Development of a novel RNAi therapy: Engineered miR-31 exosomes promoted the healing of diabetic wounds

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.

Review of Metal-Polyphenol Self-Assembled Nanoparticles: Synthesis, Properties, and Biological Applications in Inflammatory Diseases

Polyphenols, which are compounds characterized by the presence of phenolic hydroxyl groups, are abundantly found in natural plants and exist in highly complex forms within living organisms. As some of the most prevalent compounds in nature, polyphenols possess significant medicinal value due to their unique structural features, particularly their therapeutic efficacy in antitumor, anti-inflammatory, and antibacterial applications. In the context of inflammation therapy, polyphenolic compounds can inhibit the excessive release of inflammatory mediators from inflammatory cells, thereby mitigating inflammation. Furthermore, these compounds exhibit strong antioxidant properties, enabling them to scavenge free radicals and reactive oxygen species (ROS), reduce oxidative stress-related damage, and exert anti-inflammatory effects. Due to their multiple phenolic hydroxyl groups and their ability to chelate various metals, polyphenols are extensively utilized in the synthesis of self-assembled nanoparticles for the treatment of various diseases. Numerous studies have demonstrated that the therapeutic profile of nanoparticles formed through self-assembly with metal ions surpasses that of polyphenolic compounds alone. This Review will focus on the self-assembly of different polyphenolic compounds with various metal ions to generate nanoparticles, their characterization, and their therapeutic applications in inflammation-related diseases, providing researchers with new insights into the synthetic study of metal-polyphenol nanocomposites and their biological applications.

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.

Emerging roles of extracellular vesicles in oral and maxillofacial areas

The oral and maxillofacial region is a highly complex area composed of multiple tissue types and bears various critical functions of the human body. Diseases in this region pose significant diagnostic and management challenges; therefore, exploring new strategies for early diagnosis, targeted treatment, and tissue reconstruction is key to improving patient prognosis and quality of life. Extracellular vesicles are a group of heterogeneous lipid-bilayer membrane structures secreted by most cell types, including exosomes, microvesicles, and apoptotic bodies. Present in various body fluids and tissues, they act as messengers via the transfer of nucleic acids, proteins, and metabolites to recipient cells. To date, studies have revealed the different roles of extracellular vesicles in physiological or pathological processes, as well as applications in disease diagnosis, prognosis, and treatment. The importance and tissue specificity of the dental and maxillofacial tissues indicate that extracellular vesicles derived from this region are promising for further research. This paper reviews the published data on extracellular vesicles derived from cells, body fluids, and tissues in oral and maxillofacial regions, summarizes the latest advances in extracellular vesicles from extensive sources, and concludes with a focus on the current research progress and application prospects of engineered exosomes in oral science.

The Potential for Extracellular Vesicles in Nanomedicine: A Review of Recent Advancements and Challenges Ahead

Extracellular vesicles (EVs) have emerged as promising tools in diagnostics and therapy for chronic diseases, including cancer and Alzheimer's. Small EVs, also called exosomes, are lipid-bound particles (≈30-150 nm) that play a role in healthy and pathophysiological interactions, including intercellular communication, by transporting bioactive molecules, including proteins, lipids, and nucleic acids. Their ability to cross biological barriers, such as the blood-brain barrier, makes them ideal candidates for targeted therapeutic interventions. In the context of chronic diseases, exosomes can be engineered to deliver active agents, including small molecules and siRNAs to specific target cells, providing a novel approach to precision medicine. Moreover, exosomes show great promise as repositories for diagnostic biomarkers. Their cargo can reflect the physiological and pathological status of the parent cells, making them valuable indicators of disease progression and response to treatment. This paper presents a comprehensive review of the application of exosomes in four chronic diseases: cancer, cardiovascular disease, neurodegenerative disease, and orthopedic disease, which significantly impact global public health due to their high prevalence and associated morbidity and mortality rates. Furthermore, the potential of exosomes as valuable tools for theranostics and disease management is highlighted. Finally, the challenges associated with exosomes and their demonstrated potential for advancing future nanomedicine applications are discussed.

Higher expression of mir-31-5p is associated with reduced risk of head and neck keloid recurrence following surgical resection

Objective

In this study, we aimed to evaluate mir-31-5p as a prognostic biomarker of keloid disease (KD) recurrence using a retrospective, treatment naïve, surgical cohort of head and neck KD cases from Henry Ford Health.

Methods

Using a tissue microarray, mir-31-5p expression was measured with miRNAscope, and mir-31-5p cell positivity was determined with QuPath. Logistic regression was used to test the association between mir-31-5p positive cells and KD recurrence at 1 year. In an independent dataset, associations between mir-31-5p and messenger RNA (mRNA) expression were assessed. Ingenuity Pathway Analysis identified target genes and pathways impacted by mir-31-5p.

Results

Of the 58 KD patients, 42 (72%) received adjuvant triamcinolone injections, and 8 recurred (14%). mir-31-5p was expressed in 48 (83%) specimens. Increasing mir-31-5p expression was associated with decreased risk of recurrence (p = .031), with an odds ratio of 0.86 (95% CI 0.75-0.98) for each 20% increase in mir-31-5p cellular positivity. This effect persisted with triamcinolone treatment (odds ratio 0.82; 95% CI 0.71-0.95; p = .015). mir-31-5p correlated with gene expression enriched in KD pathways, including mRNA splicing and autophagy.

Conclusion

Taken together, our data supports the association between mir-31-5p expression and KD recurrence. Its potential as a prognostic biomarker should be further investigated.

Level of Evidence

Level 2.

EMP1 knockdown mitigated high glucose-induced pyroptosis and oxidative stress in rat H9c2 cardiomyocytes by inhibiting the RAS/RAF/MAPK signaling pathway

The purpose of this study was to investigate the mechanism of EMP1 action in high glucose (HG)-induced H9c2 cardiac cell pyroptosis and oxidative injury. Rat cardiomyocytes H9c2 were exposed to 33 mM glucose for 24, 48, or 72 h to induce cytotoxicity. EMP1-siRNA, NLRP3 agonist Nigericin, and pcNDA-RAS were used to treat H9c2 cells under HG conditions. Cell Counting Kit (CCK)-8 assay showed that cell proliferation was decreased following HG induction, which was rescued by EMP1 knockdown. Our results also suggested that EMP1 siRNA transfection significantly decreased the apoptosis and pyroptosis of HG-induced cells, as indicated by the reduction of NLRP3 IL-1β, ASC, GSDMD, cleaved-caspase1 and cleaved-caspase3 levels in HG-induced H9c2 cells. In addition, EMP1 knockdown alleviated HG-induced mitochondrial damage and oxidative stress in H9c2 cells. NLRP3 activation reversed the inhibitory effects of EMP1 knockdown on pyroptosis and oxidative stress in HG-induced H9c2 cells. Mechanistically, we found that EMP1 knockdown suppressed the RAS/RAF/MAPK signaling pathway in HG-induced H9c2 cells. RAS overexpression blocked the protective effect of EMP1 knockdown on HG-induced H9c2 cell apoptosis, pyroptosis, and oxidative injury. Our findings suggest that EMP1 knockdown treatment might provide a novel therapy for diabetic cardiomyopathy.

Epithelial membrane protein 1 in human cancer: a potential diagnostic biomarker and therapeutic target

Epithelial membrane protein 1 (EMP1) is a member of the small hydrophobic membrane protein subfamily. EMP1 is aberrantly expressed in various tumor tissues and governs multiple cellular behaviors (e.g., proliferation, differentiation, and migration). The resultant regulation of the cancer pathway is responsible for the metastasis of cancer cells and determines the risk of malignant tumor progression. This review provides an updated overview of EMP1 as either an oncogene or a tumor suppressor contingent on the cancer type and summarizes its upstream regulators and downstream target genes. This systematic review summarizes our current understanding of the role of EMP1 in malignant tumor development, including critical functional mechanisms and implications for its potential use as the biomarker and therapeutic target.

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.

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.

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.

Exosomes: compositions, biogenesis, and mechanisms in diabetic wound healing

Diabetic wounds are characterized by incomplete healing and delayed healing, resulting in a considerable global health care burden. Exosomes are lipid bilayer structures secreted by nearly all cells and express characteristic conserved proteins and parent cell-associated proteins. Exosomes harbor a diverse range of biologically active macromolecules and small molecules that can act as messengers between different cells, triggering functional changes in recipient cells and thus endowing the ability to cure various diseases, including diabetic wounds. Exosomes accelerate diabetic wound healing by regulating cellular function, inhibiting oxidative stress damage, suppressing the inflammatory response, promoting vascular regeneration, accelerating epithelial regeneration, facilitating collagen remodeling, and reducing scarring. Exosomes from different tissues or cells potentially possess functions of varying levels and can promote wound healing. For example, mesenchymal stem cell-derived exosomes (MSC-exos) have favorable potential in the field of healing due to their superior stability, permeability, biocompatibility, and immunomodulatory properties. Exosomes, which are derived from skin cellular components, can modulate inflammation and promote the regeneration of key skin cells, which in turn promotes skin healing. Therefore, this review mainly emphasizes the roles and mechanisms of exosomes from different sources, represented by MSCs and skin sources, in improving diabetic wound healing. A deeper understanding of therapeutic exosomes will yield promising candidates and perspectives for diabetic wound healing management.

Suppression of gastric cancer cell proliferation by miR-494-3p inhibitor-loaded engineered exosomes

Background

Gastric cancer necessitates novel treatments, and exosomes are promising therapeutic carriers. We created miR-494-3p inhibitor exosomes to assess their effects on gastric cancer cells.

Methods

We conducted a comprehensive investigation into the expression of the oncogenic miR-494-3p in gastric cancer tissues from patients. Subsequently, we engineered miR-494-3p inhibitor-loaded exosomes and characterized their morphology and size through transmission electron microscopy and nanoparticle tracking analysis. We next determined the encapsulation efficiency of the miR-494-3p inhibitor within these exosomes and evaluated the exosomes' structural integrity by quantifying the presence of exosomal markers. Following these validations, we co-cultured miR-494-3p inhibitor exosomes with cancer cells and employed PKH26 staining to visualize the efficient endocytosis of engineered exosomes by gastric cancer cells and assess the impact of these modified exosomes on gastric cancer cell proliferation, apoptosis, migration, and invasion.

Results

Increased expression of miR-494-3p was observed in gastric cancer tissues as compared to controls. Significant low miR-494-3p levels were found within miR-494-3p inhibitor exosomes, signifying effective encapsulation. The incorporation of miR-494-3p inhibitor into engineered exosomes did not alter exosome morphology or size. Finally, PKH26-stained exosomes clearly demonstrated efficient endocytosis by gastric cancer cells, leading to reduced proliferation, migration, invasion, and increased apoptosis.

Conclusion

Our study identifies elevated miR-494-3p in gastric cancer tissues prompting the development of miR-494-3p inhibitor-loaded exosomes with efficient encapsulation. These engineered exosomes demonstrate successful endocytosis by cancer cells. This highlights their potential for therapeutic use in gastric cancer treatment by suppressing proliferation, migration, and invasion while enhancing apoptosis.

MicroRNA Nano-Shuttles: Engineering Extracellular Vesicles as a Cutting-Edge Biotechnology Platform for Clinical Use in Therapeutics

Extracellular vesicles (EVs) are nano-sized, membranous transporters of various active biomolecules with inflicting phenotypic capabilities, that are naturally secreted by almost all cells with a promising vantage point as a potential leading drug delivery platform. The intrinsic characteristics of their low toxicity, superior structural stability, and cargo loading capacity continue to fuel a multitude of research avenues dedicated to loading EVs with therapeutic and diagnostic cargos (pharmaceutical compounds, nucleic acids, proteins, and nanomaterials) in attempts to generate superior natural nanoscale delivery systems for clinical application in therapeutics. In addition to their well-known role in intercellular communication, EVs harbor microRNAs (miRNAs), which can alter the translational potential of receiving cells and thus act as important mediators in numerous biological and pathological processes. To leverage this potential, EVs can be structurally engineered to shuttle therapeutic miRNAs to diseased recipient cells as a potential targeted 'treatment' or 'therapy'. Herein, this review focuses on the therapeutic potential of EV-coupled miRNAs; summarizing the biogenesis, contents, and function of EVs, as well as providing both a comprehensive discussion of current EV loading techniques and an update on miRNA-engineered EVs as a next-generation platform piloting benchtop studies to propel potential clinical translation on the forefront of nanomedicine.

Developing Plant Exosomes as an Advanced Delivery System for Cosmetic Peptide

Peptides are a promising skincare ingredient, but due to their inherent instability and the barrier function of the skin's surface, they often have limited skin absorption and penetration, which can significantly hinder their skincare benefits. To address this, a novel technique called NanoGlow has been introduced for encapsulating peptide-based cosmetic raw materials into engineered nanosized plant-derived exosomes (pExo) to achieve the goal of a healthier and more radiant skin state. In this approach, pExo served as carriers for cosmetic peptides across the intact skin barrier, enhancing their biological effectiveness in skin beauty. The NanoGlow strategy combines chemical activation and physical proencapsulation, boasting a high success rate and straightforward and stable operation, making it suitable for large-scale production. Comprehensive analysis using in vitro cellular absorption and skin penetration models has demonstrated that the nanosized pExo carriers significantly improve peptide penetration into the skin compared to free peptides. Furthermore, in vivo tissue slice studies have shown that pExo carriers efficiently deliver acetyl hexapeptide-8 to the skin's dermis, surpassing the performance of free peptides. Cosmetic skincare effect analysis has also indicated that pExo-loaded cosmetic peptides deliver superior results. Therefore, the NanoGlow technique harnesses the natural size and properties of pExo to maximize the bioavailability of cosmetic peptides, holding great promise for developing advanced peptide delivery systems in both the cosmetic and medical drug industries.

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.

Engineered Extracellular Vesicles in Wound Healing: Design, Paradigms, and Clinical Application

The severe quality of life and economic burden imposed by non-healing skin wounds, infection risks, and treatment costs are affecting millions of patients worldwide. To mitigate these challenges, scientists are relentlessly seeking effective treatment measures. In recent years, extracellular vesicles (EVs) have emerged as a promising cell-free therapy strategy, attracting extensive attention from researchers. EVs mediate intercellular communication, possessing excellent biocompatibility and stability. These features make EVs a potential tool for treating a plethora of diseases, including those related to wound repair. However, there is a growing focus on the engineering of EVs to overcome inherent limitations such as low production, relatively fixed content, and targeting capabilities of natural EVs. This engineering could improve both the effectiveness and specificity of EVs in wound repair treatments. In light of this, the present review will introduce the latest progress in the design methods and experimental paradigms of engineered EVs applied in wound repair. Furthermore, it will comprehensively analyze the current clinical research status and prospects of engineered EVs within this field.

Advancements in engineered exosomes for wound repair: current research and future perspectives

Wound healing is a complex and prolonged process that remains a significant challenge in clinical practice. Exosomes, a type of nanoscale extracellular vesicles naturally secreted by cells, are endowed with numerous advantageous attributes, including superior biocompatibility, minimal toxicity, and non-specific immunogenicity. These properties render them an exceptionally promising candidate for bioengineering applications. Recent advances have illustrated the potential of exosome therapy in promoting tissue repair. To further augment their therapeutic efficacy, the concept of engineered exosomes has been proposed. These are designed and functionally modifiable exosomes that have been tailored on the attributes of natural exosomes. This comprehensive review delineates various strategies for exosome engineering, placing specific emphasis on studies exploring the application of engineered exosomes for precision therapy in wound healing. Furthermore, this review sheds light on strategies for integrating exosomes with biomaterials to enhance delivery effectiveness. The insights presented herein provide novel perspectives and lay a robust foundation for forthcoming research in the realm of cutaneous wound repair therapies.

Engineered exosomes for tissue regeneration: from biouptake, functionalization and biosafety to applications

Exosomes are increasingly recognized as important effector molecules that regulate intercellular signaling pathways. Notably, certain types of exosomes can induce therapeutic responses, including cell proliferation, angiogenesis, and tissue repair. The use of exosomes in therapy is a hot spot in current research, especially in regenerative medicine. Despite the therapeutic potential, problems have hindered their success in clinical applications. These shortcomings include low concentration, poor targeting and limited loading capability. To fully realize their therapeutic potential, certain modifications are needed in native exosomes. In the present review, we summarize the exosome modification and functionalization strategies. In addition, we provide an overview of potential clinical applications and highlight the issues associated with the biosafety and biocompatibility of engineered exosomes in applications.

Exosomes as biomarkers and therapy in type 2 diabetes mellitus and associated complications

Type 2 diabetes mellitus (T2DM) is one of the most prevalent metabolic disorders worldwide. However, T2DM still remains underdiagnosed and undertreated resulting in poor quality of life and increased morbidity and mortality. Given this ongoing burden, researchers have attempted to locate new therapeutic targets as well as methodologies to identify the disease and its associated complications at an earlier stage. Several studies over the last few decades have identified exosomes, small extracellular vesicles that are released by cells, as pivotal contributors to the pathogenesis of T2DM and its complications. These discoveries suggest the possibility of novel detection and treatment methods. This review provides a comprehensive presentation of exosomes that hold potential as novel biomarkers and therapeutic targets. Additional focus is given to characterizing the role of exosomes in T2DM complications, including diabetic angiopathy, diabetic cardiomyopathy, diabetic nephropathy, diabetic peripheral neuropathy, diabetic retinopathy, and diabetic wound healing. This study reveals that the utilization of exosomes as diagnostic markers and therapies is a realistic possibility for both T2DM and its complications. However, the majority of the current research is limited to animal models, warranting further investigation of exosomes in clinical trials. This review represents the most extensive and up-to-date exploration of exosomes in relation to T2DM and its complications.

Exosome-based drug delivery systems for the treatment of diabetes and its complications: current opinion

Diabetes medication is based on controlling blood glucose and delaying the onset of related complications and is not a complete cure for diabetes. Conventional drug therapy fails to stop progressive islet β cell failure in diabetic patients. Recent studies have shown that "exosome-based therapy" holds great promise in treating diabetes and its complications. Exosomes are small vesicles that are stable in the bloodstream and can effectively deliver therapeutic drugs to specific tissues or organs through intercellular communication. Using exosomes as carriers for drug delivery offers several advantages. This review summarizes the benefits of exosomal drug delivery systems, drug loading methods, and their applications in treating diabetes and its complications. However, there are still challenges to overcome in using exosomal drug delivery systems, such as large-scale production, assessing the contents of exosomes, and monitoring the safety and effectiveness of the treatment in vivo. In conclusion, this review proposes the therapeutical potential of exosomes as drug carriers for developing novel drugs to provide new strategies for treating diabetes and its complications.

Mesenchymal stem cell-derived extracellular vesicles in skin wound healing: roles, opportunities and challenges

Skin wounds are characterized by injury to the skin due to trauma, tearing, cuts, or contusions. As such injuries are common to all human groups, they may at times represent a serious socioeconomic burden. Currently, increasing numbers of studies have focused on the role of mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) in skin wound repair. As a cell-free therapy, MSC-derived EVs have shown significant application potential in the field of wound repair as a more stable and safer option than conventional cell therapy. Treatment based on MSC-derived EVs can significantly promote the repair of damaged substructures, including the regeneration of vessels, nerves, and hair follicles. In addition, MSC-derived EVs can inhibit scar formation by affecting angiogenesis-related and antifibrotic pathways in promoting macrophage polarization, wound angiogenesis, cell proliferation, and cell migration, and by inhibiting excessive extracellular matrix production. Additionally, these structures can serve as a scaffold for components used in wound repair, and they can be developed into bioengineered EVs to support trauma repair. Through the formulation of standardized culture, isolation, purification, and drug delivery strategies, exploration of the detailed mechanism of EVs will allow them to be used as clinical treatments for wound repair. In conclusion, MSC-derived EVs-based therapies have important application prospects in wound repair. Here we provide a comprehensive overview of their current status, application potential, and associated drawbacks.

Advancements and Insights in Exosome-Based Therapies for Wound Healing: A Comprehensive Systematic Review (2018-June 2023)

Exosomes have shown promising potential as a therapeutic approach for wound healing. Nevertheless, the translation from experimental studies to commercially available treatments is still lacking. To assess the current state of research in this field, a systematic review was performed involving studies conducted and published over the past five years. A PubMed search was performed for English-language, full-text available papers published from 2018 to June 2023, focusing on exosomes derived from mammalian sources and their application in wound healing, particularly those involving in vivo assays. Out of 531 results, 148 papers were selected for analysis. The findings revealed that exosome-based treatments improve wound healing by increasing angiogenesis, reepithelization, collagen deposition, and decreasing scar formation. Furthermore, there was significant variability in terms of cell sources and types, biomaterials, and administration routes under investigation, indicating the need for further research in this field. Additionally, a comparative examination encompassing diverse cellular origins, types, administration pathways, or biomaterials is imperative. Furthermore, the predominance of rodent-based animal models raises concerns, as there have been limited advancements towards more complex in vivo models and scale-up assays. These constraints underscore the substantial efforts that remain necessary before attaining commercially viable and extensively applicable therapeutic approaches using exosomes.

The role of microRNAs in pathophysiology and diagnostics of metabolic complications in obstructive sleep apnea patients

Obstructive sleep apnea (OSA) is one of the most common sleep disorders, which is characterized by recurrent apneas and/or hypopneas occurring during sleep due to upper airway obstruction. Among a variety of health consequences, OSA patients are particularly susceptible to developing metabolic complications, such as metabolic syndrome and diabetes mellitus type 2. MicroRNAs (miRNAs) as epigenetic modulators are promising particles in both understanding the pathophysiology of OSA and the prediction of OSA complications. This review describes the role of miRNAs in the development of OSA-associated metabolic complications. Moreover, it summarizes the usefulness of miRNAs as biomarkers in predicting the aforementioned OSA complications.

Extracellular vesicles: a rising star for therapeutics and drug delivery

Extracellular vesicles (EVs) are nano-sized, natural, cell-derived vesicles that contain the same nucleic acids, proteins, and lipids as their source cells. Thus, they can serve as natural carriers for therapeutic agents and drugs, and have many advantages over conventional nanocarriers, including their low immunogenicity, good biocompatibility, natural blood-brain barrier penetration, and capacity for gene delivery. This review first introduces the classification of EVs and then discusses several currently popular methods for isolating and purifying EVs, EVs-mediated drug delivery, and the functionalization of EVs as carriers. Thereby, it provides new avenues for the development of EVs-based therapeutic strategies in different fields of medicine. Finally, it highlights some challenges and future perspectives with regard to the clinical application of EVs.

CO2-Induced Ocean Acidification Alters the Burrowing Behavior of Manila Clam Ruditapes philippinarum by Reversing GABAA Receptor Function

Biological burrowing behavior is an important driver shaping ecosystems that is being threatened by CO₂-induced ocean acidification; however, the effects of ocean acidification on burrowing behavior and its neurological mechanism remain unclear. This study showed that elevated pCO₂ significantly affected the burrowing behaviors of the Manila clam Ruditapes philippinarum, such as increased foot contraction, burrowing time, and intrabottom movement and decreased burrowing depth. Delving deeper into the mechanism, exposure to elevated pCO₂ significantly decreased extracellular pH and increased [HCO₃^-]. Moreover, an indicator GABA_A receptor, a neuroinhibitor for movement, was found to be closely associated with behavioral changes. In situ hybridization confirmed that the GABA_A receptor was widely distributed in ganglia and foot muscles, and elevated pCO₂ significantly increased the mRNA level and GABA concentration. However, the increase in GABA_A receptor and its ligand did not suppress the foot movement, but rather sent "excitatory" signals for foot contraction. The destabilization of acid-base homeostasis was demonstrated to induce an increase in the reversal potential for GABA_A receptor and an alteration in GABA_A receptor function under elevated pCO₂. This study revealed that elevated pCO₂ affects the burrowing behavior of Manila clams by altering GABA_A receptor function from inhibitory to excitatory.

Exosomal IRF1-loaded rat adipose-derived stem cell sheet contributes to wound healing in the diabetic foot ulcers

BACKGROUND

Cell-based therapy has been recognized as a novel technique for the management of diabetic foot ulcers, and cell-sheet engineering leads to improved efficacy in cell transplantation. This study aims to explore the possible molecular mechanism of the rat adipose-derived stem cell (ASC) sheet loaded with exosomal interferon regulatory factor 1 (IRF1) in foot wound healing.

METHODS

Rats were rendered diabetic with streptozotocin, followed by measurement of miR-16-5p expression in wound tissues. Relationship between IRF1, microRNA (miR)-16-5p, and trans-acting transcription factor 5 (SP5) was analyzed using luciferase activity, RNA pull-down, and chromatin immunoprecipitation assays. IRF1 was overexpressed in rat ASCs (rASCs) or loaded onto the rASC sheet, and then exosomes were extracted from rASCs. Accordingly, we assessed the effects of IRF1-exosome or IRF1-rASC sheet on the proliferation and migration of the fibroblasts along with endothelial cell angiogenesis.

RESULTS

miR-16-5p was poorly expressed in the wound tissues of diabetic rats. Overexpression of miR-16-5p promoted fibroblast proliferation and migration as well as endothelial cell angiogenesis, thus expediting wound healing. IRF1 was an upstream transcription factor that could bind to the miR-16-5p promoter and increase its expression. In addition, SP5 was a downstream target gene of miR-16-5p. IRF1-exosome from rASCs or the IRF1-rASC sheet facilitated the foot wound healing in diabetic rats through miR-16-5p-dependent inhibition of SP5.

CONCLUSION

The present study demonstrates that exosomal IRF1-loaded rASC sheet regulates miR-16-5p/SP5 axis to facilitate wound healing in diabetic rats, which aids in development of stem cell-based therapeutic strategies for diabetic foot wounds.

Engineering exosome-based biomimetic nanovehicles for wound healing

Complexity and difficulties in wound management are pressing concerns that affect patients' quality of life and may result in tissue infection, necrosis, and loss of local and systemic functions. Hence, novel approaches to accelerate wound healing are being actively explored over the last decade. Exosomes as important mediators of intercellular communications are promising natural nanocarriers due to their biocompatibility, low immunogenicity, drug loading and targeting capacities, and innate stability. More importantly, exosomes are developed as a versatile pharmaceutical engineering platform for wound repair. This review provides an overview of the biological and physiological functions of exosomes derived from a variety of biological origins during wound healing phases, strategies for exosomal engineering, and therapeutic applications in skin regeneration.

Separable Microneedles with Photosynthesis-Driven Oxygen Manufactory for Diabetic Wound Healing

Oxygen plays an important role in diabetic chronic wound healing by regulating various life activities such as cell proliferation, migration, and angiogenesis. Therefore, oxygen-delivering systems have drawn much attention and evolved continuously. Here, we propose that an active Chlorella vulgaris (Cv)-loaded separable microneedle (MN) can be used to control oxygen delivery, which then promotes wound healing. The Cv-loaded microneedles (CvMN) consist of a polyvinyl acetate (PVA) substrate and gelatin methacryloyl (GelMA) tips with encapsulated Cv. Once CvMN is applied to diabetic wound, the PVA basal layer is rapidly dissolved in a short time, while the noncytotoxic and biocompatible GelMA tips remain in the skin. By taking advantage of the photosynthesis of Cv, oxygen would be continuously produced in a green way and released from CvMN in a controlled manner. Both in vitro and in vivo results showed that CvMN could promote cell proliferation, migration, and angiogenesis and enhance wound healing in diabetic mice effectively. The remarkable therapeutic effect is mainly attributed to the continuous generation of dissolved oxygen in CvMN and the presence of antioxidant vitamins, γ-linolenic acid, and linoleic acid in Cv. Thus, CvMN provides a promising strategy for diabetic wound healing with more possibility of clinical transformations.

The role and underlying mechanism of dental pulp stem cell-derived exosomal miR-31 in the treatment of osteoarthritis by targeting mTOR to enhance chondrocyte autophagy levels

Introduction

Osteoarthritis is the most prevalent progressive musculoskeletal disease. It leads to functional impairment and decreased quality of life. However, the current treatments remain unsatisfactory. Recent studies have revealed that exosomes derived from mesenchymal stem cells offer a promising approach to improve the pathological changes in osteoarthritis, cartilage tissue, and chondrocyte homeostasis.

Material and methods

In this in vitro and in vivo study, we studied the effects and mechanisms of dental pulp stem cell-derived exosomes (DPSC-exosomes) on osteoarthritis in a mouse model.

Results

The study findings showed that a dental pulp stem cell could generate typical characteristic exosomes. The injection of DPSC-exosomes ameliorated destruction of cartilage, promoted matrix synthesis, inhibited cell apoptosis, and decreased the expression of catabolic factors. However, this effect was shown to be almost eliminated when miR-31 antagomir was injected.

Conclusions

Furthermore, DPSC-exosomes show an ability to promote autophagy in chondrocytes through mTOR inhibition, in addition to reducing the mTOR luciferase activity. The ability of DPSC-exosomes to partially regulate autophagy was blocked upon inhibition of miR-31. In brief, DPSC-exosomes have a chondroprotective role in a mouse osteoarthritis model. The underlying mechanism is possibly related to miR-31-mediated suppression of the mTOR-autophagy pathway.

Structure of pre-miR-31 reveals an active role in Dicer processing

As an essential post-transcriptional regulator of gene expression, microRNA (miR) levels must be strictly maintained. The biogenesis of many, but not all, miRs is mediated by trans-acting protein partners through a variety of mechanisms, including remodeling of the RNA structure. miR-31 functions as an oncogene in numerous cancers and interestingly, its biogenesis is not known to be regulated by protein binding partners. Therefore, the intrinsic structural properties of pre-miR-31 can provide a mechanism by which its biogenesis is regulated. We determined the solution structure of the precursor element of miR-31 (pre-miR-31) to investigate the role of distinct structural elements in regulating Dicer processing. We found that the presence or absence of mismatches within the helical stem do not strongly influence Dicer processing of the pre-miR. However, both the apical loop size and structure at the Dicing site are key elements for discrimination by Dicer. Interestingly, our NMR-derived structure reveals the presence of a triplet of base pairs that link the Dicer cleavage site and the apical loop. Mutational analysis in this region suggests that the stability of the junction region strongly influence both Dicer binding and processing. Our results enrich our understanding of the active role that RNA structure plays in regulating Dicer processing which has direct implications for control of gene expression.

Bioengineered MSC-derived exosomes in skin wound repair and regeneration

Refractory skin defects such as pressure ulcers, diabetic ulcers, and vascular ulcers represent a challenge for clinicians and researchers in many aspects. The treatment strategies for wound healing have high cost and limited efficacy. To ease the financial and psychological burden on patients, a more effective therapeutic approach is needed to address the chronic wound. MSC-derived exosomes (MSC-exosomes), the main bioactive extracellular vesicles of the paracrine effect of MSCs, have been proposed as a new potential cell-free approach for wound healing and skin regeneration. The benefits of MSC-exosomes include their ability to promote angiogenesis and cell proliferation, increase collagen production, regulate inflammation, and finally improve tissue regenerative capacity. However, poor targeting and easy removability of MSC-exosomes from the wound are major obstacles to their use in clinical therapy. Thus, the concept of bioengineering technology has been introduced to modify exosomes, enabling higher concentrations and construction of particles of greater stability with specific therapeutic capability. The use of biomaterials to load MSC-exosomes may be a promising strategy to concentrate dose, create the desired therapeutic efficacy, and maintain a sustained release effect. The beneficial role of MSC-exosomes in wound healing is been widely accepted; however, the potential of bioengineering-modified MSC-exosomes remains unclear. In this review, we attempt to summarize the therapeutic applications of modified MSC-exosomes in wound healing and skin regeneration. The challenges and prospects of bioengineered MSC-exosomes are also discussed.

Delivery of a peptide/microRNA blend via electrospun antimicrobial nanofibres for wound repair

Downregulation of microRNA-31 (miR-31) and microRNA-132 (miR-132) has been associated with delayed wound healing. Therefore, it was hypothesised that intracellular delivery of miR-31 and miR-132, both as individual and blend formulations, could promote tissue repair. The use of a blend could minimise potential toxicity and achieve synergistic effects, thus maximising the therapeutic effect. miR-31 and miR-132 were condensed with a 30-mer positively charged amphipathic peptide, RALA, to form nanocomplexes with an average size <200 nm and zeta-potential ≥10 designed to facilitate cellular internalisation. This enabled a fold increase in miR-31 and miR-132 expression of ≥100,000 in a murine fibroblast cell line (NCTC-929) and a skin human keratinocyte cell line (HaCaT), with intracellular delivery >70% for individual and blend formulations. Moreover, incubation with the nanocomplexes increased the migration of HaCaT cells ≥25% at 4 and 8 h post-incubation, as well as downregulation of EMP-1 and RASA1 and HB-EGF and RASA1, target genes for miR-31 and miR-132, respectively. Electrospinning was then employed to produce an alginate/polyvinyl alcohol/ciprofloxacin nanofibrous wound patch to facilitate the controlled delivery of the nanocomplexes. Nanofibres were crosslinked with glutaraldehyde to improve stability in aqueous solvents, and they were proven to be biocompatible with antimicrobial activity without cellular attachment to avoid injury upon removal. RALA/miR nanoparticles were incorporated to the nanofibrous wound dressing and in vivo wound healing studies using C57BL/6J mice demonstrated a >60% acceleration in the wound closure rate at Day 7 post-wounding, a ≥1.5 increase in epidermal thickness, and a ≥2 increase in blood vessel count with respect to commercial and untreated controls. Taken together, this data proves that delivery of RALA/miR-31 and RALA/miR-132 from an alginate/polyvinyl alcohol/ciprofloxacin nanofibrous wound dressing constitutes an advanced therapy for wound healing, by accelerating wound closure and improving healed tissue quality. STATEMENT OF SIGNIFICANCE: In this study, we report for the first time the use of the RALA peptide to deliver two miRNA 31 & 132 simultaneously from an electrospun patch. Both miRs have been shown to be downregulated in wounds and this study endeavoured to deliver a blend of the miRs from a nanofibre patch. Electrospinning was used to produce an alginate/polyvinyl alcohol/ciprofloxacin wound patch to enable controlled delivery of the miRs without cellular attachment to the wound with the added benefit of anti-microbial activity. Application of the nanofibre patch loaded with the blended RALA/miR nanoparticles demonstrated a synergistic effect with acceleration of wound closure rate, a significant increase in epidermal thickness and blood vessel count with respect to commercial and untreated controls.

Microenvironment-Based Diabetic Foot Ulcer Nanomedicine

Diabetic foot ulcers (DFU), one of the most serious complications of diabetes, are essentially chronic, nonhealing wounds caused by diabetic neuropathy, vascular disease, and bacterial infection. Given its pathogenesis, the DFU microenvironment is rather complicated and characterized by hyperglycemia, ischemia, hypoxia, hyperinflammation, and persistent infection. However, the current clinical therapies for DFU are dissatisfactory, which drives researchers to turn attention to advanced nanotechnology to address DFU therapeutic bottlenecks. In the last decade, a large number of multifunctional nanosystems based on the microenvironment of DFU have been developed with positive effects in DFU therapy, forming a novel concept of "DFU nanomedicine". However, a systematic overview of DFU nanomedicine is still unavailable in the literature. This review summarizes the microenvironmental characteristics of DFU, presents the main progress of wound healing, and summaries the state-of-the-art therapeutic strategies for DFU. Furthermore, the main challenges and future perspectives in this field are discussed and prospected, aiming to fuel and foster the development of DFU nanomedicines successfully.

A combined miRNA-piRNA signature in the serum and urine of rabbits infected with Toxoplasma gondii oocysts

BACKGROUND

Increasing evidence has shown that non-coding RNA (ncRNA) molecules play fundamental roles in cells, and many are stable in body fluids as circulating RNAs. Study on these ncRNAs will provide insights into toxoplasmosis pathophysiology and/or help reveal diagnostic biomarkers.

METHODS

We performed a high-throughput RNA-Seq study to comprehensively profile the microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs) in rabbit serum and urine after infection with Toxoplasma gondii oocysts during the whole infection process.

RESULTS

Total RNA extracted from serum and urine samples of acutely infected [8 days post-infection (DPI)], chronically infected (70 DPI) and uninfected rabbits were subjected to genome-wide small RNA sequencing. We identified 2089 miRNAs and 2224 novel piRNAs from the rabbit sera associated with T. gondii infection. Meanwhile, a total of 518 miRNAs and 4182 novel piRNAs were identified in the rabbit urine associated with T. gondii infection. Of these identified small ncRNAs, 1178 and 1317 serum miRNAs and 311 and 294 urine miRNAs were identified as differentially expressed (DE) miRNAs in the acute and chronic stages of infections, respectively. A total of 1748 and 1814 serum piRNAs and 597 and 708 urine piRNAs were found in the acute and chronic infection stages, respectively. Of these dysregulated ncRNAs, a total of 88 common DE miRNAs and 120 DE novel piRNAs were found in both serum and urine samples of infected rabbits.

CONCLUSIONS

These findings provide valuable data for revealing the physiology of herbivore toxoplasmosis caused by oocyst infection. Circulating ncRNAs identified in this study are potential novel diagnostic biomarkers for the detection/diagnosis of toxoplasmosis in herbivorous animals.

Native and engineered extracellular vesicles for wound healing

Extracellular vesicles (EVs) that act as messengers mediate communication between parent and recipient cells through their contents, including nucleic acids, proteins, and lipids. These endogenous vesicles have emerged as a novel cell-free strategy for the treatment of diseases. EVs can be released by various types of cells with unique biological properties. Recent studies have shown that native EVs are used as therapeutic agents to promote tissue repair by delivering various growth factors and trophic factors including VEGF, EGF, TFN-α, IL-1β, and TGF-β to participate in all physiological processes of wound healing. Furthermore, to improve their specificity, safety, and efficiency for wound healing, the content and surface of EVs can be designed, modified, and engineered. The engineering strategies of EVs are divided into parent cell modification and indirect modification of EVs. The therapeutic potential of current EVs and engineered EVs for wound healing still requires the exploration of their large-scale clinical applications through innovative approaches. Herein, we provide an overview of the current biological knowledge about wound healing and EVs, as well as the application of native EVs in promoting wound healing. We also outline recent advances in engineering EV methodologies to achieve ideal therapeutic potential. Finally, the therapeutic applications of engineered EVs in wound healing are reviewed, and the challenges and prospects for the translation of engineered EVs to clinical applications are discussed.

The Asparagine Hydroxylase FIH: A Unique Oxygen Sensor

Significance: Limited oxygen availability (hypoxia) commonly occurs in a range of physiological and pathophysiological conditions, including embryonic development, physical exercise, inflammation, and ischemia. It is thus vital for cells and tissues to monitor their local oxygen availability to be able to adjust in case the oxygen supply is decreased. The cellular oxygen sensor factor inhibiting hypoxia-inducible factor (FIH) is the only known asparagine hydroxylase with hypoxia sensitivity. FIH uniquely combines oxygen and peroxide sensitivity, serving as an oxygen and oxidant sensor. Recent Advances: FIH was first discovered in the hypoxia-inducible factor (HIF) pathway as a modulator of HIF transactivation activity. Several other FIH substrates have now been identified outside the HIF pathway. Moreover, FIH enzymatic activity is highly promiscuous and not limited to asparagine hydroxylation. This includes the FIH-mediated catalysis of an oxygen-dependent stable (likely covalent) bond formation between FIH and selected substrate proteins (called oxomers [oxygen-dependent stable protein oligomers]). Critical Issues: The (patho-)physiological function of FIH is only beginning to be understood and appears to be complex. Selective pharmacologic inhibition of FIH over other oxygen sensors is possible, opening new avenues for therapeutic targeting of hypoxia-associated diseases, increasing the interest in its (patho-)physiological relevance. Future Directions: The contribution of FIH enzymatic activity to disease development and progression should be analyzed in more detail, including the assessment of underlying molecular mechanisms and relevant FIH substrate proteins. Also, the molecular mechanism(s) involved in the physiological functions of FIH remain(s) to be determined. Furthermore, the therapeutic potential of recently developed FIH-selective pharmacologic inhibitors will need detailed assessment. Antioxid. Redox Signal. 37, 913-935.

Engineered stem cell exosomes for oral and maxillofacial wound healing

Wound healing of the oral and maxillofacial area affects the quality of life and mental health of the patient; therefore, effective therapies are required to promote wound healing. However, traditional treatment methods have limited efficacy. Exosomes secreted by stem cells used for oral and maxillofacial wound healing have shown outstanding results. Stem cell-derived exosomes possess the regenerative and repair ability of stem cells. Moreover, they are nontumorigenic and have good biosafety. However, the application of natural stem cell exosomes is limited owing to their low yield, impurity, lack of targeting, and low drug delivery rate. Many modification methods have been developed to engineered stem cell exosomes with beneficial properties, such as modifying parent cells and directly processing stem cell exosomes. These methods include coincubation, genetic engineering, electroporation, ultrasound, and artificial synthesis of engineered stem cell exosomes. These engineered stem cell exosomes can cargo nucleic acids, proteins, and small molecules. This gives them anti-inflammatory and cell proliferation regulatory abilities and enables the targeted promotion of efficient soft tissue repair after trauma. Engineered stem cell exosomes can decrease inflammation, promote fibroblast proliferation, and angiogenesis, and decrease scar formation to promote oral and maxillofacial wound healing, including diabetic and burn wounds. Thus, engineered stem cell exosomes are an effective treatment that has the potential for oral and maxillofacial wound healing.

Small extracellular vesicles derived from hypoxic mesenchymal stem cells promote vascularized bone regeneration through the miR-210-3p/EFNA3/PI3K pathway

Angiogenesis is closely coupled with osteogenesis and has equal importance. Thus, promoting angiogenesis during the bone repair process is vital for ideal bone regeneration. As important mediators of cell-cell communication and biological homeostasis, mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) have been proved to be highly involved in bone and vascular regeneration. Because hypoxia microenvironment promotes the proangiogenic activity of MSCs, in the present study, we investigate the effect and underlying molecular mechanisms of sEVs from hypoxia-preconditioned MSCs (hypo-sEVs) on angiogenesis and develop an effective strategy to promote vascularized bone regeneration. Compared to sEVs from normoxia MSCs (nor-sEVs), hypo-sEVs promoted the proliferation, migration, and angiogenesis of HUVECs and ultimately enhanced bone regeneration and new blood vessel reconstruction in a critical-size calvarial bone defect model. miRNA sequence and the verified results showed that miR-210-3p in hypo-sEVs was increased via HIF-1α under hypoxia. The upregulated miR-210-3p in hypo-sEVs promoted angiogenesis by downregulating EFNA3 expression and enhancing the phosphorylation of the PI3K/AKT pathway. Thus, this study suggests a successful strategy to enhance vascularized bone regeneration by utilizing hypo-sEVs via the miR-210-3p/EFNA3/PI3K/AKT pathway. STATEMENT OF SIGNIFICANCE: Considering the significance of vascularization in ideal bone regeneration, strategies to promote angiogenesis during bone repair are required. Hypoxia microenvironment can promote the proangiogenic potential of mesenchymal stem cells (MSCs). Nonetheless, the therapeutic effect of small extracellular vesicles (sEVs) from hypoxia-preconditioned MSCs on cranio-maxillofacial bone defect remains unknown, and the underlying mechanism is poorly understood. This study shows that hypo-sEVs significantly enhance the proliferation, migration, and angiogenesis of HUVECs as well as promote vascularized bone formation. Moreover, this work indicates that HIF-1α can induce overexpression of miR-210-3p under hypoxia, and miR-210-3p can hinder EFNA3 expression and subsequently activate the PI3K/AKT pathway. The application of hypo-sEVs provides a facile and promising strategy to promote vascularized bone regeneration in a critical-size bone defect model.

The Emerging Role of Immune Cells and Targeted Therapeutic Strategies in Diabetic Wounds Healing

Poor wound healing in individuals with diabetes has long plagued clinicians, and immune cells play key roles in the inflammation, proliferation and remodeling that occur in wound healing. When skin integrity is damaged, immune cells migrate to the wound bed through the actions of chemokines and jointly restore tissue homeostasis and barrier function by exerting their respective biological functions. An imbalance of immune cells often leads to ineffective and disordered inflammatory responses. Due to the maladjusted microenvironment, the wound is unable to smoothly transition to the proliferation and remodeling stage, causing it to develop into a chronic refractory wound. However, chronic refractory wounds consistently lead to negative outcomes, such as long treatment cycles, high hospitalization rates, high medical costs, high disability rates, high mortality rates, and many adverse consequences. Therefore, strategies that promote the rational distribution and coordinated development of immune cells during wound healing are very important for the treatment of diabetic wounds (DW). Here, we explored the following aspects by performing a literature review: 1) the current situation of DW and an introduction to the biological functions of immune cells; 2) the role of immune cells in DW; and 3) existing (or undeveloped) therapies targeting immune cells to promote wound healing to provide new ideas for basic research, clinical treatment and nursing of DW.

Cyanobacteria-based self-oxygenated photodynamic therapy for anaerobic infection treatment and tissue repair

Photodynamic therapy (PDT) is an important technique to deal with drug-resistant bacterial infections in the post-antibiotic era. However, the hypoxic environment in intractable infections such as refractory keratitis and periodontitis, makes PDT more difficult. In this work, spontaneous oxygen-producing cyanobacteria were used as the carrier of photosensitizer (Ce6), and ultrasmall Cu5.4O nanoparticles (Cu5.4O USNPs) with catalase activity for infection and inflammation elimination and rapid tissue repair (CeCycn-Cu5.4O). The loading of Ce6 and Cu5.4O USNPs onto cyanobacteria surface were confirmed by transmission electron microscopy, nano particle size analyzer, scanning electron microscopy. In vitro sterilization and biofilm removal experiments demonstrated that the restriction of hypoxic environment to PDT was significantly alleviated due to the oxygen production of cyanobacteria. Under laser irradiation, the close transfer of energy photons to oxygen produced by cyanobacteria reduced more than 90% of Ce6 dosages (660 nm, 200 mW/cm2, 2 min). It is worth mentioning that both rapid sterilization through PDT and long-term oxidized free radicals elimination were achieved by adjusting the ratio of Ce6 and Cu5.4O USNPs. Both periodontitis and refractory keratitis animal models proved the excellent self-oxygenation enhanced antibacterial property and promotion of tissue repair.

Circulating serum microRNAs including senescent miR-31-5p are associated with incident fragility fractures in older postmenopausal women with type 2 diabetes mellitus

Fragility fractures are an important hallmark of aging and an increasingly recognized complication of Type 2 diabetes (T2D). T2D individuals have been found to exhibit an increased fracture risk despite elevated bone mineral density (BMD) by dual x-ray absorptiometry (DXA). However, BMD and FRAX-scores tend to underestimate fracture risk in T2D. New, reliable biomarkers are therefore needed. MicroRNAs (miRNAs) are secreted into the circulation from cells of various tissues proportional to local disease severity. Serum miRNA-classifiers were recently found to discriminate T2D women with and without prevalent fragility fractures with high specificity and sensitivity (AUC > 0.90). However, the association of circulating miRNAs with incident fractures in T2D has not been examined yet. In 168 T2D postmenopausal women in the AGES-Reykjavik cohort, miRNAs were extracted from baseline serum and a panel of 10 circulating miRNAs known to be involved in diabetic bone disease and aging was quantified by qPCR and Ct-values extracted. Unadjusted and adjusted Cox proportional hazard models assessed the associations between serum miRNAs and incident fragility fracture. Additionally, Receiver operating curve (ROC) analyses were performed. Of the included 168 T2D postmenopausal women who were on average 77.2 ± 5.6 years old, 70 experienced at least one incident fragility fracture during the mean follow-up of 5.8 ± 2.7 years. We found that 3 serum miRNAs were significantly associated with incident diabetic fragility fracture: while low expression of miR-19b-1-5p was associated with significantly lower risk of incident fragility fracture (HR 0.84 (95% CI: 0.71-0.99, p = 0.0323)), low expression of miR-203a and miR-31-5p was each significantly associated with a higher risk of incident fragility fracture per unit increase in Ct-value (miR-203a: HR 1.29 (95% CI: 1.12-1.49), p = 0.0004, miR-31-5p HR 1.27 (95% CI: 1.06-1.52), p = 0.009). Hazard ratios of the latter two miRNAs remained significant after adjustments for age, body mass index (BMI), areal bone mineral density (aBMD), clinical FRAX or FRAXaBMD. Women with miR-203a and miR-31-5p serum levels in the lowest expression quartiles exhibited a 2.4-3.4-fold larger fracture risk than women with miR-31-5p and miR-203a serum expressions in the highest expression quartile (0.002 ≤ p ≤ 0.039). Women with both miR-203a and miR-31-5p serum levels below the median had a significantly increased fracture risk (Unadjusted HR 3.26 (95% CI: 1.57-6.78, p = 0.001) compared to those with both expression levels above the median, stable to adjustments. We next built a diabetic fragility signature consisting of the 3 miRNAs that showed the largest associations with incident fracture (miR-203a, miR-31-5p, miR-19b-1-5p). This 3-miRNA signature showed with an AUC of 0.722 comparable diagnostic accuracy in identifying incident fractures to any of the clinical parameters such as aBMD, Clinical FRAX or FRAXaBMD alone. When the 3 miRNAs were combined with aBMD, this combined 4-feature signature performed with an AUC of 0.756 (95% CI: 0.680, 0.823) significantly better than aBMD alone (AUC 0.666, 95% CI: 0.585, 0.741) (p = 0.009). Our data indicate that specific serum microRNAs including senescent miR-31-5p are associated with incident fragility fracture in older diabetic women and can significantly improve fracture risk prediction in diabetics when combined with aBMD measurements of the femoral neck.

Extracellular vesicles: Emerging tools as therapeutic agent carriers

Extracellular vesicles (EVs) are secreted by both eukaryotes and prokaryotes, and are present in all biological fluids of vertebrates, where they transfer DNA, RNA, proteins, lipids, and metabolites from donor to recipient cells in cell-to-cell communication. Some EV components can also indicate the type and biological status of their parent cells and serve as diagnostic targets for liquid biopsy. EVs can also natively carry or be modified to contain therapeutic agents (e.g., nucleic acids, proteins, polysaccharides, and small molecules) by physical, chemical, or bioengineering strategies. Due to their excellent biocompatibility and stability, EVs are ideal nanocarriers for bioactive ingredients to induce signal transduction, immunoregulation, or other therapeutic effects, which can be targeted to specific cell types. Herein, we review EV classification, intercellular communication, isolation, and characterization strategies as they apply to EV therapeutics. This review focuses on recent advances in EV applications as therapeutic carriers from in vitro research towards in vivo animal models and early clinical applications, using representative examples in the fields of cancer chemotherapeutic drug, cancer vaccine, infectious disease vaccines, regenerative medicine and gene therapy. Finally, we discuss current challenges for EV therapeutics and their future development.

Exosomes as Promising Nanostructures in Diabetes Mellitus: From Insulin Sensitivity to Ameliorating Diabetic Complications

Diabetes mellitus (DM) is among the chronic metabolic disorders that its incidence rate has shown an increase in developed and wealthy countries due to lifestyle and obesity. The treatment of DM has always been of interest, and significant effort has been made in this field. Exosomes belong to extracellular vesicles with nanosized features (30-150 nm) that are involved in cell-to-cell communication and preserving homeostasis. The function of exosomes is different based on their cargo, and they may contain lipids, proteins, and nucleic acids. The present review focuses on the application of exosomes in the treatment of DM; both glucose and lipid levels are significantly affected by exosomes, and these nanostructures enhance lipid metabolism and decrease its deposition. Furthermore, exosomes promote glucose metabolism and affect the level of glycolytic enzymes and glucose transporters in DM. Type I DM results from the destruction of β cells in the pancreas, and exosomes can be employed to ameliorate apoptosis and endoplasmic reticulum (ER) stress in these cells. The exosomes have dual functions in mediating insulin resistance/sensitivity, and M1 macrophage-derived exosomes inhibit insulin secretion. The exosomes may contain miRNAs, and by transferring among cells, they can regulate various molecular pathways such as AMPK, PI3K/Akt, and β-catenin to affect DM progression. Noteworthy, exosomes are present in different body fluids such as blood circulation, and they can be employed as biomarkers for the diagnosis of diabetic patients. Future studies should focus on engineering exosomes derived from sources such as mesenchymal stem cells to treat DM as a novel strategy.

Exosomes for diabetes syndrome: ongoing applications and perspective

Diabetes mellitus, ranking the ninth death cause in the world, is a kind of metabolic disease characterized by hyperglycemia. Without timely and effective treatment, many ensuing complications involved with heart,...

Transient Hyperglycemia and Hypoxia Induce Memory Effects in AngiomiR Expression Profiles of Feto-Placental Endothelial Cells

Gestational diabetes (GDM) and preeclampsia (PE) are associated with fetal hyperglycemia, fetal hypoxia, or both. These adverse conditions may compromise fetal and placental endothelial cells. In fact, GDM and PE affect feto-placental endothelial function and also program endothelial function and cardiovascular disease risk of the offspring in the long-term. MicroRNAs are short, non-coding RNAs that regulate protein translation and fine tune biological processes. A group of microRNAs termed angiomiRs is particularly involved in the regulation of endothelial function. We hypothesized that transient hyperglycemia and hypoxia may alter angiomiR expression in feto-placental endothelial cells (fpEC). Thus, we isolated primary fpEC after normal, uncomplicated pregnancy, and induced hyperglycemia (25 mM) and hypoxia (6.5%) for 72 h, followed by reversal to normal conditions for another 72 h. Current vs. transient effects on angiomiR profiles were analyzed by RT-qPCR and subjected to miRNA pathway analyses using DIANA miRPath, MIENTURNET and miRPathDB. Both current and transient hypoxia affected angiomiR profile stronger than current and transient hyperglycemia. Both stimuli altered more angiomiRs transiently, i.e., followed by 72 h culture at control conditions. Pathway analysis revealed that hypoxia significantly altered the pathway ‘Proteoglycans in cancer’. Transient hypoxia specifically affected miRNAs related to ‘adherens junction’. Our data reveal that hyperglycemia and hypoxia induce memory effects on angiomiR expression in fpEC. Such memory effects may contribute to long-term adaption and maladaption to hyperglycemia and hypoxia.

Emerging Treatment Strategies for Diabetes Mellitus and Associated Complications: An Update

The occurrence of diabetes mellitus (DM) is increasing rapidly at an accelerating rate worldwide. The status of diabetes has changed over the last three generations; whereas before it was deemed a minor disease of older people but currently it is now one of the leading causes of morbidity and mortality among middle-aged and young people. High blood glucose-mediated functional loss, insulin sensitivity, and insulin deficiency lead to chronic disorders such as Type 1 and Type 2 DM. Traditional treatments of DM, such as insulin sensitization and insulin secretion cause undesirable side effects, leading to patient incompliance and lack of treatment. Nanotechnology in diabetes studies has encouraged the development of new modalities for measuring glucose and supplying insulin that hold the potential to improve the quality of life of diabetics. Other therapies, such as β-cells regeneration and gene therapy, in addition to insulin and oral hypoglycemic drugs, are currently used to control diabetes. The present review highlights the nanocarrier-based drug delivery systems and emerging treatment strategies of DM.

Extracellular Vesicles in Skin Wound Healing

Each year, millions of individuals suffer from a non-healing wound, abnormal scarring, or injuries accompanied by an infection. For these cases, scientists are searching for new therapeutic interventions, from which one of the most promising is the use of extracellular vesicles (EVs). Naturally, EV-based signaling takes part in all four wound healing phases: hemostasis, inflammation, proliferation, and remodeling. Such an extensive involvement of EVs suggests exploiting their action to modulate the impaired healing phase. Furthermore, next to their natural wound healing capacity, EVs can be engineered for better defined pharmaceutical purposes, such as carrying specific cargo or targeting specific destinations by labelling them with certain surface proteins. This review aims to promote scientific awareness in basic and translational research of EVs by summarizing the current knowledge about their natural role in each stage of skin repair and the most recent findings in application areas, such as wound healing, skin regeneration, and treatment of dermal diseases, including the stem cell-derived, plant-derived, and engineered EVs.