Induced Pluripotent Stem Cell-Derived Extracellular Vesicles Promote Wound Repair in a Diabetic Mouse Model via an Anti-Inflammatory Immunomodulatory Mechanism

MSC-derived extracellular vesicles: Precision miRNA delivery for overcoming cancer therapy resistance

Cancer remains a prominent worldwide health concern, presenting existing therapies with frequent difficulties, including major toxicity, limited effectiveness, and treatment resistance emergence. These issues highlight the necessity for novel and enhanced remedies. Exosomes, tiny extracellular vesicles that facilitate intercellular communication, have attracted interest for their potential medicinal applications. Carrying a variety of molecules, including microRNAs, small interfering RNAs, long non-coding RNAs, proteins, lipids, and DNA, these vesicles are positioned as promising cancer treatment options. Current studies have increasingly investigated the capacity of microRNAs as a strategic approach for combating malignancy. Mesenchymal stem cells (MSC) are recognized for their aptitude to augment blood vessel formation, safeguard against cellular death, and modulate immune responses. Consequently, researchers examine exosomes derived from MSCs as a safer, non-cellular choice over therapies employing MSCs, which risk undesirable differentiation. The focus is shifting towards employing miRNA-encapsulated exosomes sourced from MSCs to target and heal cancerous cells selectively. However, the exact functions of miRNAs within MSC-derived exosomes in the context of cancer are still not fully understood. Additional exploration is necessary to clarify the role of these miRNAs in malignancy progression and to pinpoint viable therapeutic targets. This review offers a comprehensive examination of exosomes derived from mesenchymal stem cells, focusing on the encapsulation of miRNAs, methods for enhancing cellular uptake and stability, and their potential applications in cancer treatment. It also addresses the difficulties linked to this methodology and considers future avenues, including insights from current clinical oncology research.

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.

Neuron-Derived Extracellular Vesicles: Emerging Regulators in Central Nervous System Disease Progression

The diagnosis and exploration of central nervous system (CNS) diseases remain challenging due to the blood-brain barrier (BBB), complex signaling pathways, and heterogeneous clinical manifestations. Neurons, as the core functional units of the CNS, play a pivotal role in CNS disease progression. Extracellular vesicles (EVs), capable of crossing the BBB, facilitate intercellular and cell-extracellular matrix (ECM) communication, making neuron-derived extracellular vesicles (NDEVs) a focal point of research. Recent studies reveal that NDEVs, carrying various bioactive substances, can exert either pathogenic or protective effects in numerous CNS diseases. Additionally, NDEVs show significant potential as biomarkers for CNS diseases. This review summarizes the emerging roles of NDEVs in CNS diseases, including Alzheimer's disease, depression, traumatic brain injury, schizophrenia, ischemic stroke, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis. It aims to provide a novel perspective on developing therapeutic and diagnostic strategies for CNS diseases through the study of NDEVs.

Recent advances in the roles of extracellular vesicles in cardiovascular diseases: pathophysiological mechanisms, biomarkers, and cell-free therapeutic strategy

Cardiovascular diseases (CVDs) represent a profound challenge with inflammation playing a significant role in their pathophysiology. Extracellular vesicles (EVs), which are membranous structures encapsulated by a lipid bilayer, are essential for intercellular communication by facilitating the transport of specific bioactive molecules, including microRNAs, proteins, and lipids. Emerging evidence suggests that the regulatory mechanisms governing cardiac resident cells are influenced by EVs, which function as messengers in intercellular communication and thereby contribute to the advancement of CVDs. In this review, we discuss the multifaceted biological functions of EVs and their involvement in the pathogenesis of various CVDs, encompassing myocardial infarction, ischemia-reperfusion injury, heart failure, atherosclerosis, myocarditis, cardiomyopathy, and aneurysm. Furthermore, we summarize the recent advancements in utilizing EVs as non-invasive biomarkers and in cell-free therapy based on EVs for the diagnosis and treatment of CVDs. Future research should investigate effective techniques for the isolation and purification of EVs from body fluids, while also exploring the pathways for the clinical translation of therapy based on EVs. Additionally, it is imperative to identify appropriate EV-miRNA profiles or combinations present in the circulation of patients, which could serve as biomarkers to improve the diagnostic accuracy of CVDs. By synthesizing and integrating recent research findings, this review aims to provide innovative perspectives for the pathogenesis of CVDs and potential therapeutic strategies.

Biomanufacturing and lipidomics analysis of extracellular vesicles secreted by human blood vessel organoids in a vertical wheel bioreactor

BACKGROUND

Extracellular vesicles (EVs) derived from human organoids are phospholipid bilayer-bound nanoparticles that carry therapeutic cargo. However, the low yield of EVs remains a critical bottleneck for clinical translation. Vertical-Wheel bioreactors (VWBRs), with unique design features, facilitate the scalable production of EVs secreted by human blood vessel organoids (BVOs) under controlled shear stress, using aggregate- and microcarrier-based culture systems.

METHODS

Human induced pluripotent stem cell-derived BVOs cultured as aggregates or on Synthemax II microcarriers within VWBRs (40 and 80 rpm) were compared to static controls. The organoids were characterized by metabolite profiling, flow cytometry, and gene expression of EV biogenesis markers. EVs were characterized by nanoparticle tracking analysis, electron microscopy, and Western blotting. Lipidomics provided insights into EV lipid composition, while functional assays assessed the impact of EVs in a D-galactose-induced senescence model.

RESULTS

VWBR cultures showed more aerobic metabolism and higher expression of EV biogenesis genes compared to the static control. EVs from different conditions were comparable in size, but the yields were significantly higher for microcarrier and dynamic cultures than static aggregates. Lipidomic profiling revealed minimal variation (< 0.36%) in total lipid content; however, distinct differences were identified in lipid chain lengths and saturation levels, affecting key pathways such as sphingolipid and neurotrophin signaling. Human BVO EVs demonstrated the abilities of reducing oxidative stress and increasing cell proliferation in vitro.

CONCLUSIONS

Human BVOs differentiated in VWBRs (in particular 40 rpm) produce 2-3 fold higher yield of EVs (per mL) than static control. The bio manufactured EVs from VWBRs have exosomal characteristics and therapeutic cargo, showing functional properties in in vitro assays. This innovative approach establishes VWBRs as a scalable platform for producing functional EVs with defined lipid profiles and therapeutic potential, paving the way for future in vivo studies.

Batch variability and anti-inflammatory effects of iPSC-derived mesenchymal stromal cell extracellular vesicles in osteoarthritis in vitro model

Mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) hold promise as a cell-free therapy for osteoarthritis (OA), due to their immunomodulatory and anti-inflammatory properties. However, the need for large-scale expansion to obtain MSC-EVs for clinical use can lead to senescence-related changes and loss of stem-like properties. In this scenario, induced pluripotent stem cell (iPSC)-derived MSCs (iMSCs) offer the unique opportunity to address obstacles associated with traditional MSC-based therapies. This study used a xeno-free (XFS) medium for long-term expansion of both MSCs and iMSCs, and their EVs comparison. Characterization of both cells and EVs was conducted across different passages, and the anti-inflammatory potential of EVs and iEVs was assessed using an in vitro model of osteoarthritis. Long-term expansion of MSCs resulted in cellular senescence and a reduction in trilineage differentiation capacity by passage five, accompanied by diminished anti-inflammatory properties of EVs. On the other hand, iMSCs exhibited batch-to-batch variability in differentiation and EV biological properties. However, the effects of iMSC-EVs were prolonged compared to MSC-EVs, providing a wider window of activity for therapeutic purposes. Despite this, the variability among iMSC batches poses challenges for their reliability in OA treatment. Further work is needed to overcome these limitations for clinical application.

Exosome-based miRNA delivery: Transforming cancer treatment with mesenchymal stem cells

Recently, increasing interest has been in utilizing mesenchymal stem cell-derived extracellular vesicles (MSC-EVs), especially exosomes, as nanocarriers for miRNA delivery in cancer treatment. Due to such characteristics, nanocarriers are specific: biocompatible, low immunogenicity, and capable of spontaneous tumor accumulation. MSC-EVs were loaded with therapeutic miRNAs and minimized their susceptibility to degradation by protecting the miRNA from accessibility to degrading enzymes and providing targeted delivery of the miRNAs to the tumor cells to modulate oncogenic pathways. In vitro and in vivo experiments suggest that MSC-EVs loaded with miRNAs may inhibit tumor growth, prevent metastasis, and increase the effectiveness of chemotherapy and radiotherapy. However, these improvements present difficulties such as isolation, scalability, and stability of delivered miRNA during storage. Furthermore, the issues related to off-target effects, as well as immunogenicity, can be a focus. The mechanisms of miRNA loading into MSC-EVs, as well as their targeting efficiency and therapeutic potential, can be outlined in this manuscript. For the final part of the manuscript, the current advances in MSC-EV engineering and potential strategies for clinical application have been described. The findings of MSC-EVs imply that they present MSC-EVs as a second-generation tool for precise oncology.

Exploring the therapeutic potential of small extracellular vesicles derived from induced pluripotent stem cell in periodontal regeneration

OBJECTIVES

To investigate the role of small extracellular vesicles derived from induced pluripotent stem cells (iPSC-sEVs) in periodontal tissue regeneration, elucidate their potential molecular mechanisms, and provide theoretical guidance for the clinical application of iPSC-sEVs as a cell-free therapeutic strategy for periodontal tissue regeneration.

METHODS

We investigated the effects of iPSC-sEVs on the proliferation, migration, and osteogenic differentiation of periodontal ligament stem cells (PDLSCs) in vitro. The regenerative potential of iPSC-sEVs was evaluated in vivo, using a periodontal defect model. Bulk RNA sequencing was performed to elucidate the underlying molecular mechanisms.

RESULTS

iPSC-sEVs were isolated, characterized, and systemically evaluated for regenerative potential. The results revealed that treatment with iPSC-sEVs significantly enhanced the proliferation, migration, and osteogenic differentiation of PDLSCs. In situ treatment with iPSC-sEVs loaded onto collagen sponges was performed in a rat model of periodontal defects. Micro-CT and histological analyses indicated that iPSC-sEV treatment markedly promoted alveolar bone repair and periodontal ligament regeneration. Mechanistically, the analysis of bulk RNA sequencing data coupled with experimental validation revealed that iPSC-sEV treatment significantly activated the mitogen-activated protein kinase (MAPK) signaling pathway in PDLSCs. Further investigation showed that the inhibition of this pathway completely abolished the proliferative effects of iPSC-sEVs on PDLSCs.

CONCLUSIONS

iPSC-sEVs promote PDLSC proliferation through MAPK signaling pathway activation, while also enhancing PDLSC migratory and osteogenic differentiation capacities, facilitates the repair and regeneration of damaged periodontal tissue and presents a potential novel therapeutic strategy for clinical periodontal tissue regeneration.

Extracellular Vesicles from Human Induced Pluripotent Stem Cells Exhibit a Unique MicroRNA and CircRNA Signature

Extracellular vesicles (EV) have emerged as promising cell-free therapeutics in regenerative medicine. However, translating primary cell line-derived EV to clinical applications requires large-scale manufacturing and several challenges, such as replicative senescence, donor heterogeneity, and genetic instability. To address these limitations, we used a reprogramming approach to generate human induced pluripotent stem cells (hiPSC) from the young source of cord blood mesenchymal stem/stromal cells (CBMSC). Capitalizing on their inexhaustible supply potential, hiPSC offer an attractive EV reservoir. Our approach encompassed an exhaustive characterization of hiPSC-EV, aligning with the rigorous MISEV2023 guidelines. Analyses demonstrated physical features compatible with small EV (sEV) and established their identity and purity. Moreover, the sEV-shuttled non-coding (nc) RNA landscape, focusing on the microRNA and circular RNA cargo, completed the molecular signature. The kinetics of the hiPSC-sEV release and cell internalization assays unveiled robust EV production and consistent uptake by human neurons. Furthermore, hiPSC-sEV demonstrated ex vivo cell tissue-protective properties. Finally, via bioinformatics, the potential involvement of the ncRNA cargo in the hiPSC-sEV biological effects was explored. This study significantly advances the understanding of pluripotent stem cell-derived EV. We propose cord blood MSC-derived hiPSC as a promising source for potentially therapeutic sEV.

Enhanced Extracellular Vesicle Cargo Loading via microRNA Biogenesis Pathway Modulation

Extracellular vesicles (EVs) are physiological vectors for the intercellular transport of a variety of molecules. Among these, small RNAs, and especially microRNAs (miRNAs), have been identified as prevalent components, and there has thus been a robust investigation of EVs for therapeutic miRNAs delivery. However, intrinsic levels of EV-associated miRNAs are generally too low to enable efficient and effective therapeutic outcomes. We hypothesized that miRNA localization to EVs could be improved by limiting competing interactions that occur throughout the miRNA biogenesis process. Using miR-146a-5p as a model, modulation of transcription, nuclear export, and enzymatic cleavage steps of miRNA biogenesis were tested for impact on EV miRNA loading. Working in HEK293T cells, various alterations in the EV biogenesis pathway were shown to impact miRNA localization to EVs. The system was then applied in induced pluripotent stem cells (iPSCs), a more promising substrate for therapeutic EV production, and EVs were separated and assessed for anti-inflammatory efficacy in vitro and in a murine colitis model, where the preservation of function was validated. Overall, the results highlight necessary considerations when designing a cell culture system for the devoted production of miRNA-loaded EVs.

The application potential of iMSCs and iMSC-EVs in diseases

The immune system, functioning as the body's "defense army", plays a role in surveillance, defense. Any disruptions in immune system can lead to the development of immune-related diseases. Extensive researches have demonstrated the crucial immunoregulatory role of mesenchymal stem cells (MSCs) in these diseases. Of particular interest is the ability to induce somatic cells under specific conditions, generating a new cell type with stem cell characteristics known as induced pluripotent stem cell (iPSC). The differentiation of iPSCs into MSCs, specifically induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs), hold promise as a potential solution to the challenges of MSCs, potentially serving as an alternative to traditional drug therapies. Moreover, the products of iMSCs, termed induced pluripotent stem cell-derived mesenchymal stem cell-derived extracellular vesicles (iMSC-EVs), may exhibit functions similar to iMSCs. With the biological advantages of EVs, they have become the focus of "cell-free therapy". Here, we provided a comprehensive summary of the biological impact of iMSCs on immune cells, explored the applications of iMSCs and iMSC-EVs in diseases, and briefly discussed the fundamental characteristics of EVs. Finally, we overviewed the current advantages and challenges associated with iMSCs and iMSC-EVs. It is our hope that this review related to iMSCs and iMSC-EVs will contribute to the development of new approaches for the treatment of diseases.

Activation of the Wnt/β-catenin signalling pathway enhances exosome production by hucMSCs and improves their capability to promote diabetic wound healing

BACKGROUND

The use of stem cell-derived exosomes (Exos) as therapeutic vehicles is receiving increasing attention. Exosome administration has several advantages over cell transplantation, thus making exosomes promising candidates for large-scale clinical implementation and commercialization. However, exosome extraction and purification efficiencies are relatively low, and therapeutic heterogeneity is high due to differences in culture conditions and cell viability. Therefore, in this study, we investigated a priming procedure to enhance the production and therapeutic effects of exosomes from human umbilical cord mesenchymal stem cells (hucMSCs). After preconditioning hucMSCs with agonists/inhibitors that target the Wnt/β-catenin pathway, we assessed both the production of exosomes and the therapeutic efficacy of the optimized exosomes in the context of diabetic wound healing, hoping to provide a safer, more stable and more effective option for clinical application.

RESULTS

The Wnt signalling pathway agonist CHIR99021 increased exosome production by 1.5-fold without causing obvious changes in the characteristics of the hucMSCs or the size of the exosome particles. Further studies showed that CHIR99021 promoted the production of exosomes by facilitating exocytosis. This process was partly mediated by SNAP25. To further explore whether CHIR99021 changed the cargo that was loaded into the exosomes and its therapeutic effects, we performed proteomic and transcriptomic analyses of exosomes from primed and control hucMSCs. The results showed that CHIR99021 significantly upregulated the expression of proteins that are associated with cell migration and wound healing. Animal experiments confirmed that, compared to control hucMSC-derived exosomes, CHIR99021-pretreated hucMSC-derived exosomes (CHIR-Exos) significantly accelerated wound healing in diabetic mice, enhanced local collagen deposition, promoted angiogenesis, and reduced chronic inflammation. Subsequent in vitro experiments confirmed that the CHIR-Exos promoted wound healing by facilitating cell migration, inhibiting oxidative stress-induced apoptosis, and preventing cell cycle arrest.

CONCLUSIONS

The Wnt agonist CHIR99021 significantly increased exosome secretion by hucMSCs, which was partly mediated by SNAP25. Notably, CHIR99021 treatment also significantly increased the exosomal levels of proteins that are associated with wound healing and cell migration, resulting in enhanced acceleration of wound healing. All of these results suggested that pretreatment of hucMSCs with CHIR99021 not only promoted exosome production but also improved the exosome therapeutic efficacy, thus providing a promising option for large-scale clinical implementation and commercialization.

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

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

Advances in the application of extracellular vesicles derived from three-dimensional culture of stem cells

Stem cells (SCs) have been used therapeutically for decades, yet their applications are limited by factors such as the risk of immune rejection and potential tumorigenicity. Extracellular vesicles (EVs), a key paracrine component of stem cell potency, overcome the drawbacks of stem cell applications as a cell-free therapeutic agent and play an important role in treating various diseases. However, EVs derived from two-dimensional (2D) planar culture of SCs have low yield and face challenges in large-scale production, which hinders the clinical translation of EVs. Three-dimensional (3D) culture, given its ability to more realistically simulate the in vivo environment, can not only expand SCs in large quantities, but also improve the yield and activity of EVs, changing the content of EVs and improving their therapeutic effects. In this review, we briefly describe the advantages of EVs and EV-related clinical applications, provide an overview of 3D cell culture, and finally focus on specific applications and future perspectives of EVs derived from 3D culture of different SCs.

Microenvironment Remodeling Self-Healing Hydrogel for Promoting Flap Survival

Random flap grafting is a routine procedure used in plastic and reconstructive surgery to repair and reconstruct large tissue defects. Flap necrosis is primarily caused by ischemia-reperfusion injury and inadequate blood supply to the distal flap. Ischemia-reperfusion injury leads to the production of excessive reactive oxygen species, creating a pathological microenvironment that impairs cellular function and angiogenesis. In this study, we developed a microenvironment remodeling self-healing hydrogel [laminarin-chitosan-based hydrogel-loaded extracellular vesicles and ceria nanozymes (LCH@EVs&CNZs)] to improve the flap microenvironment and synergistically promote flap regeneration and survival. The natural self-healing hydrogel (LCH) was created by the oxidation laminarin and carboxymethylated chitosan via a Schiff base reaction. We loaded this hydrogel with CNZs and EVs. CNZs are a class of nanomaterials with enzymatic activity known for their strong scavenging capacity for reactive oxygen species, thus alleviating oxidative stress. EVs are cell-secreted vesicular structures containing thousands of bioactive substances that can promote cell proliferation, migration, differentiation, and angiogenesis. The constructed LCH@EVs&CNZs demonstrated a robust capacity for scavenging excess reactive oxygen species, thereby conferring cellular protection in oxidative stress environments. Moreover, these constructs notably enhance cell migration and angiogenesis. Our results demonstrate that LCH@EVs&CNZs effectively remodel the pathological skin flap microenvironment and marked improve flap survival. This approach introduces a new therapeutic strategy combining microenvironmental remodeling with EV therapy, which holds promise for promoting flap survival.

Extracellular vesicles as therapeutics for inflammation and infection

Extracellular vesicles (EVs) are an emergent next-generation biotechnology with broad application potential. In particular, immunomodulatory bioactivity of EVs leading to anti-inflammatory effects is well-characterized. Cell source and culture conditions are critical determinants of EV therapeutic efficacy, while augmenting EV anti-inflammatory bioactivity via diverse strategies, including RNA cargo loading and protein surface display, has proven effective. Yet, translational challenges remain. Additionally, the potential of direct antimicrobial EV functionality has only recently emerged but offers the possibility of overcoming drug-resistant bacterial and fungal infections through novel, multifactorial mechanisms. As discussed herein, these application areas are brought together by the potential for synergistic benefit from technological developments related to EV cargo loading and biomanufacturing.

[Research advances on stem cell-based treatments in animal studies and clinical trials of lymphedema]

Objective

To summarize the progress of the roles and mechanisms of various types of stem cell-based treatments and their combination therapies in both animal studies and clinical trials of lymphedema.

Methods

The literature on stem cell-based treatments for lymphedema in recent years at home and abroad was extensively reviewed, and the animal studies and clinical trials on different types of stem cells for lymphedema were summarized.

Results

Various types of stem cells have shown certain effects in animal studies and clinical trials on the treatment of lymphedema, mainly through local differentiation into lymphoid endothelial cells and paracrine cytokines with different functions. Current research focuses on two cell types, adipose derived stem cells and bone marrow mesenchymal stem cells, both of which have their own advantages and disadvantages, mainly reflected in the therapeutic effect of stem cells, the difficulty of obtaining stem cells and the content in vivo. In addition, stem cells can also play a synergistic role in combination with other treatments, such as conservative treatment, surgical intervention, cytokines, biological scaffolds, and so on. However, it is still limited to the basic research stage, and only a small number of studies have completed clinical trials.

Conclusion

Stem cells have great transformation potential in the treatment of lymphedema, but there is no unified standard in the selection of cell types, the amount of transplanted cells, and the timing of transplantation.