Simultaneous detection of multiple exosomal microRNAs for exosome screening based on rolling circle amplification

Emerging role of exosomal microRNA in liver cancer in the era of precision medicine; potential and challenges

Exosomal microRNAs (miRNAs) have great potential in the fight against hepatocellular carcinoma (HCC), the fourth most common cause of cancer-related death worldwide. In this study, we explored the various applications of these small molecules while analyzing their complex roles in tumor development, metastasis, and changes in the tumor microenvironment. We also discussed the complex interactions that exist between exosomal miRNAs and other non-coding RNAs such as circular RNAs, and show how these interactions coordinate important biochemical pathways that propel the development of HCC. The possibility of targeting exosomal miRNAs for therapeutic intervention is paramount, even beyond their mechanistic significance. We also highlighted their growing potential as cutting-edge biomarkers that could lead to tailored treatment plans by enabling early identification, precise prognosis, and real-time treatment response monitoring. This thorough analysis revealed an intricate network of exosomal miRNAs lead to HCC progression. Finally, strategies for purification and isolation of exosomes and advanced biosensing techniques for detection of exosomal miRNAs are also discussed. Overall, this comprehensive review sheds light on the complex web of exosomal miRNAs in HCC, offering valuable insights for future advancements in diagnosis, prognosis, and ultimately, improved outcomes for patients battling this deadly disease.

Exosomes as Powerful Biomarkers in Cancer: Recent Advances in Isolation and Detection Techniques

Exosomes, small extracellular vesicles derived from cells, are known to carry important bioactive molecules such as proteins, nucleic acids, and lipids. These bioactive components play crucial roles in cell signaling, immune response, and tumor metastasis, making exosomes potential diagnostic biomarkers for various diseases. However, current methods for detecting tumor exosomes face scientific challenges including low sensitivity, poor specificity, complicated procedures, and high costs. It is essential to surmount these obstacles to enhance the precision and dependability of diagnostics that rely on exosomes. Merging DNA signal amplification techniques with the signal boosting capabilities of nanomaterials presents an encouraging strategy to overcome these constraints and improve exosome detection. This article highlights the use of DNA signal amplification technology and nanomaterials' signal enhancement effect to improve the detection of exosomes. This review seeks to offer valuable perspectives for the enhancement of amplification methods applied in practical cancer diagnosis and prognosis by providing an overview of how these novel technologies are utilized in exosome-based diagnostic procedures.

Chitosan functionalized gold nanostars as a theranostic platform for intracellular microRNA detection and photothermal therapy

The development of a theranostic platform that integrates both diagnostic and therapeutic capabilities is in great need for precise and personalized medicine. Here, we present a novel nanoplatform (AuNS@CS-hpDNA) formulated by chitosan functionalized gold nanostar composites and further complexed with fluorescent hairpin DNA (hpDNA) probes for tumor-related miRNA imaging and photothermal therapy (PTT). The optimized AuNS@CS-hpDNA nanoplatform mediated efficient hpDNA probe loading and intracellular delivery. Subsequently, the cytosol transfer of the hpDNA probe enabled specific hybridization using the targeted miRNA, which triggered the recovery of fluorescence for the precise detection of biomarker miR21 in living cells and realized the distinguishing cancer cell line MCF-7 and normal cells. Meanwhile, the AuNS@CS-hpDNA nanoplatform exhibited excellent photothermal conversion properties, which induced efficient cancer cell killing under laser irradiation. Thus, the developed AuNS@CS-hpDNA nanoplatform could simultaneously realize the precise detection of cancer cells and accurately initiate efficient PTT, which represents a promising strategy for precise cancer therapy.

Deciphering the Functional Status of Breast Cancers through the Analysis of Their Extracellular Vesicles

Breast cancer (BC) accounts for the highest incidence of tumor-related mortality among women worldwide, justifying the growing search for molecular tools for the early diagnosis and follow-up of BC patients under treatment. Circulating extracellular vesicles (EVs) are membranous nanocompartments produced by all human cells, including tumor cells. Since minimally invasive methods collect EVs, which represent reservoirs of signals for cell communication, these particles have attracted the interest of many researchers aiming to improve BC screening and treatment. Here, we analyzed the cargoes of BC-derived EVs, both proteins and nucleic acids, which yielded a comprehensive list of potential markers divided into four distinct categories, namely, (i) modulation of aggressiveness and growth; (ii) preparation of the pre-metastatic niche; (iii) epithelial-to-mesenchymal transition; and (iv) drug resistance phenotype, further classified according to their specificity and sensitivity as vesicular BC biomarkers. We discuss the therapeutic potential of and barriers to the clinical implementation of EV-based tests, including the heterogeneity of EVs and the available technologies for analyzing their content, to present a consistent, reproducible, and affordable set of markers for further evaluation.

Signal differentiation models for multiple microRNA detection: a critical review

MicroRNAs (miRNAs) are a class of small, single-stranded non-coding RNAs which have critical functions in various biological processes. Increasing evidence suggested that abnormal miRNA expression was closely related to many human diseases, and they are projected to be very promising biomarkers for non-invasive diagnosis. Multiplex detection of aberrant miRNAs has great advantages including improved detection efficiency and enhanced diagnostic precision. Traditional miRNA detection methods do not meet the requirements of high sensitivity or multiplexing. Some new techniques have opened novel paths to solve analytical challenges of multiple miRNA detection. Herein, we give a critical overview of the current multiplex strategies for the simultaneous detection of miRNAs from the perspective of two different signal differentiation models, including label differentiation and space differentiation. Meanwhile, recent advances of signal amplification strategies integrated into multiplex miRNA methods are also discussed. We hope this review provides the reader with future perspectives on multiplex miRNA strategies in biochemical research and clinical diagnostics.

Analysis and Biomedical Applications of Functional Cargo in Extracellular Vesicles

Extracellular vesicles (EVs) can facilitate essential communication among cells in a range of pathophysiological conditions including cancer metastasis and progression, immune regulation, and neuronal communication. EVs are membrane-enclosed vesicles generated through endocytic origin and contain many cellular components, including proteins, lipids, nucleic acids, and metabolites. Over the past few years, the intravesicular content of EVs has proven to be a valuable biomarker for disease diagnostics, involving cancer, cardiovascular diseases, and central nervous system diseases. This review aims to provide insight into EV biogenesis, composition, function, and isolation, present a comprehensive overview of emerging techniques for EV cargo analysis, highlighting their major technical features and limitations, and summarize the potential role of EV cargos as biomarkers in disease diagnostics. Further, progress and remaining challenges will be discussed for clinical diagnostic outlooks.

MicroRNAs in extracellular vesicles: Sorting mechanisms, diagnostic value, isolation, and detection technology

MicroRNAs (miRNAs) are a class of short, single-stranded, noncoding RNAs, with a length of about 18–22 nucleotides. Extracellular vesicles (EVs) are derived from cells and play a vital role in the development of diseases and can be used as biomarkers for liquid biopsy, as they are the carriers of miRNA. Existing studies have found that most of the functions of miRNA are mainly realized through intercellular transmission of EVs, which can protect and sort miRNAs. Meanwhile, detection sensitivity and specificity of EV-derived miRNA are higher than those of conventional serum biomarkers. In recent years, EVs have been expected to become a new marker for liquid biopsy. This review summarizes recent progress in several aspects of EVs, including sorting mechanisms, diagnostic value, and technology for isolation of EVs and detection of EV-derived miRNAs. In addition, the study reviews challenges and future research avenues in the field of EVs, providing a basis for the application of EV-derived miRNAs as a disease marker to be used in clinical diagnosis and even for the development of point-of-care testing (POCT) platforms.

Role of Nano-miRNAs in Diagnostics and Therapeutics

MicroRNAs (miRNA) are key regulators of gene expression, controlling different biological processes such as cellular development, differentiation, proliferation, metabolism, and apoptosis. The relationships between miRNA expression and the onset and progression of different diseases, such as tumours, cardiovascular and rheumatic diseases, and neurological disorders, are well known. A nanotechnology-based approach could match miRNA delivery and detection to move beyond the proof-of-concept stage. Different kinds of nanotechnologies can have a major impact on the diagnosis and treatment of miRNA-related diseases such as cancer. Developing novel methodologies aimed at clinical practice represents a big challenge for the early diagnosis of specific diseases. Within this context, nanotechnology represents a wide emerging area at the forefront of research over the last two decades, whose potential has yet to be fully attained. Nanomedicine, derived from nanotechnology, can exploit the unique properties of nanometer-sized particles for diagnostic and therapeutic purposes. Through nanomedicine, specific treatment to counteract only cancer-cell proliferation will be improved, while leaving healthy cells intact. In this review, we dissect the properties of different nanocarriers and their roles in the early detection and treatment of cancer.

A sensing system constructed by combining a structure-switchable molecular beacon with nicking-enhanced rolling circle amplification for highly sensitive miRNA detection

A novel amplification assay strategy is developed for the highly sensitive detection of miRNA-21 based on a combination of a structure-switchable molecular beacon with nicking-enhanced rolling circle amplification.

Signal-on electrochemical DNA (E-DNA) sensor for accurate quantification of nicking-assisted rolling circle amplification (N-RCA) products with attomolar sensitivity

Rolling circle amplification (RCA) has become an increasingly important amplification technique in nucleic acid analysis, immunoassay, and molecular diagnosis due to its high specificity and sensitivity. However, the accurate quantification of RCA products via the extensively used fluorescent signaling method has been challenged primarily by the non-specific and sequence-independent binding of the fluorescent dyes to DNA. Here, we have developed a signal-on E-DNA sensor for accurate quantification of the RCA products with high specificity and sensitivity. A restriction enzyme was introduced to cleave the long tandem repeat sequences generated in the RCA reaction into many short monomers. The short monomers were then used as secondary targets to trigger the E-DNA sensor to produce an amplified redox current and thus the resulting RCA products were detected. The method was successfully applied to the detection of miR-7a with high specificity and the detection limit was as low as 0.59 fM.

Advances of Exosomal miRNAs in Breast Cancer Progression and Diagnosis

Breast cancer is one of the most commonly diagnosed malignancies and the leading cause of cancer death in women worldwide. Although many factors associated with breast cancer have been identified, the definite etiology of breast cancer is still unclear. In addition, early diagnosis of breast cancer remains challenging. Exosomes are membrane-bound nanovesicles secreted by most types of cells and contain a series of biologically important molecules, such as lipids, proteins, and miRNAs, etc. Emerging evidence shows that exosomes can affect the status of cells by transmitting substances and messages among cells and are involved in various physiological and pathological processes. In breast cancer, exosomes play a significant role in breast tumorigenesis and progression through transfer miRNAs which can be potential biomarkers for early diagnosis of breast cancer. This review discusses the potential utility of exosomal miRNAs in breast cancer progression such as tumorigenesis, metastasis, immune regulation and drug resistance, and further in breast cancer diagnosis.

A Theoretical and Simulation Analysis of the Sensitivity of SiNWs-FET Sensors

Theoretical study and software simulation on the sensitivity of silicon nanowires (SiNWs) field effect transistor (FET) sensors in terms of surface-to-volume ratio, depletion ratio, surface state and lattice quality are carried out. Generally, SiNWs-FET sensors with triangular cross-sections are more sensitive than sensors with circular or square cross-sections. Two main reasons are discussed in this article. Firstly, SiNWs-FET sensors with triangular cross-sections have the largest surface-to-volume ratio and depletion ratio which significantly enhance the sensors’ sensitivity. Secondly, the manufacturing processes of the electron beam lithography (EBL) and chemical vapor deposition (CVD) methods seriously affect the surface state and lattice quality, which eventually influence SiNWs-FET sensors’ sensitivity. In contrast, wet etching and thermal oxidation (WETO) create fewer surface defects and higher quality lattices. Furthermore, the software simulation confirms that SiNWs-FET sensors with triangular cross-sections have better sensitivity than the other two types of SiNWs-FET sensors under the same conditions, consistent with the theoretical analysis. The article fully proved that SiNWs-FET sensors fabricated by the WETO method produced the best sensitivity and it will be widely used in the future.