Recent advances in microfluidic approaches for the isolation and detection of exosomes

Elucidation of extracellular vesicles behavior during capillary isoelectric focusing

In this study, we investigated the behavior of extracellular vesicles (EVs), during capillary isoelectric focusing (cIEF). For that, we used different approaches, imaging cIEF with a whole-column imaging detection (WCID) and conventional cIEF as well as different detection methods (LIF after EV labelling, native fluorescence and UV). Our study reveals that EVs exhibit significant aggregation during their migration toward, and upon reaching, their isoelectric point (pI). By optimizing key parameters such as voltage and the addition of solubilizers, we successfully reduced this issue, particularly with bovine milk EVs. Our findings also showed distinct pI regions observed for EVs isolated from different sources: bovine milk EVs shows acidic pI characteristics (4.0-4.1), while pig and human plasma EVs exhibit more basic pI zones (4.7-4.9 and 5.8-6.7, respectively). The study was extended to cIEF coupled to laser induced fluorescence detection (LIF) using intra-vesicular CFDA-labeled EVs, to better understand their susceptibilities. Prolonged mobilization time due to long capillary lengths adversely affected EV's integrity in conventional cIEF. Our study reveals the necessity to specific cIEF optimization for each EV source due to variations in charge distribution and aggregation behavior across different pI regions. The use of a short capillary length (<10 cm), low electric field and solubilizers such as Tween-20 is recommended to preserve EVs integrity during cIEF-EV studies.

From bench to bedside: The evolution of extracellular vesicle diagnostics through microfluidic and paper-based technologies

"Extracellular vesicles (EVs) have emerged as key mediators of intercellular communication and valuable biomarkers for various diseases. However, traditional EV isolation and detection methods often struggle with efficiency, scalability, and purity, limiting their clinical utility. Recent advances in microfluidic and paper-based technologies offer innovative solutions that enhance EV isolation and detection by reducing sample volume, accelerating processing times, and integrating multiple analytical steps into compact platforms. These technologies hold significant promise for advancing point-of-care diagnostics, enabling rapid disease detection, personalized treatment monitoring, and better patient outcomes. For example, early detection of cancer biomarkers through EVs can facilitate timely intervention, potentially improving survival rates, while rapid infectious disease diagnostics can support prompt treatment. Despite their potential, challenges such as standardization, scalability, and regulatory hurdles remain. This review discusses recent advancements in microfluidic and paper-based EV diagnostic technologies, their comparative advantages over traditional methods, and their transformative potential in clinical practice."

Mesenchymal stem cell-derived exosomes and the Wnt/β-catenin pathway: Unifying mechanisms of multi-organ regeneration and the path to precision clinical translation

In this editorial, we discuss the article by Fu Y et al, indicating that hair development is influenced by exosomes from human adipose-derived stem/stromal cell-mediated cell-to-cell communication via the Wnt/β-catenin pathway. In recent years, mesenchymal stem cells (MSCs) and MSC-derived exosomes (MSC-Exos) have emerged as a promising cell-free therapeutic strategy due to their robust regenerative capabilities across multiple tissues. MSC-Exos are enriched with bioactive molecules, including proteins, microRNAs, and growth factors, which activate critical signaling pathways, notably the Wnt/β-catenin pathway, to promote cell proliferation, differentiation, and tissue repair. This editorial systematically examines the application of MSC-Exos in regenerating diverse tissues such as hair follicles and kidney, lung, and cardiac muscle tissue. Central to their mechanism is the activation of the Wnt/β-catenin pathway, which drives cell cycle progression (via cyclin B1/cyclin-dependent kinase 1), suppresses apoptosis (through Bcl-2/Bax modulation), and attenuates fibrosis (by inhibiting transforming growth factor-β/alpha-smooth muscle actin). The challenges related to the clinical translation of exosome-based therapies, including standardization of isolation protocols, optimization of dosing and delivery methods, and safety evaluation, are discussed. The most important challenge is standardizing isolation protocols because exosomes obtained from different sources or treatment methods are different, which leads to differences in the therapeutic effects of exosomes. Overall, MSC-Exos provide an effective cell-free strategy for tissue repair and offer a robust foundation to develop personalized regenerative medicine.

An Au-Se bond-based fluorescent nanoprobe for thermophoretic aggregation imaging of exosomal miRNAs

Exosomal microRNAs (miRNAs) have recently gained prominence as promising biomarkers for non-invasive lung cancer screening. In this study, we innovatively developed an innovative fluorescent nanoprobe based on stable Au-Se bonds to detect lung cancer-associated miRNAs in exosomes. This nanoprobe integrates gold nanoparticles with selenated DNA molecular beacons (MBs) conjugated via 1,4-phenyldiisothiocyanate (PDITC). It demonstrates exceptional stability in high-thiol environments, making it ideal for high-fidelity imaging and biomarker detection in biological settings. By integrating molecular beacons that specifically recognize and bind to target exosomal miRNAs, the nanoprobe enables precise detection. Thermophoretic aggregation imaging of exosomes was achieved using confocal fluorescence microscopy with 1064 nm laser irradiation. Our findings demonstrate that this nanoprobe efficiently identifies lung cancer-related miRNAs in exosomes, providing a promising candidate for early lung cancer detection in clinical applications.

Brazil nut (Bertholletia excelsa Bonpl.) in health and disease: A narrative review

Brazil nut is one of the most consumed nut-producing species from South America. This narrative review evaluates the potential benefits of Brazil nut in health and disease. Various preclinical studies have shown that Brazil nut possesses antioxidant and anti-inflammatory actions and may be associated with antihypertensive, anti-nephrotoxic, cardioprotective (by reversing obesity, diabetes, hypertension, and dyslipidemia), and antineoplastic properties. Additionally, several clinical trials showed that Brazil nut can improve antioxidant defense, reduce inflammatory processes, attenuate glycemia, prevent obesity and hypertension, reduce visceral adiposity, reduce endothelial dysfunction, and improve vascular tone. Besides its various health benefits, Brazil nut can be a promising agent in the food industry for enhancing products with a better nutritional profile and meeting the growing demand for functional and sustainable foods. Moreover, secondary products derived from the Brazil nut, such as Brazil nut oil and phytocompounds, have potential for use in multiple pharmaceutical and cosmetics industries.

Exosome-Based Therapeutics in Dermatology

Exosomes (Exos) are tiny extracellular vesicles containing a variety of active biomolecules that play important parts in intercellular communication and influence the functions of target cells. The potential of Exos in the treatment of dermatological diseases has recently been well appreciated. This review highlights the constituents, function, and delivery of Exos, with a particular focus on their applications in skin therapy. Firstly, we offer a concise overview of the biochemical properties of Exos, including their sources, structures, and internal constituents. Subsequently, the biomedical functions of Exos and the latest advances in the extraction and purification of Exos are summarized. We further discuss the modes of delivery of Exos and underscore the potential of biomaterials in this regard. Finally, we summarize the application of Exo-aided therapy in dermatology. Overall, the objective of this review is to provide a comprehensive perspective on the applications and recent advancements of Exo-based approaches in treating skin diseases, with the intention of guiding future research efforts.

Unlocking exosome therapeutics: The critical role of pharmacokinetics in clinical applications

Exosomes are microscopic vesicles released by cells that transport various biological materials and play a vital role in intercellular communication. When they are engineered, they serve as efficient delivery systems for therapeutic agents, making it possible to precisely deliver active pharmaceutical ingredients to organs, tissues, and cells. Exosomes' pharmacokinetics, or how they are transported and metabolized inside the body, is affected by several factors, including their source of origination and the proteins in their cell membranes. The pharmacokinetics and mobility of both native and modified exosomes are being observed in living organisms using advanced imaging modalities such as in vitro-in vivo simulation, magnetic resonance imaging, and positron emission tomography. Establishing comprehensive criteria for the investigation of exosomal pharmacokinetic is essential, given its increasing significance in both therapy and diagnostics. To obtain a thorough understanding of exosome intake, distribution, metabolism, and excretion, molecular imaging methods are crucial. The development of industrial processes and therapeutic applications depends on the precise measurement of exosome concentration in biological samples. To ensure a seamless incorporation of exosomes into clinical practice, as their role in therapeutics grows, it is imperative to conduct a complete assessment of their pharmacokinetics. This review provides a brief on how exosome-based research is evolving and the need for pharmacokinetic consideration to realize the full potential of these promising new therapeutic approaches.

Extracellular Vesicle-Based Antitumor Nanomedicines

Extracellular vesicles (EVs) have emerged as promising bioactive carriers for delivering therapeutic agents, including nucleic acids, proteins, and small-molecule drugs, owing to their excellent physicochemical stability and biocompatibility. However, comprehensive reviews on the various types of EV-based nanomedicines for cancer therapy remain scarce. This review explores the potential of EVs as antitumor nanomedicines. Methods for EV extraction, drug loading, and engineering modifications are systematically examined, and the strengths and limitations of these technical approaches are critically assessed. Additionally, key strategies for developing EV-based antitumor therapies are highlighted. Finally, the opportunities and challenges associated with advancing EVs toward clinical translation are discussed. With the integration of multiple disciplines, robust EV-based therapeutic platforms are expected to be manufactured to provide more personalized and effective solutions for oncology patients.

Exosome isolation and characterization for advanced diagnostic and therapeutic applications

Advancements in exosome isolation technologies are pivotal for transforming personalized medicine and enhancing clinical diagnostics. Exosomes, small extracellular vesicles with diameters ranging between 30 and 150 nm, are secreted into bodily fluids by a variety of cells and play essential roles in intercellular communication. These vesicles facilitate the transfer of nucleic acids, lipids, and proteins, affecting a wide range of biological and pathological processes. Given their importance in disease diagnostics, therapy, and as biomarkers, there has been a surge in developing methods to isolate them from fluids such as urine, saliva, blood, and cerebrospinal fluid. While traditional isolation techniques like ultracentrifugation and polymer-based precipitation have been foundational, recent technological advances have introduced more precise methods like microfluidics and immunoaffinity capture. These newer methods enable high-throughput and specific exosome isolation by targeting surface markers, thus enhancing purity. However, challenges such as balancing purity with yield and the lack of standardized protocols across different laboratories persist, impacting the consistency of findings. By integrating advanced isolation techniques and discussing their implications in diagnostics and therapy, this review aims to catalyze further research and adoption of exosome-based technologies in medicine, marking a significant stride towards tailored healthcare solutions.

Exosomes as a Therapeutic Strategy in Cancer: Potential Roles as Drug Carriers and Immune Modulators

Exosome-based cancer immunotherapy is advancing quickly on the concept of artificially activating the immune system to combat cancer. They can mechanistically change the tumor microenvironment, increase immune responses, and function as efficient drug delivery vehicles because of their inherent bioactivity, low toxicity, and immunogenicity. Accurate identification of the mechanisms of action of exosomes in tumor environments, along with optimization of their isolation, purification, and characterization methods, is necessary to increase clinical applications. Exosomes can be modified through cargo loading and surface modification to enhance their therapeutic applications, either before or after the donor cells' isolation. These engineered exosomes can directly target tumor cells at the tumor site or indirectly activate innate and adaptive immune responses in the tumor microenvironment. This approach is particularly effective when combined with traditional cancer immunotherapy techniques such as vaccines, immune checkpoints, and CAR-T cells. It can improve anti-tumor responses, induce long-term immunity, and address the limitations of traditional therapies, such as poor penetration in solid tumors and immunosuppressive environments. This review aims to provide a comprehensive and detailed overview of the direct role of engineered exosomes as drug delivery systems and their immunomodulatory effects on tumors as an indirect approach to fighting cancer. Additionally, it will discuss novel immunotherapy options.

Dual Biomarker Strategies for Liquid Biopsy: Integrating Circulating Tumor Cells and Circulating Tumor DNA for Enhanced Tumor Monitoring

The liquid biopsy has gained significant attention in cancer diagnostics, with circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) being recognized as key biomarkers for tumor detection and monitoring. However, each biomarker possesses inherent limitations that restrict its standalone clinical utility, such as the rarity and heterogeneity of CTCs and the variable sensitivity and specificity of ctDNA assays. This highlights the necessity of integrating both biomarkers to maximize diagnostic and prognostic potential, offering a more comprehensive understanding of the tumor biology and therapeutic response. In this review, we summarize clinical studies that have explored the combined analysis of CTCs and ctDNA as biomarkers, providing insights into their synergistic value in diverse tumor types. Specifically, this paper examines the individual advantages and limitations of CTCs and ctDNA, details the findings of combined biomarker studies across various cancers, highlights the benefits of dual biomarker approaches over single-biomarker strategies, and discusses future prospects for advancing personalized oncology through liquid biopsies. By offering a comprehensive overview of clinical studies combining CTCs and ctDNA, this review serves as a guideline for researchers and clinicians aiming to enhance biomarker-based strategies in oncology and informs biosensor design for improved biomarker detection.

Microfluidic Nanoparticle Separation for Precision Medicine

A deeper understanding of disease heterogeneity highlights the urgent need for precision medicine. Microfluidics, with its unique advantages, such as high adjustability, diverse material selection, low cost, high processing efficiency, and minimal sample requirements, presents an ideal platform for precision medicine applications. As nanoparticles, both of biological origin and for therapeutic purposes, become increasingly important in precision medicine, microfluidic nanoparticle separation proves particularly advantageous for handling valuable samples in personalized medicine. This technology not only enhances detection, diagnosis, monitoring, and treatment accuracy, but also reduces invasiveness in medical procedures. This review summarizes the fundamentals of microfluidic nanoparticle separation techniques for precision medicine, starting with an examination of nanoparticle properties essential for separation and the core principles that guide various microfluidic methods. It then explores passive, active, and hybrid separation techniques, detailing their principles, structures, and applications. Furthermore, the review highlights their contributions to advancements in liquid biopsy and nanomedicine. Finally, it addresses existing challenges and envisions future development spurred by emerging technologies such as advanced materials science, 3D printing, and artificial intelligence. These interdisciplinary collaborations are anticipated to propel the platformization of microfluidic separation techniques, significantly expanding their potential in precision medicine.

Isoorientin: Unveiling the hidden flavonoid's promise in combating cancer development and progression - A comprehensive review

Cancer remains one of the leading causes of mortality worldwide, characterized by uncontrolled cell growth and the ability of tumors to invade surrounding tissues and spread to distant organs. Despite significant advancements in early detection, diagnosis, and treatment, many cancers still present substantial challenges due to their heterogeneity, resistance to conventional therapies, and severe side effects of existing treatments. Consequently, there is an ongoing need for novel therapeutic agents to selectively target cancer cells, enhance the efficacy of current treatments, and minimize adverse effects. Isoorientin (ISO) is a naturally occurring flavonoid known for its anticancer properties. ISO has demonstrated the ability to influence several critical processes in cancer progression, such as cell proliferation, apoptosis, and metastasis. Due to the absence of clinical trials, we included only in vitro studies, reviewing 13 investigations. These studies covered diverse cancer types, including lung, brain, oral, liver, pancreatic, and gastric cancers, and assessed various outcomes related to cell viability, apoptosis, migration, and molecular pathway modulation. By synthesizing data from these investigations, our review seeks to provide a thorough understanding of ISO's anticancer effects, its mechanisms of action, and its potential as a therapeutic agent.

Advancements in Exosome Proteins for Breast Cancer Diagnosis and Detection: With a Focus on Nanotechnology

Breast cancer, a leading cause of mortality among women, has been recognized as requiring improved diagnostic methods. Exosome proteins, found in small extracellular vesicles, have emerged as a promising solution, reflecting the state of their cell of origin and playing key roles in cancer progression. This review examines their potential in breast cancer diagnosis, discussing advanced isolation and characterization techniques such as ultracentrifugation and microfluidic-based approaches. Various detection methods-including electrochemical, nano-based, optical, and machine learning platforms-were evaluated for their high sensitivity, specificity, and non-invasive capabilities. Electrochemical methods were used to identify unique protein signatures for rapid, cost-effective diagnosis, while machine learning enhanced the classification of exosome proteins. Nano-based techniques leveraged nanomaterials to detect low-abundance proteins, and optical methods offered real-time, label-free monitoring. Despite their promise, challenges in standardizing protocols and integrating these diagnostics into clinical practice remain. Future directions include technological advancements, personalized medicine, and exploring the therapeutic potential of exosome proteins.

The detection, biological function, and liquid biopsy application of extracellular vesicle-associated DNA

Cell-derived extracellular vesicles (EVs), which carry diverse biomolecules such as nucleic acids, proteins, metabolites, and lipids reflecting their cell of origin, are released under both physiological and pathological conditions. EVs have been demonstrated to mediate cell-to-cell communication and serve as biomarkers. EV-associated DNA (EV-DNA) comprises genomic and mitochondrial DNA (i.e., gDNA and mtDNA) fragments. Some studies have revealed that EV-DNA can represent the full nuclear genome and mitochondrial genome of parental cells. Furthermore, DNA fragments loaded into EVs are stable and can be transferred to recipient cells to regulate their biological functions. In this review, we summarized and discussed EV-DNA research advances with an emphasis on EV-DNA detection at the population-EV and single-EV levels, gene transfer-associated biological functions, and clinical applications as biomarkers for disease liquid biopsy. We hope that this review will provide potential directions or guidance for future EV-DNA investigations.

Vascularized platforms for investigating cell communication via extracellular vesicles

The vascular network plays an essential role in the maintenance of all organs in the body via the regulated delivery of oxygen and nutrients, as well as tissue communication via the transfer of various biological signaling molecules. It also serves as a route for drug administration and affects pharmacokinetics. Due to this importance, engineers have sought to create physiologically relevant and reproducible vascular systems in tissue, considering cell-cell and extracellular matrix interaction with structural and physical conditions in the microenvironment. Extracellular vesicles (EVs) have recently emerged as important carriers for transferring proteins and genetic material between cells and organs, as well as for drug delivery. Vascularized platforms can be an ideal system for studying interactions between blood vessels and EVs, which are crucial for understanding EV-mediated substance transfer in various biological situations. This review summarizes recent advances in vascularized platforms, standard and microfluidic-based techniques for EV isolation and characterization, and studies of EVs in vascularized platforms. It provides insights into EV-related (patho)physiological regulations and facilitates the development of EV-based therapeutics.

Investigation of on-line electrokinetic enrichment strategies for capillary electrophoresis of extracellular vesicles

This work explores strategies for electrokinetic preconcentration of extracellular vesicles (EVs) that are potential source of biomarkers for different diseases. The first approach that led to successful preconcentration of EVs is based on large volume sample stacking (LVSS), allowing an enrichment factor of 7 for CE of EVs with long-end injection (using a capillary with an effective length of 50 cm). Attempts were also made to perform multiple cycles of LVSS, field amplified sample stacking (FASS) and field amplified sample injection (FASI), to improve EVs preconcentration performance. The focus was then put on development of capillary isotachophoresis under high ionic strengths (IS) for electrokinetic enrichment of slow migrating EVs having heterogeneous mobilities. This approach relies on the use of extremely high concentrations of the terminating electrolyte (TE) to slow down the mobility of TE co-ions, rendering them slower than those of EVs. The limit of detection for intact EVs using the developed ITP-UV method reached 8.3 × 108 EVs/mL, allowing an enrichment of 25 folds and a linear calibration up to 4 × 1010 EVs/mL. The ITP-UV and ITP-LIF approaches were applied to provide the electrokinetic signature of EVs of bovine milk and human plasma as well as to visualize more specifically intravesicular fluorescently labelled EVs. The investigation of these strategies shredded light into the challenges still encountered with electrokinetic preconcentration and separation of heterogeneous EVs sub-populations which are discussed herein based on our results and other attempts reported in the literature.

Extracellular Vesicle Preparation and Analysis: A State-of-the-Art Review

In recent decades, research on Extracellular Vesicles (EVs) has gained prominence in the life sciences due to their critical roles in both health and disease states, offering promising applications in disease diagnosis, drug delivery, and therapy. However, their inherent heterogeneity and complex origins pose significant challenges to their preparation, analysis, and subsequent clinical application. This review is structured to provide an overview of the biogenesis, composition, and various sources of EVs, thereby laying the groundwork for a detailed discussion of contemporary techniques for their preparation and analysis. Particular focus is given to state-of-the-art technologies that employ both microfluidic and non-microfluidic platforms for EV processing. Furthermore, this discourse extends into innovative approaches that incorporate artificial intelligence and cutting-edge electrochemical sensors, with a particular emphasis on single EV analysis. This review proposes current challenges and outlines prospective avenues for future research. The objective is to motivate researchers to innovate and expand methods for the preparation and analysis of EVs, fully unlocking their biomedical potential.

Design and Application of Microfluidic Capture Device for Physical-Magnetic Isolation of MCF-7 Circulating Tumor Cells

Circulating tumor cells (CTCs) are a type of cancer cell that spreads from the main tumor to the bloodstream, and they are often the most important among the various entities that can be isolated from the blood. For the diagnosis of cancer, conventional biopsies are often invasive and unreliable, whereas a liquid biopsy, which isolates the affected item from blood or lymph fluid, is a less invasive and effective diagnostic technique. Microfluidic technologies offer a suitable channel for conducting liquid biopsies, and this technology is utilized to extract CTCs in a microfluidic chip by physical and bio-affinity-based techniques. This effort uses functionalized magnetic nanoparticles (MNPs) in a unique microfluidic chip to collect CTCs using a hybrid (physical and bio-affinity-based/guided magnetic) capturing approach with a high capture rate. Accordingly, folic acid-functionalized Fe3O4 nanoparticles have been used to capture MCF-7 (breast cancer) CTCs with capture efficiencies reaching up to 95% at a 10 µL/min flow rate. Moreover, studies have been conducted to support this claim, including simulation and biomimetic investigations.

Therapeutic potential of exosomes in spermatogenesis regulation and male infertility

BACKGROUND

Spermatogenesis is a fundamental process crucial for male reproductive health and fertility. Exosomes, small membranous vesicles released by various cell types, have recently garnered attention for their role in intercellular communication.

OBJECTIVE

This review aims to comprehensively explore the role of exosomes in regulating spermatogenesis, focusing on their involvement in testicular development and cell-to-cell communication.

METHODS

A systematic examination of literature was conducted to gather relevant studies elucidating the biogenesis, composition, and functions of exosomes in the context of spermatogenesis.

RESULTS

Exosomes play a pivotal role in orchestrating the complex signaling networks required for proper spermatogenesis. They facilitate the transfer of key regulatory molecules between different cell populations within the testes, including Sertoli cells, Leydig cells, and germ cells.

CONCLUSION

The emerging understanding of exosome-mediated communication sheds light on novel mechanisms underlying spermatogenesis regulation. Further research in this area holds promise for insights into male reproductive health and potential therapeutic interventions.

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.

Fully Integrated Ratiometric Fluorescence Enrichment Platform for High-Sensitivity POC Testing of Salivary Cancer Biomarkers

The point-of-care (POC) testing of cancer biomarkers in saliva with both high sensitivity and accuracy remains a serious challenge in modern clinical medicine. Herein, we develop a new fully integrated ratiometric fluorescence enrichment platform that utilizes acoustic radiation forces to enrich dual-emission sandwich immune complexes for a POC visual assay. As a result, the color signals from red and green fluorescence (capture probe and report probe, respectively) are enhanced by nearly 10 times, and colorimetric sensitivity is effectively improved. When illuminated using a portable UV lamp, the fluorescence color changing from red to green can be clearly seen with the naked eye, which allows a semiqualitative assessment of the carcinoembryonic antigen (CEA) level. In combination with a homemade smartphone-based portable device, cancer biomarkers like CEA are quantified, achieving a limit of detection as low as 0.012 ng/mL. We also directly quantify CEA in human saliva samples to investigate the reliability of this fully integrated platform, thus validating the usefulness of the proposed strategy for clinical diagnosis and home monitoring of physical conditions.

Methylene Blue-Stained Single-Stranded DNA Aptamers as a Highly Efficient Electronic Switch for Quasi-Reagentless Exosomes Detection: An Old Dog with New Tricks

Improving the convenience, sensitivity, and cost-effectiveness of electrochemical biosensors is crucial for advancing their clinical diagnostic applications. Herein, we presented an elegant approach to construct electrochemical aptasensors for tumor-derived exosome detection by harnessing the alterable interaction between methylene blue (MB) and DNA aptamer. In detail, the anti-EpCAM aptamer, named SYL3C, was found to exhibit a strong affinity toward MB due to the specific interaction between MB and unbound guanine bases. Thereby, SYL3C could be stained with MB to arouse a strong electrochemical signal on a gold electrode (AuE). Upon binding to EpCAM-positive exosomes, SYL3C underwent a conformational transformation. The resulting conformation, or exosomes-SYL3C complex, not only reduced the accumulation of MB on SYL3C by obstructing the accessibility of guanines to MB but also impeded the transfer of electrons from the bound MB to AuE, leading to a notable decrease in the electrochemical signal. Using MB-stained SYL3C as an electronic switch, an electrochemical aptasensor was readily established for the detection of EpCAM-positive exosome detection. Without the need for signal amplification strategies, expensive auxiliary reagents, and complex operation, this unique signal transduction mechanism alone could endow the aptasensor with ultrahigh sensitivity. A limit of detection (LOD) of 234 particles mL-1 was achieved, surpassing the performance of most reported methods. As a proof of concept, the aptasensor was applied to analyze clinical serum samples and effectively distinguish non-small-cell lung cancer (NSCLC) patients from healthy individuals. As EpCAM exhibits broad expression in exosomes derived from different tumor sources, the developed aptasensor holds promise for diagnosing other tumor types.

A review of acoustofluidic separation of bioparticles

Acoustofluidics is an emerging interdisciplinary research field that involves the integration of acoustics and microfluidics to address challenges in various scientific areas. This technology has proven to be a powerful tool for separating biological targets from complex fluids due to its label-free, biocompatible, and contact-free nature. Considering a careful designing process and tuning the acoustic field particles can be separated with high yield. Recently the advancement of acoustofluidics led to the development of point-of-care devices for separations of micro particles which address many of the limitations of conventional separation tools. This review article discusses the working principles and different approaches of acoustofluidic separation and provides a synopsis of its traditional and emerging applications, including the theory and mechanism of acoustofluidic separation, blood component separation, cell washing, fluorescence-activated cell sorting, circulating tumor cell isolation, and exosome isolation. The technology offers great potential for solving clinical problems and advancing scientific research.

Potential Avenues for Exosomal Isolation and Detection Methods to Enhance Small-Cell Lung Cancer Analysis

Around the world, lung cancer has long been the main factor in cancer-related deaths, with small-cell lung cancer (SCLC) being the deadliest form of lung cancer. Cancer cell-derived exosomes and exosomal miRNAs are considered promising biomarkers for diagnosing and prognosis of various diseases, including SCLC. Due to the rapidity of SCLC metastasis, early detection and diagnosis can offer better diagnosis and prognosis and therefore increase the patient's chances of survival. Over the past several years, many methodologies have been developed for analyzing non-SCLC-derived exosomes. However, minimal advances have been made in SCLC-derived exosome analysis methodologies. This Review discusses the epidemiology and prominent biomarkers of SCLC. Followed by a discussion about the effective strategies for isolating and detecting SCLC-derived exosomes and exosomal miRNA, highlighting the critical challenges and limitations of current methodologies. Finally, an overview is provided detailing future perspectives for exosome-based SCLC research.

CuMoO4 nanorods-based acetone chemiresistor-enabled non-invasive breathomic-diagnosis of human diabetes and environmental monitoring

A nano-enabled low-trace monitoring system for acetone has the potential to revolutionize breath omics-based non-invasive diagnosis of human diabetes and environmental monitoring technologies. This unprecedented study presents the state-of-the-art facile and economic template-assisted hydrothermal route to fabricate novel CuMoO₄ nanorods for room temperature breath and airborne acetone detection. Physicochemical attribute analysis reveals the formation of crystalline CuMoO₄ nanorods with diameters ranging from 90 to 150 nm, and an optical band gap of approximately 3.87 eV. CuMoO₄ nanorods-based chemiresistor demonstrates excellent acetone monitoring performance, with a sensitivity of approximately 33.85 at a concentration of 125 ppm. Acetone detection is rapid, with a response time of 23 s and fast recovery within 31 s. Furthermore, the chemiresistor exhibits long-term stability and selectivity towards acetone, compared to other interfering volatile organic compounds (VOCs) commonly found in human breath such as ethanol, propanol, formaldehyde, humidity, and ammonia. The linear detection range of acetone from 25 to 125 ppm achieved by the fabricated sensor is well-suited for human breath-based diagnosis of diabetes. This work represents a significant advancement in the field, as it offers a promising alternative to time-consuming and costly invasive biomedical diagnostics, with the potential for application in cleanroom facilities for indoor contamination monitoring. The utilization of CuMoO₄ nanorods as sensing nanoplatform opens new possibilities for the development of nano-enabled, low-trace acetone monitoring technologies for non-invasive diabetes diagnosis and environmental sensing applications.

A Short Review on Miniaturized Biosensors for the Detection of Nucleic Acid Biomarkers

Even today, most biomarker testing is executed in centralized, dedicated laboratories using bulky instruments, automated analyzers, and increased analysis time and expenses. The development of miniaturized, faster, low-cost microdevices is immensely anticipated for substituting for these conventional laboratory-oriented assays and transferring diagnostic results directly onto the patient's smartphone using a cloud server. Pioneering biosensor-based approaches might make it possible to test biomarkers with reliability in a decentralized setting, but there are still a number of issues and restrictions that must be resolved before the development and use of several biosensors for the proper understanding of the measured biomarkers of numerous bioanalytes such as DNA, RNA, urine, and blood. One of the most promising processes to address some of the issues relating to the growing demand for susceptible, quick, and affordable analysis techniques in medical diagnostics is the creation of biosensors. This article critically discusses a short review of biosensors used for detecting nucleic acid biomarkers, and their use in biomedical prognostics will be addressed while considering several essential characteristics.