MiR-223-3p overexpressed adipose mesenchymal stem cell-derived exosomes promote wound healing via targeting MAPK10

Milk-derived exosomes as functional nanocarriers in wound healing: Mechanisms, applications, and future directions

Wound healing presents a significant challenge in healthcare, imposing substantial physiological and economic burdens. While traditional treatments and stem cell therapies have shown benefits, milk-derived exosomes (MDEs) offer distinct advantages as a cell-free therapeutic approach. MDEs, isolated from mammalian milk, are characterized by their biocompatibility, ease of acquisition, and high yield, making them a promising tool for enhancing wound repair. This review provides a comprehensive analysis of the composition, sources, and extraction methods of MDEs, with a focus on their therapeutic role in both acute and diabetic chronic wounds. MDEs facilitate wound healing through the delivery of bioactive molecules, modulating key processes such as inflammation, angiogenesis, and collagen synthesis. Their ability to regulate complex wound-healing pathways underscores their potential for widespread clinical application. This review highlights the importance of MDEs in advancing wound management and proposes strategies to optimize their use in regenerative medicine.

Mechanistic insights of diabetic wound: Healing process, associated pathways and microRNA-based delivery systems

Wounds that represent one of the most critical complications can occur in individuals suffering from diabetes mellitus, and results in the need for hospitalisation and, in severe cases, require amputation. This condition is primarily characterized by infections, persistent inflammation, and delayed healing processes, which exacerbate the overall health of the patients. As per the standard mechanism, signalling pathways such as PI3K/AKT, HIF-1, TGF-β, Notch, Wnt/β-Cat, NF-κB, JAK/STAT, TLR, and Nrf2 play major roles in inflammatory, proliferative and remodelling phases of wound healing. However, dysregulation of the above pathways has been seen during the healing of diabetic wounds. MicroRNAs (miRNAs) are small, non-coding RNAs that regulate the expression of various genes and signalling pathways which are associated with the process of wound healing. In the past few years, there has been a great deal of interest in the potential of miRNAs as biological agents in the management of a number of disorders. These miRNAs have been shown to modulate expression of genes involved in the healing process of wounds. There have been previous reviews pertaining to clinical trials examining miRNAs in several disorders, but only a few clinical studies have examined involvement of miRNAs in healing of wounds. Considering the therapeutic promise, there are several obstacles concerning their instabilities and inefficient delivery into the target cells. Therefore, this review is an attempt to discuss precise roles of signalling pathways and miRNAs in different phases of wound healing, and their aberrant regulation in diabetic wounds, particularly. It has also compiled a range of delivery mechanisms as well as an overview of the latest findings pertaining to miRNAs and associated delivery systems for improved healing of diabetic wounds.

A glimpse into the world of microRNAs and their putative roles in hard ticks

Ticks are important blood feeding ectoparasites that transmit pathogens to wildlife, domestic animals, and humans. Hard ticks can feed for several days to weeks, nevertheless they often go undetected. This phenomenon can be explained by a tick's ability to release analgesics, immunosuppressives, anticoagulants, and vasodilators within their saliva. Several studies have identified extracellular vesicles (EVs) as carriers of some of these effector molecules. Further, EVs, and their contents, enhance pathogen transmission, modulate immune responses, and delay wound healing. EVs are double lipid-membrane vesicles that transport intracellular cargo, including microRNAs (miRNAs) to recipient cells. miRNAs are involved in regulating gene expression post-transcriptionally. Interestingly, tick-derived miRNAs have been shown to enhance pathogen transmission and affect vital biological processes such as oviposition, blood digestion, and molting. miRNAs have been found within tick salivary EVs. This review focuses on current knowledge of miRNA loading into EVs and homologies reported in ticks. We also describe findings in tick miRNA profiles, including miRNAs packed within tick salivary EVs. Although no functional studies have been done to investigate the role of EV-derived miRNAs in tick feeding, we discuss the functional characterization of miRNAs in tick biology and pathogen transmission. Lastly, we propose the possible uses of tick miRNAs to develop management tools for tick control and to prevent pathogen transmission. The identification and functional characterization of conserved and tick-specific salivary miRNAs targeting important molecular and immunological pathways within the host could lead to the discovery of new therapeutics for the treatment of tick-borne and non-tick-borne human diseases.

miR-200a-3p-enriched MSC-derived extracellular vesicles reverse erectile function in diabetic rats by targeting Keap1

BACKGROUND

The administration of mesenchymal stem cells (MSCs) through intracavernous injection is a potential therapeutic approach for managing diabetes mellitus-induced erectile dysfunction (DMED). However, pulmonary embolism and tumorigenicity are fatal adverse events that limit the clinical application of MSCs. In this study, we examined the therapeutic efficacy and potential mechanism of MSC-derived extracellular vesicles (MSC-EVs).

METHODS

In this study, forty 8-week-old male SpragueDawley (SD) rats were utilised. In the control group, ten rats were administered an intraperitoneal injection of PBS. STZ (60 mg/kg) was intraperitoneally injected into the remaining rats to establish a diabetes mellitus (DM) model. Afterwards, the diabetic rats were divided into three groups at random: the DM group (intracavernosal injection of PBS), the EVs group (intracavernosal injection of MSC-EVs), and the EVs-200a group (intracavernosal injection of miR-200a-3p-enriched extracellular vesicles). Erectile function was determined by measuring intracavernous pressure in real time and utilising electrical stimulation of the cavernous nerves. The smooth muscle content was evaluated through the investigation of penile tissue using immunofluorescence staining, Masson's trichrome staining, and western blotting after euthanasia. Superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) levels in the corpus cavernosum were measured via ELISA. In vitro, hydrogen peroxide (H2O2) was used to induce oxidative stress. The viability of corpus cavernosum smooth muscle cells (ccSMCs) incubated with or without H2O2 was measured using a CCK8 assay. Flow cytometry was used to assess the levels of reactive oxygen species (ROS) and apoptosis in ccSMCs. Furthermore, a dual-luciferase reporter assay was performed to validate the relationship between miR-200a-3p and Keap1.

RESULTS

Reversal of erectile function was observed in the EVs groups, especially in the EVs-200a group. DM increased the MDA level and decreased the SOD and GSH levels. In the DM group, the expression of alpha-smooth muscle actin (α-SMA) and smooth muscle 22 alpha (SM22α) was decreased, and the expression of osteopontin (OPN) was increased. Western blotting revealed decreased Nrf2, HO-1, and Bcl2 expression and increased Keap1, Bax and cleaved caspase3 expression in the cavernous tissue. miR-200a-3p-enriched extracellular vesicles (EVs-200a) reversed these changes and inhibited the loss of smooth muscle content and cavernous fibrosis. In vitro, H2O2 induced high ROS levels in ccSMCs and increased apoptosis, and these effects reversed by EVs-200a. H2O2 reduced Nrf2, HO-1, and Bcl2 expression and increased Keap1, Bax and cleaved caspase-3 expression, and these effects were reversed by MSC-EVs, especially EVs-200a. The of dual-luciferase reporter assay results indicated that miR-200a-3p directly targeted Keap1 in a negative manner.

CONCLUSION

MSC-EVs, especially EVs-200a, alleviated erectile dysfunction in diabetic rats through the regulation of phenotypic switching, apoptosis and fibrosis. Mechanistically, miR-200a-3p targeted the Keap1/Nrf2 pathway to attenuate oxidative stress in diabetic rats.

Release of exosomes from injectable silk fibroin and alginate composite hydrogel for treatment of myocardial infarction

Myocardial infarction (MI) is considered as a significant cause of death globally. Exosomes (EXOs) are essential for intercellular communication and pathophysiology of several cardiovascular diseases. Nevertheless, the short half-life and rapid clearance of EXOs leads to a lack of therapeutic doses delivered to the lesioned area. Therefore, an injectable silk fibroin and alginate (SF/Alg) composite hydrogel was developed to bind folate receptor-targeted EXOs (FA-EXOs) derived from H9C2 cells for the therapy of myocardial injury following myocardial infarction-ischemia/reperfusion (MI-I/R). The resulting composite exhibits a variety of properties, including adjustable gelation kinetics, shear-thinning injectability, soft and dynamic stability that adapts to the heartbeat, and outstanding cytocompatibility. After injected into the damaged rat heart, administration of SF/Alg + FA-EXOs significantly enhanced cardiac function as demonstrated by improved ejection fraction, fractional shortening and decreased fibrosis area. The results of real-time PCR and immunofluorescence staining show a remarkable up-regulation in the expression of proteins (CD31) and genes (VWF and Serca2a) related to the heart. Conversely, expression of fibrosis-related genes (TGF-β1) decreased significantly. Therefore, the obtained SF/Alg + FA-EXOs system remarkably enhanced the intercellular interactions, promoted cell proliferation and angiogenesis, and achieved an outstanding therapeutic effect on MI.

Silk fibroin and hydroxypropyl cellulose composite injectable hydrogel-containing extracellular vesicles for myocardial infarction repair

Extracellular vesicles (EVs) have been recognized as one of the promising specific drugs for myocardial infarction (MI) prognosis. Nevertheless, low intramyocardial retention of EVs remains a major impediment to their clinical application. In this study, we developed a silk fibroin/hydroxypropyl cellulose (SF/HPC) composite hydrogel combined with AC16 cell-derived EVs targeted modification by folic acid for the treatment of acute myocardial infarction repair. EVs were functionalized by distearoylphosphatidyl ethanolamine-polyethylene glycol (DSPE-PEG-FA) via noncovalent interaction for targeting and accelerating myocardial infarction repair.In vitro, cytocompatibility analyses revealed that the as-prepared hydrogels had excellent cell viability by MTT assay and the functionalized EVs had higher cell migration by scratch assay.In vivo, the composite hydrogels can promote myocardial tissue repair effects by delaying the process of myocardial fibrosis and promoting angiogenesis of infarct area in MI rat model.

A carboxymethyl chitosan/oxidized hyaluronic acid composite hydrogel dressing loading with stem cell exosome for chronic inflammation wounds healing

Stem cell exosomes (Exo) play an important role in the transformation of macrophages, but the rapid clearance of Exo in vivo limits their therapeutic effects for chronic inflammation wounds healing. Here, stem cell Exo was isolated and introduced to a composite hydrogel including carboxymethyl chitosan (CMCS) and oxidized hyaluronic acid (OHA) through chemical cross-linking, which formed an Exo-loaded (CMCS/OHA/Exo) hydrogel. The CMCS/OHA/Exo hydrogel exhibited a function of Exo sustained release and an Exo protection within 6 days. This CMCS/OHA/Exo hydrogel was much better than CMCS/OHA hydrogel or Exo solution in macrophage cell phagocytosis, proliferation and migration in vitro, especially, played an obviously positive role in the transformation of macrophages compared with the reference groups. For the treatment of the chronic inflammation wounds in vivo, the CMCS/OHA/Exo hydrogel had the best results at wound heal rate and inhibiting the secretion of inflammatory factors, and it was far superior to reference groups in wound re-epithelization and collagen production. CMCS/OHA/Exo hydrogels can promote Exo release based on hydrogel degradation to regulate macrophages transformation and accelerate chronic wound healing. The study offers a method for preparing Exo-loaded hydrogels that effectively promote the transformation of macrophages and accelerate chronic inflammatory wound healing.