Future of Digital Assays to Resolve Clinical Heterogeneity of Single Extracellular Vesicles

Construction of a sensitive SWCNTs integrated SPR biosensor for detecting PD-L1+ exosomes based on Fe3O4@TiO2 specific enrichment and signal amplification

Programmed cell death-ligand 1 positive (PD-L1+) exosomes play a crucial role in the realm of cancer diagnosis and treatment. Nevertheless, due to the intricate nature of biological specimens, coupled with the heterogeneity, low refractive index (RI), and scant surface coverage density of exosomes, traditional surface plasmon resonance (SPR) sensors still do not meet clinical detection requirements. This study utilizes the exceptional electrical and optical attributes of single-walled carbon nanotubes (SWCNTs) as the substrate for SPR sensing, thereby markedly enhancing sensitivity. Furthermore, sp2 hybridized SWCNTs have the ability to load specific recognition elements. Additionally, through the coordination interaction of Ti with phosphate groups and the ferromagnetism of Fe3O4, efficient exosomes isolation and enrichment in complex samples are achievable with the aid of an external magnetic field. Owing to the high-quality and high-RI of Fe3O4@TiO2, the response signal experiences amplification, thus further improving the performance of the SPR biosensor. The linear range of the SPR biosensor constructed by this method is 1.0 × 103 to 1.0 × 107 particles/mL, with a limit of detection (LOD) of 31.9 particles/mL. In the analysis of clinical serum samples, cancer patients can be differentiated from healthy individuals with an Area Under Curve (AUC) of 0.9835. This study not only establishes a novel platform for exosomes direct detection but also offers new perspectives for the sensitive detection of other biomarkers.

Ultrasensitive quantification of PD-L1+ extracellular vesicles in melanoma patient plasma using a parallelized high throughput droplet digital assay

The expression of programmed death-ligand 1 (PD-L1) on extracellular vesicles (EVs) is an emerging biomarker for cancer, and has gained particular interest for its role mediating immunotherapy. However, precise quantification of PD-L1+ EVs in clinical samples remains challenging due to their sparse concentration and the enormity of the number of background EVs in human plasma, limiting applicability of conventional approaches. In this study, we develop a high-throughput droplet-based extracellular vesicle analysis (DEVA) assay for ultrasensitive quantification of EVs in plasma that are dual positive for both PD-L1 and tetraspanin (CD81) known to be expressed on EVs. We achieve a performance that significantly surpasses conventional approaches, demonstrating 360× enhancement in the limit of detection (LOD) and a 750× improvement in the limit of quantitation (LOQ) compared to conventional plate enzyme-linked immunoassay (ELISA). Underlying this performance is DEVA's high throughput analysis of individual EVs one at a time and the high specificity to targeted EVs versus background. We achieve a 0.006% false positive rate per droplet by leveraging avidity effects that arise from EVs having multiple copies of their target ligands on their surface. We use parallelized optofluidics to rapidly process 10 million droplets per minute, ∼100× greater than conventional approaches. A validation study on a cohort of 14 patients with melanoma confirms DEVA's ability to match conventional ELISA measurements with reduced plasma sample volume and without the need for prior EV purification. This proof-of-concept study demonstrates DEVA's potential for clinical utility to enhance prognosis as well as guide treatment for cancer.

Current knowledge on therapeutic, diagnostic, and prognostics applications of exosomes in multiple myeloma: Opportunities and challenges

Interactions between the plasma cells and the BM microenvironment of Multiple myeloma (MM) take place through factors such as exosomes. Many studies have confirmed the role of exosomes in these interactions. By carrying proteins, cytokines, lipids, microRNAs, etc. as their cargo, exosomes can regulate the interactions between MM plasma cells and neighboring cells and participate in the signaling between cancer cells and the environment. It has been shown that MM-derived exosomes can induce angiogenesis, enhance osteoblast activity, confer drug resistance, and have immunosuppressive properties. Abnormal cargos in endosomes originating from MM patients, can be used as a cancer biomarker to detect or screen early prognosis in MM patients. The native nanostructure of exosomes, in addition to their biocompatibility, stability, and safety, make them excellent candidates for therapeutic, drug delivery, and immunomodulatory applications against MM. On the other hand, exosomes derived from dendritic cells (DC) may be used as vaccines against MM. Thanks to the development of new 'omics' approaches, we anticipate to hear more about exosomes in fight against MM. In the present review, we described the most current knowledge on the role of exosomes in MM pathogenesis and their potential role as novel biomarkers and therapeutic tools in MM.

Advances of machine learning-assisted small extracellular vesicles detection strategy

Detection of extracellular vesicles (EVs), particularly small EVs (sEVs), is of great significance in exploring their physiological characteristics and clinical applications. The heterogeneity of sEVs plays a crucial role in distinguishing different types of cells and diseases. Machine learning, with its exceptional data processing capabilities, offers a solution to overcome the limitations of conventional detection methods for accurately classifying sEV subtypes and sources. Principal component analysis, linear discriminant analysis, partial least squares discriminant analysis, XGBoost, support vector machine, k-nearest neighbor, and deep learning, along with some combined methods such as principal component-linear discriminant analysis, have been successfully applied in the detection and identification of sEVs. This review focuses on machine learning-assisted detection strategies for cell identification and disease prediction via sEVs, and summarizes the integration of these strategies with surface-enhanced Raman scattering, electrochemistry, inductively coupled plasma mass spectrometry and fluorescence. The performance of different machine learning-based detection strategies is compared, and the advantages and limitations of various machine learning models are also evaluated. Finally, we discuss the merits and limitations of the current approaches and briefly outline the perspective of potential research directions in the field of sEV analysis based on machine learning.

Advanced Nanoencapsulation-Enabled Ultrasensitive Analysis: Unraveling Tumor Extracellular Vesicle Subpopulations for Differential Diagnosis of Hepatocellular Carcinoma via DNA Cascade Reactions

Tumor-derived extracellular vesicles (tEVs) hold immense promise as potential biomarkers for the precise diagnosis of hepatocellular carcinoma (HCC). However, their clinical translation is hampered by their inherent characteristics, such as small size and high heterogeneity and complex environment, including non-EV particles and normal cell-derived EVs, which prolong separation procedures and compromise detection accuracy. In this study, we devised a DNA cascade reaction-triggered individual EV nanoencapsulation (DCR-IEVN) strategy to achieve the ultrasensitive and specific detection of tEV subpopulations via routine flow cytometry in a one-pot, one-step fashion. DCR-IEVN enables the direct and selective packaging of multiple tEV subpopulations in clinical serum samples into flower-like particles exceeding 600 nm. This approach bypasses the need for EV isolation, effectively reducing interference from non-EV particles and nontumor EVs. Compared with conventional analytical technologies, DCR-IEVN exhibits superior efficacy in diagnosing HCC owing to its high selectivity for tEVs. Integration of machine learning algorithms with DCR-IEVN resulted in differential diagnosis accuracy of 96.7% for the training cohort (n = 120) and 93.3% for the validation cohort (n = 30), effectively distinguishing HCC, cirrhosis, and healthy donors. This strategy offers a streamlined workflow and rapid assay completion and requires only small-volume serum samples and routine clinical devices, facilitating the clinical translation of tEV-based tumor diagnosis.

The Landscape of Exosomes Biogenesis to Clinical Applications

Exosomes are extracellular vesicles that originate from various cells and mediate intercellular communication, altering the behavior or fate of recipient cells. They carry diverse macromolecules, such as lipids, proteins, carbohydrates, and nucleic acids. Environmental stressors can change the exosomal contents of many cells, making them useful for diagnosing many chronic disorders, especially neurodegenerative, cardiovascular, cancerous, and diabetic diseases. Moreover, exosomes can be engineered as therapeutic agents to modulate disease processes. State-of-art techniques are employed to separate exosomes including ultracentrifugation, size-exclusion chromatography and immunoaffinity. However, modern technologies such as aqueous two-phase system as well as microfluidics are gaining attention in the recent years. The article highlighted the composition, biogenesis, and implications of exosomes, as well as the standard and novel methods for isolating them and applying them as biomarkers and therapeutic cargo carriers.

Stem Cell-Derived Exosomes: An Advanced Horizon to Cancer Regenerative Medicine

Cancer research has made significant progress in recent years, and extracellular vesicles (EVs) based cancer investigation reveals several facts about cancer. Exosomes are a subpopulation of EVs. In the present decade, exosomes is mostly highlighted for cancer theranostic research. Tumor cell derived exosomes (TEXs) promote cancer but there are multiple sources of exosomes that can be used as cancer therapeutic agents (plant exosomes, stem cell-derived exosomes, modified or synthetic exosomes). Stem cells based regenerative medicine faces numerous challenges, such as promote tumor development, cellular reprogramming etc., and therefore addressing these complications becomes essential. Stem cell-derived exosomes serves as an answer to these problems and offers a better solution. Global research indicates that stem cell-derived exosomes also play a dual role in the cellular system by either inhibiting or promoting cancer. Modified exosomes which are genetically engineered exosomes or surface modified exosomes to increase the efficacy of the therapeutic properties can also be considered to target the above concerns. However, the difficulties associated with the exosomes include variations in exosomes heterogenity, isolation protocols, large scale production, etc., and these have to be managed effectively. In this review, we explore exosomes biogenesis, multiple stem cell-derived exosome sources, drug delivery, modified stem cells exosomes, clinical trial of stem cells exosomes, and the related challenges in this domain and future orientation. This article may encourage researchers to explore stem cell-derived exosomes and develop an effective and affordable cancer therapeutic solution.

A Panorama of Extracellular Vesicle Applications: From Biomarker Detection to Therapeutics

Extracellular vesicles (EVs) secreted by all cell types are involved in the cell-to-cell transfer of regulatory factors that influence cell and tissue phenotypes in normal and diseased tissues. EVs are thus a rich source of biomarker targets for assays that analyze blood and urinary EVs for disease diagnosis. Sensitive biomarker detection in EVs derived from specific cell populations is a key major hurdle when analyzing complex biological samples, but innovative approaches surveyed in this Perspective can streamline EV isolation and enhance the sensitivity of EV detection procedures required for clinical application of EV-based diagnostics and therapeutics, including nanotechnology and microfluidics, to achieve EV characterizations. Finally, this Perspective also outlines opportunities and challenges remaining for clinical translation of EV-based assays.

Targeted therapies for HPV-associated cervical cancer: Harnessing the potential of exosome-based chipsets in combating leukemia and HPV-mediated cervical cancer

Exosomes play a crucial role in intercellular communication and have emerged as significant vehicles for transporting disease-specific biomarkers. This feature provides profound insights into the progression of diseases and the responses of patients to treatments. For example, in leukemia, exosomes convey critical information through the carriage of specific proteins and nucleic acids. In the case of human papillomavirus (HPV)-mediated cervical cancer, exosomes are particularly useful for noninvasive detection as they transport high-risk HPV DNA and specific biomolecules, which can be indicators of the disease. Despite their vast potential, there are several challenges associated with the use of exosomes in medical diagnostics. These include their inherent heterogeneity, the need for enhanced sensitivity in detection methods, the establishment of standardization protocols, and the requirement for cost-effective scalability in their application. Addressing these challenges is crucial for the effective implementation of exosome-based diagnostics. Future research and development are geared towards overcoming these obstacles. Efforts are concentrated on refining the processes of biomarker discovery, establishing comprehensive regulatory frameworks, developing convenient point-of-care devices, exploring methods for multimodal detection, and conducting extensive clinical trials. The ultimate goal of these efforts is to inaugurate a new era of precision diagnostics within healthcare. This would significantly improve patient outcomes and reduce the burden of diseases such as leukemia and HPV-mediated cervical cancer. The integration of exosomes with cutting-edge technology holds the promise of significantly reinforcing the foundations of healthcare, leading to enhanced diagnostic accuracy, better disease monitoring, and more personalized therapeutic approaches.

Exosomes: A Cutting-Edge Theranostics Tool for Oral Cancer

Exosomes are a subpopulation of extracellular vesicles (EVs) secreted by cells. In cancer, they are key cellular messengers during cancer development and progression. Tumor-derived exosomes (TEXs) promote cancer progression. In oral cancer, the major complication is oral squamous cell carcinoma (OSCC). Exosomes show strong participation in several OSCC-related activities such as uncontrolled cell growth, immune suppression, angiogenesis, metastasis, and drug and therapeutic resistance. It is also a potential biomarker source for oral cancer. Some therapeutic exosome sources such as stem cells, plants (it is more effective compared to others), and engineered exosomes reduce oral cancer development. This therapeutic approach is effective because of its specificity, biocompatibility, and cell-free therapy (it reduced side effects in cancer treatment). This article highlights exosome-based theranostics signatures in oral cancer, clinical trials, challenges of exosome-based oral cancer research, and future improvements. In the future, exosomes may become an effective and affordable solution for oral cancer.

Plant-derived exosomes: a green approach for cancer drug delivery

Plant-derived exosomes (PDEs) are natural extracellular vesicles (EVs). In the current decade, they have been highlighted for cancer therapeutic development. Cancer is a global health crisis and it requires an effective, affordable, and less side effect-based treatment. Emerging research based on PDEs suggests that they have immense potential to be considered as a therapeutic option. Research evidences indicate that PDEs' internal molecular cargos show impressive cancer prevention activity with less toxicity. PDEs-based drug delivery systems overcome several limitations of traditional drug delivery tools. Extraction of PDEs from plant sources employ diverse methodologies, encompassing ultracentrifugation, immunoaffinity, size-based isolation, and precipitation, each with distinct advantages and limitations. The core constituents of PDEs comprise of lipids, proteins, DNA, and RNA. Worldwide, a few clinical trials on plant-derived exosomes are underway, and regulatory affairs for their use as therapeutic agents are still not understood with clarity. This review aims to comprehensively analyze the current state of research on plant-derived exosomes as a promising avenue for drug delivery, highlighting anticancer activity, challenges, and future orientation in effective cancer therapeutic development.

Peptide-based capture-and-release purification of extracellular vesicles and statistical algorithm enabled quality assessment

Circulating extracellular vesicles (EVs) have gained significant attention for discovering tumor biomarkers. However, isolating EVs with well-defined homogeneous populations from complex biological samples is challenging. Different isolation methods have been found to derive different EV populations carrying different molecular contents, which confounds current investigations and hinders subsequent clinical translation. Therefore, standardizing and building a rigorous assessment of isolated EV quality associated with downstream molecular analysis is essential. To address this need, we introduce a statistical algorithm (ExoQuality Index, EQI) by integrating multiple EV characterizations (size, particle concentration, zeta potential, total protein, and RNA), enabling direct EV quality assessment and comparisons between different isolation methods. We also introduced a novel capture-release isolation approach using a pH-responsive peptide conjugated with NanoPom magnetic beads (ExCy) for simple, fast, and homogeneous EV isolation from various biological fluids. Bioinformatic analysis of next-generation sequencing (NGS) data of EV total RNAs from pancreatic cancer patient plasma samples using our novel EV isolation approach and quality index strategy illuminates how this approach improves the identification of tumor associated molecular markers. Results showed higher human mRNA coverage compared to existing isolation approaches in terms of both pancreatic cancer pathways and EV cellular component pathways using gProfiler pathway analysis. This study provides a valuable resource for researchers, establishing a workflow to prepare and analyze EV samples carefully and contributing to the advancement of reliable and rigorous EV quality assessment and clinical translation.

Role of Exosomes in Epithelial-Mesenchymal Transition

Epithelial-mesenchymal transition (EMT) is a fundamental process driving cancer metastasis, transforming non-motile cells into a motile population that migrates to distant organs and forms secondary tumors. In recent years, cancer research has revealed a strong connection between exosomes and the EMT. Exosomes, a subpopulation of extracellular vesicles, facilitate cellular communication and dynamically regulate various aspects of cancer metastasis, including immune cell suppression, extracellular matrix remodeling, metastasis initiation, EMT initiation, and organ-specific metastasis. Tumor-derived exosomes (TEXs) and their molecular cargo, comprising proteins, lipids, nucleic acids, and carbohydrates, are essential components that promote EMT in cancer. TEXs miRNAs play a crucial role in reprogramming the tumor microenvironment, while TEX surface integrins contribute to organ-specific metastasis. Exosome-based cancer metastasis research offers a deeper understanding about cancer and an effective theranostic platform development. Additionally, various therapeutic sources of exosomes are paving the way for innovative cancer treatment development. In this Review, we spotlight the role of exosomes in EMT and their theranostic impact, aiming to inspire cancer researchers worldwide to explore this fascinating field in more innovative ways.

Role of exosomes in prostate cancer and male fertility

Prostate cancer (PCa) is the second most common and fifth most aggressive neoplasm among men worldwide. In the last decade, extracellular vesicle (EV) research has decoded multiple unsolved cancer-related mysteries. EVs can be classified as microvesicles, apoptotic bodies, and exosomes, among others. Exosomes play a key role in cellular signaling. Their internal cargos (nucleic acids, proteins, lipids) influence the recipient cell. In PCa, the exosome is the regulator of cancer progression. It is also a promising theranostics tool for PCa. Moreover, exosomes have strong participation in male fertility complications. This review aims to highlight the exosome theranostics signature in PCa and its association with male fertility.

Double Digital Assay for Single Extracellular Vesicle and Single Molecule Detection

Extracellular vesicles (EVs) have emerged as a promising source of biomarkers for disease diagnosis. However, current diagnostic methods for EVs present formidable challenges, given the low expression levels of biomarkers carried by EV samples, as well as their complex physical and biological properties. Herein, a highly sensitive double digital assay is developed that allows for the absolute quantification of individual molecules from a single EV. Because the relative abundance of proteins is low for a single EV, tyramide signal amplification (TSA) is integrated to increase the fluorescent signal readout for evaluation. With the integrative microfluidic technology, the technology's ability to compartmentalize single EVs is successfully demonstrated, proving the technology's digital partitioning capacity. Then the device is applied to detect single PD-L1 proteins from single EVs derived from a melanoma cell line and it is discovered that there are ≈2.7 molecules expressed per EV, demonstrating the applicability of the system for profiling important prognostic and diagnostic cancer biomarkers for therapy response, metastatic status, and tumor progression. The ability to accurately quantify protein molecules of rare abundance from individual EVs will shed light on the understanding of EV heterogeneity and discovery of EV subtypes as new biomarkers.

Unlocking Exosome-Based Theragnostic Signatures: Deciphering Secrets of Ovarian Cancer Metastasis

Ovarian cancer (OC) is a common gynecological cancer worldwide. Unfortunately, the lack of early detection methods translates into a substantial cohort of women grappling with the pressing health crisis. The discovery of extracellular vesicles (EVs) (their major subpopulation exosomes, microvesicles, and apoptotic bodies) has provided new insights into the understanding of cancer. Exosomes, a subpopulation of EVs, play a crucial role in cellular communication and reflect the cellular status under both healthy and pathological conditions. Tumor-derived exosomes (TEXs) dynamically influence ovarian cancer progression by regulating uncontrolled cell growth, immune suppression, angiogenesis, metastasis, and the development of drug and therapeutic resistance. In the field of OC diagnostics, TEXs offer potential biomarkers in various body fluids. On the other hand, exosomes have also shown promising abilities to cure ovarian cancer. In this review, we address the interlink between exosomes and ovarian cancer and explore their theragnostic signature. Finally, we highlight future directions of exosome-based ovarian cancer research.

Theranostic signature of tumor-derived exosomes in cancer

Cancer is the most challenging global health crisis. In the recent times, studies on extracellular vesicles (EVs) are adding a new chapter to cancer research and reports on EVs explores cancer in a new dimension. Exosomes are a group of subpopulations of EVs. It originates from the endosomes and carries biologically active molecules to the neighboring cells which in turn transforms the recipient cell activity. In general, it plays a role in cellular communication. The correlation between exosomes and cancer is fascinating. Tumor-derived exosomes (TEXs) play a dynamic role in cancer progression and are associated with uncontrolled cell growth, angiogenesis, immune suppression, and metastasis. Its molecular cargo is an excellent source of cancer biomarkers. Several advanced molecular profiling approaches assist in exploring the TEXs in depth. This paves the way for a strong foundation for identifying and detecting more specific and efficient biomarkers. TEXs are also gaining importance in scientific society for its role in cancer therapy and several clinical trials based on TEXs is a proof of its significance. In this review, we have highlighted the role of TEXs in mediating immune cell reprogramming, cancer development, metastasis, EMT, organ-specific metastasis, and its clinical significance in cancer theranostics. TEXs profiling is an effective method to understand the complications associated with cancer leading to good health and well-being of the individual and society as a whole.

Extracellular Vesicles: Techniques and Biomedical Applications Related to Single Vesicle Analysis

Extracellular vesicles (EVs) are extensively dispersed lipid bilayer membrane vesicles involved in the delivery and transportation of molecular payloads to certain cell types to facilitate intercellular interactions. Their significant roles in physiological and pathological processes make EVs outstanding biomarkers for disease diagnosis and treatment monitoring as well as ideal candidates for drug delivery. Nevertheless, differences in the biogenesis processes among EV subpopulations have led to a diversity of biophysical characteristics and molecular cargos. Additionally, the prevalent heterogeneity of EVs has been found to substantially hamper the sensitivity and accuracy of disease diagnosis and therapeutic monitoring, thus impeding the advancement of clinical applications. In recent years, the evolution of single EV (SEV) analysis has enabled an in-depth comprehension of the physical properties, molecular composition, and biological roles of EVs at the individual vesicle level. This review examines the sample acquisition tactics prior to SEV analysis, i.e., EV isolation techniques, and outlines the current state-of-the-art label-free and label-based technologies for SEV identification. Furthermore, the challenges and prospects of biomedical applications based on SEV analysis are systematically discussed.

Digital-like Enzyme Inhibition Mechanism-Based Strategy for the Digital Sensing of Heparin-Specific Biomarkers

A new microbead (MB)-based digital flow cytometric sensing system is proposed for the sensitive detection of heparin-specific biomarkers, including heparin-binding protein (HBP) and heparinase. This strategy takes advantage of the inherent space-confined enzymatic behavior of T4 polynucleotide kinase phosphatase (T4 PNKP) around a single MB and the heparin's digital-like inhibitory effect on T4 PNKP. By integrating with an on-bead terminal deoxynucleotidyl transferase (TdT)-catalyzed fluorescence signal amplification technology, the concentration of HBP and heparinase can be digitally determined by the number of fluorescence-positive/-negative MBs which can be easily counted by flow cytometry. This is not only the first test to expand the application scenario of T4 PNKP to the digital detection of different biomarkers but also pioneers a new direction for fabricating digital biosensing platforms based on the enzyme inhibition mechanism.

Clinical Theranostics Trademark of Exosome in Glioblastoma Metastasis

Glioblastoma (GBM) is an aggressive type of cancer that has led to the death of a large population. The traditional approach fails to develop a solution for GBM's suffering life. Extensive research into tumor microenvironments (TME) indicates that TME extracellular vesicles (EVs) play a vital role in cancer development and progression. EVs are classified into microvacuoles, apoptotic bodies, and exosomes. Exosomes are the most highlighted domains in cancer research. GBM cell-derived exosomes participate in multiple cancer progression events such as immune suppression, angiogenesis, premetastatic niche formation (PMN), ECM (extracellular matrix), EMT (epithelial-to-mesenchymal transition), metastasis, cancer stem cell development and therapeutic and drug resistance. GBM exosomes also carry the signature of a glioblastoma-related status. The exosome-based GBM examination is part of the new generation of liquid biopsy. It also solved early diagnostic limitations in GBM. Traditional therapeutic approaches do not cross the blood-brain barrier (BBB). Exosomes are a game changer in GBM treatment and it is emerging as a potential platform for effective, efficient, and specific therapeutic development. In this review, we have explored the exosome-GBM interlink, the clinical impact of exosomes on GBM biomarkers, the therapeutics signature of exosomes in GBM, exosome-based research challenges, and future directions in GBM. Therefore, the GBM-derived exosomes offer unique therapeutic opportunities, which are currently under preclinical and clinical testing.

Clinical Theragnostic Signature of Extracellular Vesicles in Traumatic Brain Injury (TBI)

Traumatic brain injury (TBI) is a common cause of disability and fatality worldwide. Depending on the clinical presentation, it is a type of acquired brain damage that can be mild, moderate, or severe. The degree of patient's discomfort, prognosis, therapeutic approach, survival rates, and recurrence can all be strongly impacted by an accurate diagnosis made early on. The Glasgow Coma Scale (GCS), along with neuroimaging (MRI (Magnetic Resonance Imaging) and CT scan), is a neurological assessment tools used to evaluate and categorize the severity of TBI based on the patient's level of consciousness, eye opening, and motor response. Extracellular vesicles (EVs) are a growing domain, explaining neurological complications in a more detailed manner. EVs, in general, play a role in cellular communication. Its molecular signature such as DNA, RNA, protein, etc. contributes to the status (health or pathological stage) of the parental cell. Brain-derived EVs support more specific screening (diagnostic and prognostic) in TBI research. Therapeutic impact of EVs are more promising for aiding in TBI healing. It is nontoxic, biocompatible, and capable of crossing the blood-brain barrier (BBB) to transport therapeutic molecules. This review has highlighted the relationships between EVs and TBI theranostics, EVs and TBI-related clinical trials, and related research domain-associated challenges and solutions. This review motivates further exploration of associations between EVs and TBI and develops a better approach to TBI management.

Exosomal miRNAs and breast cancer: a complex theranostics interlink with clinical significance

Breast cancer (BC) remains the most challenging global health crisis of the current decade, impacting a large population of females annually. In the field of cancer research, the discovery of extracellular vesicles (EVs), specifically exosomes (a subpopulation of EVs), has marked a significant milestone. In general, exosomes are released from all active cells but tumour cell-derived exosomes (TDXs) have a great impact (TDXs miRNAs, proteins, lipid molecules) on cancer development and progression. TDXs regulate multiple events in breast cancer such as tumour microenvironment remodelling, immune cell suppression, angiogenesis, metastasis (EMT-epithelial mesenchymal transition, organ-specific metastasis), and therapeutic resistance. In BC, early detection is the most challenging event, exosome-based BC screening solved the problem. Exosome-based BC treatment is a sign of the transforming era of liquid biopsy, it is also a promising therapeutic tool for breast cancer. Exosome research goes to closer precision oncology via a single exosome profiling approach. Our hope is that this review will serve as motivation for researchers to explore the field of exosomes and develop an efficient, and affordable theranostics approach for breast cancer.

Modeling and optimization of parallelized immunomagnetic nanopore sorting for surface marker specific isolation of extracellular vesicles from complex media

The isolation of specific subpopulations of extracellular vesicles (EVs) based on their expression of surface markers poses a significant challenge due to their nanoscale size (< 800 nm), their heterogeneous surface marker expression, and the vast number of background EVs present in clinical specimens (1010-1012 EVs/mL in blood). Highly parallelized nanomagnetic sorting using track etched magnetic nanopore (TENPO) chips has achieved precise immunospecific sorting with high throughput and resilience to clogging. However, there has not yet been a systematic study of the design parameters that control the trade-offs in throughput, target EV recovery, and ability to discard background EVs in this approach. We combine finite-element simulation and experimental characterization of TENPO chips to elucidate design rules to isolate EV subpopulations from blood. We demonstrate the utility of this approach by reducing device background > 10× relative to prior published designs without sacrificing recovery of the target EVs by selecting pore diameter, number of membranes placed in series, and flow rate. We compare TENPO-isolated EVs to those of gold-standard methods of EV isolation and demonstrate its utility for wide application and modularity by targeting subpopulations of EVs from multiple models of disease including lung cancer, pancreatic cancer, and liver cancer.

Single-Cell Analysis and Classification according to Multiplexed Proteins via Microdroplet-Based Self-Driven Magnetic Surface-Enhanced Raman Spectroscopy Platforms Assisted with Machine Learning Algorithms

A microdroplet-based surface-enhanced Raman spectroscopy (microdroplet SERS) platform was constructed to envelop individual cells in microdroplets, followed by the SERS detection of their extracellular vesicle-proteins (EV-proteins) via the in-drop immunoassays by use of immunomagnetic beads (iMBs) and immuno-SERS tags (iSERS tags). A unique phenomenon is found that iMBs can start a spontaneous reorientation on the probed cell surface based on the electrostatic force-driven interfacial aggregation effect, which leads EV-proteins and iSERS tags to be gathered from a liquid phase to a cell membrane interface and significantly improves SERS sensitivity to the single-cell analysis level due to the formation of numbers of SERS hotspots. Three EV-proteins from two breast cancer cell lines were collected and further analyzed by machine learning algorithmic tools, which will be helpful for a deeper understanding of breast cancer subtypes from the view of EV-proteins.

Towards artificial intelligence-enabled extracellular vesicle precision drug delivery

Extracellular Vesicles (EVs), particularly exosomes, recently exploded into nanomedicine as an emerging drug delivery approach due to their superior biocompatibility, circulating stability, and bioavailability in vivo. However, EV heterogeneity makes molecular targeting precision a critical challenge. Deciphering key molecular drivers for controlling EV tissue targeting specificity is in great need. Artificial intelligence (AI) brings powerful prediction ability for guiding the rational design of engineered EVs in precision control for drug delivery. This review focuses on cutting-edge nano-delivery via integrating large-scale EV data with AI to develop AI-directed EV therapies and illuminate the clinical translation potential. We briefly review the current status of EVs in drug delivery, including the current frontier, limitations, and considerations to advance the field. Subsequently, we detail the future of AI in drug delivery and its impact on precision EV delivery. Our review discusses the current universal challenge of standardization and critical considerations when using AI combined with EVs for precision drug delivery. Finally, we will conclude this review with a perspective on future clinical translation led by a combined effort of AI and EV research.

DNA-Driven Photothermal Amplification Transducer for Highly Sensitive Visual Determination of Extracellular Vesicles

Extracellular vesicles (EVs) are crucial focus of current biomedical research and future medical diagnosis. However, the requirement for specialized sophisticated instruments for quantitative readouts has limited the sensitive measurement of EVs to specialized laboratory settings, which in turn has limited bench-to-bedside translation of EV-based liquid biopsies. In this work, a straightforward temperature-output platform based on a DNA-driven photothermal amplification transducer was developed for the highly sensitive visual detection of EVs using a simple household thermometer. The EVs were specifically recognized by the antibody-aptamer sandwich immune-configuration that was constructed on portable microplates. Via a one-pot reaction, cutting-mediated exponential rolling circle amplification was initiated in situ on the EV surface, generating substantial G-quadruplex-DNA-hemin conjugates. Significant amplification in temperature was achieved from the effective photothermal conversion and regulation guided by the G-quadruplex-DNA-hemin conjugates in the 3,3',5,5'-tetramethylbenzidine-H2O2 system. Through obvious temperature outputs, the DNA-driven photothermal transducer enabled highly sensitive EV detection at close to the single-particle level and supported the highly specific identification of tumor-derived EVs directly in serum samples, without the requirement of any sophisticated instrument or labeling process. Benefiting from highly sensitive visual quantification, an easy-to-use readout, and portable detection, this photothermometric strategy is expected to be deliverable across professional on-site screening to home self-testing as EV-based liquid biopsies.

Parallelized immunomagnetic nanopore sorting: modeling, scaling, and optimization of surface marker specific isolation of extracellular vesicles from complex media

The isolation of specific subpopulations of extracellular vesicles (EVs) based on their expression of surface markers poses a significant challenge due to their nanoscale size (< 800 nm), their heterogeneous surface marker expression, and the vast number of background EVs present in clinical specimens (10 10 -10 12 EVs/mL in blood). Highly parallelized nanomagnetic sorting using track etched magnetic nanopore (TENPO) chips has achieved precise immunospecific sorting with high throughput and resilience to clogging. However, there has not yet been a systematic study of the design parameters that control the trade-offs in throughput, target EV recovery, and specificity in this approach. We combine finite-element simulation and experimental characterization of TENPO chips to elucidate design rules to isolate EV subpopulations from blood. We demonstrate the utility of this approach by increasing specificity > 10x relative to prior published designs without sacrificing recovery of the target EVs by selecting pore diameter, number of membranes placed in series, and flow rate. We compare TENPO-isolated EVs to those of gold-standard methods of EV isolation and demonstrate its utility for wide application and modularity by targeting subpopulations of EVs from multiple models of disease including lung cancer, pancreatic cancer, and liver cancer.

Exosome and epithelial-mesenchymal transition: A complex secret of cancer progression

This short communication will enlighten the readers about the exosome and the epithelial-mesenchymal transition (EMT) related to several complicated events. It also highlighted the therapeutic potential of exosomes against EMT. Exosome toxicology, exosome heterogeneity, and a single exosome profiling approach are also covered in this article. In the future, exosomes could help us get closer to cancer vaccine and precision oncology.

Extracellular vesicles: a comprehensive review of their roles as biomarkers and potential therapeutics in psoriasis and psoriatic arthritis

Psoriasis is a chronic immune-mediated condition that affects the skin and joints, with current treatments still unable to offer a cure and long-term use of treatments posing health risks. Understanding the pathogenesis of the disease has helped identify new targets that have allowed for the expansion of the therapeutic arsenal. Extracellular vesicles (EVs) have recently emerged as pathophysiological mediators of psoriasis, and there have been increasing reports of EVs as potential biomarkers and therapeutics. Given their innate role as natural vehicles for cell-to-cell communication, EVs have vast potential in their ability to determine disease status based on EV-specific cargo as well as act as therapeutics because of their anti-inflammatory properties and potential for enhancement. In this review we summarize the role of EVs in the pathogenesis of psoriasis and discuss EVs as both diagnostic and therapeutic agents.

From Conventional to Microfluidic: Progress in Extracellular Vesicle Separation and Individual Characterization

Extracellular vesicles (EVs) are nanoscale membrane vesicles, which contain a wide variety of cargo such as proteins, miRNAs, and lipids. A growing body of evidence suggests that EVs are promising biomarkers for disease diagnosis and therapeutic strategies. Although the excellent clinical value, their use in personalized healthcare practice is not yet feasible due to their highly heterogeneous nature. Taking the difficulty of isolation and the small size of EVs into account, the characterization of EVs at a single-particle level is both imperative and challenging. In a bid to address this critical point, more research has been directed into a microfluidic platform because of its inherent advantages in sensitivity, specificity, and throughput. This review discusses the biogenesis and heterogeneity of EVs and takes a broad view of state-of-the-art advances in microfluidics-based EV research, including not only EV separation, but also the single EV characterization of biophysical detection and biochemical analysis. To highlight the advantages of microfluidic techniques, conventional technologies are included for comparison. The current status of artificial intelligence (AI) for single EV characterization is then presented. Furthermore, the challenges and prospects of microfluidics and its combination with AI applications in single EV characterization are also discussed. In the foreseeable future, recent breakthroughs in microfluidic platforms are expected to pave the way for single EV analysis and improve applications for precision medicine.

Extracellular vesicles and their cells of origin: Open issues in autoimmune diseases

The conventional therapeutic approaches to treat autoimmune diseases through suppressing the immune system, such as steroidal and non-steroidal anti-inflammatory drugs, are not adequately practical. Moreover, these regimens are associated with considerable complications. Designing tolerogenic therapeutic strategies based on stem cells, immune cells, and their extracellular vesicles (EVs) seems to open a promising path to managing autoimmune diseases' vast burden. Mesenchymal stem/stromal cells (MSCs), dendritic cells, and regulatory T cells (Tregs) are the main cell types applied to restore a tolerogenic immune status; MSCs play a more beneficial role due to their amenable properties and extensive cross-talks with different immune cells. With existing concerns about the employment of cells, new cell-free therapeutic paradigms, such as EV-based therapies, are gaining attention in this field. Additionally, EVs' unique properties have made them to be known as smart immunomodulators and are considered as a potential substitute for cell therapy. This review provides an overview of the advantages and disadvantages of cell-based and EV-based methods for treating autoimmune diseases. The study also presents an outlook on the future of EVs to be implemented in clinics for autoimmune patients.