Molecular and functional extracellular vesicle analysis using nanopatterned microchips monitors tumor progression and metastasis

Hydrogel-exosome system in tissue engineering: A promising therapeutic strategy

Characterized by their pivotal roles in cell-to-cell communication, cell proliferation, and immune regulation during tissue repair, exosomes have emerged as a promising avenue for "cell-free therapy" in clinical applications. Hydrogels, possessing commendable biocompatibility, degradability, adjustability, and physical properties akin to biological tissues, have also found extensive utility in tissue engineering and regenerative repair. The synergistic combination of exosomes and hydrogels holds the potential not only to enhance the efficiency of exosomes but also to collaboratively advance the tissue repair process. This review has summarized the advancements made over the past decade in the research of hydrogel-exosome systems for regenerating various tissues including skin, bone, cartilage, nerves and tendons, with a focus on the methods for encapsulating and releasing exosomes within the hydrogels. It has also critically examined the gaps and limitations in current research, whilst proposed future directions and potential applications of this innovative approach.

Metal-organic framework-interfaced ELISA probe enables ultrasensitive detection of extracellular vesicle biomarkers

The enzyme-linked immunosorbent assay (ELISA) remains the prevailing method for quantifying protein biomarkers. Enzymatic signal generation and amplification are key mechanisms that govern its analytical performance. This study reports the synthesis and application of microscale metal-organic framework (MOF)/enzyme composite particles as a novel detection probe to substantially enhance the sensitivity of ELISA. An optimal one-pot approach was established to incorporate a substantial amount of streptavidin-horseradish peroxidase (SA-HRP) either within or on the surface of the metal-azolate framework (MAF-7) microparticles. This approach enables the labeling of a single sandwich antibody-antigen complex with numerous enzymes, which markedly amplifies the enzymatic colorimetric signal generation. Moreover, MAF-7 caging was found to enhance the reactivity of the caged HRP enzyme, further promoting the overall detection sensitivity of ELISA. Compared to other developments that are often associated with more complicated detection modalities, our method is compatible with standard immunoassays and commonly used photometrical signal detection. The implementation of this strategy in the detection of CD147 results in a remarkably low limit of detection of 2.8 fg mL-1, representing a 105-fold improvement compared to that obtained with the standard ELISA. Moreover, the heightened sensitivity of this technique renders it particularly suitable for diagnosing breast cancer, thus presenting a promising tool for the early detection of the disease in clinical settings.

Critical review and recent advances of emerging real-time and non-destructive strategies for meat spoilage monitoring

Monitoring and evaluating food quality, especially meat quality, has received a growing interest to ensure human health and decrease waste of raw materials. Standard analytical approaches used for meat spoilage assessment suffer from time consumption, being labor-intensive, operation complexity, and destructiveness. To overcome shortfalls of these traditional methods and monitor spoilage microorganisms or related metabolites of meat products across the supply chain, emerging analysis devices/systems with higher sensitivity, better portability, on-line/in-line, non-destructive and cost-effective property are urgently needed. Herein, we first overview the basic concepts, causes, and critical monitoring indicators associated with meat spoilage. Then, the conventional detection methods for meat spoilage are outlined objectively in their strengths and weaknesses. In addition, we place the focus on the recent research advances of emerging non-destructive devices and systems for assessing meat spoilage. These novel strategies demonstrate their powerful potential in the real-time evaluation of meat spoilage.

Small extracellular vesicle CA1 as a promising diagnostic biomarker for nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC), a malignant cancer originating from the epithelial cells of the nasopharynx, presents diagnostic challenges with current methods such as plasma Epstein-Barr virus (EBV) DNA testing showing limited efficacy. This study focused on identifying small extracellular vesicle (sEV) proteins as potential noninvasive biomarkers to enhance NPC diagnostic accuracy. We isolated sEVs from plasma and utilized 4D label-free proteomics to identify differentially expressed proteins (DEPs) among healthy controls (NC = 10), early-stage NPC (E-NPC = 10), and late-stage NPC (L-NPC = 10). Eighteen sEV proteins were identified as potential biomarkers. Subsequently, parallel reaction monitoring (PRM) proteomic analysis preliminarily confirmed sEV carbonic anhydrase 1 (CA1) as a highly promising biomarker for NPC, particularly in early-stage diagnosis (NC = 15; E-NPC = 10; L-NPC = 15). To facilitate this, we developed an automated, high-throughput and highly sensitive CA1 immune-chemiluminescence chip technology characterized by a broad linear detection range and robust controls. Further validation in an independent retrospective cohort (NC = 89; E-NPC = 39; L-NPC = 172) using this technology confirmed sEV CA1 as a reliable diagnostic biomarker for NPC (AUC = 0.9809) and E-NPC (AUC = 0.9893), independent of EBV-DNA testing. Notably, sEV CA1 exhibited superior diagnostic performance compared to EBV-DNA, with a significant incremental net reclassification improvement of 27.61 % for NPC and 72.11 % for E-NPC detection. Thus, this study identifies sEV CA1 as an innovative diagnostic biomarker for NPC and E-NPC independent of EBV-DNA. Additionally, it establishes an immune-chemiluminescence chip technology for the detection of sEV CA1 protein, paving the way for further validation and clinical application.

Proteomic Identification of Small Extracellular Vesicle Proteins LAMB1 and Histone H4 for Prostate Cancer Diagnosis and Risk Stratification

Diagnosis and stratification of prostate cancer (PCa) patients using the prostate-specific antigen (PSA) test is challenging. Extracellular vesicles (EVs), as a new star of liquid biopsy, has attracted interest to complement inaccurate PSA screening and invasiveness of tissue biopsy. In this study, a panel of potential small EV (sEV) protein biomarkers is identified from PCa cell lines using label-free LC-MS/MS proteomics. These biomarkers underwent further validation with plasma and urine samples from different PCa stages through parallel reaction monitoring-based targeted proteomics, western blotting, and ELISA. Additionally, a tissue microarray containing cancerous and noncancerous tissues is screened to provide additional evidence of selected sEV proteins associated with cancer origin. Results indicate that sEV protein LAMB1 is highly expressed in human plasma of metastatic PCa patients compared with localised PCa patients and control subjects, while sEV protein Histone H4 is highly expressed in human urine of high-risk PCa patients compared to low-risk PCa patients and control subjects. These two sEV proteins demonstrate higher specificity and sensitivity than the PSA test and show promise for metastatic PCa diagnosis, progression monitoring, and risk stratification.

Recent Advances in Microfluidic-Based Extracellular Vesicle Analysis

Extracellular vesicles (EVs) serve as vital messengers, facilitating communication between cells, and exhibit tremendous potential in the diagnosis and treatment of diseases. However, conventional EV isolation methods are labor-intensive, and they harvest EVs with low purity and compromised recovery. In addition, the drawbacks, such as the limited sensitivity and specificity of traditional EV analysis methods, hinder the application of EVs in clinical use. Therefore, it is urgent to develop effective and standardized methods for isolating and detecting EVs. Microfluidics technology is a powerful and rapidly developing technology that has been introduced as a potential solution for the above bottlenecks. It holds the advantages of high integration, short analysis time, and low consumption of samples and reagents. In this review, we summarize the traditional techniques alongside microfluidic-based methodologies for the isolation and detection of EVs. We emphasize the distinct advantages of microfluidic technology in enhancing the capture efficiency and precise targeting of extracellular vesicles (EVs). We also explore its analytical role in targeted detection. Furthermore, this review highlights the transformative impact of microfluidic technology on EV analysis, with the potential to achieve automated and high-throughput EV detection in clinical samples.

Thermophoretic glycan profiling of extracellular vesicles for triple-negative breast cancer management

Triple-negative breast cancer (TNBC) is a highly metastatic and heterogeneous type of breast cancer with poor outcomes. Precise, non-invasive methods for diagnosis, monitoring and prognosis of TNBC are particularly challenging due to a paucity of TNBC biomarkers. Glycans on extracellular vesicles (EVs) hold the promise as valuable biomarkers, but conventional methods for glycan analysis are not feasible in clinical practice. Here, we report that a lectin-based thermophoretic assay (EVLET) streamlines vibrating membrane filtration (VMF) and thermophoretic amplification, allowing for rapid, sensitive, selective and cost-effective EV glycan profiling in TNBC plasma. A pilot cohort study shows that the EV glycan signature reaches 91% accuracy for TNBC detection and 96% accuracy for longitudinal monitoring of TNBC therapeutic response. Moreover, we demonstrate the potential of EV glycan signature for predicting TNBC progression. Our EVLET system lays the foundation for non-invasive cancer management by EV glycans.

Recent advances in micro-physiological systems for investigating tumor metastasis and organotropism

Tumor metastasis involves complex processes that traditional 2D cultures and animal models struggle to fully replicate. Metastatic tumors undergo a multitude of transformations, including genetic diversification, adaptation to diverse microenvironments, and modified drug responses, contributing significantly to cancer-related mortality. Micro-physiological systems (MPS) technology emerges as a promising approach to emulate the metastatic process by integrating critical biochemical, biomechanical, and geometrical cues at a microscale. These systems are particularly advantageous simulating metastasis organotropism, the phenomenon where tumors exhibit a preference for metastasizing to particular organs. Organotropism is influenced by various factors, such as tumor cell characteristics, unique organ microenvironments, and organ-specific vascular conditions, all of which can be effectively examined using MPS. This review surveys the recent developments in MPS research from the past five years, with a specific focus on their applications in replicating tumor metastasis and organotropism. Furthermore, we discuss the current limitations in MPS-based studies of organotropism and propose strategies for more accurately replicating and analyzing the intricate aspects of organ-specific metastasis, which is pivotal in the development of targeted therapeutic approaches against metastatic cancers.

Exploiting Sound for Emerging Applications of Extracellular Vesicles

Extracellular vesicles are nano- to microscale, membrane-bound particles released by cells into extracellular space, and act as carriers of biomarkers and therapeutics, holding promising potential in translational medicine. However, the challenges remain in handling and detecting extracellular vesicles for disease diagnosis as well as exploring their therapeutic capability for disease treatment. Here, we review the recent engineering and technology advances by leveraging the power of sound waves to address the challenges in diagnostic and therapeutic applications of extracellular vesicles and biomimetic nanovesicles. We first introduce the fundamental principles of sound waves for understanding different acoustic-assisted extracellular vesicle technologies. We discuss the acoustic-assisted diagnostic methods including the purification, manipulation, biosensing, and bioimaging of extracellular vesicles. Then, we summarize the recent advances in acoustically enhanced therapeutics using extracellular vesicles and biomimetic nanovesicles. Finally, we provide perspectives into current challenges and future clinical applications of the promising extracellular vesicles and biomimetic nanovesicles powered by sound.

Engineering Heterogeneous Tumor Models for Biomedical Applications

Tumor tissue engineering holds great promise for replicating the physiological and behavioral characteristics of tumors in vitro. Advances in this field have led to new opportunities for studying the tumor microenvironment and exploring potential anti-cancer therapeutics. However, the main obstacle to the widespread adoption of tumor models is the poor understanding and insufficient reconstruction of tumor heterogeneity. In this review, the current progress of engineering heterogeneous tumor models is discussed. First, the major components of tumor heterogeneity are summarized, which encompasses various signaling pathways, cell proliferations, and spatial configurations. Then, contemporary approaches are elucidated in tumor engineering that are guided by fundamental principles of tumor biology, and the potential of a bottom-up approach in tumor engineering is highlighted. Additionally, the characterization approaches and biomedical applications of tumor models are discussed, emphasizing the significant role of engineered tumor models in scientific research and clinical trials. Lastly, the challenges of heterogeneous tumor models in promoting oncology research and tumor therapy are described and key directions for future research are provided.

Promising and Minimally Invasive Biomarkers: Targeting Melanoma

The therapeutic landscape of malignant melanoma has been radically reformed in recent years, with novel treatments emerging in both the field of cancer immunotherapy and signalling pathway inhibition. Large-scale tumour genomic characterization has accurately classified malignant melanoma into four different genomic subtypes so far. Despite this, only somatic mutations in BRAF oncogene, as assessed in tumour biopsies, has so far become a validated predictive biomarker of treatment with small molecule inhibitors. The biology of tumour evolution and heterogeneity has uncovered the current limitations associated with decoding genomic drivers based only on a single-site tumour biopsy. There is an urgent need to develop minimally invasive biomarkers that accurately reflect the real-time evolution of melanoma and that allow for streamlined collection, analysis, and interpretation. These will enable us to face challenges with tumour tissue attainment and process and will fulfil the vision of utilizing "liquid biopsy" to guide clinical decisions, in a manner akin to how it is used in the management of haematological malignancies. In this review, we will summarize the most recent published evidence on the role of minimally invasive biomarkers in melanoma, commenting on their future potential to lead to practice-changing discoveries.

A Magnetically Driven Tandem Chip Enables Rapid Isolation and Multiplexed Profiling of Extracellular Vesicles

The protein phenotypes of extracellular vesicles (EVs) have emerged as promising biomarkers for cancer diagnosis and treatment monitoring. However, the technical challenges in rapid isolation and multiplexed molecular detection of EVs have limited their clinical practice. Herein, we developed a magnetically driven tandem chip to achieve streamlined rapid isolation and multiplexed profiling of surface protein biomarkers of EVs. Driven by magnetic force, the magnetic nanomixers not only act as tiny stir bars to promote mass transfer and enhance reaction efficiency of EVs, but also transport on communicating vessels of the tandem chip continuously and expedite the assay workflow. We designed cyclic surface enhancement of Raman scattering (SERS) tags to bind with target EVs and then release them by exonuclease I, eliminating steric hindrance and amplifying the SERS signal of multiple protein biomarkers on EVs. Due to the excellent assay performance, six breast cancer biomarkers were detected simultaneously on EVs using only 10 μL plasma within 1.5 h. The unweighted SUM signature offers great accuracy in discriminating breast cancer patients from healthy donors. Overall, the dynamic magnetic driving tandem chip offers a new avenue to advance the clinical application of EV-based liquid biopsy.

Hierarchical Fluid Interface Enables Spatiotemporal Regulation of Ligand Distribution to Increase Kinetics and Thermodynamics of Interfacial Binding Reaction

In nature, regulation of the spatiotemporal distribution of interfacial receptors and ligands leads to optimum binding kinetics and thermodynamics of receptor-ligand binding reactions within interfaces. Inspired by this, we report a hierarchical fluid interface (HieFluidFace) to regulate the spatiotemporal distribution of interfacial ligands to increase the rate and thermodynamic favorability of interfacial binding reactions. Each aptamer-functionalized gold nanoparticle, termed spherical aptamer (SAPT), is anchored on a supported lipid bilayer without fluidity, like an "island", and is surrounded by many fluorescent aptamers (FAPTs) with free fluidity, like "rafts". Such ligand "island-rafts" model provides a large reactive cross-section for rapid binding to cellular receptors. The synergistic multivalency of SAPTs and FAPTs improves interfacial affinity for tight capture. Moreover, FAPTs accumulate at binding sites to bind to cellular receptors with clustered fluorescence to "lighten" cells for direct identification. Thus, HieFluidFace in a microfluidic chip achieves high-performance capture and identification of circulating tumor cells from clinical samples, providing a new paradigm to optimize the kinetics and thermodynamics of interfacial binding reactions.

A one-pot isothermal Cas12-based assay for the sensitive detection of microRNAs

The use of microRNAs as clinical cancer biomarkers is hindered by the absence of accurate, fast and inexpensive assays for their detection in biofluids. Here we report a one-step and one-pot isothermal assay that leverages rolling-circle amplification and the endonuclease Cas12a for the accurate detection of specific miRNAs. The assay exploits the cis-cleavage activity of Cas12a to enable exponential rolling-circle amplification of target sequences and its trans-cleavage activity for their detection and for signal amplification. In plasma from patients with pancreatic ductal adenocarcinoma, the assay detected the miRNAs miR-21, miR-196a, miR-451a and miR-1246 in extracellular vesicles at single-digit femtomolar concentrations with single-nucleotide specificity. The assay is rapid (sample-to-answer times ranged from 20 min to 3 h), does not require specialized instrumentation and is compatible with a smartphone-based fluorescence detection and with the lateral-flow format for visual readouts. Simple assays for the detection of miRNAs in blood may aid the development of miRNAs as biomarkers for the diagnosis and prognosis of cancers.

EphA2 Proteolytic Fragment as a Sensitive Diagnostic Biomarker for Very Early-stage Pancreatic Ductal Carcinoma

Cleavage of erythropoietin-producing hepatocellular ephrin receptor A2 (EphA2) triggers malignant progression and yields an N-terminal fragment (EphA2-NF) detectable in sera from patients with pancreatic ductal carcinoma. We established a quantitative automated chemiluminescence immunoassay for EphA2-NF and evaluated serum EphA2-NF levels as a biomarker to diagnose pancreatic ductal carcinoma in the test and validation cohorts. The EphA2-NF value was elevated (above the cutoff: mean ± SD) in more than half of the patients with stage I/II pancreatic ductal carcinoma. Among patients receiving standard chemotherapy for pancreatic ductal carcinoma [gemcitabine plus nab-paclitaxel (GnP)], the median survival time of patients with elevated serum EphA2-NF was half that of patients with values below the cutoff. Patients with intraductal papillary mucinous neoplasm (IPMN), a precancerous pancreatic ductal carcinoma lesion, also show high serum EphA2 levels, which are associated with an increase in pancreatic duct size and the development of pancreatic ductal carcinoma in some cases. IHC showed loss of EphA2-NF staining in IPMN with pancreatic ductal carcinoma, but not in the normal epithelium or IPMN without pancreatic ductal carcinoma, regardless of the histologic grade. These results suggest that EphA2 cleavage is an essential event that occurs very early in pancreatic ductal carcinoma development, and that the consequent release of EphA2-NF can be detected in the serum. Thus, serum EphA2-NF could be a diagnostic biomarker for very early-stage pancreatic ductal carcinoma and pancreatic ductal carcinoma development from high-risk IPMN and as a prognostic biomarker after chemotherapy with GnP.

SIGNIFICANCE

EphA2 N-terminus deletion is involved in pancreatic ductal carcinoma development from high-risk IPMN and EphA2-NF produced by cleavage can be used as a serum biomarker to diagnose pancreatic ductal carcinoma and predict pancreatic ductal carcinoma development from high-risk IPMN.

Micro-/nanoscale robotics for chemical and biological sensing

The field of micro-/nanorobotics has attracted extensive interest from a variety of research communities and witnessed enormous progress in a broad array of applications ranging from basic research to global healthcare and to environmental remediation and protection. In particular, micro-/nanoscale robots provide an enabling platform for the development of next-generation chemical and biological sensing modalities, owing to their unique advantages as programmable, self-sustainable, and/or autonomous mobile carriers to accommodate and promote physical and chemical processes. In this review, we intend to provide an overview of the state-of-the-art development in this area and share our perspective in the future trend. This review starts with a general introduction of micro-/nanorobotics and the commonly used methods for propulsion of micro-/nanorobots in solution, along with the commonly used methods in their fabrication. Next, we comprehensively summarize the current status of the micro/nanorobotic research in relevance to chemical and biological sensing (e.g., motion-based sensing, optical sensing, and electrochemical sensing). Following that, we provide an overview of the primary challenges currently faced in the micro-/nanorobotic research. Finally, we conclude this review by providing our perspective detailing the future application of soft robotics in chemical and biological sensing.

Multiplexed RNA profiling by regenerative catalysis enables blood-based subtyping of brain tumors

Current technologies to subtype glioblastoma (GBM), the most lethal brain tumor, require highly invasive brain biopsies. Here, we develop a dedicated analytical platform to achieve direct and multiplexed profiling of circulating RNAs in extracellular vesicles for blood-based GBM characterization. The technology, termed 'enzyme ZIF-8 complexes for regenerative and catalytic digital detection of RNA' (EZ-READ), leverages an RNA-responsive transducer to regeneratively convert and catalytically enhance signals from rare RNA targets. Each transducer comprises hybrid complexes - protein enzymes encapsulated within metal organic frameworks - to configure strong catalytic activity and robust protection. Upon target RNA hybridization, the transducer activates directly to liberate catalytic complexes, in a target-recyclable manner; when partitioned within a microfluidic device, these complexes can individually catalyze strong chemifluorescence reactions for digital RNA quantification. The EZ-READ platform thus enables programmable and reliable RNA detection, across different-sized RNA subtypes (miRNA and mRNA), directly in sample lysates. When clinically evaluated, the EZ-READ platform established composite signatures for accurate blood-based GBM diagnosis and subtyping.

Integrated "lab-on-a-chip" microfluidic systems for isolation, enrichment, and analysis of cancer biomarkers

The liquid biopsy has garnered considerable attention as a complementary clinical tool for the early detection, molecular characterization and monitoring of cancer over the past decade. In contrast to traditional solid biopsy techniques, liquid biopsy offers a less invasive and safer alternative for routine cancer screening. Recent advances in microfluidic technologies have enabled handling of liquid biopsy-derived biomarkers with high sensitivity, throughput, and convenience. The integration of these multi-functional microfluidic technologies into a 'lab-on-a-chip' offers a powerful solution for processing and analyzing samples on a single platform, thereby reducing the complexity, bio-analyte loss and cross-contamination associated with multiple handling and transfer steps in more conventional benchtop workflows. This review critically addresses recent developments in integrated microfluidic technologies for cancer detection, highlighting isolation, enrichment, and analysis strategies for three important sub-types of cancer biomarkers: circulating tumor cells, circulating tumor DNA and exosomes. We first discuss the unique characteristics and advantages of the various lab-on-a-chip technologies developed to operate on each biomarker subtype. This is then followed by a discussion on the challenges and opportunities in the field of integrated systems for cancer detection. Ultimately, integrated microfluidic platforms form the core of a new class of point-of-care diagnostic tools by virtue of their ease-of-operation, portability and high sensitivity. Widespread availability of such tools could potentially result in more frequent and convenient screening for early signs of cancer at clinical labs or primary care offices.

Simultaneous Detection of Tumor Derived Exosomal Protein-MicroRNA Pairs with an Exo-PROS Biosensor for Cancer Diagnosis

Tumor derived exosomes (TEXs) have emerged as promising biomarkers for cancer liquid biopsy. Conventional methods (such as ELISA and qRT-PCR) and emerging biosensing technologies mainly detect a single type of exosomal biomarker due to the distinct properties of different biomolecules. Sensitive detection of two different types of TEX biomarkers, i.e., protein and microRNA combined biomarkers, may greatly improve cancer diagnostic accuracy. We developed an exosome protein microRNA one-stop (Exo-PROS) biosensor that not only selectively captured TEXs but also enabled in situ, simultaneous detection of TEX protein-microRNA pairs via a surface plasmon resonance mechanism. Exo-PROS assay is a fast, reliable, low sample consumption, and user-friendly test. With a total of 175 cancer patients and normal controls, we demonstrated that TEX protein-microRNA pairs measured by Exo-PROS assay detected lung cancer and breast cancer with 99% and 96% accuracy, respectively. Exo-PROS assay also showed superior diagnostic performance to conventional ELISA and qRT-PCR methods. Our results demonstrated that Exo-PROS assay is a potent liquid biopsy assay for cancer diagnosis.

The role of extracellular vesicles in cancer

Intercellular communication is a key feature of cancer progression and metastasis. Extracellular vesicles (EVs) are generated by all cells, including cancer cells, and recent studies have identified EVs as key mediators of cell-cell communication via packaging and transfer of bioactive constituents to impact the biology and function of cancer cells and cells of the tumor microenvironment. Here, we review recent advances in understanding the functional contribution of EVs to cancer progression and metastasis, as cancer biomarkers, and the development of cancer therapeutics.

Analytical device miniaturization for the detection of circulating biomarkers

Diverse (sub)cellular materials are secreted by cells into the systemic circulation at different stages of disease progression. These circulating biomarkers include whole cells, such as circulating tumour cells, subcellular extracellular vesicles and cell-free factors such as DNA, RNA and proteins. The biophysical and biomolecular state of circulating biomarkers carry a rich repertoire of molecular information that can be captured in the form of liquid biopsies for disease detection and monitoring. In this Review, we discuss miniaturized platforms that allow the minimally invasive and rapid detection and analysis of circulating biomarkers, accounting for their differences in size, concentration and molecular composition. We examine differently scaled materials and devices that can enrich, measure and analyse specific circulating biomarkers, outlining their distinct detection challenges. Finally, we highlight emerging opportunities in biomarker and device integration and provide key future milestones for their clinical translation.

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.

Plasmon-Enhanced Single Extracellular Vesicle Analysis for Cholangiocarcinoma Diagnosis

Cholangiocarcinoma (CCA) is a fatal disease often detected late in unresectable stages. Currently, there are no effective diagnostic methods or biomarkers to detect CCA early with high confidence. Analysis of tumor-derived extracellular vesicles (tEVs) harvested from liquid biopsies can provide a new opportunity to achieve this goal. Here, an advanced nanoplasmonic sensing technology is reported, termed FLEX (fluorescence-amplified extracellular vesicle sensing technology), for sensitive and robust single EV analysis. In the FLEX assay, EVs are captured on a plasmonic gold nanowell surface and immunolabeled for cancer-associated biomarkers to identify tEVs. The underlying plasmonic gold nanowell structures then amplify EVs' fluorescence signals, an effective amplification process at the single EV level. The FLEX EV analysis revealed a wide heterogeneity of tEVs and their marker levels. FLEX also detected small tEVs not detected by conventional EV fluorescence imaging due to weak signals. Tumor markers (MUC1, EGFR, and EPCAM) are identified in CCA, and this marker combination is applied to detect tEVs in clinical bile samples. The FLEX assay detected CCA with an area under the curve of 0.93, significantly better than current clinical markers. The sensitive and accurate nanoplasmonic EV sensing technology can aid in early CCA diagnosis.

Integrating CRISPR-Cas12a into a Microfluidic Dual-Droplet Device Enables Simultaneous Detection of HPV16 and HPV18

Fast, simplified, and multiplexed detection of human papillomaviruses (HPVs) is of great importance for both clinical management and population screening. However, current HPV detection methods often require sophisticated instruments and laborious procedures to detect multiple targets. In this work, we developed a simple microfluidic dual-droplet device (M-D3) for the simultaneous detection of HPV16 and HPV18 by combining the CRISPR-Cas12a system and multiplexed recombinase polymerase amplification (RPA) assay. A new approach of combining pressure/vacuum was proposed for efficient droplet generation with minimal sample consumption. Two groups of droplets that separately encapsulate the relevant Cas12a/crRNA and the fluorescent green or red reporters are parallelly generated, followed by automatic imaging to discriminate the HPV subtypes based on the specific fluorescence of the droplets. The M-D3 platform performs with high sensitivity (∼0.02 nM for unamplified plasmids) and specificity in detecting HPV16 and HPV18 DNA. By combining the RPA and Cas12a assay, M-D3 allows on-chip detection of HPV16 and HPV18 DNA simultaneously within 30 min, reaching a detection limit of 10^-18 M (∼1 copy/reaction). Moreover, the outstanding performance of M-D3 was validated in testing 20 clinical patient samples with HPV infection risk, showing a sensitivity of 92.3% and a specificity of 100%. By integrating the dual-droplet generator, CRISPR-Cas12a, and multiplexed RPA, the M-D3 platform provides an efficient way to discriminate the two most harmful HPV subtypes and holds great potential in the applications of multiplexed nucleic acid testing.

All-in-One Nanowire Assay System for Capture and Analysis of Extracellular Vesicles from an ex Vivo Brain Tumor Model

Extracellular vesicles (EVs) have promising potential as biomarkers for early cancer diagnosis. The EVs have been widely studied as biological cargo containing essential biological information not only from inside vesicles such as nucleic acids and proteins but also from outside vesicles such as membrane proteins and glycolipids. Although various methods have been developed to isolate EVs with high yields such as captures based on density, size, and immunoaffinity, different measurement systems are needed to analyze EVs after isolation, and a platform that enables all-in-one analysis of EVs from capture to detection in multiple samples is desired. Since a nanowire-based approach has shown an effective capability for capturing EVs via surface charge interaction compared to other conventional methods, here, we upgraded the conventional well plate assay to an all-in-one nanowire-integrated well plate assay system (i.e., a nanowire assay system) that enables charge-based EV capture and EV analysis of membrane proteins. We applied the nanowire assay system to analyze EVs from brain tumor organoids in which tumor environments, including vascular formations, were reconstructed, and we found that the membrane protein expression ratio of CD31/CD63 was 1.42-fold higher in the tumor organoid-derived EVs with a p-value less than 0.05. Furthermore, this ratio for urine samples from glioblastoma patients was 2.25-fold higher than that from noncancer subjects with a p-value less than 0.05 as well. Our results demonstrated that the conventional well plate method integrated with the nanowire-based EV capture approach allows users not only to capture EVs effectively but also to analyze them in one assay system. We anticipate that the all-in-one nanowire assay system will be a powerful tool for elucidating EV-mediated tumor-microenvironment crosstalk.

Fluid nanoporous microinterface enables multiscale-enhanced affinity interaction for tumor-derived extracellular vesicle detection

Tumor-derived extracellular vesicles (T-EVs) represent valuable markers for tumor diagnosis and treatment guidance. However, nanoscale sizes and the low abundance of marker proteins of T-EVs restrict interfacial affinity reaction, leading to low isolation efficiency and detection sensitivity. Here, we engineer a fluid nanoporous microinterface (FluidporeFace) in a microfluidic chip by decorating supported lipid bilayers (SLBs) on nanoporous herringbone microstructures with a multiscale-enhanced affinity reaction for efficient isolation of T-EVs. At the microscale level, the herringbone micropattern promotes the mass transfer of T-EVs to the surface. At the nanoscale level, nanoporousity can overcome boundary effects for close contact between T-EVs and the interface. At the molecular level, fluid SLBs afford clustering of recognition molecules at the binding site, enabling multivalent binding with an ∼83-fold increase of affinity compared with the nonfluid interface. With the synergetic enhanced mass transfer, interface contact, and binding affinity, FluidporeFace affords ultrasensitive detection of T-EVs with a limit of detection of 10 T-EVs μL −1 , whose PD-L1 expression levels successfully distinguish cancer patients from healthy donors. We expect this multiscale enhanced interfacial reaction strategy will inspire the biosensor design and expand liquid biopsy applications, especially for low-abundant targets in clinical samples.

Extracellular vesicle isolation, purification and evaluation in cancer diagnosis

Strategies for non-invasive biomarker discovery in early detection of cancer are an urgent need. Extracellular vesicles (EVs) have generated increasing attention from the scientific community and are under intensive investigations due to their unique biological profiles and their non-invasive nature. EVs are membrane-enclosed vesicles with variable sizes and function. Such vesicles are actively secreted from multiple cell types and are considered as key vehicles for inter-cellular communications and signalling. The stability and potential to easily cross biological barriers enable EVs for exerting durable effects on target cells. These along with easy access to such vesicles, the consistent secretion from tumour during all stages of tumorigenesis and their content providing a reservoir of molecules as well as mirroring the identity of the cell of origin are virtues that have made EVs appealing to be assessed in liquid biopsy approaches and for using as a promising resource of biomarkers in cancer diagnosis and therapy and monitoring targeted cancer therapy. Early detection of EVs will guide time-scheduled personalised therapy. Surveying reliable and sensitive methods for rapid isolation of EVs from biofluids, the purity of isolated vesicles and their molecular profiling and marker specification for clinical translation in patients with cancer are issues in the area and the hot topics of many recent studies. Here, the focus is over methods for EV isolation and stratification for digging more information about liquid biopsy-based diagnosis. Extending knowledge regarding EV-based strategies is a key to validate independent patient follow-up for cancer diagnosis at early stages and inspecting the efficacy of therapeutics.

Highly Selective Purification of Plasma Extracellular Vesicles Using Titanium Dioxide Microparticles for Depicting the Metabolic Signatures of Diabetic Retinopathy

Extracellular vesicle (EV) cargos with regular fluctuations hold the potential for providing chemical predictors toward clinical diagnosis and prognosis. A plasma sample is one of the most important sources of circulating EVs, yet the technical barrier and cost consumption in plasma-EV isolation still limit its application in disease diagnosis and biomarker discovery. Here, we introduced an easy-to-use strategy that allows selectively purifying small EVs (sEVs) from human plasma and detecting their metabolic alternations. Fe₃O₄@TiO₂ microbeads with a rough island-shaped surface have proven the capability of performing efficient and reversible sEV capture owing to the phospholipid affinity, enhanced binding sites, and size-exclusion-like effect of the rough TiO₂ shell. The proposed system can also shorten the separation procedure from hours to 20 min when compared with the ultracentrifugation method and yield approximately 10⁸ sEV particles from 100 μL of plasma. Metabolome variations of sEVs among progressive diabetic retinopathy subjects were finally studied, observing a cluster of metabolites with elevated levels and suggesting potential roles of these sEV chemicals in diabetic retinopathy onset and progression. Such a scalable and flexible EV capture system can be seen as an effective analytical tool for facilitating plasma-based liquid biopsies.

Bimetallic Metal-Organic Framework Fe/Co-MIL-88(NH2) Exhibiting High Peroxidase-like Activity and Its Application in Detection of Extracellular Vesicles

Metal-organic frameworks (MOFs) have many attractive features, including tunable composition, rigid structure, controllable pore size, and large specific surface area, and thus are highly applicable in molecular analysis. Depending on the MOF structure, a high number of unsaturated metal sites can be exposed to catalyze chemical reactions. In the present work, we report that using both Co(II) and Fe(III) to prepare the MIL-88(NH₂) MOF, we can produce the bimetallic MOF that can catalyze the conversion of 3,3',5,5″-tetramethylbenzidine (TMB) to a color product through a reaction with H₂O₂ at a higher reaction rate than the monometallic Fe-MIL-88(NH₂). The Michaelis constants (K_m) of the catalytic reaction for TMB and H₂O₂ are 3-5 times smaller, and the catalytic constants (k_cat) are 5-10 times higher than those of the horseradish peroxidase (HRP), supporting ultrahigh peroxidase-like activity. These values are also much more superior to those of the HRP-mimicking MOFs reported previously. Interestingly, the bimetallic MOF can be coupled with glucose oxidase (GOx) to trigger the cascade enzymatic reaction for highly sensitive detection of extracellular vesicles (EVs), a family of important biomarkers. Through conjugation to the aptamer that recognizes the marker protein on EV surface, the MOF can help isolate the EVs from biological matrices, which are subsequently labeled by GOx via antibody recognition. The cascade enzymatic reaction between MOF and GOx enables the detection of EVs at a concentration as low as 7.8 × 10⁴ particles/mL. The assay can be applied to monitor EV secretion by cultured cells and also can successfully detect the different EV quantities in the sera samples collected from cancer patients and healthy controls. Overall, we prove that the bimetallic Fe/Co-MIL-88(NH₂) MOF, with its high peroxidase activity and high biocompatibility, is a valuable tool deployable in clinical assays to facilitate disease diagnosis and prognosis.

Discovering the Secret of Diseases by Incorporated Tear Exosomes Analysis via Rapid-Isolation System: iTEARS

Nanoscale small extracellular vesicles (sEVs, exosomes) in tears allow us to investigate the multisignatures of diseases. However, the translations of tear sEVs for biomarker discovery and clinical diagnostics are practically limited by low recovery, long processing time, and small sample volume. Here, we report an incorporated tear-exosomes analysis via rapid-isolation system (iTEARS) via nanotechnology to discover the secrets of ocular disorders and systemic diseases. We isolate exosomes rapidly with high yield and purity from a few teardrops (∼10 μL) within 5 min via nanoporous membrane-based resonators for the quantitative detection and biomarker discovery through proteomic and transcriptomic analysis. We have identified 904 proteins, among which 228 proteins are discovered, 426 proteins are detected from exosomes of dry eye disease, and demonstrate CALML5, KRT6A, and S100P for the classification of dry eye disease. We have also investigated 484 miRNAs in tear exosomes and show miR-145-5p, miR-214-3p, miR-218-5p, and miR-9-5p are dysregulated during diabetic retinopathy development. We believe iTEARS can be used for improving molecular diagnostics via tears to identify ocular disorders, systemic diseases, and numerous other neurodegenerative diseases and cancer.

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

Extracellular vesicles (EVs) are complex lipid membrane vehicles with variable expressions of molecular cargo, composed of diverse subpopulations that participate in the intercellular signaling of biological responses in disease. EV-based liquid biopsies demonstrate invaluable clinical potential for overhauling current practices of disease management. Yet, EV heterogeneity is a major needle-in-a-haystack challenge to translate their use into clinical practice. In this review, existing digital assays will be discussed to analyze EVs at a single vesicle resolution, and future opportunities to optimize the throughput, multiplexing, and sensitivity of current digital EV assays will be highlighted. Furthermore, this review will outline the challenges and opportunities that impact the clinical translation of single EV technologies for disease diagnostics and treatment monitoring.

One-Step Thermophoretic AND Gate Operation on Extracellular Vesicles Improves Diagnosis of Prostate Cancer

Circulating extracellular vesicles (EVs) have emerged as a valuable source of cancer biomarkers. However, the high degree of EV heterogeneity and the complexity of clinical samples pose a challenge in the sensitive identification of tumor-derived EVs. Here we introduce a one-step thermophoretic AND gate operation (Tango) assay that integrates polyethylene glycol (PEG)-enhanced thermophoretic accumulation of EVs and simultaneous AND gate operation on EV membranes by dual-aptamers recognition. By using the Tango assay to detect tumor-derived EVs with co-presence of EpCAM and PSMA directly from serum in a homogeneous, separation-free format, we can discriminate prostate cancer (PCa) patients from benign prostatic hyperplasia (BPH) patients in the diagnostic gray zone with an accuracy of 91 % in 15 min. Our approach streamlines EV enrichment and AND gate operation on EVs in a single assay, providing a rapid, straightforward, and powerful method for precise and non-invasive diagnosis of cancer.

Extraction of small extracellular vesicles by label-free and biocompatible on-chip magnetic separation

Small vesicles (sEVs) are closely related to many diseases as they carry various bio-markers. Efficient separation of sEVs from complex biological samples is essential and prerequisite for the following treatment and further disease diagnosis. Here we propose a label-free and biocompatible on-chip magnetic separation system for efficient extraction of sEVs from cell culture supernatant. Through an on-chip ultra-high gradient magnetic field module, a magnetic field gradient close to 100 000 T m^-1 is generated inside the separation microchannel. By using fluorescent particles of 200 nm and 1000 nm to simulate sEVs and other bioparticles in a complex sample, the system design and the experimental parameters are optimized. Flow cytometry and a proposed fluorescence intensity analysis method both verify that the recovery rate and purity of 200 nm particles can reach 84.91% and 98.02%, respectively. Then, a biocompatible ferrofluid is utilized in the separation system to separate sEVs from the cell culture supernatant. The results tested by nanoparticle tracking analysis show that the recovery rate and purity of sEVs are 85.80% and 80.45%, superiorly exceeding the performance that the ultracentrifugation method can provide.

Ultrasensitive Single Extracellular Vesicle Detection Using High Throughput Droplet Digital Enzyme-Linked Immunosorbent Assay

Extracellular vesicles (EVs) have attracted enormous attention for their diagnostic and therapeutic potential. However, it has proven challenging to achieve the sensitivity to detect individual nanoscale EVs, the specificity to distinguish EV subpopulations, and a sufficient throughput to study EVs among an enormous background. To address this fundamental challenge, we developed a droplet-based optofluidic platform to quantify specific individual EV subpopulations at high throughput. The key innovation of our platform is parallelization of droplet generation, processing, and analysis to achieve a throughput (∼20 million droplets/min) more than 100× greater than typical microfluidics. We demonstrate that the improvement in throughput enables EV quantification at a limit of detection = 9EVs/μL, a >100× improvement over gold standard methods. Additionally, we demonstrate the clinical potential of this system by detecting human EVs in complex media. Building on this work, we expect this technology will allow accurate quantification of rare EV subpopulations for broad biomedical applications.

Physisorption of Affinity Ligands Facilitates Extracellular Vesicle Detection with Low Non-Specific Binding to Plasmonic Gold Substrates

Plasmonic biosensors are increasingly being used for the analysis of extracellular vesicles (EVs) originating from disease areas. However, the high non-specific binding of EVs to a gold-sensing surface has been a critical problem and hindered the true translational potential. Here, we report that direct antibody immobilization on the plasmonic gold surface via physisorption shows excellent capture of cancer-derived EVs with ultralow non-specific binding even at very high concentrations. Contrary to commonly used methods that involve thiol-based linker attachment and an EDC/sulfo-NHS reaction, we show a higher specific capture rate and >50-fold lower non-specific on citrate-capped plain and nanopatterned gold surfaces. The method provides a simple, fast, and reproducible means to functionalize plasmonic gold surfaces with antibodies for robust EV biosensing.

Aptamer-Functionalized Barcodes in Herringbone Microfluidics for Multiple Detection of Exosomes

Tumor-derived exosomes are vital for clinical dynamic and accurate tumor diagnosis, thus developing sensitive and multiple exosomes detection technology has attracted remarkable attention of scientists. Here, a novel herringbone microfluidic device with aptamer-functionalized barcodes integration for specific capture and multiple detection of tumor-derived exosomes is presented. The barcodes with core-shell constructions are obtained by partially replicating the periodically ordered hexagonal close-packaged colloidal crystal beads. As their inverse opal hydrogel shell possesses rich interconnected pores, the barcodes could provide abundant surface area for functionalization of DNA aptamers to realize specific recognition of target exosomes. Besides, the encoded structure colors of the barcodes can be maintained stably during the detection events as their hardish cores are with sufficient mechanical strength. It is demonstrated that by embedding these barcodes in herringbone groove microfluidic device with designed patterns, the specific capture efficiency and synergetic detection of multiple tumor-derived exosomes in peripheral blood can be significantly improved due to enhanced resistance of turbulent flow. These features make the aptamer-functionalized barcodes and herringbone microfluidics integrated platform promising for exosomes extraction and dynamic tumor diagnosis.

A Journey on Extracellular Vesicles for Matrix Metalloproteinases: A Mechanistic Perspective

Matrix metalloproteinases (MMPs) are key players in matrix remodeling and their function has been particularly investigated in cancer biology. Indeed, through extracellular matrix (ECM) degradation and shedding of diverse cell surface macromolecules, they are implicated in different steps of tumor development, from local expansion by growth to tissue invasion and metastasis. Interestingly, MMPs are also components of extracellular vesicles (EVs). EVs are membrane-limited organelles that cells release in their extracellular environment. These "secreted" vesicles are now well accepted players in cell-to-cell communication. EVs have received a lot of interest in recent years as they are also envisioned as sources of biomarkers and as potentially outperforming vehicles for the delivery of therapeutics. Molecular machineries governing EV biogenesis, cargo loading and delivery to recipient cells are complex and still under intense investigation. In this review, we will summarize the state of the art of our knowledge about the molecular mechanisms implicated in MMP trafficking and secretion. We focus on MT1-MMP, a major effector of invasive cell behavior. We will also discuss how this knowledge is of interest for a better understanding of EV-loading of MMPs. Such knowledge might be of use to engineer novel strategies for cancer treatment. A better understanding of these mechanisms could also be used to design more efficient EV-based therapies.

The RNA-binding protein HuR in human cancer: A friend or foe?

The RNA-binding proteins (RBPs) are critical trans factors that associate with specific cis elements present in mRNAs whose stability and translation are subject to regulation. The RBP Hu antigen R (HuR) is overexpressed in a wide variety of human cancers and serves as a prognostic factor of poor clinical outcome. HuR promotes tumorigenesis by interacting with a subset of oncogenic mRNAs implicated in different cancer hallmarks, and resistance to therapy. Reduction of HuR levels in cancer cells leads to tumor regression in mouse xenograft models. These findings prompt a working model whereby cancer cells use HuR, a master switch of multiple oncogenic mRNAs, to drive drug resistance and promote cell survival and metastasis, thus rendering the tumor cells with high cytoplasmic HuR more progressive and resistant to therapy. This review summarizes the roles of HuR in cancer and other diseases, therapeutic potential of HuR inhibition, and the current status of drug discovery on HuR.

Multi-Modal Microfluidics (M3) for Sample Preparation of Liquid Biopsy: Bridging the Gap between Proof-of-Concept Demonstrations and Practical Applications

Liquid biopsy, the technique used to shed light on diseases via liquid samples, has displayed various advantages, including minimal invasiveness, low risk, and ease of multiple sampling for dynamic monitoring, and has drawn extensive attention from multidisciplinary fields in the past decade. With the rapid development of microfluidics, it has been possible to manipulate targets of interest including cells, microorganisms, and exosomes at a single number level, which dramatically promotes the characterization and analysis of disease-related markers, and thus improves the capability of liquid biopsy. However, when lab-ready techniques transfer into hospital-applicable tools, they still face a big challenge in processing raw clinical specimens, which are usually of a large volume and consist of rare targets drowned in complex backgrounds. Efforts toward the sample preparation of clinical specimens (i.e., recovering/concentrating the rare targets among complex backgrounds from large-volume liquids) are required to bridge the gap between the proof-of-concept demonstrations and practical applications. The throughput, sensitivity, and purity (TSP performance criteria) in sample preparation, i.e., the volume speed in processing liquid samples and the efficiencies of recovering rare targets and depleting the backgrounds, are three key factors requiring careful consideration when implementing microfluidic-based liquid biopsy for clinical practices. Platforms based on a single microfluidic module (single-modal microfluidics) can hardly fulfill all the aforementioned TSP performance criteria in clinical practices, which puts forward an urgent need to combine/couple multiple microfluidic modules into one working system (i.e., multi-modal microfluidics, M³) to realize practically applicable techniques for the sample preparation of liquid biopsy. This perspective briefly summarizes the typical microfluidic-based liquid biopsy techniques and discusses potential strategies to develop M³ systems for clinical practices of liquid biopsy from the aspect of sample preparation.

Review on Strategies and Technologies for Exosome Isolation and Purification

Exosomes, a nano-sized subtype of extracellular vesicles secreted from almost all living cells, are capable of transferring cell-specific constituents of the source cell to the recipient cell. Cumulative evidence has revealed exosomes play an irreplaceable role in prognostic, diagnostic, and even therapeutic aspects. A method that can efficiently provide intact and pure exosomes samples is the first step to both exosome-based liquid biopsies and therapeutics. Unfortunately, common exosomal separation techniques suffer from operation complexity, time consumption, large sample volumes and low purity, posing significant challenges for exosomal downstream analysis. Efficient, simple, and affordable methods to isolate exosomes are crucial to carrying out relevant researches. In the last decade, emerging technologies, especially microfluidic chips, have proposed superior strategies for exosome isolation and exhibited fascinating performances. While many excellent reviews have overviewed various methods, a compressive review including updated/improved methods for exosomal isolation is indispensable. Herein, we first overview exosomal properties, biogenesis, contents, and functions. Then, we briefly outline the conventional technologies and discuss the challenges of clinical applications of these technologies. Finally, we review emerging exosomal isolation strategies and large-scale GMP production of engineered exosomes to open up future perspectives of next-generation Exo-devices for cancer diagnosis and treatment.

Recent Advances in Device Engineering and Computational Analysis for Characterization of Cell-Released Cancer Biomarkers

During cancer progression, tumors shed different biomarkers into the bloodstream, including circulating tumor cells (CTCs), extracellular vesicles (EVs), circulating cell-free DNA (cfDNA), and circulating tumor DNA (ctDNA). The analysis of these biomarkers in the blood, known as 'liquid biopsy' (LB), is a promising approach for early cancer detection and treatment monitoring, and more recently, as a means for cancer therapy. Previous reviews have discussed the role of CTCs and ctDNA in cancer progression; however, ctDNA and EVs are rapidly evolving with technological advancements and computational analysis and are the subject of enormous recent studies in cancer biomarkers. In this review, first, we introduce these cell-released cancer biomarkers and briefly discuss their clinical significance in cancer diagnosis and treatment monitoring. Second, we present conventional and novel approaches for the isolation, profiling, and characterization of these markers. We then investigate the mathematical and in silico models that are developed to investigate the function of ctDNA and EVs in cancer progression. We convey our views on what is needed to pave the way to translate the emerging technologies and models into the clinic and make the case that optimized next-generation techniques and models are needed to precisely evaluate the clinical relevance of these LB markers.

Transcription phenotype of circulating tumor cells in non-metastatic breast cancer

The presented research is relevant, as breast cancer is the most commonly diagnosed cancer in the female population worldwide, with the exception of skin cancer. The aim of this article is to study the transcription phenotype of circulating tumor cells in non-metastatic breast cancer. The transcriptional phenotype of circulating tumor cells (CTCs) was studied using real-time polymerase chain reaction (PCR). Three-year OS was 79.2, and 90.8 without the expression with p Log-Rank=0.04. Independent prognostic factors for the recurrence of disease include the presence of CTCs expressing BIRC5 genes and ABC transporter genes in the peripheral blood before the start of special treatment for resectable breast cancer, as well as the preservation of CTCs per se after completion of special anticancer therapy. In patients with breast cancer stage I-IIIC, circulating tumor cells before special treatment have significant heterogeneity, manifested by a different transcriptional phenotype, including both actively growing and stem tumor cells, and cells at the epithelial-to-mesenchymal transition.

Multiplexed Profiling of Extracellular Vesicles for Biomarker Development

Extracellular vesicles (EVs) are cell-derived membranous particles that play a crucial role in molecular trafficking, intercellular transport and the egress of unwanted proteins. They have been implicated in many diseases including cancer and neurodegeneration. EVs are detected in all bodily fluids, and their protein and nucleic acid content offers a means of assessing the status of the cells from which they originated. As such, they provide opportunities in biomarker discovery for diagnosis, prognosis or the stratification of diseases as well as an objective monitoring of therapies. The simultaneous assaying of multiple EV-derived markers will be required for an impactful practical application, and multiplexing platforms have evolved with the potential to achieve this. Herein, we provide a comprehensive overview of the currently available multiplexing platforms for EV analysis, with a primary focus on miniaturized and integrated devices that offer potential step changes in analytical power, throughput and consistency.

The Advancing Roles of Exosomes in Breast Cancer

Breast cancer (BC) develops from breast tissue and is the most common aggressive malignant tumor in women worldwide. Although advanced treatment strategies have been applied and reduced current mortality rates, BC control remains unsatisfactory. It is essential to elucidate the underlying molecular mechanisms to assist clinical options. Exosomes are a type of extracellular vesicles and mediate cellular communications by delivering various biomolecules (oncogenes, oncomiRs, proteins, and even pharmacological compounds). These bioactive molecules can be transferred to change the transcriptome of target cells and influence tumor-related signaling pathways. Extensive studies have implicated exosomes in BC biology, including therapeutic resistance and the surrounding microenvironment. This review focuses on discussing the functions of exosomes in tumor treatment resistance, invasion and metastasis of BC. Moreover, we will also summarize multiple interactions between exosomes and the BC tumor microenvironment. Finally, we propose promising clinical applications of exosomes in BC.