MiR146a-loaded engineered exosomes released from silk fibroin patch promote diabetic wound healing by targeting IRAK1

From bench to bedside: the research status and application opportunity of extracellular vesicles and their engineering strategies in the treatment of skin defects

Engineered extracellular vesicles (EVs), which are EVs modified to enhance certain biological properties, offer a promising therapeutic strategy for the treatment of skin defects. Conventional nanomaterials often encounter clinical translation challenges due to potential toxicity and limited targeting. Engineered EVs, utilizing inherent biocompatibility and effective physiological barrier traversal, can ameliorate the limitations of conventional EV therapies to some extent, including detection, isolation, purification, and therapeutic validation. Recent advances in EV engineering, such as genetic modification of production cells to control cargo, surface engineering for targeted delivery, and pre-treatment of parental cells to optimize production and bioactivity, have improved therapeutic efficacy in laboratory studies through enhanced targeting, prolonged retention time, and increased yield. Many studies have suggested the potential ability of engineered EVs to treat a variety of skin defects, including diabetic wounds, burns, and hypertrophic scars, providing a promising avenue for their clinical translation in this area. This paper reviews the therapeutic potential of engineered EVs in skin regeneration, highlighting their role in promoting cell migration and angiogenesis, modulating inflammation and reducing scar formation during wound healing. In addition, given the investment in this rapidly evolving field and the growing clinical trial activity, this review also explores recent global advances and provides an outlook on future application opportunities for EVs in the treatment of skin defects.

Precision exosome engineering for enhanced wound healing and scar revision

The dysfunction of wound-healing processes can result in chronic non-healing wounds and pathological scar formation. Current treatment options often fall short, necessitating innovative approaches. Exosomes, extracellular vesicles secreted by various cells, have emerged as promising therapeutic agents serving as an intercellular communication system. By engineering exosomes, their cargo and surface properties can be tailored to enhance therapeutic efficacy and specificity. Engineered exosomes (eExo) are emerging as a favorable tool for treating non-healing wounds and pathological scars. In this review, we delve into the underlying mechanisms of non-healing wounds and pathological scars, outline the current state of engineering strategies, and explore the clinical potential of eExo based on preclinical and clinical studies. In addition, we address the current challenges and future research directions, including standardization, safety and efficacy assessments, and potential immune responses. In conclusion, eExo hold great promise as a novel therapeutic approach for non-healing wounds and non-healing wounds and pathological scars. Further research and clinical trials are warranted to translate preclinical findings into effective clinical treatments.

Smart Silk-Based In Situ Sol-Gel Modulates Rectal Microenvironment for Effective Ulcerative Colitis Alleviation

Ulcerative colitis (UC) is a chronic inflammatory bowel disease, with untreated cases often progressing to colorectal cancer. Current treatments aim to induce inflammatory remission but often neglect the surrounding microenvironment, which significantly impairs mucosal healing and contributes to treatment failures. This study presents a novel silk fibroin-based fucoidan (SFU) in situ rectal gel, with sol-gel transition confirmed through rheological analysis under physiological pH and temperature conditions. The SFU gel exhibits strong antioxidant activity, achieving a DPPH radical scavenging rate of 73.3 ± 1.52%. The gel efficiently reduces reactive oxygen species (ROS) and nitric oxide (NO) production, demonstrating its reliable antioxidant effects. In a DSS-induced UC mouse model, SFU effectively alleviates colitis symptoms, including weight loss and disease activity index (DAI) reduction, with improved stool consistency and reduced rectal bleeding. Moreover, SFU therapy reprograms macrophages from proinflammatory M1 to anti-inflammatory M2 phenotypes, significantly lowering IL-6 and TNF-α levels, suggesting anti-inflammatory properties. Furthermore, SFU increased tight junction proteins Occludin-1 and ZO-1, indicating gut mucosal barrier integrity. SFU treatment restores goblet cells and mucin production while preventing fibrosis, demonstrating its potential as a natural therapy for UC treatment.

Ellagic Acid-Loaded sEVs Encapsulated in GelMA Hydrogel Accelerate Diabetic Wound Healing by Activating EGFR on Skin Repair Cells

Delayed diabetic wound healing is partially attributed to the functional disorder of skin repair cells caused by high glucose (HG). Small extracellular vehicles (sEVs) loaded with small-molecule drugs represent a highly promising therapeutic strategy. This study aims to evaluate the therapeutic efficacy of ellagic acid-encapsulated small extracellular vesicles (EA-sEVs) in diabetic wound regeneration and to unravel related mechanisms. Cytotoxicity tests of ellagic acid (EA) as liposomal small molecules (LSMs) were performed with the CCK8 assay. EA was incorporated into sEVs obtained from chorionic plate-mesenchymal stem cells (CP-MSCs) to construct EA-engineered sEVs. The protective effects of EA-sEVs on human dermal fibroblasts (HDFs) and human epidermal keratinocytes (HEKs) induced by high glucose (HG) were assessed through the evaluation of their proliferative, migrative and differentiative capabilities. Furthermore, to illustrate the underlying mechanism, the specific biological targets of EA were predicted and confirmed. Finally, EA-sEVs were encapsulated in GelMA hydrogel for investigating the pro-healing effects on diabetic wounds. EA was harmless to cell viability, increasing the possibility and safety of drug development. EA-engineered sEVs were fabricated by loading EA in sEVs. In vitro, EA-sEVs promoted the proliferation, migration, and transdifferentiation of HG-HDFs and the proliferation and migration of HG-HEKs. Mechanism analysis elucidated that epidermal growth factor receptor (EGFR) was the specific biological target of EA. EA interacting with EGFR was responsible for the functional improvement of HG-HDFs and HG-HEKs. In vivo, EA-sEVs encapsulated in GelMA promoted the healing of diabetic wounds by improving re-epithelialisation, collagen formation and the expression of EGFR. Gel-EA-sEVs promoted diabetic wound healing by improving biological functions of HDFs and HEKs. EGFR was first identified as the specific biological target of EA and was responsible for the functional improvement of HG-HDFs and HG-HEKs by Gel-EA-sEVs. Hence, Gel-EA-sEVs can serve as a new promising active dressing for diabetic wound treatment.

The Role of Omics Techniques in Diabetic Wound Healing: Recent Insights into the Application of Single-Cell RNA Sequencing, Bulk RNA Sequencing, Spatial Transcriptomics, and Proteomics

Diabetic foot ulcers (DFUs) are a devastating complication of diabetes mellitus (DM) that affect millions of people worldwide every year. They have a long-term impact on patients' quality of life and pose a significant challenge for both patients and clinicians, alongside negative economic implications on affected individuals. The current therapeutic approaches are costly and, in many cases, ineffective, highlighting the urgent need to develop novel, affordable, more efficient, and personalized treatments. Recent advances in high-throughput omics technologies, including proteomics, bulk RNA sequencing (bulk RNA-seq), single-cell RNA sequencing (scRNA-seq), and spatial transcriptomics in both preclinical animal and human clinical studies, have enhanced our understanding of the molecular function and mechanisms of DFUs, thereby offering potential for targeted therapies. Additionally, these technologies provide valuable insights behind the mechanism of action of novel wound dressings and treatments. In this review, we outline the latest application of omics technologies in DFU preclinical animal and human clinical research on diabetic wound healing, and spotlight recent findings.A graphical abstract is available with this article.

Exosome-Based Therapeutics in Dermatology

Exosomes (Exos) are tiny extracellular vesicles containing a variety of active biomolecules that play important parts in intercellular communication and influence the functions of target cells. The potential of Exos in the treatment of dermatological diseases has recently been well appreciated. This review highlights the constituents, function, and delivery of Exos, with a particular focus on their applications in skin therapy. Firstly, we offer a concise overview of the biochemical properties of Exos, including their sources, structures, and internal constituents. Subsequently, the biomedical functions of Exos and the latest advances in the extraction and purification of Exos are summarized. We further discuss the modes of delivery of Exos and underscore the potential of biomaterials in this regard. Finally, we summarize the application of Exo-aided therapy in dermatology. Overall, the objective of this review is to provide a comprehensive perspective on the applications and recent advancements of Exo-based approaches in treating skin diseases, with the intention of guiding future research efforts.

Extracellular vesicle as therapeutic agents in anti-aging: Mechanistic insights and future potential

Aging is a multifaceted biological process marked by a gradual decline in physiological functions, driven by cellular senescence, oxidative stress, chronic inflammation, and stem cell exhaustion. Extracellular vesicles (EVs), naturally occurring nanoscale vesicles secreted by various cell types, have gained attention as potential therapeutic agents due to their ability to mediate intercellular communication by delivering bioactive molecules, including proteins, lipids, and RNAs. This review provides a comprehensive overview of EV biogenesis, cargo composition, and their mechanistic roles in counteracting aging processes. EVs from diverse sources-such as mesenchymal stem cells, embryonic stem cells, dermal fibroblasts, and colostrum-exhibit regenerative properties by modulating immune responses, enhancing tissue repair, and promoting extracellular matrix homeostasis. Recent preclinical and clinical studies further highlight their potential in addressing age-related diseases and skin rejuvenation. However, significant challenges remain, including standardization of EV production, large-scale manufacturing, safety profiling, and regulatory approval. By leveraging advancements in EV engineering, targeted delivery systems, and combination strategies with existing anti-aging interventions, EV-based therapies hold promise as next-generation approaches in regenerative medicine and longevity enhancement.

Extracellular vesicles and bioactive peptides for regenerative medicine in cosmetology

As life quality improves and the life pressure increases, people's awareness of maintaining healthy skin and hair grows. However, the use of bioactive peptides in regenerative medical aesthetics is often constrained by the high molecular weight, which impedes skin penetration. In contrast, extracellular vesicles not only possess regenerative properties but also serve as effective carriers for bioactive peptides. Given their anti-inflammatory and bactericidal properties, capacity to promote angiogenesis, optimize collagen alignment, facilitate re-epithelialization and stimulate hair growth, extracellular vesicles become an emerging and promising solution for skin regeneration treatments. The combination of peptides and extracellular vesicles enhances therapeutic efficacy and improves the bioavailability of bioactive peptides. In this review, we summarize the functions of bioactive peptides and plant- and animal-derived extracellular vesicles in regenerative medicine with cosmetology, along with examples of their combined applications. Additionally, we provide an overview of peptides and extracellular vesicles currently available on the market and in clinical practice, discussing the challenges and solutions associated with their use.

Role of Non-Coding RNAs in White and Brown Adipose Tissue Differentiation and Development

Adipocyte differentiation is a complex process in which pluripotent mesenchymal stem cells (MSCs) differentiate and develop into mature fat cells, also known as adipocytes. This process is controlled by various transcription factors, hormones, and signaling molecules that regulate the development of these cells. Recently, an increasing number of non-coding RNAs (ncRNAs), especially microRNAs (miRNAs), have been established to be involved in the regulation of many biological processes, including adipocyte differentiation, development, metabolism, and energy homeostasis of white and brown adipose tissue. Several in vitro and in vivo studies reported the significant role of ncRNAs in either promoting or inhibiting adipocyte differentiation into white or brown fat cells by targeting specific transcription factors and regulating the expression of key adipogenic genes. Identifying the function of ncRNAs and their subsequent targets contributes to our understanding of how these molecules can be used as potential biomarkers and tools for therapies against obesity, diabetes, and other diseases related to obesity. This could also contribute to advancements in tissue-engineering based treatments. In this review, we intended to present an up-to-date comprehensive literature overview of the role of ncRNAs, including miRNAs, long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), focusing particularly on miRNAs, in regulating the differentiation and development of cells into white and brown adipose tissue. In addition, we further discuss the potential use of these molecules as biomarkers for the development of novel therapeutic strategies for future personalized treatment options for patients.

Non-coding RNAs in adipose-derived stem cell exosomes: Mechanisms, therapeutic potential, and challenges in wound healing

The treatment of complex wounds presents a significant clinical challenge due to the limited availability of standardized therapeutic options. Adipose-derived stem cell exosomes (ADSC-Exos) are promising for their capabilities to enhance angiogenesis, mitigate oxidative stress, modulate inflammatory pathways, support skin cell regeneration, and promote epithelialization. These exosomes deliver non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs, which facilitate collagen remodeling, reduce scar formation, and expedite wound healing. This study reviews the mechanisms, therapeutic roles, and challenges of non-coding RNA-loaded ADSC-Exos in wound healing and identifies critical directions for future research. It aims to provide insights for researchers into the potential mechanisms and clinical applications of ADSC-Exos non-coding RNAs in wound healing.

Cutting-Edge Progress in the Acquisition, Modification and Therapeutic Applications of Exosomes for Drug Delivery

Exosomes are vesicles secreted by cells, typically ranging from 30 to 150 nm in diameter, and serve as crucial mediators of intercellular communication. Exosomes are capable of loading various therapeutic substances, such as small molecule compounds, proteins, and oligonucleotides, thereby making them an ideal vehicle for drug delivery. The distinctive biocompatibility, high stability, and targeting properties of exosomes render them highly valuable for future treatments of diseases like cancer and cardiovascular diseases. Despite the potential advantage of exosomes in delivering biologically active molecules, the techniques for the preparation, purification, preservation, and other aspects of stem cell exosomes are not yet mature enough. In this paper, we briefly introduce the composition, biogenesis, and benefits of exosomes, and primarily focus on summarizing the isolation and purification methods of exosomes, the preparation of engineered exosomes, and their clinical applications, to better provide new ideas for the development of exosome drug delivery systems.

A Smart MMP-9-responsive Hydrogel Releasing M2 Macrophage-derived Exosomes for Diabetic Wound Healing

Chronic diabetic wounds are characterized by prolonged inflammation and excessive accumulation of M1 macrophages, which impede the healing process. Therefore, resolving inflammation promptly and transitioning to the proliferative phase are critical steps for effective diabetic wound healing. Exosomes have emerged as a promising therapeutic strategy. In this study, a smart hydrogel capable of responding to pathological cues in the inflammatory microenvironment to promote the transition from inflammation to proliferation by delivering M2 macrophage-derived exosomes (M2-Exos) is developed. The smart hydrogel is synthesized through the cross-linking of oxidized dextran, a matrix metalloproteinase (MMP)-9-sensitive peptide, and carboxymethyl chitosan containing M2-Exos. In response to elevated MMP-9 concentrations in the inflammatory microenvironment, the hydrogel demonstrates diagnostic logic, adjusting the release kinetics of M2-Exos accordingly. The on-demand release of M2-Exos facilitated macrophage polarization from the M1 to the M2 phenotype, thereby promoting the transition from the inflammatory to the proliferative phase and accelerating diabetic wound healing. The transcriptomic analysis further reveals that the MMP-9-responsive hydrogel with M2-Exos delivery exerts anti-inflammatory and regenerative effects by downregulating inflammation-related pathways. This study introduces an innovative, microenvironment-responsive exosome delivery system that enables precise control of therapeutic agent release, offering a personalized approach for the treatment of chronic diabetic wounds.

Exosome-carried miR-1248 from adipose-derived stem cells improves angiogenesis in diabetes-associated wounds

Chronic non-healing wounds are a common complication of diabetes, marked by impaired angiogenesis. This study explores how exosomes (Exo-miR-1248) from miR-1248-overexpressing adipose-derived stem cells enhance diabetic wound healing by modulating endothelial cell function. Adipose-derived stem cells were transfected with a lentivirus carrying miR-1248 to produce Exo-miR-1248, isolated via differential centrifugation. In vitro, Exo-miR-1248's effects on proliferation, scratch wound healing, and tube formation in human umbilical vein endothelial cells (HUVECs) were assessed. For in vivo analysis, diabetic mice were induced with streptozotocin (STZ) and full-thickness skin defects were created. The impact of Exo-miR-1248 on wound healing was evaluated through subcutaneous injections. Histological analysis included H&E staining for epithelial regeneration and wound width, Masson's staining for collagen deposition, immunofluorescence for CD31 and α-SMA expression, RT-qPCR and WB for mRNA and protein levels of pro-angiogenic genes (VEGF-A, TGF-β, and Angpt-1). Exo-miR-1248 significantly enhanced HUVEC proliferation and migration. Tube formation assays showed increased capillary-like structures. In vivo, Exo-miR-1248-treated wounds healed faster, with improved collagen deposition and blood vessel formation. RT-qPCR and WB show that the mRNA and protein levels of VEGF-A, Angpt-1, and TGF-β are upregulated. Exo-miR-1248 may enhance diabetic wound healing by upregulating pro-angiogenic factors, offering a novel therapeutic approach.

Exos-Loaded Gox-Modified Smart-Response Self-Healing Hydrogel Improves the Microenvironment and Promotes Wound Healing in Diabetic Wounds

Wound management has always been a challenge in the clinical treatment of diabetes. In this study, glucose oxidase (GOx) is grafted onto natural pullulan polysaccharides, and oxidization is carried out to form a self-healing hydrogel using carboxymethyl chitosan by means of reversible Schiff base covalent bonding. The smart-response drug release properties of this natural self-healing hydrogel are demonstrated in diabetic wounds by taking advantage of two key factors, namely the pH-responsive nature of Schiff base bonding and the fact that GOx reduces the pH in diabetic wounds. To further enhance the biological functions of the hydrogel dressing, exosomes (Exos) are introduced into the hydrogel system. The GOx present in the hydrogel system improves the high-glucose microenvironment of diabetic wounds, releasing H2O2 to impart antimicrobial effects, and ensuring that the hydrogel realizes a smart-response function. The carboxymethyl chitosan component used to construct the hydrogel plays an effective antibacterial role. Moreover, the Exos loaded into the hydrogel effectively promotes neovascularization of the wound. The Exos also regulates macrophage polarization and reduces the levels of persistent inflammation in diabetic wounds. These results suggest that this smart responsive, multifunctional, and self-healing hydrogel dressing is ideal for the management of diabetic wounds.

Exploring the ncRNA landscape in exosomes: Insights into wound healing mechanisms and therapeutic applications

Exosomal non-coding RNAs (ncRNAs), including miRNAs, lncRNAs, and circRNAs, have emerged as crucial modulators in cellular signaling, influencing wound healing processes. Stem cell-derived exosomes, which serve as vehicles for these ncRNAs, show remarkable therapeutic potential due to their ability to modulate wound healing stages, from initial inflammation to collagen formation. These ncRNAs act as molecular signals, regulating gene expression and protein synthesis necessary for cellular responses in healing. Wound healing is a complex, staged process involving inflammation, hemostasis, fibroblast proliferation, angiogenesis, and tissue remodeling. Stem cell-derived exosomal ncRNAs enhance these stages by reducing excessive inflammation, promoting anti-inflammatory responses, guiding fibroblast and keratinocyte maturation, enhancing vascularization, and ensuring organized collagen deposition. Their molecular cargo, particularly ncRNAs, specifically targets pathways to aid chronic wound repair and support scarless regeneration. This review delves into the unique composition and signaling roles of Stem cell-derived exosomes and ncRNAs, highlighting their impact across wound healing stages and their potential as innovative therapeutics. Understanding the interaction between exosomal ncRNAs and cellular signaling pathways opens new avenues in regenerative medicine, positioning Stem cell-derived exosomes and their ncRNAs as promising molecular-level interventions in wound healing.

Advances of exosomes in diabetic wound healing

Poor wound healing is a refractory process that places an enormous medical and financial burden on diabetic patients. Exosomes have recently been recognized as crucial players in the healing of diabetic lesions. They have excellent stability, homing effects, biocompatibility, and reduced immunogenicity as novel cell-free therapies. In addition to transporting cargos to target cells to enhance intercellular communication, exosomes are beneficial in nearly every phase of diabetic wound healing. They participate in modulating the inflammatory response, accelerating proliferation and reepithelization, increasing angiogenesis, and regulating extracellular matrix remodeling. Accumulating evidence indicates that hydrogels or dressings in conjunction with exosomes can prolong the duration of exosome residency in diabetic wounds. This review provides an overview of the mechanisms, delivery, clinical application, engineering, and existing challenges of the use of exosomes in diabetic wound repair. We also propose future directions for biomaterials incorporating exosomes: 2D or 3D scaffolds, biomaterials loaded with wound healing-promoting gases, intelligent biomaterials, and the prospect of systematic application of exosomes. These findings may might shed light on future treatments and enlighten some studies to improve quality of life among diabetes patients.

Compliant immune response of silk-based biomaterials broadens application in wound treatment

The unique properties of sericin and silk fibroin (SF) favor their widespread application in biopharmaceuticals, particularly in wound treatment and bone repair. The immune response directly influences wound healing cycle, and the extensive immunomodulatory functions of silk-based nanoparticles and hydrogels have attracted wide attention. However, different silk-processing methods may trigger intense immune system resistance after implantation into the body. In this review, we elaborate on the inflammation and immune responses caused by the implantation of sericin and SF and also explore their anti-inflammatory properties and immune regulatory functions. More importantly, we describe the latest research progress in enhancing the immunotherapeutic and anti-inflammatory effects of composite materials prepared from silk from a mechanistic perspective. This review will provide a useful reference for using the correct processes to exploit silk-based biomaterials in different wound treatments.

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.

Engineered Extracellular Vesicles as a New Class of Nanomedicine

Extracellular vesicles (EVs) are secreted from biological cells and contain many molecules with diagnostic values or therapeutic functions. There has been great interest in academic and industrial communities to utilize EVs as tools for diagnosis or therapeutics. In addition, EVs can also serve as delivery vehicles for therapeutic molecules. An indicator of the enormous interest in EVs is the large number of review articles published on EVs, with the focus ranging from their biology to their applications. An emerging trend in EV research is to produce and utilize "engineered EVs", which are essentially the enhanced version of EVs. EV engineering can be conducted by cell culture condition control, genetic engineering, or chemical engineering. Given their nanometer-scale sizes and therapeutic potentials, engineered EVs are an emerging class of nanomedicines. So far, an overwhelming majority of the research on engineered EVs is preclinical studies; there are only a very small number of reported clinical trials. This Review focuses on engineered EVs, with a more specific focus being their applications in therapeutics. The various approaches to producing engineered EVs and their applications in various diseases are reviewed. Furthermore, in vivo imaging of EVs, the mechanistic understandings, and the clinical translation aspects are discussed. The discussion is primarily on preclinical studies while briefly mentioning the clinical trials. With continued interdisciplinary research efforts from biologists, pharmacists, physicians, bioengineers, and chemical engineers, engineered EVs could become a powerful solution for many major diseases such as neurological, immunological, and cardiovascular diseases.

Exosomes derived from umbilical cord mesenchymal stem cells promote healing of complex perianal fistulas in rats

BACKGROUND

Complex perianal fistulas, challenging to treat and prone to recurrence, often require surgical intervention that may cause fecal incontinence and lower quality of life due to large surgical wounds and potential sphincter damage. Human umbilical cord-derived MSCs (hUC-MSCs) and their exosomes (hUCMSCs-Exo) may promote wound healing.

METHODS

This study assessed the efficacy, mechanisms, and safety of these exosomes in treating complex perianal fistulas in SD rats. We established a rat model, divided rats with fistulas into the control and the exosome groups. We assessed treatment efficacy through ultrasound, clinical observations, and histopathological analysis. We also evaluated the activation of the HIF-1α/TGF-β/Smad signaling pathway via PCR and Western blot and assessed serological markers for HIF-1α and inflammatory indices through ELISA. We analyzed gut microbiota and the systemic metabolic environment via untargeted metabolomics.

RESULTS

The hUCMSCs-Exo effectively promoted healing of wound, regulated the immune balance enhanced collagen synthesis and angiogenesis in the perianal fistulas model of rats, and regulated the gut microbiota and metabolomic profiles. Results of PCR and Western blot analyses indicated that the exosomes activated HIF-1α/TGF-β/Smad signaling pathways. To the dosages tested, the 10ug/100ul concentration (medium dose) was found to be the most effective to the treatment of complex perianal fistulas.

CONCLUSIONS

The hUCMSCs-Exo significantly promoted the healing of wound in perianal fistulas of rats and demonstrated higher safety. The underlying mechanism facilitating the healing process was likely associated with the activation of the HIF-1α/TGF-β/Smad signaling pathway.

Epidermal keratinocytes-specific PD-L1 knockout causes delayed healing of diabetic wounds

BACKGROUND

Diabetic ulcers (DUs) is a common complication of diabetes, for which the morbidity and mortality increasing annually worldwide. The deficiency of PD-L1 in keratinocytes (KCs) may be linked to the diabetic wound healing impediments.

OBJECTIVE

Our study utilized transgenic mice to assess the functions of epidermal KCs-specific PD-L1 in DUs treatment.

METHODS AND RESULTS

Epidermal KCs-specific PD-L1 knockouted mice demonstrate deteriorated healing rates, concomitant with exacerbated inflammatory infiltration and excessive angiogenesis. The streptozotocin-induced murine diabetes model was used to imitate DUs in-vivo context, and the delayed healing was found under diabetic conditions. We then generated transgenic mice overexpressing PD-L1 in the epidermis. PD-L1 overexpression accelerate the DUs healing process accompanied by a reduction in inflammatory infiltration and a corresponding decreasion of angiogenesis. Therefore, overexpression of PD-L1 accelerates the healing process of DUs.

CONCLUSION

In sum, epidermal KCs-specific PD-L1 plays vital roles in epidermis regeneration, inflammatory infiltration, and angiogenesis during DUs restoration, and would not be easily to format fibrous scar. Our study elucidated a new therapeutic idea for slow-healing wound care.

Nano-Delivery Revolution: Harnessing Mesenchymal Stem Cell-Derived Exosomes' Potential for Wound Healing

Stem cell transplantation has proven effective in treating acute and chronic wounds, but its limitations, such as low cellular viability and the need for specialized transportation, highlight the necessity for alternative approaches. This review explores the potential of engineered exosomes, containing identified miRNAs/peptides, as a more stable and efficient cell-free therapy for regenerative medicine, particularly in wound healing. The discussion emphasizes the benefits of exosomes, including their stability, reduced damage, and consistent biological activity, paving the way for innovative applications like lyophilized exosomes, mist spray delivery, and exosome-based scaffolds. The exploration of cell-free therapy in this review holds promising implications for advancing wound-healing strategies.

Oral Delivery of miR146a Conjugated to Cerium Oxide Nanoparticles Improves an Established T Cell-Mediated Experimental Colitis in Mice

Background: Dysregulated inflammation and oxidative stress are strongly implicated in the pathogenesis of inflammatory bowel disease. We have developed a novel therapeutic that targets inflammation and oxidative stress. It is comprised of microRNA-146a (miR146a)-loaded cerium oxide nanoparticles (CNPs) (CNP-miR146a). We hypothesized that oral delivery of CNP-miR146a would reduce colonic inflammation in a mouse model of established, chronic, T cell-mediated colitis. Methods: The stability of CNP-miR146a and mucosal delivery was assessed in vitro with simulated gastrointestinal fluid and in vivo after oral gavage by quantitative real-time RT-PCR. The efficacy of orally administered CNP-miR146a was tested in mice with established colitis using the model of adoptive naïve T-cell transfer in recombinant activating gene 2 knockout (Rag2-/-) mice. Measured outcomes included histopathology; CD45+ immune cell infiltration; oxidative DNA damage (tissue 8-hydroxy-2'-deoxyguanosine; 8-OHdG); expression of IL-6 and TNF mRNA and protein, and flow cytometry analysis of lamina propria Th1 and Th17 cell populations. Results: miR146a expression remained stable in simulated gastric and intestinal conditions. miR146a expression increased in the intestines of mice six hours following oral gavage of CNP-miR146a. Oral delivery of CNP-miR146a in mice with colitis was associated with reduced inflammation and oxidative stress in the proximal and distal colons as evidenced by histopathology scoring, reduced immune cell infiltration, reduced IL-6 and TNF expression, and decreased populations of CD4+Tbet+IFNg+ Th1, CD4+RorgT+IL17+ Th17, as well as pathogenic double positive IFNg+IL17+ T cells. Conclusions: CNP-miR146a represents a novel orally available therapeutic with high potential to advance into clinical trials.

A Multifunctional Nanocomplex as miRNA/Antibiotic Co-Delivery System Based on Tetrahedral Framework DNA: Application to Infected Wound Healing

Infected wounds are a complex disease involving bacterial infections and dysregulated inflammation. However, current research has mostly focused on bacterial inhibition rather than on inflammation. Thus, combined therapeutic strategies with anti-bacterial and anti-inflammation efficacies are urgently needed. Antibiotics are the main treatment strategy for infections. However, the excessive use of antibiotics throughout the body can cause serious side effects. In addition, miRNA-based therapeutics are superior for the treatment of wounds, but their rapid degradation and poor cellular uptake limit their clinical application. Tetrahedral framework DNA (tFNA) is an ideal drug delivery system owing to its excellent stability and remarkable transport ability. Herein, a novel multi-functional miRNA and antibiotic co-delivery system based on tFNA is presented for the first time, called B/L. B/L has heightened resistance to serum and excellent codelivery ability. After transdermal administration, B/L can specifically target TNF receptor-associated factor 6(TRAF6) and IL-1receptor-associated kinase 1(IRAK1), thereby regulating nuclear factor kappa-B (NF-𝜿B) and thus effectively reducing inflammation and promoting the healing of infected wounds. This novel multi-functional co-delivery system provides a versatile, simple, biocompatible, and powerful platform for the personalized and combined treatment of multiple diseases.

Near Infrared-Triggered Nitric Oxide-Release Nanovesicles with Mild-Photothermal Antibacterial and Immunomodulation for Healing MRSA-Infected Diabetic Wounds

Bacterial infection-induced excessive inflammation is a major obstacle in diabetic wound healing. Nitric oxide (NO) exhibits significant antibacterial activity but is extremely deficient in diabetes. Hence, a near-infrared (NIR)-triggered NO release system is constructed through codelivery of polyarginine (PArg) and gold nanorods (Au) in an NIR-activatable methylene blue (MB) polypeptide-assembled nanovesicle (Au/PEL-PBA-MB/PArg). Upon NIR irradiation, the quenched MB in the nanovesicles is photoactivated to generate more reactive oxygen species (ROS) to oxidize PArg and release NO in an on-demand controlled manner. With the specific bacterial capture of phenylboronic acid (PBA), NO elevated membrane permeability and boosted bacterial vulnerability in the photothermal therapy (PTT) of the Au nanorods, which is displayed by superior mild PTT antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) at temperatures < 49.7 °C in vitro. Moreover, in vivo, the antibacterial nanovesicles greatly suppressed the burst of MRSA-induced excessive inflammation, NO relayed immunomodulated macrophage polarization from M1 to M2, and the excessive inflammatory phase is successfully transferred to the repair phase. In cooperation with angiogenesis by NO, tissue regeneration is accelerated in MRSA-infected diabetic wounds. Therefore, nanoplatform has considerable potential for accelerating the healing of infected diabetic wounds.

Emerging technologies in regenerative medicine: The future of wound care and therapy

Wound healing, an intricate biological process, comprises orderly phases of simple biological processed including hemostasis, inflammation, angiogenesis, cell proliferation, and ECM remodeling. The regulation of the shift in these phases can be influenced by systemic or environmental conditions. Any untimely transitions between these phases can lead to chronic wounds and scarring, imposing a significant socio-economic burden on patients. Current treatment modalities are largely supportive in nature and primarily involve the prevention of infection and controlling inflammation. This often results in delayed healing and wound complications. Recent strides in regenerative medicine and tissue engineering offer innovative and patient-specific solutions. Mesenchymal stem cells (MSCs) and their secretome have gained specific prominence in this regard. Additionally, technologies like tissue nano-transfection enable in situ gene editing, a need-specific approach without the requirement of complex laboratory procedures. Innovating approaches like 3D bioprinting and ECM bioscaffolds also hold the potential to address wounds at the molecular and cellular levels. These regenerative approaches target common healing obstacles, such as hyper-inflammation thereby promoting self-recovery through crucial signaling pathway stimulation. The rationale of this review is to examine the benefits and limitations of both current and emerging technologies in wound care and to offer insights into potential advancements in the field. The shift towards such patient-centric therapies reflects a paradigmatic change in wound care strategies.

Dissolvable microneedle-based wound dressing transdermally and continuously delivers anti-inflammatory and pro-angiogenic exosomes for diabetic wound treatment

Due to overactive inflammation and hindered angiogenesis, self-healing of diabetic wounds (DW) remains challenging in the clinic. Platelet-derived exosomes (PLT-Exos), a novel exosome capable of anti-inflammation and pro-angiogenesis, show great potential in DW treatment. However, previous administration of exosomes into skin wounds is topical daub or intradermal injection, which cannot intradermally deliver PLT-Exos into the dermis layer, thus impeding its long-term efficacy in anti-inflammation and pro-angiogenesis. Herein, a dissolvable microneedle-based wound dressing (PLT-Exos@ADMMA-MN) was developed for transdermal and long-term delivery of PLT-Exos. Firstly, a photo-crosslinking methacrylated acellular dermal matrix-based hydrogel (ADMMA-GEL), showing physiochemical tailorability, fast-gelling performance, excellent biocompatibility, and pro-angiogenic capacities, was synthesized as a base material of our dressing. For endowing the dressing with anti-inflammation and pro-angiogenesis, PLT-Exos were encapsulated into ADMMA-GEL with a minimum effective concentration determined by our in-vitro experiments. Then, in-vitro results show that this dressing exhibits excellent properties in anti-inflammation and pro-angiogenesis. Lastly, in-vivo experiments showed that this dressing could continuously and transdermally deliver PLT-Exos into skin wounds to switch local macrophage into M2 phenotype while stimulating neovascularization, thus proving a low-inflammatory and pro-angiogenic microenvironment for DW healing. Collectively, this study provides a novel wound dressing capable of suppressing inflammation and stimulating vascularization for DW treatment.

Inflammation-Modulating Biomedical Interventions for Diabetic Wound Healing: An Overview of Preclinical and Clinical Studies

A diabetic wound exemplifies the challenge of chronic, nonhealing wounds. Elevated blood sugar levels in diabetes profoundly disrupt macrophage function, impairing crucial activities such as phagocytosis, immune response, cell migration, and blood vessel formation, all essential for effective wound healing. Moreover, the persistent presence of pro-inflammatory cytokines and reactive oxygen species, coupled with a decrease in anti-inflammatory factors, exacerbates the delay in wound healing associated with diabetes. This review emphasizes the dysfunctional inflammatory responses underlying diabetic wounds and explores preclinical studies of inflammation-modulating bioactives and biomaterials that show promise in expediting diabetic wound healing. Additionally, this review provides an overview of selected clinical studies employing biomaterials and bioactive molecules, shedding light on the gap between extensive preclinical research and limited clinical studies in this field.

Drug conjugates crosslinked bioresponsive hydrogel for combination therapy of diabetic wound

Basic fibroblast growth factor (bFGF) has proved to be effective for wound healing, yet its effectiveness is extremely retarded in diabetic wounds due to the severe oxidative stress in wound beds. To solve this issue, herein a novel combination therapy of bFGF and N-acetylcysteine (NAC, antioxidant) was devised for improved diabetic wound repair. To avoid rapid loss of both drugs in the wound beds, a bioresponsive hydrogel (bFGF-HSPP-NAC) was engineered by incorporating bFGF and NAC into polymer-drug conjugates (HSPP) via thiol-disulfide exchange reactions. In response to oxidative stress (e.g., reactive oxygen species), the disulfide bonds (SS) within the hydrogel are broken into thiol groups (-S-H), thereby promoting hydrogel degradation and enabling controlled drug release. Initially, NAC is released to scavenge free radicals and ameliorate oxidative damage. Subsequently, bFGF is released to expedite tissue regeneration. This combinatorial strategy is tailored to the specific characteristics of the wound microenvironment at various stages of diabetic wound healing, thereby achieving therapeutic efficacy. The results indicate that the bFGF-HSPP-NAC hydrogel markedly enhances re-epithelialization, collagen deposition, hair follicle regeneration, and neovascularization. In conclusion, the bioresponsive bFGF-HSPP-NAC hydrogel demonstrates significant potential for application in combinatorial therapeutic approaches for diabetic wound healing.

Current advances in the development of microRNA-integrated tissue engineering strategies: a cornerstone of regenerative medicine

Regenerative medicine is an innovative scientific field focused on repairing, replacing, or regenerating damaged tissues and organs to restore their normal functions. A central aspect of this research arena relies on the use of tissue-engineered scaffolds, which serve as structural supports that mimic the extracellular matrix, providing an environment that orchestrates cell growth and tissue formation. Remarkably, the therapeutic efficacy of these scaffolds can be improved by harnessing the properties of other molecules or compounds that have crucial roles in healing and regeneration pathways, such as phytochemicals, enzymes, transcription factors, and non-coding RNAs (ncRNAs). In particular, microRNAs (miRNAs) are a class of tiny (20-24 nt), highly conserved ncRNAs that play a critical role in the regulation of gene expression at the post-transcriptional level. Accordingly, miRNAs are involved in a myriad of biological processes, including cell differentiation, proliferation, and apoptosis, as well as tissue regeneration, angiogenesis, and osteogenesis. On this basis, over the past years, a number of research studies have demonstrated that miRNAs can be integrated into tissue-engineered scaffolds to create advanced therapeutic platforms that precisely modulate cellular behavior and offer a controlled and targeted release of miRNAs to optimize tissue repair and regeneration. Therefore, in this current review, we discuss the most recent advances in the development of miRNA-loaded tissue-engineered scaffolds and provide an overview of the future outlooks that should be aborded in this area of study in order to lay the groundwork for the clinical translation of these tissue engineering approaches.

Smart Hydrogel Dressing Enhances the Healing of Chronic Infectious Diabetic Wounds through Dual-Barrier Drug Delivery Action

Chronic diabetic wounds struggle to heal due to drug-resistant bacterial infections, oxidative stress microenvironment, and immune dysfunction. At present, the disease has become a huge clinical challenge. Multifunctional hydrogels with antibacterial, antioxidant, and anti-inflammatory properties are becoming an emerging trend in the treatment of chronic wounds. However, matching different bioactive functions with the wound healing process to sequentially exert antibacterial, antioxidant, anti-inflammatory, and immunomodulatory functions remains a significant challenge. In this research, a hydrogel dressing with bactericidal and anti-inflammatory properties was synthesized by crafting a pH/ROS-responsive scaffold from phenylboronic acid-grafted hyaluronic acid (HA-PBA) and 4-arm-PEG-dopamine (4A-PEG-Dopa), employing dynamic borate ester bonds. This structure was then infused with the antimicrobial peptide (AMP) and ROS-sensitive micelle mPEG-TK-PLGA loaded with quercetin (QC). This dressing embodied a dual-barrier drug delivery mechanism, engineered for the prolonged and consistent liberation of QC. In the experiment, the hydrogel dissociated within the acidic microenvironment of diabetic wounds, thereby liberating the encapsulated micelles and AMP. Upon further dissociation, the micelles release QC due to the ROS-abundant microenvironment, which could relieve oxidative stress and encourage M2 polarization of macrophage via the Akt/STAT6 signaling pathway. Therefore, this smart delivery system, developed through our innovative approach, holds promise for treating chronic infectious diabetic wounds.

Interleukin-1 Receptor-Associated Kinase 1 in Cancer Metastasis and Therapeutic Resistance: Mechanistic Insights and Translational Advances

Interleukin-1 Receptor Associated Kinase 1 (IRAK1) is a serine/threonine kinase that plays a critical role as a signaling transducer of the activated Toll-like receptor (TLR)/Interleukin-1 receptor (IL-1R) signaling pathway in both immune cells and cancer cells. Upon hyperphosphorylation by IRAK4, IRAK1 forms a complex with TRAF6, which results in the eventual activation of the NF-κB and MAPK pathways. IRAK1 can translocate to the nucleus where it phosphorylates STAT3 transcription factor, leading to enhanced IL-10 gene expression. In immune cells, activated IRAK1 coordinates innate immunity against pathogens and mediates inflammatory responses. In cancer cells, IRAK1 is frequently activated, and the activation is linked to the progression and therapeutic resistance of various types of cancers. Consequently, IRAK1 is considered a promising cancer drug target and IRAK1 inhibitors have been developed and evaluated preclinically and clinically. This is a comprehensive review that summarizes the roles of IRAK1 in regulating metastasis-related signaling pathways of importance to cancer cell proliferation, cancer stem cells, and dissemination. This review also covers the significance of IRAK1 in mediating cancer resistance to therapy and the underlying molecular mechanisms, including the evasion of apoptosis and maintenance of an inflammatory tumor microenvironment. Finally, we provide timely updates on the development of IRAK1-targeted therapy for human cancers.

The Influence of Circadian Rhythms on DNA Damage Repair in Skin Photoaging

Circadian rhythms, the internal timekeeping systems governing physiological processes, significantly influence skin health, particularly in response to ultraviolet radiation (UVR). Disruptions in circadian rhythms can exacerbate UVR-induced skin damage and increase the risk of skin aging and cancer. This review explores how circadian rhythms affect various aspects of skin physiology and pathology, with a special focus on DNA repair. Circadian regulation ensures optimal DNA repair following UVR-induced damage, reducing mutation accumulation, and enhancing genomic stability. The circadian control over cell proliferation and apoptosis further contributes to skin regeneration and response to UVR. Oxidative stress management is another critical area where circadian rhythms exert influence. Key circadian genes like brain and muscle ARNT-like 1 (BMAL1) and circadian locomotor output cycles kaput (CLOCK) modulate the activity of antioxidant enzymes and signaling pathways to protect cells from oxidative stress. Circadian rhythms also affect inflammatory and immune responses by modulating the inflammatory response and the activity of Langerhans cells and other immune cells in the skin. In summary, circadian rhythms form a complex defense network that manages UVR-induced damage through the precise regulation of DNA damage repair, cell proliferation, apoptosis, inflammatory response, oxidative stress, and hormonal signaling. Understanding these mechanisms provides insights into developing targeted skin protection and improving skin cancer prevention.

The emerging modulators of non-coding RNAs in diabetic wound healing

Diabetic wound healing is a complex physiological process often hindered by the underlying metabolic dysfunctions associated with diabetes. Despite existing treatments, there remains a critical need to explore innovative therapeutic strategies to improve patient outcomes. This article comprehensively examines the roles of non-coding RNAs (ncRNAs), specifically microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in regulating key phases of the wound healing process: inflammation, angiogenesis, re-epithelialization, and tissue remodeling. Through a deep review of current literature, we discuss recent discoveries of ncRNAs that have been shown to either promote or impair the wound healing process in diabetic wound healing, which were not covered in earlier reviews. This review highlights the specific mechanisms by which these ncRNAs impact cellular behaviors and pathways critical to each healing stage. Our findings indicate that understanding these recently identified ncRNAs provides new insights into their potential roles in diabetic wound healing, thereby contributing valuable knowledge for future research directions in this field.

Emerging Nanotherapeutic Approaches for Diabetic Wound Healing

Diabetic wounds pose a significant challenge in modern healthcare due to their chronic and complex nature, often resulting in delayed healing, infections, and, in severe cases, amputations. In recent years, nanotherapeutic approaches have emerged as promising strategies to address the unique pathophysiological characteristics of diabetic wounds. This review paper provides a comprehensive overview of the latest advancements in nanotherapeutics for diabetic wound treatment. We discuss various nanomaterials and delivery systems employed in these emerging therapies. Furthermore, we explore the integration of biomaterials to enhance the efficacy of nanotherapeutic interventions. By examining the current state-of-the-art research, challenges, and prospects, this review aims to offer valuable insights for researchers, clinicians, and healthcare professionals working in the field of diabetic wound care.

Signaling pathways activated and regulated by stem cell-derived exosome therapy

Stem cell-derived exosomes exert comparable therapeutic effects to those of their parental stem cells without causing immunogenic, tumorigenic, and ethical disadvantages. Their therapeutic advantages are manifested in the management of a broad spectrum of diseases, and their dosing versatility are exemplified by systemic administration and local delivery. Furthermore, the activation and regulation of various signaling cascades have provided foundation for the claimed curative effects of exosomal therapy. Unlike other relevant reviews focusing on the upstream aspects (e.g., yield, isolation, modification), and downstream aspects (e.g. phenotypic changes, tissue response, cellular behavior) of stem cell-derived exosome therapy, this unique review endeavors to focus on various affected signaling pathways. After meticulous dissection of relevant literature from the past five years, we present this comprehensive, up-to-date, disease-specific, and pathway-oriented review. Exosomes sourced from various types of stem cells can regulate major signaling pathways (e.g., the PTEN/PI3K/Akt/mTOR, NF-κB, TGF-β, HIF-1α, Wnt, MAPK, JAK-STAT, Hippo, and Notch signaling cascades) and minor pathways during the treatment of numerous diseases encountered in orthopedic surgery, neurosurgery, cardiothoracic surgery, plastic surgery, general surgery, and other specialties. We provide a novel perspective in future exosome research through bridging the gap between signaling pathways and surgical indications when designing further preclinical studies and clinical trials.

Hydrogel-exosome system in tissue engineering: A promising therapeutic strategy

Characterized by their pivotal roles in cell-to-cell communication, cell proliferation, and immune regulation during tissue repair, exosomes have emerged as a promising avenue for "cell-free therapy" in clinical applications. Hydrogels, possessing commendable biocompatibility, degradability, adjustability, and physical properties akin to biological tissues, have also found extensive utility in tissue engineering and regenerative repair. The synergistic combination of exosomes and hydrogels holds the potential not only to enhance the efficiency of exosomes but also to collaboratively advance the tissue repair process. This review has summarized the advancements made over the past decade in the research of hydrogel-exosome systems for regenerating various tissues including skin, bone, cartilage, nerves and tendons, with a focus on the methods for encapsulating and releasing exosomes within the hydrogels. It has also critically examined the gaps and limitations in current research, whilst proposed future directions and potential applications of this innovative approach.

Therapeutic potential of microRNA-engineered exosomes in diabetic wound healing: a meta-analysis

Diabetic wounds, a prevalent diabetes complication, pose significant challenges in treatment. MicroRNA-engineered exosomes (miR-exo) are a promising new treatment for diabetic wounds; however, their mechanism remains to be completely understood. Therefore, we aimed to conduct a meta-analysis to evaluate the efficacy of miR-exo treatment in the management of diabetic wounds. To achieve this aim, academic databases, including PubMed, Embase, Web of Science, and the Cochrane Library, were searched for papers published before July 4, 2023. Outcome indicators (e.g., rate of wound healing, neovascular count, rate of re-epithelialization, deposition of collagen, breadth of scar, and inflammatory factors) were assessed. Six studies (total of 72 animals) met inclusion criteria and were analyzed. The amalgamated data revealed that miR-exo treatment exhibited superior results compared to those of control therapy. miR-exo treatment significantly enhanced the rate of wound healing, increased the number of neovascular formations, accelerated the rate of re-epithelialization, increased collagen deposition, reduced scar width, while significantly downregulating the expression of inflammatory factors. Our findings indicate that miR-exo treatment augments overall diabetic wound healing, especially when administered in conjunction with innovative dressings. To ascertain the optimal parameters for miR-exo treatment in managing diabetic wounds, future studies must encompass rigorous, large-scale, double-blinded clinical trials while incorporating long-term follow-up assessments for enhanced reliability and accuracy.

Engineered exosomes as a prospective therapy for diabetic foot ulcers

Diabetic foot ulcer (DFU), characterized by high recurrence rate, amputations and mortality, poses a significant challenge in diabetes management. The complex pathology involves dysregulated glucose homeostasis leading to systemic and local microenvironmental complications, including peripheral neuropathy, micro- and macro-angiopathy, recurrent infection, persistent inflammation and dysregulated re-epithelialization. Novel approaches to accelerate DFU healing are actively pursued, with a focus on utilizing exosomes. Exosomes are natural nanovesicles mediating cellular communication and containing diverse functional molecular cargos, including DNA, mRNA, microRNA (miRNA), lncRNA, proteins, lipids and metabolites. While some exosomes show promise in modulating cellular function and promoting ulcer healing, their efficacy is limited by low yield, impurities, low loading content and inadequate targeting. Engineering exosomes to enhance their curative activity represents a potentially more efficient approach for DFUs. This could facilitate focused repair and regeneration of nerves, blood vessels and soft tissue after ulcer development. This review provides an overview of DFU pathogenesis, strategies for exosome engineering and the targeted therapeutic application of engineered exosomes in addressing critical pathological changes associated with DFUs.

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.

Healing the diabetic wound: Unlocking the secrets of genes and pathways

Diabetic wounds (DWs) are open sores that can occur anywhere on a diabetic patient's body. They are often complicated by infections, hypoxia, oxidative stress, hyperglycemia, and reduced growth factors and nucleic acids. The healing process involves four phases: homeostasis, inflammation, proliferation, and remodeling, regulated by various cellular and molecular events. Numerous genes and signaling pathways such as VEGF, TGF-β, NF-κB, PPAR-γ, MMPs, IGF, FGF, PDGF, EGF, NOX, TLR, JAK-STAT, PI3K-Akt, MAPK, ERK, JNK, p38, Wnt/β-catenin, Hedgehog, Notch, Hippo, FAK, Integrin, and Src pathways are involved in these events. These pathways and genes are often dysregulated in DWs leading to impaired healing. The present review sheds light on the pathogenesis, healing process, signaling pathways, and genes involved in DW. Further, various therapeutic strategies that target these pathways and genes via nanotechnology are also discussed. Additionally, clinical trials on DW related to gene therapy are also covered in the present review.

Customized Proteinaceous Nanoformulation for In Vivo Chemical Reprogramming

Sweat gland (SwG) regeneration is crucial for the functional rehabilitation of burn patients. In vivo chemical reprogramming that harnessing the patient's own cells in damaged tissue is of substantial interest to regenerate organs endogenously by pharmacological manipulation, which could compensate for tissue loss in devastating diseases and injuries, for example, burns. However, achieving in vivo chemical reprogramming is challenging due to the low reprogramming efficiency and an unfavorable tissue environment. Herein, this work has developed a functionalized proteinaceous nanoformulation delivery system containing prefabricated epidermal growth factor structure for on-demand delivery of a cocktail of seven SwG reprogramming components to the dermal site. Such a chemical reprogramming system can efficiently induce the conversion of epidermal keratinocytes into SwG myoepithelial cells, resulting in successful in situ regeneration of functional SwGs. Notably, in vivo chemical reprogramming of SwGs is achieved for the first time with an impressive efficiency of 30.6%, surpassing previously reported efficiencies. Overall, this proteinaceous nanoformulation provides a platform for coordinating the target delivery of multiple pharmacological agents and facilitating in vivo SwG reprogramming by chemicals. This advancement greatly improves the clinical accessibility of in vivo reprogramming and offers a non-surgical, non-viral, and cell-free strategy for in situ SwG regeneration.

The science of exosomes: Understanding their formation, capture, and role in cellular communication

Extracellular vesicles (EVs) serve as a crucial method for transferring information among cells, which is vital in multicellular organisms. Among these vesicles, exosomes are notable for their small size, ranging from 20 to 150 nm, and their role in cell-to-cell communication. They carry lipids, proteins, and nucleic acids between cells. The creation of exosomes begins with the inward budding of the cell membrane, which then encapsulates various macromolecules as cargo. Once filled, exosomes are released into the extracellular space and taken up by target cells via endocytosis and similar processes. The composition of exosomal cargo varies, encompassing diverse macromolecules with specific functions. Because of their significant roles, exosomes have been isolated from various cell types, including cancer cells, endothelial cells, macrophages, and mesenchymal cells, with the aim of harnessing them for therapeutic applications. Exosomes influence cellular metabolism, and regulate lipid, glucose, and glutamine pathways. Their role in pathogenesis is determined by their cargo, which can manipulate processes such as apoptosis, proliferation, inflammation, migration, and other molecular pathways in recipient cells. Non-coding RNA transcripts, a common type of cargo, play a pivotal role in regulating disease progression. Exosomes are implicated in numerous biological and pathological processes, including inflammation, cancer, cardiovascular diseases, diabetes, wound healing, and ischemic-reperfusion injury. As a result, they hold significant potential in the treatment of both cancerous and non-cancerous conditions.

Modulating the immune system towards a functional chronic wound healing: A biomaterials and Nanomedicine perspective

Chronic non-healing wounds persist as a substantial burden for healthcare systems, influenced by factors such as aging, diabetes, and obesity. In contrast to the traditionally pro-regenerative emphasis of therapies, the recognition of the immune system integral role in wound healing has significantly grown, instigating an approach shift towards immunological processes. Thus, this review explores the wound healing process, highlighting the engagement of the immune system, and delving into the behaviors of innate and adaptive immune cells in chronic wound scenarios. Moreover, the article investigates biomaterial-based strategies for the modulation of the immune system, elucidating how the adjustment of their physicochemical properties or their synergistic combination with other agents such as drugs, proteins or mesenchymal stromal cells can effectively modulate the behaviors of different immune cells. Finally this review explores various strategies based on synthetic and biological nanostructures, including extracellular vesicles, to finely tune the immune system as natural immunomodulators or therapeutic nanocarriers with promising biophysical properties.

Advances in skin gene therapy: utilizing innovative dressing scaffolds for wound healing, a comprehensive review

The skin, serving as the body's outermost layer, boasts a vast area and intricate structure, functioning as the primary barrier against external threats. Disruptions in the composition and functionality of the skin can lead to a diverse array of skin conditions, such as wounds, burns, and diabetic ulcers, along with inflammatory disorders, infections, and various types of skin cancer. These disorders not only exacerbate concerns regarding skin health and beauty but also have a significant impact on mental well-being. Due to the complexity of these disorders, conventional treatments often prove insufficient, necessitating the exploration of new therapeutic approaches. Researchers develop new therapies by deciphering these intricacies and gaining a thorough understanding of the protein networks and molecular processes in skin. A new window of opportunity has opened up for improving wound healing processes because of recent advancements in skin gene therapy. To enhance skin regeneration and healing, this extensive review investigates the use of novel dressing scaffolds in conjunction with gene therapy approaches. Scaffolds that do double duty as wound protectors and vectors for therapeutic gene delivery are being developed using innovative biomaterials. To improve cellular responses and speed healing, these state-of-the-art scaffolds allow for the targeted delivery and sustained release of genetic material. The most recent developments in gene therapy techniques include RNA interference, CRISPR-based gene editing, and the utilization of viral and non-viral vectors in conjunction with scaffolds, which were reviewed here to overcome skin disorders and wound complications. In the future, there will be rare chances to develop custom methods for skin health care thanks to the combination of modern technology and collaboration among disciplines.

Injectable hydrogel harnessing foreskin mesenchymal stem cell-derived extracellular vesicles for treatment of chronic diabetic skin wounds

Chronic skin wounds are a serious complication of diabetes with a high incidence rate, which can lead to disability or even death. Previous studies have shown that mesenchymal stem cells derived extracellular vesicles (EVs) have beneficial effects on wound healing. However, the human foreskin mesenchymal stem cell (FSMSCs)-derived extracellular vesicle (FM-EV) has not yet been isolated and characterized. Furthermore, the limited supply and short lifespan of EVs also hinder their practical use. In this study, we developed an injectable dual-physical cross-linking hydrogel (PSiW) with self-healing, adhesive, and antibacterial properties, using polyvinylpyrrolidone and silicotungstic acid to load FM-EV. The EVs were evenly distributed in the hydrogel and continuously released. In vivo and vitro tests demonstrated that the synergistic effect of EVs and hydrogel could significantly promote the repair of diabetic wounds by regulating macrophage polarization, promoting angiogenesis, and improving the microenvironment. Overall, the obtained EVs-loaded hydrogels developed in this work exhibited promising applicability for the repair of chronic skin wounds in diabetes patients.

Recent advancements in natural polymers-based self-healing nano-materials for wound dressing

The field of wound healing has witnessed remarkable progress in recent years, driven by the pursuit of advanced wound dressings. Traditional dressing materials have limitations like poor biocompatibility, nonbiodegradability, inadequate moisture management, poor breathability, lack of inherent therapeutic properties, and environmental impacts. There is a compelling demand for innovative solutions to transcend the constraints of conventional dressing materials for optimal wound care. In this extensive review, the therapeutic potential of natural polymers as the foundation for the development of self-healing nano-materials, specifically for wound dressing applications, has been elucidated. Natural polymers offer a multitude of advantages, possessing exceptional biocompatibility, biodegradability, and bioactivity. The intricate engineering strategies employed to fabricate these polymers into nanostructures, thereby imparting enhanced mechanical robustness, flexibility, critical for efficacious wound management has been expounded. By harnessing the inherent properties of natural polymers, including chitosan, alginate, collagen, hyaluronic acid, and so on, and integrating the concept of self-healing materials, a comprehensive overview of the cutting-edge research in this emerging field is presented in the review. Furthermore, the inherent self-healing attributes of these materials, wherein they exhibit innate capabilities to autonomously rectify any damage or disruption upon exposure to moisture or body fluids, reducing frequent dressing replacements have also been explored. This review consolidates the existing knowledge landscape, accentuating the benefits and challenges associated with these pioneering materials while concurrently paving the way for future investigations and translational applications in the realm of wound healing.

Insight into the Functional Dynamics and Challenges of Exosomes in Pharmaceutical Innovation and Precision Medicine

Of all the numerous nanosized extracellular vesicles released by a cell, the endosomal-originated exosomes are increasingly recognized as potential therapeutics, owing to their inherent stability, low immunogenicity, and targeted delivery capabilities. This review critically evaluates the transformative potential of exosome-based modalities across pharmaceutical and precision medicine landscapes. Because of their precise targeted biomolecular cargo delivery, exosomes are posited as ideal candidates in drug delivery, enhancing regenerative medicine strategies, and advancing diagnostic technologies. Despite the significant market growth projections of exosome therapy, its utilization is encumbered by substantial scientific and regulatory challenges. These include the lack of universally accepted protocols for exosome isolation and the complexities associated with navigating the regulatory environment, particularly the guidelines set forth by the U.S. Food and Drug Administration (FDA). This review presents a comprehensive overview of current research trajectories aimed at addressing these impediments and discusses prospective advancements that could substantiate the clinical translation of exosomal therapies. By providing a comprehensive analysis of both the capabilities and hurdles inherent to exosome therapeutic applications, this article aims to inform and direct future research paradigms, thereby fostering the integration of exosomal systems into mainstream clinical practice.

Stem Cell-Derived Extracellular Vesicles: Promising Therapeutic Opportunities for Diabetic Wound Healing

Wound healing is a sophisticated and orderly process of cellular interactions in which the body restores tissue architecture and functionality following injury. Healing of chronic diabetic wounds is difficult due to impaired blood circulation, a reduced immune response, and disrupted cellular repair mechanisms, which are often associated with diabetes. Stem cell-derived extracellular vesicles (SC-EVs) hold the regenerative potential, encapsulating a diverse cargo of proteins, RNAs, and cytokines, presenting a safe, bioactivity, and less ethical issues than other treatments. SC-EVs orchestrate multiple regenerative processes by modulating cellular communication, increasing angiogenesis, and promoting the recruitment and differentiation of progenitor cells, thereby potentiating the reparative milieu for diabetic wound healing. Therefore, this review investigated the effects and mechanisms of EVs from various stem cells in diabetic wound healing, as well as their limitations and challenges. Continued exploration of SC-EVs has the potential to revolutionize diabetic wound care.