Rapid and specific detection nanoplatform of serum exosomes for prostate cancer diagnosis

TiO2-coated honeycomb-like super-macroporous silica for high-purity extraction of exosomes from human plasma

Screening biomarkers from exosomes has emerged as a new strategy for non-invasive early diagnosis of diseases. Nevertheless, the present screening efficiency and accuracy of biomarkers are limited by the low extraction efficiency and purity of exosomes. To address this issue, a highly selective adsorbent, which integrates size-exclusion and chemisorption, was created by coating TiO2 on honeycomb-like super-macroporous silica. Cell culture medium and human plasma were employed to investigate the enrichment performance, and the results indicate that the super-macropores ranging from 63.5 to 147.5 nm together with thin pore walls allow exosomes to enter and be adsorbed by TiO2 in the pores, enhancing the available surface area for exosomes meanwhile physically excluding the large-sized cell debris and vesicles. Taking advantages of these properties, the prepared adsorbent achieves a higher extraction efficiency, recovery and purity of exosomes compared with the normal adsorbents and ultracentrifugation (UC) method. Combining this method with proteomic analysis, a total of 392 proteins were identified in exosomes from healthy human plasma, which is significantly higher than the number obtained by UC (200 proteins). For clinical samples, 59 upregulated and 124 downregulated proteins were identified in the plasma from colorectal cancer (CRC) patients, of which 44 upregulated proteins and 69 downregulated proteins are strongly associated with the progression of CRC. These findings suggest that this adsorbent possesses considerable potential in the extraction of exosomes for screening biomarkers and diagnosing tumor progress.

Colorimetric aptasensor coupled with a deep-learning-powered smartphone app for programmed death ligand-1 expressing extracellular vesicles

Lung cancer is a devastating public health threat and a leading cause of cancer-related deaths. Therefore, it is imperative to develop sophisticated techniques for the non-invasive detection of lung cancer. Extracellular vesicles expressing programmed death ligand-1 (PD-L1) markers (PD-L1@EVs) in the blood are reported to be indicative of lung cancer and response to immunotherapy. Our approach is the development of a colorimetric aptasensor by combining the rapid capturing efficiency of (Fe3O4)-SiO2-TiO2 for EV isolation with PD-L1 aptamer-triggered enzyme-linked hybridization chain reaction (HCR) for signal amplification. The numerous HRPs catalyze their substrate dopamine (colorless) into polydopamine (blackish brown). Change in chromaticity directly correlates with the concentration of PD-L1@EVs in the sample. The colorimetric aptasensor was able to detect PD-L1@EVs at concentrations as low as 3.6×102 EVs/mL with a wide linear range from 103 to 1010 EVs/mL with high specificity and successfully detected lung cancer patients' serum from healthy volunteers' serum. To transform the qualitative colorimetric approach into a quantitative operation, we developed an intelligent convolutional neural network (CNN)-powered quantitative analyzer for chromaticity in the form of a smartphone app named ExoP, thereby achieving the intelligent analysis of chromaticity with minimal user intervention or additional hardware attachments for the sensitive and specific quantification of PD-L1@EVs. This combined approach offers a simple, sensitive, and specific tool for lung cancer detection using PD-L1@EVs. The addition of a CNN-powered smartphone app further eliminates the need for specialized equipment, making the colorimetric aptasensor more accessible for low-resource settings.

Transferrin-conjugated magnetic nanoparticles for the isolation of brain-derived blood exosomal MicroRNAs: A novel approach for Parkinson's disease diagnosis

BACKGROUND

Brain-derived exosomes circulate in the bloodstream and other bodily fluids, serving as potential indicators of neurological disease progression. These exosomes present a promising avenue for the early and precise diagnosis of neurodegenerative conditions. Notably, miRNAs found in plasma extracellular vesicles (EVs) offer distinct diagnostic benefits due to their stability, abundance, and resistance to breakdown.

RESULTS

In this study, we introduce a method using transferrin conjugated magnetic nanoparticles (TMNs) to isolate these exosomes from the plasma of patients with neurological disorders. This TMNs technique is both quick (<35 min) and cost-effective, requiring no high-priced ingredients or elaborate equipment for EV extraction. Our method successfully isolated EVs from 33 human plasma samples, including those from patients with Parkinson's disease (PD), Multiple Sclerosis (MS), and Dementia. Using quantitative polymerase chain reaction (PCR) analysis, we evaluated the potential of 8 exosomal miRNA profiles as biomarker candidates. Six exosomal miRNA biomarkers (miR-195-5p, miR-495-3p, miR-23b-3P, miR-30c-2-3p, miR-323a-3p, and miR-27a-3p) were consistently linked with all stages of PD.

SIGNIFICANCE

The TMNs method provides a practical, cost-efficient way to isolate EVs from biological samples, paving the way for non-invasive neurological diagnoses. Furthermore, the identified miRNA biomarkers in these exosomes may emerge as innovative tools for precise diagnosis in neurological disorders including PD.

Recent research on material-based methods for isolation of extracellular vesicles

Extracellular vesicles (EVs) are nanoparticles secreted by cells with a closed phospholipid bilayer structure, which can participate in various physiological and pathological processes and have significant clinical value in disease diagnosis, targeted therapy and prognosis assessment. EV isolation methods currently include differential ultracentrifugation, ultrafiltration, size exclusion chromatography, immunoaffinity, polymer co-precipitation and microfluidics. In addition, material-based biochemical or biophysical approaches relying on intrinsic properties of the material or its surface-modified functionalized monomers, demonstrated unique advantages in the efficient isolation of EVs. In order to provide new ideas for the subsequent development of material-based EV isolation methods, this review will focus on the principle, research status and application prospects of material-based EV isolation methods based on different material carriers and functional monomers.

Metal oxide nanomaterials based electrochemical and optical biosensors for biomedical applications: Recent advances and future prospectives

The amalgamation of nanostructures with modern electrochemical and optical techniques gave rise to interesting devices, so-called biosensors. A biosensor is an analytical tool that incorporates various biomolecules with an appropriate physicochemical transducer. Over the past few years, metal oxide nanomaterials (MONMs) have significantly stimulated biosensing research due to their desired functionalities, versatile chemical stability, and low cost along with their unique optical, catalytic, electrical, and adsorption properties that provide an attractive platform for linking the biomolecules, for example, antibodies, nucleic acids, enzymes, and receptor proteins as sensing elements with the transducer for the detection of signals or signal amplifications. The signals to be measured are in direct proportionate to the concentration of the bioanalyte. Because of their simplicity, cost-effectiveness, portability, quick analysis, higher sensitivity, and selectivity against a broad range of biosamples, MONMs-based electrochemical and optical biosensing platforms are exhaustively explored as powerful early-diagnosis tools for point of care applications. Herein, we made a bibliometric analysis of past twenty years (2004-2023) on the application of MONMs as electrochemical and optical biosensing units using Web of Science database and the results of which clearly reveal the increasing number of publications since 2004. Geographical area distribution analysis of these publications shows that China tops the list followed by the United States of America and India. In this review, we first describe the electrochemical and optical properties of MONMs that are crucial for the creation of extremely stable, specific, and sensitive sensors with desirable characteristics. Then, the biomedical applications of MONMs-based bare and hybrid electrochemical and optical biosensing frameworks are highlighted in the light of recent literature. Finally, current limitations and future challenges in the field of biosensing technology are addressed.

Bibliometric analysis of aptamer-conjugated nanoparticles for diagnosis in the last two decades

Objective.Aptamer-conjugated nanoparticles for diagnosis have recently gained increasing attention. Here, we performed a bibliometric analysis to provide an overview of this field over the past two decades.Methods. The terms 'aptamer, nanoparticles and diagnosis' were used to search for relevant original articles published in English from 2003 to 2022 in the Web of Science database. VOSviewer and CiteSpace software were employed to analyze the development process, knowledge structure, research hotspots, and potential trends in the field of aptamer-conjugated nanoparticles for diagnosis.Results. A total of 1076 original articles were retrieved, with a rapid increase in the annual output and citation. The journal 'Biosensors and Bioelectronics' has contributed the most in this field, and the most influential researcher, institution and country were Weihong Tan, the Chinese Academy of Sciences, China, respectively. Gold nanoparticles and quantum dots were the most used, but in the past three years, research hotspots focused on carbon dots and graphene quantum dots. Diagnostic directions primarily focused on cancer. The most used strategy was label-free electrochemical detection, but in the past two years, colorimetric analysis and fluorescence imaging emerged as hot topics.Conclusion.The bibliometric analysis reveals a rapid increase in the research on aptamer-conjugated nanoparticles for diagnosis, major contributors at the levels of journals, authors, institutions, and countries, and research preferences in diagnostic objects, nanoparticle types, and detection methods, as well as the evolution of research hotspots and future trends.

Biogenesis, Isolation, and Detection of Exosomes and Their Potential in Therapeutics and Diagnostics

The increasing research and rapid developments in the field of exosomes provide insights into their role and significance in human health. Exosomes derived from various sources, such as mesenchymal stem cells, cardiac cells, and tumor cells, to name a few, can be potential therapeutic agents for the treatment of diseases and could also serve as biomarkers for the early detection of diseases. Cellular components of exosomes, several proteins, lipids, and miRNAs hold promise as novel biomarkers for the detection of various diseases. The structure of exosomes enables them as drug delivery vehicles. Since exosomes exhibit potential therapeutic applications, their efficient isolation from complex biological/clinical samples and precise real-time analysis becomes significant. With the advent of microfluidics, nano-biosensors are being designed to capture exosomes efficiently and rapidly. Herein, we have summarized the history, biogenesis, characteristics, functions, and applications of exosomes, along with the isolation, detection, and quantification techniques. The implications of surface modifications to enhance specificity have been outlined. The review also sheds light on the engineered nanoplatforms being developed for exosome detection and capture.

The multifaceted role of extracellular vesicles in prostate cancer-a review

Prostate cancer is the second most prominent form of cancer in men and confers the highest mortality after lung cancer. The term "extracellular vesicles" refers to minute endosomal-derived membrane microvesicles and it was demonstrated that extracellular vesicles affect the environment in which tumors originate. Extracellular vesicles' involvement is also established in the development of drug resistance, angiogenesis, stemness, and radioresistance in various cancers including prostate cancer. Extracellular vesicles influence the general environment, processes, and growth of prostate cancer and can be a potential area that offers a significant lead in prostate cancer therapy. In this review, we have elaborated on the multifaceted role of extracellular vesicles in various processes involved in the development of prostate cancer, and their multitude of applications in the diagnosis and treatment of prostate cancer through the encapsulation of various bioactives.

Fluorescent aptasensor based on the MNPs-CRISPR/Cas12a-TdT for the determination of nasopharyngeal carcinoma-derived exosomes

A fluorescence aptasensor based on taking the advantage of the combination of magnetic nanoparticles (MNPs), terminal deoxynucleotidyl transferase (TdT), and CRISPR/Cas12a was developed for the determination of nasopharyngeal carcinoma (NPC)-derived exosomes. The MNPs can eliminate background interference due to their magnetic separation capability. TdT can form an ultra-long polynucleotide tail which can bind with multiple crRNA, generating a signal amplification effect. The trans-cleavage activity of CRISPR/Cas12a can be specifically triggered via the crRNA binding with DNA, resulting in the bi-labeled DNA reporter with fluorophore and quencher being cleaved. The excitation wavelength of the fluorescence spectra was 490 nm. Fluorescence spectra with emission wavelengths ranging from 511 to 600 nm were collected. Under the optimization condition, the fabricated fluorescence aptasensor for NPC-derived exosome determination exhibited excellent sensitivity and specificity, with the linear range between 500 to 5 × 10⁴ particles mL^-1 and the limit of detection of 100 particles mL^-1. It can be used for the determination of NPC-derived exosomes in clinical samples, which has a considerable clinical potential and prospect.

Novel Molecular Aptamer Beacon for the Specific Simultaneous Analysis of Circulating Tumor Cells and Exosomes of Colorectal Cancer Patients

Liquid biopsy provides non-invasive and real-time detection for cancer diagnosis, but the lack of specific markers targeted to liquid biopsy components, such as circulating tumor cells (CTCs) and exosomes, has impeded its effective utilization in clinical settings. W3 is an aptamer, and its target has been previously demonstrated to be a predictor of colorectal cancer (CRC) metastasis. Herein, we developed a W3-based molecular beacon (MAB-W3-3G) to specifically detect CTCs and exosomes derived from CRC patients by modifying the W3 sequence and adding a fluorescent group FAM at the 5' end and a quencher group BHQ1 at the 3' end, resulting in a detectable green fluorescence only in the presence of the target. MAB-W3-3G retained features similar to those of the original W3, including high specificity and affinity for metastatic CRC cells, as well as excellent plasma stability. Notably, W3 target-positive CTCs were visualized, positive exosomes were quantified in CRC patients' whole blood without any sample pretreatment, and both detections could be finished in one step without any routine washing procedures. For CRC, the W3 target-positive CTC enumeration in metastasis was higher than that in non-metastasis (p < 0.01), and the quantitation of positive exosomes was correlated with CRC patients (p < 0.0001). Moreover, the MAB-W3-3G-based simultaneous detection of CTCs and exosomes was proven to have the potential for more precise clinical diagnosis. In conclusion, MAB-W3-3G could detect CTCs and exosomes in the blood samples of tumor patients with simple manipulation, rapid analysis, and high specificity, providing an effective liquid biopsy tool for the prediction of CRC.

Nanomaterials assisted exosomes isolation and analysis towards liquid biopsy

Exosomes has attracted tremendous research interests as they are emerging as a new paradigm of liquid biopsy. Although the concentration of exosomes in blood is relatively abundant, there still exists various vesicle-like nanoparticles, such as microvesicles, apoptotic bodies. It's an urgent need to isolate and enrich exosomes from the complex contaminants in biofluid samples. Moreover, the expressing level of exosomal biomarkers varies a lot, which make the sensitive molecular detection of exosomes in high demand. Unfortunately, the efficient isolation and sensitive molecular quantification of exosomes is still a major obstacle hindering the further development and clinical application of exosome-based liquid biopsy. Nanomaterials, with unique physiochemical properties, have been widely used in biosensing and analysis aspects, thus they are thought as powerful tools for effective purification and molecular analysis of exosomes. In this review, we summarized the most recent progresses in nanomaterials assisted exosome isolation and analysis towards liquid biopsy. On the one hand, nanomaterials can be used as capture substrates to afford large binding area and specific affinity to exosomes. Meanwhile, nanomaterials can also be served as promising signal transducers and amplifiers for molecular detection of exosomes. Furthermore, we also pointed out several potential and promising research directions in nanomaterials assisted exosome analysis. It's envisioned that this review will give the audience a complete outline of nanomaterials in exosome study, and further promote the intersection of nanotechnology and bio-analysis.

Recent Advances in Detection for Breast-Cancer-Derived Exosomes

Breast cancer is the most common malignant tumor in women, its incidence is secret, and more than half of the patients are diagnosed in the middle and advanced stages, so it is necessary to develop simple and efficient detection methods for breast cancer diagnosis to improve the survival rate and quality of life of breast cancer patients. Exosomes are extracellular vesicles secreted by all kinds of living cells, and play an important role in the occurrence and development of breast cancer and the formation of the tumor microenvironment. Exosomes, as biomarkers, are an important part of breast cancer fluid biopsy and have become ideal targets for the early diagnosis, curative effect evaluation, and clinical treatment of breast cancer. In this paper, several traditional exosome detection methods, including differential centrifugation and immunoaffinity capture, were summarized, focusing on the latest research progress in breast cancer exosome detection. It was summarized from the aspects of optics, electrochemistry, electrochemiluminescence and other aspects. This review is expected to provide valuable guidance for exosome detection of clinical breast cancer and the establishment of more reliable, efficient, simple and innovative methods for exosome detection of breast cancer in the future.

Ultrasensitive Analysis of Exosomes Using a 3D Self-Assembled Nanostructured SiO2 Microfluidic Chip

Conventional microfluidics with a solid mixer for exosome detection is constrained by the low binding efficiency of the solid-liquid boundary effects and reduced sensitivity of individual markers. Here, we report a 3D-SiO₂ porous chip that combines nanoscale porous characteristics and multiple exosome specific markers to greatly improve the sensitivity for biosensing. The lower limit of detection was 220 particles/μL exosomes in PBS. We applied the 3D-SiO₂ porous chip for prostate cancer (PCa) staging in mice and early detection of clinical PCa patients. The developed method could significantly differentiate the different stages of PCa in mice and improve the early detection rate in clinical patients. Expression of multiple specific markers in clinical serum samples identified disease fingerprints, alongside histological results, which supports the potential application of exosomes as a noninvasive surrogate biopsy for PCa.

Progress in Nanomaterials-Based Optical and Electrochemical Methods for the Assays of Exosomes

Exosomes with diameters of 30-150 nm are small membrane-bound vesicles secreted by a variety of cells. They play an important role in many biological processes, such as tumor-related immune response and intercellular signal transduction. Exosomes have been considered as emerging and noninvasive biomarkers for cancer diagnosis. Recently, a large number of optical and electrochemical biosensors have been proposed for sensitive detection of exosomes. To meet the increasing demands for ultrasensitive detection, nanomaterials have been integrated with various techniques as powerful components. Because of their intrinsic merits of biological compatibility, excellent physicochemical features and unique catalytic ability, nanomaterials have significantly improved the analytical performances of exosome biosensors. In this review, we summarized the recent progress in nanomaterials-based biosensors for the detection of cancer-derived exosomes, including fluorescence, colorimetry, surface plasmon resonance spectroscopy, surface enhanced Raman scattering spectroscopy, electrochemistry, electrochemiluminescence and so on.