The emergence of multidrug-resistant bacteria, particularly methicillin-resistant Staphylococcus aureus (MRSA), poses a significant threat to public health, necessitating new antimicrobial strategies. Here, we demonstrate that low doses of copper sulfate (CuSO4) exhibit potent bactericidal effects against both S. aureus and MRSA by inducing ferroptosis. CuSO4 treatment causes bacterial cell membrane perforation, increases intracellular free copper (Cu+) and ferrous ions (Fe2+), elevates reactive oxygen species (ROS) production and lipid peroxidation, and triggers the intracellular Fenton reaction. The use of ROS scavengers, copper chelators, iron chelators, and iron oxidase inhibitors attenuated ROS levels and lipid peroxidation, reducing Cu2+-mediated cell death, confirming the role of ferroptosis. Proteomic analysis revealed that Cu2+ enhances the expression of Fur protein, mediates iron release from intracellular stores, and inhibits glutathione biosynthesis. Furthermore, we developed a sodium alginate hydrogel loaded with CuSO4 (Cu-SA), which significantly improved wound healing and reduced inflammation and organ damage in an MRSA-infected mouse skin model. Our findings suggest that Cu2+-induced ferroptosis offers a promising alternative to traditional antibiotics for treating MRSA infections, providing a novel strategy to combat antibiotic resistance in S. aureus.

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.

Extracellular vesicles (EVs) hold significant promise for the prevention and treatment of various diseases. However, the translation of EV-based therapies into clinical practice faces considerable challenges, particularly in terms of production yield and therapeutic efficacy. Recent studies have emphasized the heterogeneity of EVs and the influence of parental cell microenvironmental signals on their biogenesis, cargo composition, and therapeutic outcomes. This review offers a comprehensive overview of strategies to optimize the therapeutic efficacy of EVs through physical, biochemical, and mechanical modulation. Additionally, it explores how microenvironmental signals affect EV cargoes and the mechanisms by which these signals can improve therapeutic efficacy. The review also addresses current challenges and potential solutions to accelerate the clinical translation of EV therapies. Ultimately, it highlights the potential of microenvironmental modulation in unlocking the full therapeutic capacity of EVs, providing key insights into their production and clinical use for treating various diseases.

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.

Skin diseases are a broad category of diseases and each has complex conditions, which makes it challenging for dermatologists to provide targeted treatment. Exosomes are natural vesicles secreted by cells and play a key role in cell communication. Due to their unique characteristics, including inherent stability, minimal immunogenicity, high biocompatibility, and exceptional ability to penetrate cells, exosomes are being explored as potential delivery vehicles for therapeutics across various diseases including skin problems. Utilizing exosomes for drug delivery in skin diseases can improve treatment outcomes and reduce the side effects of traditional drug delivery methods. Indeed, exosomes can be engineered or utilized as an innovative approach to deliver therapeutic agents such as small molecule drugs, genes, or proteins specifically to affected skin cells. In addition to targeting specific skin cells or tissues, these engineered exosome-based nanocarriers can reduce off-target effects and improve drug efficacy. Hence, this article highlights the transformative potential of this technology in revolutionizing drug delivery in dermatology and improving patient outcomes.

Exosomes, cell-derived vesicles produced by cells, are fascinating and drawing growing interest in biomedical exploration due to their exceptional properties. There is intriguing evidence that exosomes are involved in major biological processes, including diseases and regeneration. Exosomes from mesenchymal stem cells (MSCs) have shown promising outcomes in regenerative medicine. Numerous studies suggest that exosomes have several advantages over conventional synthetic nanocarriers, opening novel frontiers for innovative drug delivery. Regenerative medicine has demonstrated the profound therapeutic outcomes of engineered or loaded exosomes from MSCs. Different methods are being used to modify or/load exosomes. These exosomes can improve cell signaling pathways for bone and cartilage diseases, liver diseases, nerve tissues, kidney diseases, skin tissue, and cardiovascular diseases. Despite extensive research, clinical translation of these exosomes remains a challenge. The optimization of cargo loading methods, efficiency, physiological stability, and the isolation and characterization of exosomes present some challenges. The upcoming examination should include the development of large-scale, quality-controllable production approaches, the modification of drug loading approaches, and numerous in vivo investigations and clinical trials. Here, we provided an informative overview of the extracellular vesicles and modification/loading methods of exosomes. We discuss the last exosome research on regeneration disorders, highlighting the therapeutic applications of MSCs-derived exosomes. We also highlight future directions and challenges, underscoring the significance of addressing the main questions in the field.

The self-renewal ability and multipotency of stem cells give them great potential for use in wound healing. Stem cell-derived exosomes, owing to their close biological resemblance to their parent cells, offer a more efficient, safer, and economical approach for facilitating cellular communication and interactions within different environments. This potential makes them particularly valuable in the treatment of both acute and chronic wounds, such as lacerations, burns, and diabetic ulcers. Long non-coding RNAs (lncRNAs) enclosed in exosomes, as one of the leading actors of these extracellular microvesicles, through interaction with miRNAs and regulation of various signaling pathways involved in inflammation, angiogenesis, cell proliferation, and migration, could heal the wounds. Exosome-derived lncRNAs from stem cells facilitate extracellular matrix remodeling through interaction between macrophages and fibroblasts. Moreover, alongside regulating the expression of inflammatory cytokines, controlling reactive oxygen species levels, and enhancing autophagic activity, they also modulate immune responses to support wound healing. Regulating the expression of genes and signaling pathways related to angiogenesis, by increasing blood supply and accelerating the delivery of essential substances to the wound environment, is another effect exosomal lncRNAs derived from stem cells for wound healing. These lncRNAs can also enhance skin wound healing by regulating homeostasis, increasing the proliferation and differentiation of cells involved in the wound-healing process, and enhancing fibroblast viability and migration to the injury site. Ultimately, exosome-derived lncRNAs from stem cells offer valuable and novel insights into the molecular mechanisms underlying improved wound healing. They can pave the way for potential therapeutic strategies, fostering further research for a better future. Meanwhile, exosomes derived from mesenchymal stem cells, due to their exceptional regenerative properties, as well as the lncRNAs derived from these exosomes, have emerged as one of the innovative tools in wound healing. This review article aims to narrate the cellular and molecular roles of exosome-derived lncRNAs from stem cells in enhancing wound healing with a focus on mesenchymal stem cells.

Rheumatoid arthritis (RA) is a common chronic autoimmune disease that primarily affects the joints, leading to synovial inflammation and hyperplasia, which subsequently causes joint pain, swelling, and damage. The microenvironment of RA is characterized by hypoxia, high reactive oxygen species (ROS), low pH, and levels of high inflammatory factors. Traditional treatments only partially alleviate symptoms and often cause various adverse reactions with long-term use. Therefore, there is an urgent need for safer and more effective treatments. In recent years, mesenchymal stem cells (MSCs) have shown significant potential in treating RA due to their diverse immunomodulatory mechanisms. MSCs paracrine a variety of soluble factors to improve the inflammatory microenvironment in RA patients by inhibiting T cell proliferation or inducing T cell differentiation to regulatory T cells (Tregs), inhibiting B cell proliferation and differentiation and immunoglobulin production, prompting macrophage polarization toward an anti-inflammatory phenotype, and inhibiting neutrophil recruitment and preventing the maturation of dendritic cells (DCs). This review summarizes the immunomodulatory effects of MSCs in RA and their application in animal models and clinical trials. Although the immunomodulatory mechanisms of MSCs are not yet fully elucidated, their significant potential in RA treatment has been widely recognized. Future research should further explore the immunomodulatory mechanisms of MSCs and optimize their functions in different pathological microenvironments to develop more effective and safer therapeutic strategies.

Nanotechnology has emerged as a revolutionary domain with diverse applications in medicine, and one of the noteworthy developments is the exploration of bacterial magnetosomes acquired from magnetotactic bacteria (MTB) for therapeutic purposes. The demand for natural nanomaterials in the biomedical field is continuously increasing due to their biocompatibility and eco-friendly nature. MTB produces uniform, well-ordered magnetic nanoparticles inside the magnetosomes, drawing attention due to their unique and remarkable features. MTB and magnetosomes have gained popularity in cancer treatment and diagnosis, especially in magnetic resonance imaging. Distinctive features highlighted include advancements in extraction, characterization, and functionalization techniques, alongside breakthroughs in utilizing MTB-based magnetosomes as contrast agents in imaging, biocompatible drug carriers, and tools for minimally invasive therapies. The biocompatible nature, functionalizing of the surface of bacterial magnetosomes, and response to the external magnetic field make them a potential candidate for the theragnostic purpose of MTB and magnetosomes. In the present review, emphasis has been given to the foundation of magnetosomes at a genetic level, mass production of magnetosomes, etc. Further authors have reviewed the various functionalization methods of the magnetosomes for cancer treatment. Finally, the authors have reviewed the recent advancements in MTB and magnetosome-based cancer detection, diagnosis, and treatment. Challenges such as scalability, long-term safety, and clinical translation are also discussed, presenting a roadmap for future research exploiting MTBs and magnetosomes' unique properties.

Swarm behaviors are common in nature, where individual organisms collaborate via perception, communication, and adaptation. Emulating these dynamics, large groups of active agents can self-organize through localized interactions, giving rise to complex swarm behaviors, which exhibit potential for applications across various domains. This review presents a comprehensive summary and perspective of synthetic swarms, to bridge the gap between the microscale individual agents and potential applications of synthetic swarms. It is begun by examining active agents, the fundamental units of synthetic swarms, to understand the origins of their motility and functionality in the presence of external stimuli. Then inter-agent communications and agent-environment communications that contribute to the swarm generation are summarized. Furthermore, the swarm behaviors reported to date and the emergence of machine intelligence within these behaviors are reviewed. Eventually, the applications enabled by distinct synthetic swarms are summarized. By discussing the emergent machine intelligence in swarm behaviors, insights are offered into the design and deployment of autonomous synthetic swarms for real-world applications.

Extracellular vesicles (EVs) such as microparticles secreted by the cells can be manipulated and used for delivering therapeutic drugs to target and eradicate cancer cells. However, high encapsulation efficiency and mass production of the microparticles remain difficult to achieve. Efficient and targeted delivery to cancer cells is another hurdle to be addressed. To overcome these issues, we integrated superparamagnetic iron oxide nanoparticles (MNPs) with microparticles. First of all, exposure of highly aggressive tumor-repopulating cells (TRC) to UV radiation dramatically improved microparticle production. These TRC cells were selected from diverse cancer cell lines that are 3D culturing in soft fibrin gel. These microparticles derived from 3D-cultured TRCs have lower membrane stiffness than 2D-cultured cells. Ferrozine assay showed that endocytosis and encapsulation of MNPs during microparticle production were higher in 3D-cultured TRC cells than in 2D cultured cells. Packaging of MNPs into microparticles also enhanced cellular uptake of MNPs without inducing cytotoxicity to treated cells. Compared to the naked MNPs, ex vivo fluorescence imaging shows that mice tail-vein injected with microparticle-encapsulated MNPs displayed continuous increments of intratumoral accumulation of MNPs. Furthermore, MRI images revealed a higher T2 contrast and an uneven distribution of the T2 contrast in the tumor of mice tail-vein injected with microparticle-encapsulated MNPs than naked MNPs. This study provides a new platform for cancer imaging by integrating MNPs and microparticles derived from tumor-repopulating cells.

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

Exosome-nanoparticle hybrid nanoplatforms, can be prepared by combining exosomes with different types of nanoparticles. The main purpose of combining exosomes with nanoparticles is to overcome the limitations of using each of them as drug delivery systems. Using nanoparticles for drug delivery has some limitations, such as high immunogenicity, poor cellular uptake, low biocompatibility, cytotoxicity, low stability, and rapid clearance by immune cells. However, using exosomes as drug delivery systems also has its own drawbacks, such as poor encapsulation efficiency, low production yield, and the inability to load large molecules. These limitations can be addressed by utilizing hybrid nanoplatforms. Additionally, the use of exosomes allows for targeted delivery within the hybrid system. Exosome-inorganic/organic hybrid nanoparticles may be used for both therapy and diagnosis in the future. This may lead to the development of personalized medicine using hybrid nanoparticles. However, there are a few challenges associated with this. Surface modifications, adding functional groups, surface charge adjustments, and preparing nanoparticles with the desired size are crucial to the possibility of preparing exosome-nanoparticle hybrids. Additional challenges for the successful implementation of hybrid platforms in medical treatments and diagnostics include scaling up the manufacturing process and ensuring consistent quality and reproducibility across various batches. This review focuses on various types of exosome-nanoparticle hybrid systems and also discusses the preparation and loading methods for these hybrid nanoplatforms. Furthermore, the potential applications of these hybrid nanocarriers in drug/gene delivery, disease treatment and diagnosis, and cell/tissue imaging are explained.

Introduction: rhabdomyolysis (RM) is a serious syndrome. A large area of muscle injury and dissolution induces acute kidney injury (AKI), which results in a high incidence and mortality rate. Exosomes released by mesenchymal stem cells (MSCs) have been used to treat AKI induced by rhabdomyolysis and have shown regenerative effects. However, the most serious drawbacks of these methods are poor targeting and a low enrichment rate after systemic administration. Methods: in this study, we demonstrated that magnetic exosomes derived from bone marrow mesenchymal stem cells (BMSCs) can directly target damaged muscles rather than kidneys using an external magnetic field. Results: magnetic navigation exosomes reduced the dissolution of damaged muscles, greatly reduced the release of cellular contents, slowed the development of AKI. Discussion: in summary, our proposed method can overcome the shortcomings of poor targeting in traditional exosome therapy. Moreover, in the rhabdomyolysis-induced AKI model, we propose for the first time an exosome therapy mode that directly targets damaged muscles through magnetic navigation.

Mesenchymal stem cell-derived exosomes (MSC-Exo) offer promising therapeutic potential for various refractory diseases, presenting a novel therapeutic strategy. However, their clinical application encounters several obstacles, including low natural secretion, uncontrolled biological functions and inherent heterogeneity. On the one hand, physical stimuli can mimic the microenvironment dynamics where MSC-Exo reside. These factors influence not only their secretion but also, significantly, their biological efficacy. Moreover, physical factors can also serve as techniques for engineering exosomes. Therefore, the realm of physical factors assumes a crucial role in modifying MSC-Exo, ultimately facilitating their clinical translation. This review focuses on the research progress in applying physical factors to MSC-Exo, encompassing ultrasound, electrical stimulation, light irradiation, intrinsic physical properties, ionizing radiation, magnetic field, mechanical forces and temperature. We also discuss the current status and potential of physical stimuli-affected MSC-Exo in clinical applications. Furthermore, we address the limitations of recent studies in this field. Based on this, this review provides novel insights to advance the refinement of MSC-Exo as a therapeutic approach in regenerative medicine.

Endogenous stem cell homing refers to the transport of endogenous mesenchymal stem cells (MSCs) to damaged tissue. The paradigm of using well-designed biomaterials to induce resident stem cells to home in to the injured site while coordinating their behavior and function to promote tissue regeneration is known as endogenous regenerative medicine (ERM). ERM is a promising new avenue in regenerative therapy research, and it involves the mobilizing of endogenous stem cells for homing as the principal means through which to achieve it. Comprehending how mesenchymal stem cells home in and grasp the influencing factors of mesenchymal stem cell homing is essential for the understanding and design of tissue engineering. This review summarizes the process of MSC homing, the factors influencing the homing process, analyses endogenous stem cell homing studies of interest in the field of skin tissue repair, explores the integration of endogenous homing promotion strategies with cellular therapies and details tissue engineering strategies that can be used to modulate endogenous homing of stem cells. In addition to providing more systematic theories and ideas for improved materials for endogenous tissue repair, this review provides new perspectives to explore the complex process of tissue remodeling to enhance the rational design of biomaterial scaffolds and guide tissue regeneration strategies.

Efforts are made to enhance the inherent potential of extracellular vesicles (EVs) by utilizing 3D culture platforms and engineered strategies for functional cargo-loading. Three distinct types of adipose mesenchymal stem cells-derived EVs (ADSCs-EVs) are successfully isolated utilizing 3D culture platforms consisting of porous gelatin methacryloyl (PG), PG combined with sericin methacryloyl (PG/SerMA), or PG combined with chondroitin sulfate methacryloyl (PG/ChSMA). These correspond to PG-EVs, PG/SerMA-EVs, and PG/ChSMA-EVs, respectively. Unique microRNA (miRNA) profiles are observed in each type of ADSCs-EVs. Notably, PG-EVs encapsulate higher levels of hsa-miR-455-3p and deliver more hsa-miR-455-3p to chondrocytes, which results in the activation of the hsa-miR-455-3p/PAK2/Smad2/3 axis and the subsequent hyaline cartilage regeneration. Furthermore, the functionality of PG-EVs is optimized through engineered strategies, including agomir/lentivirus transfection, electroporation, and Exo-Fect transfection. These strategies, referred to as Agomir-EVs, Lentivirus-EVs, Electroporation-EVs, and Exo-Fect-EVs, respectively, are ranked based on their efficacy in encapsulating hsa-miR-455-3p, delivering hsa-miR-455-3p to chondrocytes, and promoting cartilage formation via the hsa-miR-455-3p/PAK2/Smad2/3 axis. Notably, Exo-Fect-EVs exhibit the highest efficiency. Collectively, the 3D culture conditions and engineered strategies have an impact on the miRNA profiles and cartilage regeneration capabilities of ADSCs-EVs. The findings provide valuable insights into the mechanisms underlying the promotion of cartilage regeneration by ADSCs-EVs.

We designed and performed this meta-analysis to investigate the impact of the application of extracellular small vesicle therapies on regeneration of skin and wound healing. The findings of this study were computed using fixed or random effect models. The mean differences (MDs), and odds ratio (ORs) with their 95% confidence intervals (CIs) were calculated. In this study, 43 publications were included, encompassing 530 animals with artificial wounds. Small extracellular vesicle therapy had a significant greater rate of wound closure (MD, 24.0; 95% CI, 19.98-28.02, P < 0.001), lower scar width (MD, -191.33; 95%CI, -292.26--90.4, P < 0.001), and higher blood vessel density (MD,36.11; 95%CI, 19.02-53.20, P < 0.001) compared to placebo. Our data revealed that small extracellular vesicle therapy had a significantly higher regeneration of skin and healing of wounds based on the results of wound closure rate, lower scar width, and higher blood vessel density compared to placebo. Future studies with larger sample size are needed.

Skin aging is characterized by the disruption of skin homeostasis and impaired skin injury repair. Treatment of aging skin has long been limited by the unclear intervention targets and delivery techniques. Engineering extracellular vesicles (EVs) as an upgraded version of natural EVs holds great potential in regenerative medicine. In this study, we found that the expression of the critical antioxidant and detoxification gene Gstm2 was significantly reduced in aging skin. Thus, we constructed the skin primary fibroblasts-derived EVs encapsulating Gstm2 mRNA (EVsGstm2), and found that EVsGstm2 could significantly improve skin homeostasis and accelerate wound healing in aged mice. Mechanistically, we found that EVsGstm2 alleviated oxidative stress damage of aging dermal fibroblasts by modulating mitochondrial oxidative phosphorylation, and promoted dermal fibroblasts to regulate skin epidermal cell function by paracrine secretion of Nascent Polypeptide-Associated Complex Alpha subunit (NACA). Furthermore, we confirmed that NACA is a novel skin epidermal cell protective molecule that regulates skin epidermal cell turnover through the ROS-ERK-ETS-Cyclin D pathway. Our findings demonstrate the feasibility and efficacy of EVs-mediated delivery of Gstm2 for aged skin treatment and unveil novel roles of GSTM2 and NACA for improving aging skin.

In recent years, different advancements have been observed in nanosized drug delivery systems. Factors such as stability, safety and targeting efficiency cause hindrances in the clinical translation of these synthetic nanocarriers. Therefore, researchers employed endogenous nanocarriers like exosomes as drug delivery vehicles that have an inherent ability to target more efficiently after appropriate functionalization and show higher biocompatibility and less immunogenicity and facilitate penetration through the biological barriers more quickly than the other available carriers. Exosomes are biologically derived lipid bilayer-enclosed nanosized extracellular vesicles (size ranges from 30 to 150 nm) secreted from both prokaryotic and eukaryotic cells and appears significantly in the extracellular space. These EVs (extracellular vesicles) can exist in different sources, including mammals, plants and microorganisms. Different advanced techniques have been introduced for the isolation of exosomes to overcome the existing barriers present with conventional methods. Extensive research on the application of exosomes in therapeutic delivery for treating various diseases related to central nervous system, bone, cancer, skin, etc. has been employed. Several studies are on different stages of clinical trials, and many exosomes patents have been registered.

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.

Nanoparticles (NPs) have been extensively investigated for their potential in nanomedicine. There is a significant level of enthusiasm about the potential of NPs to bring out a transformative impact on modern healthcare. NPs can serve as effective wound dressings or delivery vehicles due to their antibacterial and pro-wound-healing properties. Biopolymer-based NPs can be manufactured using various food-grade biopolymers, such as proteins, polysaccharides, and synthetic polymers, each offering distinct properties suitable for different applications which include collagen, polycaprolactone, chitosan, alginate, and polylactic acid, etc. Their biodegradable and biocompatible nature renders them ideal nanomaterials for applications in wound healing. Additionally, the nanofibers containing biopolymer-based NPs have shown excellent anti-bacterial and wound healing activity like silver NPs. These NPs represent a paradigm shift in wound healing therapies, offering targeted and personalized solutions for enhanced tissue regeneration and accelerated wound closure. The current review focuses on biopolymer NPs with their applications in wound healing.

Mesenchymal stem cell derived exosomes (MSC-Exos) demonstrate beneficial effects on wound healing via anti-inflammatory and angiogenic properties. Chitosan (CS) exhibits excellent biocompatibility and accelerates cellular migration, adhesion, and proliferation. The ions released from bioactive glass (BG) and titanium dioxide (TiO2) nanoparticles exhibit sustained angiogenic and antibacterial potency. In this study, CMCS-CEBT hydrogel was synthesized from exosomes encapsulated carboxymethyl chitosan (CMCS), chitosan nanoparticles (CS-NPs), BG, and TiO2 nanoparticles for a preliminary evaluation of its impacts on the treatment of full-thickness skin defects, diabetic wounds, and burn skin injury due to burns. In vitro analysis indicated that the hydrogel exhibits excellent cell compatibility, stimulates endothelial cell adhesion and proliferation, and presents anti-inflammatory, angiogenic, and antibacterial activities. In vivo, the composite hydrogel dressing accelerated a wound healing acceleration effect, stimulated angiogenesis, and increased collagen deposition and the expression of anti-inflammatory factors. This innovative composite hydrogel dressing as a potential clinical therapy, utilizing bioactive materials, holds promise as a potential clinical therapy that aims to facilitate the regeneration of acute and chronically damaged skin tissue.

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

Adipose mesenchymal stem cell (ADMSC)-derived exosomes (ADMSC-Exos) have shown great potential in regenerative medicine and been evidenced benefiting wound repair such as burns. However, the low yield, easy loss after direct coating, and no suitable loading system to improve their availability and efficacy hinder their clinical application for wound healing. And few studies focused on the comparison of biological functions between exosomes derived from different culture techniques, especially in exosome-releasing hydrogel system. Therefore, we designed a high-performance exosome controllable releasing hydrogel system for burn wound healing, namely loading 3D-printed microfiber culture-derived exosomes in a highly biocompatible hyaluronic acid (HA). In this project, we compared the biological functions in vitro and in a burn model among exosomes derived from the conventional two-dimensional (2D) plate culture (2D-Exos), microcarrier culture (2.5D-Exos), and 3D-printed microfiber culture (3D-Exos). Results showed that compared with 2D-Exos and 2.5D-Exos, 3D-Exos promoted HACATs and HUVECs cell proliferation and migration more significantly. Additionally, 3D-Exos had stronger angiogenesis-promoting effects in tube formation of (HUVECs) cells. Moreover, we found HA-loaded 3D-Exos showed better burn wound healing promotion compared to 2D-Exos and 2.5D-Exos, including accelerated burn wound healing rate and better collagen remodeling. The study findings reveal that the HA-loaded, controllable-release 3D-Exos repair system distinctly augments therapeutic efficacy in terms of wound healing, while concurrently introducing a facile application approach. This system markedly bolsters the exosomal loading efficiency, provides a robust protective milieu, and potentiates the inherent biological functionalities of the exosomes. Our findings provide a rationale for more efficient utilization of high-quality and high-yield 3D exosomes in the future, and a novel strategy for healing severe burns.

Engineering exosomes with nanomaterials usually leads to the damage of exosomal membrane and bioactive molecules. Here, pathological angiogenesis targeting exosomes with magnetic imaging, ferroptosis inducing, and immunotherapeutic properties is fabricated using a simple coincubation method with macrophages being the bioreactor. Extremely small iron oxide nanoparticle (ESIONPs) incorporated exosomes (ESIONPs@EXO) are acquired by sorting the secreted exosomes from M1-polarized macrophages induced by ESIONPs. ESIONPs@EXO suppress pathological angiogenesis in vitro and in vivo without toxicity. Furthermore, ESIONPs@EXO target pathological angiogenesis and exhibit an excellent T1-weighted contrast property for magnetic resonance imaging. Mechanistically, ESIONPs@EXO induce ferroptosis and exhibit immunotherapeutic ability toward pathological angiogenesis. These findings demonstrate that a pure biological method engineered ESIONPs@EXO using macrophages shows potential for targeted pathological angiogenesis therapy.

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.

Exosomes, nano-sized vesicles ranging between 30 and 150 nm secreted by human cells, play a pivotal role in long-range intercellular communication and have attracted significant attention in the field of regenerative medicine. Nevertheless, their limited productivity and cost-effectiveness pose challenges for clinical applications. These issues have recently been addressed by cell-derived nanovesicles (CDNs), which are physically synthesized exosome-mimetic nanovesicles from parent cells, as a promising alternative to exosomes. CDNs exhibit structural, physical, and biological properties similar to exosomes, containing intracellular protein and genetic components encapsulated by the cell plasma membrane. These characteristics allow CDNs to be used as regenerative medicine and therapeutics on their own, or as a drug delivery system.

The paper reviews diverse methods for CDN synthesis, current analysis techniques, and presents engineering strategies to improve lesion targeting efficiency and/or therapeutic efficacy.

CDNs, with their properties similar to those of exosomes, offer a cost-effective and highly productive alternative due to their non-living biomaterial nature, nano-size, and readiness for use, allowing them to overcome several limitations of conventional cell therapy methods.

Ongoing research and enhancement of CDNs engineering, along with comprehensive safety assessments and stability analysis, exhibit vast potential to advance regenerative medicine by enabling the development of efficient therapeutic interventions.

Lower limb microcirculatory ischemic disease is a vascular disorder primarily characterized by limb pain, gangrene, and potential amputation. It can be caused by various factors, such as hyperglycemia, atherosclerosis, and infection. Due to the extremely narrow luminal diameter in lower limb microcirculatory ischemic lesions, both surgical and medical interventions face challenges in achieving satisfactory therapeutic outcomes within the microvessels. Extracellular vesicles derived from mesenchymal stem cells (MSCs-EVs) exhibit promising potential in the treatment of microcirculation ischemic lesions due to their small size and ability to promote angiogenesis. After undergoing substantial losses during the process of EVs transportation, only a minimal fraction of EVs can effectively reach the site of microcirculatory lesions, thereby compromising the therapeutic efficacy for microcirculatory disorders. Herein, an ultrasound-responsive system utilizing 2-(dimethylamino)ethyl methacrylate-b-2-tetrahydropyranyl methacrylate (DMAEMA-b-THPMA) micelles to encapsulate MSCs-EVs has been successfully constructed, with the aim of achieving localized and targeted release of EVs at the site of microcirculatory lesions. The reversible addition-fragmentation chain transfer (RAFT) polymerization method facilitates the successful synthesis of diblock copolymers comprising monomer 2-(dimethylamino)ethyl methacrylate (DMAEMA) and monomer 2-tetrahydropyranyl methacrylate (THPMA). The DMAEMA-b-THPMA micelles exhibit a nanoscale structure, reliable biocompatibility, ultrasound responsiveness, and conspicuous protection of EVs. Furthermore, the implementation of low-energy-density ultrasound can enhance angiogenesis by upregulating the levels of the vascular endothelial growth factor (VEGF). In in vivo experiments, the ultrasound-responsive system of the DMAEMA-b-THPMA micelles and MSCs-EVs synergistically enhances therapeutic efficacy by promoting angiogenesis, improving vascular permeability, and optimizing vascular. In conclusion, this work demonstrates bioapplication of an ultrasound-responsive micellar nanosystem loaded with EVs for the treatment of lower limb microcirculatory ischemic disorders.

Oral and maxillofacial diseases are one of the most prevalent diseases in the world, which not only seriously affect the health of patients' oral and maxillofacial tissues, but also bring serious economic and psychological burdens to patients. Therefore, oral and maxillofacial diseases require effective treatment. Traditional treatments have limited effects. In recent years, nature exosomes have attracted increasing attention due to their ability to diagnose and treat diseases. However, the application of nature exosomes is limited due to low yield, high impurities, lack of targeting, and high cost. Engineered exosomes can be endowed with better comprehensive therapeutic properties by modifying exosomes of parent cells or directly modifying exosomes, and biomaterial loading exosomes. Compared with natural exosomes, these engineered exosomes can achieve more effective diagnosis and treatment of oral and maxillary system diseases, and provide reference and guidance for clinical application. This paper reviews the engineering modification methods of exosomes and the application of engineered exosomes in oral and maxillofacial diseases and looks forward to future research directions.

The advancement in novel cancer therapeutics brought a platform combining the properties of exosomes with nanoparticles to precision medicine. The novel therapeutic approach aim is cancer-targeted therapy. Exosomes from mesenchymal stem cells (MSCs-Exo) exhibit unique properties in cancer therapies, which makes them an ideal tool for delivering therapeutic agents into tumor cells. The key role of natural MSCs-Exo is controversial in cancer therapy; however, they can be engineered at their surface or cargo to serve as a smart drug delivery system for cancer-targeted therapy. In the last few years, researchers harnessed nanotechnology to enforce MSCs-Exo for cancer management including, tumor cell tracking, imaging, and tumor cell killing. Different nanoparticles such as gold nanoparticles have particularly been incorporated into MSCs-Exo, which showed an efficient accumulation at the site of tumor with improved anticancer impact. These findings indicate that a hybrid of exosomes-nanoparticles may serve as combination therapy for the effective removal of cancers.

Although exhibiting impressive potential, the use of nanoparticle-loaded MSCs-Exo as a drug-delivery tool has been troubled by some challenges, therefore, translation to clinic prerequisites further scrutiny. In this review, we focus on nanoparticle-loaded MSCs-Exo as a new cancer therapy and discuss engineered MSC-Exo for target therapy.

Inspired by the experience of relieving inflammation in infants with milk, antioxidant-engineered milk-derived extracellular vesicles (MEVs) are developed to evaluate their potential for accelerating wound healing. In this work, MEVs with polydopamines (PDA) are engineered using the co-extrusion method. Subsequently, the authors incorporated them into a Schiff-based crosslink hydrogel, forming a skin dosage form that could facilitate the wound healing process. The antioxidant properties of PDA assist in the anti-inflammatory function of engineered MEVs, while the gel provides better skin residency. The PDA@MEVs+GEL formulation exhibits excellent biocompatibility, pro-angiogenic capacity, and antioxidant ability in vitro. Furthermore, in vivo experiments demonstrate its efficacy in wound repair and inflammation inhibition. Mechanistically, PDA@MEVs+GEL simultaneously promotes the growth, migration, and anti-inflammation of 3T3 cells by activating PI3K-AKT pathway. Moreover, PDA@MEVs+GEL exhibits enhanced functionality in promoting wound healing in vivo, attributed to its ability to inhibit inflammation, stimulate angiogenesis, and promote collagen synthesis. In conclusion, this study delves into the mechanism of MEVs and underscores the improved efficacy of engineered extracellular vesicles. Additionally, the feasibility and prospect of engineered MEVs in treating skin wounds are verified, suggesting that antioxidant-engineered MEVs could be a promising therapeutic agent for wound healing applications.

Recently, stem cells and their secretomes have attracted great attention in biomedical applications, particularly extracellular vesicles (EVs). EVs are secretomes of cells for cell-to-cell communication. They play a role as intercellular messengers as they carry proteins, nucleic acids, lipids, and therapeutic agents. They have also been utilized as drug-delivery vehicles due to their biocompatibility, low immunogenicity, stability, targetability, and engineerable properties. The therapeutic potential of EVs can be further enhanced by surface engineering and modification using functional molecules such as aptamers, peptides, and antibodies. As a consequence, EVs hold great promise as effective delivery vehicles for enhancing treatment efficacy while avoiding side effects. Among various cell types that secrete EVs, stem cells are ideal sources of EVs because stem cells have unique properties such as self-renewal and regenerative potential for transplantation into damaged tissues that can facilitate their regeneration. However, challenges such as immune rejection and ethical considerations remain significant hurdles. Stem cell-derived EVs have been extensively explored as a cell-free approach that bypasses many challenges associated with cell-based therapy in cancer therapy and tissue regeneration. In this review, we summarize and discuss the current knowledge of various types of stem cells as a source of EVs, their engineering, and applications of EVs, focusing on cancer therapy and tissue engineering.

Exosomes are cell-derived nanovesicles, circulating in different body fluids, and acting as an intercellular mechanism. They can be purified from culture media of different cell types and carry an enriched content of various protein and nucleic acid molecules originating from their parental cells. It was indicated that the exosomal cargo can mediate immune responses via many signaling pathways. Over recent years, the therapeutic effects of various exosome types were broadly investigated in many preclinical studies. Herein, we present an update on recent preclinical studies on exosomes as therapeutic and/or delivery agents for various applications. The exosome origin, structural modifications, natural or loaded active ingredients, size, and research outcomes were summarized for various diseases. Overall, the present article provides an overview of the latest exosome research interests and developments to clear the way for the clinical study design and application.

Mesenchymal stem cells (MSCs) are being increasingly used in various therapeutic applications including skin tissue repair and wound healing. The positive effects of the MSCs therapy are largely elicited by immunomodulation, increasing angiogenesis, supporting extracellular matrix (ECM) and thus favoring skin structure. However, the therapeutic competences of MSC-based therapies are somewhat hindered by their apparent modest clinical merits, conferring the need for methods that would rise the efficacy of such therapies. A plethora of reports have shown that therapeutic properties of MSCs could be enhanced with other strategies and compounds like biomaterial and platelet-rich plasma (PRP) to target key possessions of MSCs and properties of adjacent tissues concurrently. Manipulation of cellular stress-response mechanisms to improve cell resistance to oxidative stress prior to or during MSC injection could also improve therapeutic efficacy of MSCs. In the current review, we shed light on the recent advances in MSCs combination therapy with other ingredients and procedures to sustain MSCs-mediated effects in wound healing.

Extracellular vesicles (EVs) are small membrane-bound vesicles released by cells. EVs are emerging as a promising class of therapeutic entity that could be adapted in formulation due to their lack of immunogenicity and targeting capabilities. EVs have been shown to have similar regenerative and therapeutic effects to their parental cells and also have potential in disease diagnosis. To improve the therapeutic potential of EVs, researchers have developed various strategies for modifying them, including genetic engineering and chemical modifications which have been examined to confer target specificity and prevent rapid clearance after systematic injection. Formulation efforts have focused on utilising hydrogel and nano-formulation strategies to increase the persistence of EV localisation in a specific tissue or organ. Researchers have also used biomaterials or bioscaffolds to deliver EVs directly to disease sites and prolong EV release and exposure. This review provides an in-depth examination of the material design of EV delivery systems, highlighting the impact of the material properties on the molecular interactions and the maintenance of EV stability and function. The various characteristics of materials designed to regulate the stability, release rate and biodistribution of EVs are described. Other aspects of material design, including modification methods to improve the targeting of EVs, are also discussed. This review aims to offer an understanding of the strategies for designing EV delivery systems, and how they can be formulated to make the transition from laboratory research to clinical use.

Extracellular vesicles (EVs) are membrane vesicles released by cells into the extracellular space. EVs mediate cell-to-cell communication through local and systemic transportation of biomolecules such as DNA, RNA, transcription factors, cytokines, chemokines, enzymes, lipids, and organelles within the human body. EVs gained a particular interest from cancer biology scientists because of their role in the modulation of the tumor microenvironment through delivering bioactive molecules. In this respect, EVs represent an attractive therapeutic target and a means for drug delivery. The advantages of EVs include their biocompatibility, small size, and low immunogenicity. However, there are several limitations that restrict the widespread use of EVs in therapy, namely, their low specificity and payload capacity. Thus, in order to enhance the therapeutic efficacy and delivery specificity, the surface and composition of extracellular vesicles should be modified accordingly. In this review, we describe various approaches to engineering EVs, and further discuss their advantages and disadvantages to promote the application of EVs in clinical practice.

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.

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.