remain unknown.

METHODS

Next-generation sequencing (NGS) was used to examine changes in circRNA expression levels following Exo treatment. Luciferase assays were used to determine the interactions between RNAs. Immunofluorescence staining was used to examine reactive oxygen species (ROS) in endothelial progenitor cells (EPCs) cultured in high glucose (HG) conditions. Therapeutic effects regarding Exos were also examined by immunofluorescence.

RESULTS

We found that Exo treatment enhanced cutaneous wound healing significantly. NGS indicated that circ-Snhg11 was involved in Exo-mediated tissue repairing. Downregulation of circ-Snhg11 decreased Exo-mediated therapy responses during wound healing in diabetic mouse. Our luciferase reporter data confirmed that SLC7A11 and miR-144-3p were circ-Snhg11 downstream targets. miR-144-3p overexpression or SLC7A11 knockdown altered the protective effects of circ-Snhg11 upon EPCs exposed to HG conditions. Upregulation of circ-Snhg11 incremented therapy effects of Exo treatment during wound healing in DM mice through enhanced angiogenesis along with a reduction in GPX4-mediated ferroptosis.

CONCLUSIONS

circ-Snhg11 in BMSC-Exos enhanced SLC7A11/GPX4-mediated anti-ferroptosis signals via miR-144-3p sponging resulting in enhanced diabetic wound healing and improved angiopoiesis.

Understanding exosomes: Part 2-Emerging leaders in regenerative medicine

Exosomes are the smallest subset of extracellular signaling vesicles secreted by most cells with the ability to communicate with other tissues and cell types over long distances. Their use in regenerative medicine has gained tremendous momentum recently due to their ability to be utilized as therapeutic options for a wide array of diseases/conditions. Over 5000 publications are currently being published yearly on this topic, and this number is only expected to dramatically increase as novel therapeutic strategies continue to be developed. Today exosomes have been applied in numerous contexts including neurodegenerative disorders (Alzheimer's disease, central nervous system, depression, multiple sclerosis, Parkinson's disease, post-traumatic stress disorders, traumatic brain injury, peripheral nerve injury), damaged organs (heart, kidney, liver, stroke, myocardial infarctions, myocardial infarctions, ovaries), degenerative processes (atherosclerosis, diabetes, hematology disorders, musculoskeletal degeneration, osteoradionecrosis, respiratory disease), infectious diseases (COVID-19, hepatitis), regenerative procedures (antiaging, bone regeneration, cartilage/joint regeneration, osteoarthritis, cutaneous wounds, dental regeneration, dermatology/skin regeneration, erectile dysfunction, hair regrowth, intervertebral disc repair, spinal cord injury, vascular regeneration), and cancer therapy (breast, colorectal, gastric cancer and osteosarcomas), immune function (allergy, autoimmune disorders, immune regulation, inflammatory diseases, lupus, rheumatoid arthritis). This scoping review is a first of its kind aimed at summarizing the extensive regenerative potential of exosomes over a broad range of diseases and disorders.

Temperature-sensitive hydrogel releasing pectolinarin facilitate scarless wound healing

The dressing that promotes scarless healing is essential for both normal function and aesthetics after a wound. With a deeper understanding of the mechanisms involved in scar formation during the wound healing process, the ideal dressing becomes clearer and more promising. For instance, the yes-associated transcriptional regulator (YAP) has been extensively studied as a key gene involved in regulating scar formation. However, there has been limited attention given to pectolinarin, a natural flavonoid that may exhibit strong binding affinity to YAP, in the context of scarless healing. In this study, we successfully developed a temperature-sensitive Pluronic@F-127 hydrogel as a platform for delivering pectolinarin to promote scarless wound healing. The bioactive pectolinarin was released from the hydrogel, effectively enhancing endothelial cell migration, proliferation and the expression of angiogenesis-related genes. Additionally, a concentration of 20 μg/mL of pectolinarin demonstrated remarkable antioxidant ability, capable of counteracting the detrimental effects of reactive oxygen species (ROS). Our results from rat wound healing models demonstrated that the hydrogel accelerated wound healing, promoting re-epithelialization and facilitating skin appendage regeneration. Furthermore, we discovered that a concentration of 50 μg/mL of pectolinarin incorporated to the hydrogel exhibited the most favourable outcomes in terms of promoting wound healing and minimizing scar formation. Overall, our study highlights that the significant potential of locally released pectolinarin might substantially inhibit YAP and promoting scarless wound healing.