New Technologies for Analysis of Extracellular Vesicles

Klebsiella pneumoniae derived outer membrane vesicles mediated bacterial virulence, antibiotic resistance, host immune responses and clinical applications

Klebsiella pneumoniae is a gram-negative pathogen that can cause multiple diseases including sepsis, urinary tract infections, and pneumonia. The escalating detections of hypervirulent and antibiotic-resistant isolates are giving rise to growing public concerns. Outer membrane vesicles (OMVs) are spherical vesicles containing bioactive substances including lipopolysaccharides, peptidoglycans, periplasmic and cytoplasmic proteins, and nucleic acids. Emerging studies have reported various roles of OMVs in bacterial virulence, antibiotic resistance, stress adaptation, and host interactions, whereas knowledge on their roles in K. pneumoniae is currently unclear. In this review, we summarized recent progress on the biogenesis, components, and biological function of K. pneumoniae OMVs, the impact and action mechanism in virulence, antibiotic resistance, and host immune response. We also deliberated on the potential of K. pneumoniae OMVs in vaccine development, as diagnostic biomarkers, and as drug nanocarriers. In conclusion, K. pneumoniae OMVs hold great promise in the prevention and control of infectious diseases, which merits further investigation.

Visual and fluorescence dual mode platform for sensitive and accurate screening of breast carcinoma

Compared to single-mode detection, dual-mode sensing strategies have garnered increasing attention from researchers due to their superior detection accuracy and reliability. Exosomes, as non-invasive biomarkers, hold significant potential for disease diagnosis. However, sensitive and precise detection of exosomes still presents considerable technical challenges. Inspired by the advantages of dual-mode detection, we developed a visual and fluorescence dual-mode platform (VFDMP) based on an aptamer strategy for exosome detection using enzyme-free nucleic acid amplification and nanomaterial-assisted cation exchange reactions (CERs). The Aptamer-ssDNA complexes capture tumor-derived exosomes, releasing abundant single-stranded DNA (ssDNAs), which then triggers the catalytic hairpin assembly (CHA) cycle, leading to the release of Ag+. The introduced CdTe quantum dots (QDs) act as signal reporters, interacting with Ag+ through CERs, and switching both fluorescence and visual signals from "on" to "off" to achieve exosome detection. Based on this innovative sensing principle, the developed FL/visual dual-mode aptasensor demonstrated excellent sensitivity and accuracy, achieving a low detection limit of 1.1 particles/μL by fluorometer, while exosome concentrations as low as 300 particles/mL could be visually distinguished by naked eye. Furthermore, this dual-mode platform can directly detect exosomes in clinical human serum samples, with only a small volume (10 μL) required. It can accurately differentiate between healthy individuals and breast cancer patients, as well as identify cancer stages (Stage II and Stage III) and subtypes (triple-negative, luminal B, and HER2+). These results suggest that the developed dual-mode detection strategy holds great promise as a sensitive, accurate method for biomarker analysis in clinical samples.

Extracellular Vesicles-in-Hydrogel (EViH) targeting pathophysiology for tissue repair

Regenerative medicine endeavors to restore damaged tissues and organs utilizing biological approaches. Utilizing biomaterials to target and regulate the pathophysiological processes of injured tissues stands as a crucial method in propelling this field forward. The Extracellular Vesicles-in-Hydrogel (EViH) system amalgamates the advantages of extracellular vesicles (EVs) and hydrogels, rendering it a prominent biomaterial in regenerative medicine with substantial potential for clinical translation. This review elucidates the development and benefits of the EViH system in tissue regeneration, emphasizing the interaction and impact of EVs and hydrogels. Furthermore, it succinctly outlines the pathophysiological characteristics of various types of tissue injuries such as wounds, bone and cartilage injuries, cardiovascular diseases, nerve injuries, as well as liver and kidney injuries, underscoring how EViH systems target these processes to address related tissue damage. Lastly, it explores the challenges and prospects in further advancing EViH-based tissue regeneration, aiming to impart a comprehensive understanding of EViH. The objective is to furnish a thorough overview of EViH in enhancing regenerative medicine applications and to inspire researchers to devise innovative tissue engineering materials for regenerative medicine.

Emerging phospholipid-targeted affinity materials for extracellular vesicle isolation and molecular profiling

Extracellular vesicles (EVs) carrying lipids, proteins, nucleic acids and small molecular metabolites have emerged as an attractive paradigm for understanding and interfering physiological and pathological processes. To this end, selective and efficient separation approaches are highly demanded to obtain target EVs from complicated biosamples. With increasing knowledges on EV lipids, recent years have witnessed rapid advances of phospholipid-targeted affinity materials and platforms for high-performance isolation and analysis of EVs. In view of this, this review is contributed to introduce recent progresses in lipid membrane-targeted affinity strategies for EV isolation and molecular detection in biofluids. Affinity ligands including lipids, peptides, small molecules and aptamers and their molecular interactions with lipids are discussed in focus. The design, construction and mechanism of actions of affinity interfaces are summarized. The EV separation performances in complex biosamples and downstream proteomic, lipidomic and metabolic profiling are introduced. Finally, the perspectives and challenges for the development of next-generation phospholipid-targeted EV separation platforms are discussed.

Review on bacterial outer membrane vesicles: structure, vesicle formation, separation and biotechnological applications

Outer membrane vesicles (OMVs), shed by Gram-negative bacteria, are spherical nanostructures that play a pivotal role in bacterial communication and host-pathogen interactions. Comprising an outer membrane envelope and encapsulating a variety of bioactive molecules from their progenitor bacteria, OMVs facilitate material and informational exchange. This review delves into the recent advancements in OMV research, providing a comprehensive overview of their structure, biogenesis, and mechanisms of vesicle formation. It also explores their role in pathogenicity and the techniques for their enrichment and isolation. Furthermore, the review highlights the burgeoning applications of OMVs in the field of biomedicine, emphasizing their potential as diagnostic tools, vaccine candidates, and drug delivery vectors.

Surface-Enhanced Raman Scattering (SERS) for exosome detection

BACKGROUND

Exosomes, nanoscale extracellular vesicles secreted by various cells, are abundantly present in biological fluids. They have been identified as carriers of specific molecules, suggesting their potential role in early disease detection. However, their clinical application is hindered by several challenges, including the need for large sample volumes for enrichment, limitations of traditional detection methods, and the complexity involved in phenotype analysis and separation.

OBJECTIVE

This review aims to explore the application of Surface-Enhanced Raman Scattering (SERS) technology in exosome detection. SERS, known for its unique photonic properties and high sensitivity, offers a promising solution for detecting exosomes without the need for large sample volumes or extensive phenotypic analysis. This review focuses on the real-time and non-invasive assessment capabilities of SERS in exosome detection, providing insights into its potential for early disease diagnosis.

CONCLUSION

The review concludes by emphasizing the potential of SERS-based exosome detection in advancing early disease diagnosis. By overcoming existing challenges, SERS technology offers a promising approach for the development of sensitive and specific diagnostic assays, contributing to better patient outcomes and personalized medicine.

An Ultrasensitive Duplex Aptasensor Featuring the Target-Triggered Lanthanide Luminescence Antenna Effect for Wash-Free Detection of Epithelial Cancerous Exosomes

Fluorescence sensing is widely used in in vitro detection due to its high sensitivity and rapid result delivery. However, detection systems based on nanomaterials involving complex and cumbersome purification steps can lead to sample loss and significantly reduce the accuracy of the results. To address this issue, we proposed a lanthanide-based aptasensor featuring the target-triggered antenna effect to significantly enhance the time-resolved luminescence (TRL) of chelated Tb3+ combined with a wash-free strategy. This sensor enabled highly sensitive detection of the epithelial cell adhesion molecule (EpCAM) on exosomes from epithelial tumors, eliminating the necessity for purification steps and thereby delivering more stable and reliable results. Specifically, using computer-aided design, a sequence capable of self-folding into a stable hairpin structure (Antenna-Hairpin-Tb) was obtained. After hybridization with an EpCAM-specific aptamer (AptEpCAM), a duplex aptasensor (Probe-Tb) was constructed for detection. When the targeted binding occurred between the AptEpCAM and exosomes, the Antenna-Hairpin-Tb dehybridized from the Probe-Tb and underwent self-folding, leading to a significant sensitized TRL signal due to the antenna effect-induced energy transfer from the antenna ligand to the chelated Tb3+. Over a broad range of exosome concentrations (spanning from 6.19 × 102 to 6.19 × 108 particles/mL), the emission intensity of chelated Tb3+ at 543 nm linearly increased with the exosome concentration (linear relationship: Y = 332.62 lg(Nexosomes) + 3690.5, R2 = 0.9956), achieving a theoretical detection limit as low as 17 particles/mL in the buffer. Furthermore, Probe-Tb enabled a swift and effective differentiation of all epithelial cancer serum samples from nonepithelial ones within just 30 min of a wash-free operation, achieving 100% sensitivity, 100% specificity, and 100% accuracy.

Intranasal delivery of extracellular vesicles: A promising new approach for treating neurological and respiratory disorders

BACKGROUND

Extracellular vesicles (EVs) are membrane vesicles secreted by all types of cells, including bacteria, animals, and plants. These vesicles contain proteins, nucleic acids, and lipids from their parent cells and can transfer these components between cells. EVs have attracted attention for their potential use in diagnosis and therapy due to their natural properties, such as low immunogenicity, high biocompatibility, and ability to cross the blood-brain barrier. They can also be engineered to carry therapeutic molecules. EVs can be delivered via various routes. The intranasal route is particularly advantageous for delivering them to the central nervous system, making it a promising approach for treating neurological disorders.

SCOPE OF REVIEW

This review delves into the promising potential of intranasally administered EVs-based therapies for various medical conditions, with a particular focus on those affecting the brain and central nervous system. Additionally, the potential use of these therapies for pulmonary conditions, cancer, and allergies is examined, offering a hopeful outlook for the future of medical treatments.

MAJOR CONCLUSIONS

The intranasal administration of EVs offers significant advantages over other delivery methods. By directly delivering EVs to the brain, specifically targeting areas that have been injured, this administration proves to be highly efficient and effective, providing reassurance about the progress in medical treatments. Intranasal delivery is not limited to brain-related conditions. It can also benefit other organs like the lungs and stimulate a mucosal immune response against various pathogens due to the highly vascularized nature of the nasal cavity and airways. Moreover, it has the added benefit of minimizing toxicity to non-targeted organs and allows the EVs to remain longer in the body. As a result, there is a growing emphasis on conducting clinical trials for intranasal administration of EVs, particularly in treating respiratory tract pathologies such as coronavirus disease.

Extracellular vesicles: from intracellular trafficking molecules to fully fortified delivery vehicles for cancer therapeutics

Extracellular vesicles (EVs) are emerging as viable tools in cancer treatment due to their ability to carry a wide range of theranostic activities. This review summarizes different forms of EVs such as exosomes, microvesicles, apoptotic bodies, and oncosomes. It also sheds the light onto isolation methodologies, characterization techniques and therapeutic applications of all discussed EVs. Evidence indicates that EVs are particularly effective in delivering chemotherapeutic medications, and immunomodulatory agents. However, the advancement of EV-based therapies into clinical practice is hindered by challenges including EVs heterogeneity, cargo loading efficiency, and in vivo stability. Overall, EVs have the potential to change cancer therapeutic paradigms. Continued research and development activities are critical for improving EV-based medications and increasing their therapeutic impact.

Shiitake mushroom-derived extracellular nanovesicles: Preparation, characterization, and inhibition of Caco-2 cells

In this study, Shiitake mushroom-derived extracellular nanovesicles (SMDENVs) were isolated from fresh Shiitake mushrooms by ultracentrifugation and sucrose gradient ultracentrifugation. The morphological characteristics of SMDENVs were investigated via Transmission Electron Microscopy and Laser Scanning Confocal Microscopy. SMDENVs were spherical, hollow, and uniform in size, with an average diameter of 177.6 ± 51.4 nm. Based on the analysis of lipidomics and proteomics, 383 lipids species and 1290 proteins were identified in SMDENVs. Compared with the conventional liposomes, SMDENVs demonstrated higher stability in different environmental conditions. Furthermore, we observed that SMDENVs were cytocompatible and inhibited the proliferation of Caco-2 cells. SMDENVs could be phagocytized by Caco-2 cells in a time-dependent manner. Further, SMDENVs also inhibited the proliferation of Caco-2 cells in a dose-dependent manner, and the half-maximal inhibitory concentration (IC50) was 236.2 ± 3.2 μg/mL. Additionally, SMDENVs induced cellular apoptosis by increasing the levels of reactive oxygen species and decreasing the mitochondrial membrane potential.

Concurrent Detection of Protein and miRNA at the Single Extracellular Vesicle Level Using a Digital Dual CRISPR-Cas Assay

The simultaneous detection of proteins and microRNA (miRNA) at the single extracellular vesicle (EV) level shows great promise for precise disease profiling, owing to the heterogeneity and scarcity of tumor-derived EVs. However, a highly reliable method for multiple-target analysis of single EVs remains to be developed. In this study, a digital dual CRISPR-Cas-powered Single EV Evaluation (ddSEE) system was proposed to enable the concurrent detection of surface protein and inner miRNA of EVs at the single-molecule level. By optimizing simultaneous reaction conditions of CRISPR-Cas12a and CRISPR-Cas13a, the surface protein of EVs was detected by Cas12a using antibody-DNA conjugates to transfer the signal of the protein to DNA, while the inner miRNA was analyzed by Cas13a through EV-liposome fusion. A microfluidic chip containing 188,000 microwells was used to convert the CRISPR-Cas system into a digital assay format to enable the absolute quantification of miRNA/protein-positive EVs without bias through fluorescence imaging, which can detect as few as 214 EVs/μL. Finally, a total of 31 blood samples, 21 from breast cancer patients and 10 from healthy donors, were collected and tested, achieving a diagnostic accuracy of 92% in distinguishing patients with breast cancer from healthy donors. With its absolute quantification, ease of use, and multiplexed detection capability, the ddSEE system demonstrates its great potential for both EV research and clinical applications.

Engineering Peptide-Based Molecular Baits for Targeted Fishing and Protein Profiling of Exosomes as a Liquid Biopsy for Gastrointestinal Adenocarcinoma

High-performance isolation of exosomes as a promising liquid biopsy target is of great importance for both fundamental research and clinical applications. This is, however, challenged by the prevalent heterogeneity of exosomes and the highly complex nature of biosamples. Here, we introduce the use of a CD81-targeting peptide as a building block for tailoring molecular baits for exosome isolation and payload analysis in clinical biofluids. To explore the full potential of multivalent interactions, peptide-functionalized affinity interfaces were covalently engineered with varied assembling topology, flexibility, and local density of the recognition motif. Capable of best fitting the surface conformation of CD81 on highly curved exosome membranes, a dual-layered exosome capture affinity interface (Exo-PepTrap2) with tandem bivalent peptide decoration outperforms the monolayered and the branched multivalent architectures. Enabled by the multivalency-enhanced affinity reaction and antifouling ability, Exo-PepTrap2 achieved a high yield and purity for targeted fishing of exosomes in complex cell culture media and clinical urine samples. By integration of Exo-PepTrap2 isolation with mass spectrometry-based proteomic profiling, differentially expressed proteins were efficiently identified in harvested exosomes as potential biomarkers for gastrointestinal adenocarcinoma. This CD81-targeted tandem peptide-functionalized affinity platform provides a new viewpoint for tailoring multivalency-based affinity interfaces and a versatile tool to explore molecular information in exosomes for precise medicine.

Simultaneous Isolation and Preparation of Extracellular Vesicles by Circular Multicavity Electrophoresis

Extracellular vesicles (EVs) play a crucial role in diagnosis and treatment, yet obtaining highly purified EVs from complex biological samples is often hindered by nanoscale contaminants. In this work, considering the charge-to-size characteristics of EVs, a circular multicavity electrophoresis (CME) with gradient pore size distribution was constructed in the gradient electric field to realize the isolation and preparation of EVs. By the gradient gel sieving effect, small cell debris, EVs, and proteins in biological samples were gradually separated. The integration of ultrafiltration (UF) with CME synergistically enhances EV purification and preparation, resulting in a purity level 3.15 times higher than that achieved through ultracentrifugation (UC). The high yield preparation of EV was achieved through continuous injection facilitated by the application of a gradient electric field, where 3.55 × 1010 ± 6.32 × 108 particle numbers mL-1 of EVs were prepared from 36 mL of cell supernatant, and the recovery approached 87.65 ± 9.03%. Further evaluation of the cell uptake efficiency of EVs derived from umbilical cord mesenchymal stem cells prepared by CME-UF revealed that this approach effectively preserves both the integrity and bioactivity of the EVs. This work presents a novel approach for the isolation and preparation of EVs, offering valuable insights into future biological studies.

Efficient and Rapid Enrichment of Extracellular Vesicles Using DNA Nanotechnology-Enabled Synthetic Nano-Glue

Swift and efficient enrichment and isolation of extracellular vesicles (EVs) are crucial for enhancing precise disease diagnostics and therapeutic strategies, as well as elucidating the complex biological roles of EVs. Conventional methods of isolating EVs are often marred by lengthy and laborious processes. In this study, we introduce an innovative approach to enrich and isolate EVs by leveraging the capabilities of DNA nanotechnology. We have developed a novel multivalent cholesterol-modified paranemic crossover DNA (PX-DNA-chol) construct, which is a four-stranded DNA structure containing adjacent double helices intertwined with their local helix axes parallel and serves as an effective synthetic nano-glue. This construct promotes the rapid coalescence of nanoscale EVs into clusters of micrometer scale, thereby streamlining their enrichment. Utilizing a conventional low-speed centrifuge, this intriguing methodology achieves a rapid concentration of EVs within minutes, bypassing the laborious and high-speed centrifugation steps typically required. The quality of EVs isolated by our technique is comparable to that obtained through ultracentrifugation methods. Given these advancements, our PX-DNA-chol-facilitated EVs enrichment protocol is poised to advance the field of EVs research, providing a robust and accessible tool for in-depth studies of EVs.

Digital Profiling of Tumor Extracellular Vesicle-Associated RNAs Directly from Unprocessed Blood Plasma

Tumor-derived extracellular vesicle (tEV)-associated RNAs hold promise as diagnostic biomarkers, but their clinical use is hindered by the rarity of tEVs among nontumor EVs. Here, we present EV-CLIP, a highly sensitive droplet-based digital method for profiling EV RNA. EV-CLIP utilizes the fusion of EVs with charged liposomes (CLIPs) in a microfluidic chip. Optimized CLIP surface charge enables exceptional sensitivity and selectivity for EV-derived miRNAs and mRNAs. This approach streamlines detection with minimal plasma volume (20 μL) and eliminates the need for prior EV isolation or RNA preparation, preventing loss of EVs or RNA. In testing with 83 patient samples, EV-CLIP detected EGFR L858R and T790M mutations with high AUC values of 1.0000 and 0.9784, respectively. Its success in serial monitoring during chemotherapy highlights its potential for precise quantification of rare EV subpopulations, facilitating the exploration of single EV RNA content and enhancing understanding of diverse EV populations in various disease states.

Serum Exosomes miR-122-5P Induces Hepatic and Renal Injury in Septic Rats by Regulating TAK1/SIRT1 Pathway

Aim

Sepsis is a potentially fatal condition characterized by organ failure resulting from an abnormal host response to infection, often leading to liver and kidney damage. Timely recognition and intervention of these dysfunctions have the potential to significantly reduce sepsis mortality rates. Recent studies have emphasized the critical role of serum exosomes and their miRNA content in mediating sepsis-induced organ dysfunction. The objective of this study is to elucidate the mechanism underlying the impact of miR-122-5p on sepsis-associated liver and kidney injury using inhibitors for miR-122-5p as well as GW4869, an inhibitor targeting exosome release.

Materials and Methods

Exosomes were isolated from serum samples of septic rats, sepsis patients, and control groups, while liver and kidney tissues were collected for subsequent analysis. The levels of miR-122-5p, inflammation indices, and organ damage were assessed using PCR, ELISA, and pathological identification techniques. Immunohistochemistry and Western blotting methods were employed to investigate the activation of inflammatory pathways. Furthermore, big data analysis was utilized to screen potential targets of miR-122-5p in vivo.

Key Findings

Serum exosomal levels of miR-122-5p were significantly elevated in septic patients as well as in LPS-induced septic rats. Inhibition of miR-122-5p reduced serum pro-inflammatory factors and ameliorated liver and kidney damage in septic rats. Mechanistically, miR-122-5p upregulated TAK1, downregulated SIRT1, and facilitated NF-κB activation.

Conclusion

Serum exosomal miR-122-5p promotes inflammation and induces liver/kidney injury in LPS-induced septic rats by modulating the TAK1/SIRT1/NF-κB pathway, highlighting potential therapeutic targets for sepsis management.

The impact of Aureobasidium melanogenum cells and extracellular vesicles on human cell lines

Aureobasidium melanogenum is a black yeast-like fungus that occurs frequently both in nature and in domestic environments. It is becoming increasingly important as an opportunistic pathogen. Nevertheless, its effect on human cells has not yet been studied. In this study, we investigated the effect of A. melanogenum cells and extracellular vesicles (EVs) on human cell lines A549 (human lung cells), HDFa (human dermal fibroblasts), and SH-SY5Y (human neuroblastoma cells). Scanning electron microscopy (SEM) showed no direct interaction between A. melanogenum cells and human cell lines, but there were some changes in HDFa cells. As a possible cause for this change, we tested the cytotoxic effect of EVs from A. melanogenum on the same cell lines. We isolated EVs from the fungus and prepared three different pools: a non-melanin pool (containing mainly EVs), a melanin pool (containing mainly melanin nanoparticles), and a total pool (containing both EVs and melanin nanoparticles). All three pools were characterized and then added to human cell lines to test their cytotoxicity. Unlike in some other fungal opportunistic pathogens, no effects of fungal EVs on human cell viability were observed. Therefore, the opportunistic potential of A. melanogenum remains only partially understood.

Comprehensive analysis of the expression and prognostic value of ARMCs in pancreatic adenocarcinoma

BACKGROUND

Pancreatic adenocarcinoma (PAAD) has a very poor prognosis, and there are few treatments for PAAD. Therefore, it is important to find some biomarkers for the diagnosis and treatment of PAAD. Although some members of Armadillo repeat containing proteins (ARMCs) have been implicated in the development of certain cancers, their relationship with PAAD remains unknown. In this study, we aimed to explore the expression and prognostic value of ARMCs in PAAD.

METHODS

We used the The Cancer Genome Atlas (TCGA) database for survival analysis. Then, Gene Expression Profiling Interactive Analysis (GEPIA), the cBioPortal database, the Human Protein Atlas (HPA), Kaplan-Meier Plotter, LinkedOmics Database, Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG), Cytoscape and Timer were used to analyze the relationship between ARMCs and PAAD. In addition, we established a prognostic model of ARMCs for PAAD. Immunohistochemistry (IHC) was also performed. Then Image-J was used to analyze all images obtained from the experiment, and GraphPad-Prism (9.5.1) was used for statistical analysis to verify the expression of ARMCs in PAAD.

RESULTS

In the TCGA database, the expressions of ARMC1, 2, 3, 5, 6, 7, 8, 9 and 10 in PAAD tissues were significantly higher than those in normal tissues. And higher expressions of ARMC1 and 10 were associated with lower survival rate of PAAD patients. In addition, ARMC2, 5, 6, and 10 were positively associated with advanced stages of PAAD. ARMCs mutations occur in 11% of PAAD patients, and missense mutations and amplification of ARMCs account for most of them. In addition, ARMC5 and ARMC10 were independent prognostic factors in univariate and multivariate Cox regression analyses. Finally, through our confirmation experiment, it was found that the expression of ARMC1 and 10 in PAAD tissues was significantly increased compared with those in paracancer tissue.

CONCLUSION

This study suggests that ARMCs may be able to play important roles in PAAD, and they can act as biomarkers, providing valuable clues for the treatment and diagnosis of PAAD.

Machine learning-assisted washing-free detection of extracellular vesicles by target recycling amplification based fluorescent aptasensor for accurate diagnosis of gastric cancer

Extracellular vesicles (EVs) are promising non-invasive biomarkers for cancer diagnosis. EVs proteins play a critical role in tumor progress and metastasis. However, accurately and reliably diagnosing cancers is greatly limited by single protein marker on EVs. Here, we reported an accurate diagnosis model of gastric cancer by analyzing five types of EVs surface proteins using machine learning in a retrospective study design. A washing-free detection method based on aptasensor and exonuclease Ⅰ was used to profile EVs surface proteins. The aptamer was designed as hairpin structure. The presence of target protein positive EVs converted the conformation of hairpin probes, which subsequently degraded by exonuclease Ⅰ. The exposed target protein could bind with and then open new hairpin probes, thus forming an amplification cycle. The lengths of different detection probes were optimized for detection. With the combination of five target proteins, five machine learning algorithms were compared to achieve a higher diagnostic accuracy. The best model, XGBoost, validated with 20 % of detection results could reach an accuracy of 0.8421. Furthermore, the XGBoost-based surface protein analysis could precisely identify gastric cancer patients with the area under the curve value of 0.9347 (95 % confidential interval (CI) = 0.8590 to 1.000). Since our method utilized a simple and versatile design of detection probes, its diagnostic scope could potentially be expanded to include different protein markers and accurately diagnose other diseases in the future.

Current advances and future prospects of blood-based techniques for identifying benign and malignant pulmonary nodules

Lung cancer is the leading cause of cancer-related mortality worldwide, highlighting the urgent need for more accurate and minimally invasive diagnostic tools to improve early detection and patient outcomes. While low-dose computed tomography (LDCT) is effective for screening in high-risk individuals, its high false-positive rate necessitates more precise diagnostic strategies. Liquid biopsy, particularly ctDNA methylation analysis, represents a promising alternative for non-invasive classification of indeterminate pulmonary nodules (IPNs). This review highlights the progress and clinical potential of liquid biopsy technologies, including traditional proteins markers, cfDNA, exosomes, metabolomics, circulating tumor cells (CTCs) and platelets, in lung cancer diagnosis. We discuss the integration of ctDNA methylation analysis with traditional imaging and clinical data to enhance the early detection of IPNs, as well as potential solutions to address the challenges of low biomarker concentration and background noise. By advancing precision diagnostics, liquid biopsy technologies could transform lung cancer management, improve survival rates, and reduce the disease burden.

Lipophilicity Modulation of Fluorescent Probes for In Situ Imaging of Cellular Microvesicle Dynamics

Real-time monitoring of dynamic microvesicles (MVs), vesicles associated with living cells, is of great significance in deeply understanding their origin, transport, and function. However, specific labeling MVs poses a challenge due to the lack of unique biomarkers that differentiate them from other cellular compartments. Here, we present a strategy to selectively label MVs by evaluating a series of lipid layer-sensitive cationic indolium-coumarin fluorescent probes (designated as IC-Cn, with n ranging from 1 to 18) that feature varying aliphatic side chains (CnH2n+1). Through in situ cell imaging and analysis, we found that IC-Cn location is highly related to their lipophilicities and the phospholipid layer hydrophobic microenvironments in cellular compartments. In detail, IC-C1 and IC-C2 specifically localize MVs both inside and outside cells. In contrast, IC-C3, IC-C4, and IC-C5 label cellular MVs and mitochondria but with distinct fluorescence lifetimes. Using these probes strategically, we have discovered that, in addition to the biogenesis of MVs from plasma membranes and damaged mitochondria, newly formed MVs can undergo fusion and fission processes. Moreover, mitochondria-derived MVs, beyond being released from parent cells, can fuse with lysosomes to facilitate the removal of dysfunctional mitochondria. The work not only provides new insights into MV physiology but also inspires the design strategies for probes used in specific labeling in cell studies.

Rapid and unbiased enrichment of extracellular vesicles via a meticulously engineered peptide

Extracellular vesicles (EVs) have garnered significant attention in biomedical applications. However, the rapid, efficient, and unbiased separation of EVs from complex biological fluids remains a challenge due to their heterogeneity and low abundance in biofluids. Herein, we report a novel approach to reconfigure and modify an artificial insertion peptide for the unbiased and rapid isolation of EVs in 20 min with ∼80% recovery in neutral conditions. Moreover, the approach demonstrates exceptional anti-interference capability and achieves a high purity of EVs comparable to standard ultracentrifugation and other methods. Importantly, the isolated EVs could be directly applied for downstream protein and nucleic acid analyses, including proteomics analysis, exome sequencing analysis, as well as the detection of both epidermal growth factor receptor (EGFR) and V-Ki-ras2 Kirsten Rat Sarcoma Viral Oncogene Homologue (KRAS) gene mutation in clinical plasma samples. Our approach offers great possibilities for utilizing EVs in liquid biopsy, as well as in various other biomedical applications.

Utility of pleural fluid-derived extracellular vesicles as a source of Mycobacterium tuberculosis antigens MPT51 and MPT64 for pleural TB diagnosis: a proof-of-concept study

Extracellular vesicles (EVs) have recently emerged as a source of microbe-specific biomarkers for disease diagnosis. In the present study, we evaluated the utility of pleural fluid-derived extracellular vesicles (pEVs) as a source of Mycobacterium tuberculosis (M. tb.) antigens for pleural TB (pTB) diagnosis. EVs were isolated from pleural fluid (PF) samples and were characterized by scanning electron microscopy, and immunoblotting by targeting CD63 and LAMP2 markers. Antigen-detection ELISAs were developed for 2 M.tb.-specific antigens, MPT51 and MPT64 in pEVs (pEV-ELISA) and direct PF samples (PF-ELISA), and were evaluated on n = 86 samples in a blinded manner. Cut-off values were calculated by ROC-curve analysis to achieve 90 % (95%CI:73.47-97.89) and 86.67 % (95%CI:69.28-96.24) specificity for MPT51 and MPT64 pEV-ELISA respectively. The sensitivity of pEV-ELISA was 71.43 % (95%CI; 29.04-96.33) for MPT51 antigen and 57.14 % (95%CI; 18.41-90.1) for MPT64 antigen in the 'Definite' pTB group, while in the 'Definite and Probable' pTB group, the sensitivity was 62.86 % (95%CI:44.92-78.53) for MPT51 and 65.71 % (95%CI:47.79-80.87) for MPT64. The performance of PF-ELISA was sub-optimal, with 28.57 % (95%CI:3.67-70.96) and 14.29 % (95%CI:0.36-57.87) sensitivity for MPT51 and MPT64 in 'Definite' pTB group respectively. We conclude that M. tb.-antigens are concentrated in the EV-fraction of PF samples and EVs can be utilized for antigen-detection assays for pTB diagnosis.

Engineering therapeutical extracellular vesicles for clinical translation

Cell-based therapies are revolutionizing medicine by replacing or modifying dysfunctional cells with healthy cells or engineered derivatives, offering disease reversal and cure. One promising approach is using cell-derived extracellular vesicles (EVs), which offer therapeutic benefits similar to cell transplants without the biosafety risks. Although EV applications face challenges like limited production, inadequate therapeutic loading, and poor targeting efficiency, recent advances in bioengineering have enhanced their effectiveness. Herein, we summarize technological breakthroughs in EV bioengineering over the past 5 years, highlighting their improved therapeutic functionalities and potential clinical prospects. We also discuss biomanufacturing processes, regulation, and safety considerations for bioengineered EV therapies, emphasizing the significance of establishing robust frameworks to ensure translation capability, safety, and therapeutic effectiveness for successful clinical adoption.

Microdroplet-enhanced chip platform for high-throughput immunotherapy marker screening from extracellular vesicle RNAs and membrane proteins

Extracellular vesicles (EVs) are considered as promising candidates for predicting patients who respond to immunotherapy. Nevertheless, simultaneous detection of multiple EVs markers still presents significant technical challenges. In this work, we developed a high-throughput microdroplet-enhanced chip (MEC) platform, which utilizes thousands of individual microchambers (∼pL) as reactors, accelerating the detection efficiency of the CRISPR/Cas systems and increasing the sensitivity by up to 100-fold (aM level). Ten biomarkers (including 5 RNAs and 5 proteins) from patients' EVs are successfully detected on one chip, and the comprehensive markers show increased accuracy (AUC 0.911) than the individual marker for the efficacy prediction of immunotherapy. This platform provides a high-throughput yet sensitive strategy for screening immunotherapy markers in clinical.

Fruit exosomes: a sustainable green cancer therapeutic

Fruit exosomes are the source of natural cancer therapeutic tools.

Extracellular vesicles derived-microRNAs predicting enzalutamide-resistance in 3D spheroid prostate Cancer model

Enzalutamide (ENZ) has emerged as a major treatment advance in castration-resistant prostate cancer (CRPC) patients; however the development of resistance remains a key challenge. The extracellular vesicles (VEs)-derived miRNAs play crucial roles tumor microenvironment cell communication, thereby influencing resistance mechanisms. Considering the urgent need for molecular biomarkers to monitor ENZ response and predict resistance, we intend to identify an EV-derived miRNA profile associated with ENZ resistance using an innovative 3D-spheroid in vitro model. Through the generation of this model, we provide a comprehensive platform for elucidating the molecular alterations involved in the process. An in vitro model of ENZ resistance was established through continuous exposure of LNCaP to increasing ENZ concentrations. A screening of 799 miRNAs from resistant and normal LNCaP cells were quantified. A bioinformatic analysis was performed using miRTarbase and Cytoscape and top 5 overexpressed miRNAs were selected, that will be analyzed in extracellular vesicles derived from ENZ resistance 3D spheroid models. We identified 12 up- and 13 downregulated miRNAs in LNCaP 30 μM ENZ cells compare to LNCaP·In silico analysis led to the construction of a 76 proteins cluster and functional enrichment revealed terms like PI3K/AKT, TFG-β and FOXO. hsa-miR-22-3p was significantly decreased at 5 and 20 μM ENZ concentration intracellularly, but significantly increased at 20 μM ENZ in EVs. hsa-miR-221-3p and miR-222-3p were upregulated in all concentrations both intracellularly and in EVs. The developed 3D-spheroid model effectively replicated the ENZ resistance to ENZ in an AR-independent manner, underscoring the importance of EVs-derived miRNAs in this adaptive process.

Sensitive phenotyping of serum extracellular vesicles on a SERS-microfluidic platform for early-stage clinical diagnosis of ovarian carcinoma

Ovarian carcinoma (OvCa) poses a severe threat to women's health due to its high mortality rate and lack of efficient early diagnosis approach. There is evidence to suggest that nanosized small extracellular vesicles (sEVs) which carrying cell-specific components from OvCa can serve as potential diagnostic biomarkers. Herein, we reported a Surface-enhanced Raman Scattering (SERS)-multichannel microchip for sEVs (S-MMEV) assay to investigate the phenotype changes of sEVs. The microchip composed of seven microchannels, which enabled the parallel detection of multiple biomarkers to improve the detection accuracy. Using SERS probes conjugated with antibodies recognizing different biomarkers including ubiquitous EV biomarkers (i.e., tetraspanins; CD9, CD81) and putative OvCa tumor biomarkers (i.e. EpCAM, CD24, CA125, EGFR), we successfully analyzed the phenotypic changes of sEVs and accurately differentiated OvCa patients from healthy controls, even at early stage (I-II), with high sensitivity, high specificity and an area under the curve value of 0.9467. Additionally, the proposed approach exhibited higher sensitivity than conventional methods, demonstrating the efficiency of precise detection from cell culture and clinical samples. Collectively, the developed EV phenotyping approach S-MMEV could serve as a potential tool to achieve the early clinical diagnosis of OvCa for further precise diagnosis and personal treatment monitoring.

Extracellular vesicles as a potential source of biomarkers for endocrine disruptors in MASLD: A short review on the case of DEHP

Metabolic dysfunction-Associated Steatotic Liver Disease (MASLD) is a chronic disease with increasing prevalence and for which non-invasive biomarkers are needed. Environmental endocrine disruptors (EDs) are known to be involved in the onset and progression of MASLD and assays to monitor their impact on the liver are being developed. Extracellular vesicles (EVs) mediate cell communication and their content reflects the pathophysiological state of the cells from which they are released. They can thus serve as biomarkers of the pathological state of the liver and of exposure to EDs. In this review, we present the relationships between DEHP (Di(2-ethylhexyl) phthalate) and MASLD and highlight the potential of EVs as biomarkers of DEHP exposure and the resulting progression of MASLD.

Unveiling urinary extracellular vesicle mRNA signature for early diagnosis and prognosis of bladder cancer

Background: Bladder cancer (BC) ranks as one of the most prevalent cancers. Its early diagnosis is clinically essential but remains challenging due to the lack of reliable biomarkers. Extracellular vesicles (EVs) carry abundant biological cargoes from parental cells, rendering them as promising cancer biomarkers. Herein, we revealed that urinary EVs (uEVs) mRNA signature could serve as non-invasive biomarker for the early diagnosis and prognostic assessment for BC. Methods: Transcriptomic sequencing was conducted to reveal the mRNA signature of EVs collected from normal cell line and different grades of BC cell lines. Candidate EV-mRNA biomarkers were further profiled using clinical urine samples (n = 97, including healthy controls, BC patients and post-surgery BC patients) by RT-qPCR. Results: Three mRNAs (SRGN, FLI1, and MACROH2A2) within uEV were identified as potential biomarkers for BC, providing an area under the receiver operating characteristic curve (AUC) of 0.973 for BC diagnosis. Moreover, the uEV-mRNA panel could discriminate early-stage BC patients from healthy controls with an AUC of 0.969. Finally, we found that the uEV-mRNAs were significantly down-regulated in the post-surgery urine samples of BC patients. Conclusions: Given the facile and non-intrusive nature of urine collection, the identified uEV-mRNAs could serve as potential liquid-biopsy biomarkers for the early diagnosis and prognosis of BC.

High-precision extracellular-vesicle isolation-analysis integrated platform for rapid cancer diagnosis directly from blood plasma

Cancer-derived small extracellular vesicles (sEVs) in body fluids hold promise as biomarkers for cancer diagnosis. For sEV-based liquid biopsy, isolation of sEVs with a high-purity and cancer-sEV detection with an extremely high sensitivity are essential because body fluids include much higher density of normal-cell-derived sEVs and other biomolecules and bioparticles. Here, we propose an isolation-analysis-integrated cancer-diagnosis platform based on dielectrophoresis(DEP)-ELISA technique which enables a three orders of magnitude higher sensitivity over conventional ELISA method and direct cancer diagnosis from blood plasma with high accuracy. The limit of detection (LOD) for sEVs in human plasma was as low as 104 sEVs/mL without a time-consuming and low-yield sEV isolation and purification process. The capability of this platform was validated by monitoring mice with cancer cell inoculation and assessing the effect of cancer-sEV-inhibiting drug. Using the developed sEV-based liquid biopsy, we diagnosed clinical samples from healthy donors (N = 39) and cancer patients (N = 90). The diagnostic accuracy was 94.2%, 98.6%, and 91.3% for breast, colon, and lung cancers, respectively. This integrated sEV isolation and analysis platform could be applied for high-sensitivity biomarker profiling and sEV-based liquid biopsy.

A Mem-dELISA platform for dual color and ultrasensitive digital detection of colocalized proteins on extracellular vesicles

Accurate, multiplex, and ultrasensitive measurement of different colocalized protein markers on individual tumor-derived extracellular vesicles (EVs) and dimerized proteins with multiple epitopes could provide insights into cancer heterogeneity, therapy management and early diagnostics that cannot be extracted from bulk methods. However, current digital protein assays lack certain features to enable robust colocalization, including multi-color detection capability, large dynamic range, and selectivity against background proteins. Here, we report a lithography-free, inexpensive (< $0.1) and ultrasensitive dual-color Membrane Digital ELISA (Mem-dELISA) platform by using track-etched polycarbonate (PCTE) membranes to overcome these shortcomings. Their through-pores remove air bubbles through wicking before they are sealed on one side by adhesion to form microwells. Immunomagnetic bead-analyte complexes and substrate solution are then loaded into the microwells from the opposite side, with >80% loading efficiency, before sealing with oil. This enables duplex digital protein colorimetric assay with beta galactosidase and alkaline phosphatase enzymes. The platform achieves 5 logs of dynamic range with a limit of detection of 10 aM for both Biotinylated β-galactosidase (B-βG) and Biotin Alkaline Phosphatase Conjugated (B-ALP) proteins. We demonstrate its potential by showing that a higher dosage of paclitaxel suppresses EpCAM-positive EVs but not GPC-1 positive EVs from breast cancer cells, a decline in chemo-resistance that cannot be detected with Western blot analysis of cell lysate. The Mem-dELISA is poised to empower researchers to conduct ultrasensitive, high throughput protein colocalization studies for disease diagnostics, treatment monitoring and biomarker discovery.

Hydrogels and hydrogel-based drug delivery systems for promoting refractory wound healing: Applications and prospects

Refractory wounds represent a significant health concern that presents considerable challenges within clinical practice. The healing process of refractory wounds, which involves various cell types and biologically active molecules, is dynamically influenced by multiple factors, including diabetes, infections, and inflammation. Owing to their hydrophilicity, biocompatibility, and capacity for drug loading, hydrogels have emerged as promising and innovative biomaterials for enhancing wound healing. In recent decades, hydrogels with inherent therapeutic properties have been identified. Moreover, advanced hydrogel-based drug delivery systems have been developed to facilitate the sustained and controlled release of therapeutic agents at the site of refractory wounds. This review aims to summarize recent advancements and applications of hydrogels, including those with intrinsic therapeutic properties and hydrogel-based drug delivery systems, in the treatment of refractory wounds. Additionally, we discuss the limitations associated with hydrogel applications and propose future perspectives, which will lead to ongoing efforts to optimize hydrogels as ideal biomaterials for refractory wound healing.

Advanced MicroRNA delivery for lung inflammatory therapy: surfactant protein A controls cellular internalisation and degradation of extracellular vesicles

INTRODUCTION

Alveolar macrophages (AMs) are the first line of defence against pathogens that initiate an inflammatory response in the lungs and exhibit a strong affinity for surfactant protein A (SP-A). Extracellular vesicles (EVs) have emerged as a promising drug delivery platform due to their minimal cytotoxicity. However, precise targeting of specific cell types and the rapid lysosomal degradation of EVs within recipient cells remain persistent challenges.

METHOD

In this study, we explored the biological significance of SP-A-EVs as novel drug delivery systems for combating lung inflammation. We first verified that respiratory EVs express SP-A receptor (SP-R210), facilitating the conjugation of SP-A with EVs. The delivery efficiency, cellular internalisation pathways and therapeutic effects were evaluated using an in vivo mouse model.

RESULTS

SP-A-EVs were robustly internalised into AMs both in vitro and in vivo. Furthermore, our investigation revealed that the toll-like receptor 4-mediated endocytosis pathway was employed for the uptake of SP-A-EVs, significantly delaying their degradation compared with natural EVs, which primarily followed the conventional lysosomal degradation pathway within AMs. In a functional study, we successfully loaded anti-inflammatory microRNA (let-7b) into SP-A-EVs, leading to the suppression of AM activation and the alleviation of lung inflammation induced by lipopolysaccharide.

CONCLUSION

These findings underscore the potential of SP-A-EVs as highly effective drug delivery systems for targeted therapeutics in lung-related disorders, capitalising on the strong affinity between AMs and SP-A and the modulation of cellular internalisation.

Label-Free Impedance Imaging of Single Extracellular Vesicles Using Interferometric Electrochemical Microscopy

Extracellular vesicles (EVs) are pivotal in various biological processes and diseases, yet their small size and heterogeneity pose challenges for single EV quantification. We introduce interferometric electrochemical microscopy (iECM), a sensitive label-free technique that combines interferometric scattering and electrochemical impedance imaging. This method enables the quantification of the impedance of single EVs, providing unique insights into their electrochemical properties, and allows for the simultaneous measurement of size and real-time monitoring of antibody binding. Notably, we discovered that the impedance spectra of EVs can serve as specific fingerprints to differentiate EVs from cancerous and healthy cells, establishing iECM as a unique platform for EV characterization and classification.

Elucidating Extracellular Vesicle Isolation Kinetics via an Integrated Off-Stoichiometry Thiol-Ene and Cyclic Olefin Copolymer Microfluidic Device

Extracellular vesicles (EVs) are promising biomarkers for diagnosing complex diseases such as cancer and neurodegenerative disorders. Yet, their clinical application is hindered by challenges in isolating cancer-derived EVs efficiently due to their broad size distribution in biological samples. This study introduces a microfluidic device fabricated using off-stoichiometry thiol-ene and cyclic olefin copolymer, addressing the absorption limitations of polydimethylsiloxane (PDMS). The device streamlines a standard laboratory assay into a semi-automated microfluidic chip, integrating sample mixing and magnetic particle separation. Using the microfluidic device, the binding kinetics between EVs and anti-CD9 nanobodies were measured for the first time. Based on the binding kinetics, already after 10 min the EV capture was saturated and comparable to standard laboratory assays, offering a faster alternative to antibody-based immunomagnetic protocols. Furthermore, this study reveals the binding kinetics of EVs to anti-CD9 nanobodies for the first time. Our findings demonstrate the potential of the microfluidic device to enhance clinical diagnostics by offering speed and reducing manual labor without compromising accuracy.

Exosome isolation based on polyethylene glycol (PEG): a review

Exosome acts as an outstanding biomarker for ongoing studies, diagnosis and prognosis of multiples diseases. Therefore, the call for economically and efficiently isolating a large number of exosomes is an active area of investigation. However, to date, the challenges including complex isolated procedure, uneconomical equipment, low protein content and distinct loss in the particle number of exosomes etc. still encounter in exosome isolation. Polyethylene glycol (PEG)-induced exosome isolation increasingly attracts wide attention of scientists. PEG precipitation reveals higher performance in the yield of exosomes among multiple common isolation techniques. PEG-based precipitation is a temporarily low-purity, but inexpensive, time-save, labor-less, convenient and high-yield technique to gain exosomes with high biological activities. Hence, the PEG-based exosome isolation approach wins the endorsement of experimental workers. Herein, we summary the existing knowledge on procedures of PEG-based exosomes separation from different biospecimens, the binding process of PEG to exosomes, some notices, demerits, merits of PEG-based exosome isolation, and at last the advantages by combining PEG-precipitation to other techniques for exosome isolation, with a view to eliciting profound insights for investigators who recruit PEG for exosome separation, and advancing references for the standardization of PEG-based exosome isolation in future.

Astragali radix vesicle-like nanoparticles improve energy metabolism disorders by repairing the intestinal mucosal barrier and regulating amino acid metabolism in sleep-deprived mice

BACKGROUND

Sleep disorder is widespread and involves a variety of intricate factors in its development. Sleep deprivation is a manifestation of sleep disorder, can lead to energy metabolism disturbances, weakened immune system, and compromised body functions. In extreme situations, sleep deprivation can cause organ failure, presenting significant risks to human health.

PURPOSE

This study aimed to investigate the efficacy and mechanisms of Astragalus Radix vesicles-like nanoparticles (AR-VLNs) in counteracting the deleterious effects of sleep deprivation.

METHODS

The ICR mice were divided into control, model, AR-VLNs high dose (equivalent to 20 g/kg crude drug), AR-VLNs low dose (equivalent to 10 g/kg crude drug), AR high dose (equivalent to 20 g/kg crude drug), and AR low dose (equivalent to 10 g/kg crude drug). The REM (rapid eye movement) sleep-deprivation model was established, and evaluations were conducted for motor function, antioxidant capacity, and energy metabolism indices. Moreover, CACO-2 cells damage was induced with lipopolysaccharide to evaluate the repairing ability of AR-VLNs on the intestinal cell mucosa by measuring permeability. Furthermore, metabolomics was employed to elucidate the mechanisms of AR-VLNs action.

RESULTS

AR-VLNs were demonstrated to enhance the motor efficiency and antioxidant capacity in REM sleep-deprived mice, while also minimized pathological damage and restored the integrity of the intestinal mucosal barrier. In vitro experiments indicated the anti-inflammatory effect of AR-VLNs against LPS-induced cell damage. Additionally, metabolomic analysis linked these effects with regulation of the amino acid metabolic pathways. Further confirmation from molecular biology experiments revealed that the protective effects of AR-VLNs against the deleterious effects of REM sleep deprivation were associated with the restoration of the intestinal mucosal barrier and the enhancement of amino acid metabolism.

CONCLUSION

AR-VLNs administration effectively improved energy metabolism disorders in REM sleep deprived mice, by facilitating the repair of the intestinal mucosal barrier and regulating the amino acid metabolism.

Advances in exosome plasmonic sensing: Device integration strategies and AI-aided diagnosis

Exosomes, as next-generation biomarkers, has great potential in tracking cancer progression. They face many detection limitations in cancer diagnosis. Plasmonic biosensors have attracted considerable attention at the forefront of exosome detection, due to their label-free, real-time, and high-sensitivity features. Their advantages in multiplex immunoassays of minimal liquid samples establish the leading position in various diagnostic studies. This review delineates the application principles of plasmonic sensing technologies, highlighting the importance of exosomes-based spectrum and image signals in disease diagnostics. It also introduces advancements in miniaturizing plasmonic biosensing platforms of exosomes, which can facilitate point-of-care testing for future healthcare. Nowadays, inspired by the surge of artificial intelligence (AI) for science and technology, more and more AI algorithms are being adopted to process the exosome spectrum and image data from plasmonic detection. Using representative algorithms of machine learning has become a mainstream trend in plasmonic biosensing research for exosome liquid biopsy. Typically, these algorithms process complex exosome datasets efficiently and establish powerful predictive models for precise diagnosis. This review further discusses critical strategies of AI algorithm selection in exosome-based diagnosis. Particularly, we categorize the AI algorithms into the interpretable and uninterpretable groups for exosome plasmonic detection applications. The interpretable AI enhances the transparency and reliability of diagnosis by elucidating the decision-making process, while the uninterpretable AI provides high diagnostic accuracy with robust data processing by a "black-box" working mode. We believe that AI will continue to promote significant progress of exosome plasmonic detection and mobile healthcare in the near future.

Approaches and Challenges in Characterizing the Molecular Content of Extracellular Vesicles for Biomarker Discovery

Extracellular vesicles (EVs) are lipid bilayer nanoparticles released from all known cells and are involved in cell-to-cell communication via their molecular content. EVs have been found in all tissues and body fluids, carrying a variety of biomolecules, including DNA, RNA, proteins, metabolites, and lipids, offering insights into cellular and pathophysiological conditions. Despite the emergence of EVs and their molecular contents as important biological indicators, it remains difficult to explore EV-mediated biological processes due to their small size and heterogeneity and the technical challenges in characterizing their molecular content. EV-associated small RNAs, especially microRNAs, have been extensively studied. However, other less characterized RNAs, including protein-coding mRNAs, long noncoding RNAs, circular RNAs, and tRNAs, have also been found in EVs. Furthermore, the EV-associated proteins can be used to distinguish different types of EVs. The spectrum of EV-associated RNAs, as well as proteins, may be associated with different pathophysiological conditions. Therefore, the ability to comprehensively characterize EVs' molecular content is critical for understanding their biological function and potential applications in disease diagnosis. Here, we set out to provide an overview of EV-associated RNAs and proteins as well as approaches currently being used to characterize them.

Single-Cell Isolation Chip Integrated with Multicolor Barcode Array for High-Throughput Single-Cell Exosome Profiling in Tissue Samples

Exosomes, functional biomarkers involved in cancer progression, have gained widespread attention for promoting tumor formation, growth, and metastasis. Current bulk exosome detections in bodily fluids enable cancer functional analysis, but average secretion levels from cell populations, losing parent cell information and ignoring exosome heterogeneity from diverse cell subgroups, necessitating an effective platform for analyzing single-cell exosome functional heterogeneity. Here, a high-throughput platform is presented, capable of efficient single-cell isolation and multi-color exosome phenotype analysis, as well as quantifying trace exosomes secreted by single cells. Photothermal-driven single-cell chips achieve significant single-cell isolation efficiency (≈97%) within 5 min, facilitating the ultra-high throughput single-cell exosome analysis. By conducting mass spectrometry and protein interaction of breast cancer exosome phenotypic proteins, key exosome phenotypes are identified. Tens of thousands of single cells from breast cancer cell lines, and clinical tissues are analyzed, revealing various subgroup differences. The study finds more CD44 and EGFR co-expressing exosome subgroups in breast cancer cell lines, while immune-evasion PD-L1 high-phenotype exosome subgroups are primarily presented in complex tumor microenvironments, especially in HER2-positive tissues. This platform offers powerful single-cell isolation, exosome quantification, and phenotypic analysis capabilities, making it a powerful tool for advancing single-cell exosome analysis in cancer research.

Extracellular vesicles in liquid biopsies: there is hope for oral squamous cell carcinoma

Current approaches to oral cancer diagnosis primarily involve physical examination, tissue biopsy, and advanced computer-aided imaging techniques. However, despite these advances, patient survival rates have not significantly improved. Hence, there is a critical need to develop minimally invasive tools with high sensitivity and specificity to improve patient survival and quality of life. Liquid biopsy is a non-invasive, real-time method for predicting cancer status and potentially serves as a biomarker source for treatment response. Liquid biopsy includes rich biologically relevant components, such as circulating tumor cells, circulating tumor DNA, and extracellular vesicles (EVs). EVs are particularly intriguing due to their relatively high abundance in most biofluids, with the potential to identify specific cargo derived from circulating tumor EVs. Moreover, normal cells in lymph nodes can uptake EVs, fostering a pre-metastatic microenvironment that facilitates lymph node metastases - a common occurrence in oral cancers. This review encompasses English language publications over the last twenty years, focusing on methods for isolating EVs from saliva, blood, and lymphatic fluids, as well as the collection methods employed. Seventeen cases met the inclusion criteria according to ISEV guidelines, including 10 saliva cases, 6 blood cases, and 1 lymphatic fluid case. This review also highlighted research gaps in oral squamous cell carcinoma (OSCC) EVs, including a lack of multi-omics studies and the exploration of potential EV markers for drug resistance, as well as a notable underutilization of microfluidic technologies to translate liquid biopsy EV findings into clinical applications.

Delivery of therapeutic RNA by extracellular vesicles derived from Saccharomyces cerevisiae for medicine applications

Employing small extracellular vesicles (EVs) as drug delivery vehicles presents a plethora of advantages over conventional drug delivery methods, including biological compatibility, engineering versatility for targeted delivery, and biodegradability. Therefore, strategies aimed at amplifying their therapeutic potential involve developing efficient, tissue-specific, and non-immunogenic delivery approaches. Despite rapid advancements in the realm of EVs as drug delivery systems in recent years, the availability of a high-yield, reproducible, and cost-effective source for EVs production and isolation remains a limiting factor for practical application. In this study, we isolated EVs from Saccharomyces cerevisiae (S.c) and loaded them with cargoes such as hsa-miR-143 (an apoptosis-inducing miRNA) or miR-H6 (a miRNA targeting HSV-1). We demonstrated the capability of these EVs to deliver microRNAs or even large mRNA to a variety of cell types. The therapeutic potential of S.c-derived EVs (S.c-EVs) was further evidenced by their ability to inhibit tumor growth in animal models. The S.c-EVs proved to be safe and non-immunogenic in vivo. Our results suggest that Saccharomyces cerevisiae represents a cost-effective source of extracellular vesicles, serving as nanocarriers for functional drug delivery in therapeutic applications.

Exosomes derived from diabetic microenvironment-preconditioned mesenchymal stem cells ameliorate nonalcoholic fatty liver disease and inhibit pyroptosis of hepatocytes

AIM

Pyroptosis, a type of programmed cell death, is a key mechanism underlying non-alcoholic fatty liver disease (NAFLD). Mesenchymal stem cell (MSC)-derived exosomes (MSC-Exos) have the potential to ameliorate NAFLD, an effect that is enhanced by curcumin preconditioning. We previously reported that diabetic microenvironment preconditioning enhances the secretion capacity and anti-inflammatory activity of MSCs. Therefore, we hypothesized that MSC-Exos would inhibit hepatocyte pyroptosis and thereby ameliorate NAFLD, and that diabetic microenvironment preconditioning would enhance these effects.

METHODS

MSCs were preconditioned in a diabetic microenvironment (pMSCs). MSC-Exos and pMSC-Exos collected from MSCs or pMSCs were applied to methionine- and choline-deficient (MCD)-induced NAFLD mice and in vitro models involving induction with lipopolysaccharide or palmitic acid to mimic hepatic steatosis and injury. MCC950 treatment was used as a positive control. We analyzed the characteristics of NAFLD and pyroptosis markers. Protein profiles of MSC-Exos and pMSC-Exos were evaluated by label-free quantitative proteomics.

RESULTS

In vivo, MSC-Exos partially attenuated inflammation and fibrosis, but not lipid deposition and NAFLD progression in the livers of NAFLD mice. pMSC-Exos significantly improved lipid metabolism, hepatic steatosis, inflammation, and fibrosis but also retarded the progression of NAFLD. Pyroptosis was upregulated in the liver of NAFLD mice. MSC-Exos and pMSC-Exos inhibited pyroptosis, and the effect of the latter was greater than that of the former. In vitro, MSC-Exos and pMSC-Exos ameliorated hepatocyte steatosis, lipid metabolism disorder, and inflammation, and pMSC-Exos exerted a greater inhibitory effect on hepatocyte pyroptosis than MSC-Exos did, which were remitted after inhibition of peroxiredoxin-1 (PRDX-1).

CONCLUSION

MSC-Exos ameliorated NAFLD and inhibited hepatocyte pyroptosis by downregulating the NLRP3/Caspase-1/GSDMD pathway, effects enhanced by pMSC-Exos, partly due to PRDX-1 upregulation.

Exosomal therapy is a luxury area for regenerative medicine

Stem cell-based therapies have made significant advancements in tissue regeneration and medical engineering. However, there are limitations to cell transplantation therapy, such as immune rejection and limited cell viability. These limitations greatly impede the translation of stem cell-based tissue regeneration into clinical practice. In recent years, exosomes, which are packaged vesicles released from cells, have shown promising progress. Specifically, exosomes derived from stem cells have demonstrated remarkable therapeutic benefits. Exosomes are nanoscale extracellular vesicles that act as paracrine mediators. They transfer functional cargos, such as miRNA and mRNA molecules, peptides, proteins, cytokines, and lipids, from MSCs to recipient cells. By participating in intercellular communication events, exosomes contribute to the healing of injured or diseased tissues and organs. Studies have shown that the therapeutic effects of MSCs in various experimental paradigms can be solely attributed to their exosomes. Consequently, MSC-derived exosomes can be modified and utilized to develop a unique cell-free therapeutic approach for treating multiple diseases, including neurological, immunological, heart, and other diseases. This review is divided into several categories, including the current understanding of exosome biogenesis, isolation techniques, and their application as therapeutic tools.

Revolutionizing medicine: recent developments and future prospects in stem-cell therapy

Stem-cell therapy is a revolutionary frontier in modern medicine, offering enormous capacity to transform the treatment landscape of numerous debilitating illnesses and injuries. This review examines the revolutionary frontier of treatments utilizing stem cells, highlighting the distinctive abilities of stem cells to undergo regeneration and specialized cell differentiation into a wide variety of phenotypes. This paper aims to guide researchers, physicians, and stakeholders through the intricate terrain of stem-cell therapy, examining the processes, applications, and challenges inherent in utilizing stem cells across diverse medical disciplines. The historical journey from foundational contributions in the late 19th and early 20th centuries to recent breakthroughs, including ESC isolation and iPSC discovery, has set the stage for monumental leaps in medical science. Stem cells' regenerative potential spans embryonic, adult, induced pluripotent, and perinatal stages, offering unprecedented therapeutic opportunities in cancer, neurodegenerative disorders, cardiovascular ailments, spinal cord injuries, diabetes, and tissue damage. However, difficulties, such as immunological rejection, tumorigenesis, and precise manipulation of stem-cell behavior, necessitate comprehensive exploration and innovative solutions. This manuscript summarizes recent biotechnological advancements, critical trial evaluations, and emerging technologies, providing a nuanced understanding of the triumphs, difficulties, and future trajectories in stem cell-based regenerative medicine. Future directions, including precision medicine integration, immune modulation strategies, advancements in gene-editing technologies, and bioengineering synergy, offer a roadmap in stem cell treatment. The focus on stem-cell therapy's potential highlights its significant influence on contemporary medicine and points to a future in which individualized regenerative therapies will alleviate various medical disorders.

Advances of M1 macrophages-derived extracellular vesicles in tumor therapy

Extracellular vesicles derived from classically activated M1 macrophages (M1 EVs) have shown great potential in both tumor treatment and drug delivery. M1 EVs inherit specific biological messengers from their parent cells and possess the capability to activate immune cells residing in close or distant tumor tissues for antitumor therapy. Moreover, M1 EVs are commonly used as an attractive drug delivery system due to their tumor-targeting ability, biocompatibility, and non-toxic. They can effectively encapsulate various therapeutic cargoes through specific methods such as electroporation, co-incubation, sonication, extrusion, transfection, or click chemistry reaction. In this review, we provide a comprehensive summary of the advancements in M1 EVs for tumor therapy, discussing their application prospects and existing problems.

[The concept of the liquid biopsy in the treatment of malignant eye tumours]

The liquid biopsy is a cutting-edge technique that involves analysing non-solid biological tissues, primarily blood but also ocular fluids, for the presence of cancer cells or fragments of tumour DNA. Unlike traditional biopsies, liquid biopsies are usually minimally invasive and can be performed more frequently, enabling continuous monitoring of disease progression and treatment efficacy. This article (and the associated series of articles) outlines the key developments in liquid biopsy, which include the analysis of circulating tumor DNA (ctDNA), circulating tumor cells (CTC) and exosomal RNA and protein biomarkers. Techniques, such as digital droplet PCR and next-generation sequencing (NGS) have made it possible to detect even very low levels of ctDNA, which is crucial for early cancer detection and monitoring minimal residual disease. The detection of rare CTCs is enhanced by techniques, such as microfluidic devices and immunomagnetic separation. Multiomic approaches, whereby exosomal RNA, protein and ctDNA analyses are combined, help to create a more comprehensive picture of tumour biology, including insights into tumour heterogeneity, potentially leading to better diagnostic and prognostic tools and helping to predict treatment response and resistance. The challenges of liquid biopsy application, which will be described in the following article, include (a) standardization, (b) cost and accessibility, (c) validation and clinical utility. However, the liquid biopsy represents a promising frontier in the application of precision ocular oncology, with ongoing research likely to expand its applications and improve its effectiveness in the coming years.

CRISPR-based dual-aptamer proximity ligation coupled hybridization chain reaction for precise detection of tumor extracellular vesicles and cancer diagnosis

Tumor cell-derived extracellular vesicles (TEVs) contain numerous cellular molecules and are considered potential biomarkers for non-invasive liquid biopsy. However, due to the low abundance of TEVs secreted by tumor cells and their phenotypic heterogeneity, there is a lack of sensitive and specific methods to quantify TEVs. Here, we developed a dual-aptamer proximity ligation-coupled hybridization chain reaction (HCR) method for tracing TEVs, exploiting CRISPR to achieve highly sensitive detection. Taking advantage of the high binding affinity of aptamers, the two aptamers (AptEpCAM, AptHER2) exhibited the high selectivity for TEVs recognition. HCR generated long-repeated sequence containing multiple crRNA targetable barcodes, and the signals were further amplified by CRISPR upon recognizing the HCR sequences, thereby enhancing the sensitivity. Under optimal conditions, the developed method demonstrated a favorable linear relationship in the range of 2 × 103-107 particles/μL, with a limit of detection (LOD) of 3.3 × 102 particles/μL. We directly applied our assay to clinical plasma analysis, achieving 100 % accuracy in cancer diagnosis, thus demonstrating the potential clinical applications of TEVs. Due to its simplicity and rapidity, excellent sensitivity and specificity, this method has broad applications in clinical medicine.

Immuno-Rolling Circle Amplification (Immuno-RCA): Biosensing Strategies, Practical Applications, and Future Perspectives

In the rapidly evolving field of life sciences and biomedicine, detecting low-abundance biomolecules, and ultraweak biosignals presents significant challenges. This has spurred a rapid development of analytical techniques aiming for increased sensitivity and specificity. These advancements, including signal amplification strategies and the integration of biorecognition events, mark a transformative era in bioanalytical precision and accuracy. A prominent method among these innovations is immuno-rolling circle amplification (immuno-RCA) technology, which effectively combines immunoassays with signal amplification via RCA. This process starts when a targeted biomolecule, such as a protein or cell, binds to an immobilized antibody or probe on a substrate. The introduction of a circular DNA template triggers RCA, leading to exponential amplification and significantly enhanced signal intensity, thus the target molecule is detectable and quantifiable even at the single-molecule level. This review provides an overview of the biosensing strategy and extensive practical applications of immuno-RCA in detecting biomarkers. Furthermore, it scrutinizes the limitations inherent to these sensors and sets forth expectations for their future trajectory. This review serves as a valuable reference for advancing immuno-RCA in various domains, such as diagnostics, biomarker discovery, and molecular imaging.