Accurate and Convenient Lung Cancer Diagnosis through Detection of Extracellular Vesicle Membrane Proteins via Förster Resonance Energy Transfer

CRISPR/Cas12a and aptamer-chemiluminescence based analysis for the relative abundance determination of tumor-related protein positive exosomes for breast cancer diagnosis

Exosomes, as novel biomarker for liquid biopsy, exhibit huge important potential value for cancer diagnosis. However, various proteins show different expression levels on exosomal membrane, and the absolute concentration of exosomes in clinical samples is easily influenced by a number of factors. Here, we developed a CRISPR/Cas12a and aptamer-chemiluminescence based analysis (CACBA) for the relative abundance determination of tumor-related protein positive exosomes in plasma for breast cancer diagnosis. The total concentration of exosomes was determined through captured CD63 using a CRISPR/Cas12a-based method with the LoD of 8.97 × 103 particles/μl. Meanwhile, EpCAM and MUC1 positive exosomes were quantitatively detected by aptamer-chemiluminescence (ACL) based method with the LoD of 1.45 × 102 and 3.73 × 102 particles/μl, respectively. It showed that the percentages of EpCAM and MUC1 positive exosomes offered an excellent capability to differentiate breast cancer patients and healthy donors. The high sensitivity, strong specificity, outstanding anti-interference capability, and steady recovery rate of this approach offered higher accuracy and robustness than the commercialized method in clinical trial. In addition with good stability, easy preparation and low cost, this method not only provides a new approach to rapid analysis of exosome proteins, it may be quickly extended to the diagnoses of various cancers.

Recent advances of biocompatible optical nanobiosensors in liquid biopsy: towards early non-invasive diagnosis

Liquid biopsy is a non-invasive diagnostic method that can reduce the risk of complications and offers exceptional benefits in the dynamic monitoring and acquisition of heterogeneous cell population information. Optical nanomaterials with excellent light absorption, luminescence, and photoelectrochemical properties have accelerated the development of liquid biopsy technologies. Owing to the unique size effect of optical nanomaterials, their improved optical properties enable them to exhibit good sensitivity and specificity for mitigating signal interference from various molecules in body fluids. Nanomaterials with biocompatible and optical sensing properties play a crucial role in advancing the maturity and diversification of liquid biopsy technologies. This article offers a comprehensive review of recent advanced liquid biopsy technologies that utilize novel biocompatible optical nanomaterials, including fluorescence, colorimetric, photoelectrochemical, and Raman broad-spectrum-based biosensors. We focused on liquid biopsy for the most significant early biomarkers in clinical medicine, and specifically reviewed reports on the effectiveness of optical nanosensing technology in the detection of real patient samples, which may provide basic evidence for the transition of optical nanosensing technology from engineering design to clinical practice. Furthermore, we introduced the integration of optical nanosensing-based liquid biopsy with modern devices, such as smartphones, to demonstrate the potential of the technology in portable clinical diagnosis.

Accurate and highly sensitive detection of Alzheimer's disease-related extracellular vesicles via förster resonance energy transfer

Alzheimer's disease (AD) is the most common neurodegenerative disease in the world and poses a huge challenge to global healthcare. Early and accurate detection of amyloid-β (1-42) (Aβ42), a key biomarker of AD, is crucial for effective diagnosis and intervention of AD. Specific or overexpressed proteins on extracellular vesicles (EVs) describe a close correlation with the occurrence and development of diseases. EVs are a very promising non-invasive biomarker for the diagnosis of AD and other diseases. As a sensitive, simple and rapid analytical method, fluorescence resonance energy transfer (FRET) has been widely applied in the detection of EVs. Herein, we developed a dual labelling strategy for simultaneously detecting EV membrane proteins of Aβ42 and CD63 based on FRET pair consisting of Au nanoclusters (AuNCs) and polydopamine nanospheres (PDANSs). The constructed nanoprobe, termed EVMPFAP assay, could specifically measure the Aβ42 and CD63 on EVs with excellent sensitivity, high specificity and satisfactory accuracy. The limit of detection of EVMPFAP assay was 1.4 × 103 particles mL-1 and the linear range was from 104 to 108 particles mL-1. EVMPFAP assay was successfully used to analyze plasma EVs to distinguish AD and healthy mice. We expect that EVMPFAP assay can be routinely applied for early diagnosis and development-monitoring of AD, thus facilitating the fight against AD.

Simultaneous Protein Colorful Imaging via Raman Signal Classification

Protein imaging aids diagnosis and drug development by revealing protein-drug interactions or protein levels. However, the challenges of imaging multiple proteins, reduced sensitivity, and high reliance on specific protein properties such as Raman peaks or refractive index hinder the understanding. Here, we introduce multiprotein colorful imaging through Raman signal classification. Our method utilized machine learning-assisted classification of Raman signals, which are the distinctive features of label-free proteins. As a result, three types of proteins could be imaged simultaneously. In addition, we could quantify individual proteins from a mixture of multiple proteins over a wide detection range (10 fg/mL-1 μg/mL). These results showed a 1000-fold improvement in sensitivity and a 30-fold increase in the upper limit of detection compared to existing methods. These advances will enhance our understanding of biology and facilitate the development of disease diagnoses and treatments.

From biogenesis to aptasensors: advancements in analysis for tumor-derived extracellular vesicles research

Extracellular vesicles (EVs) are enclosed by a nanoscale phospholipid bilayer membrane and typically range in size from 30 to 200 nm. They contain a high concentration of specific proteins, nucleic acids, and lipids, reflecting but not identical to the composition of the parent cell. The inherent characteristics and variety of EVs give them extensive and unique advantages in the field of cancer identification and treatment. Recently, EVs have been recognized as potential tumor markers for the detection of cancer. Aptamers, which are molecules of single-stranded DNA or RNA, demonstrate remarkable specificity and affinity for their targets by adopting distinct tertiary structures. Aptamers offer various advantages over their protein counterparts, such as reduced immunogenicity, the ability for convenient large-scale synthesis, and straightforward chemical modification. In this review, we summarized EVs biogenesis, sample collection, isolation, storage and characterization, and finally provided a comprehensive survey of analysis techniques for EVs detection that are based on aptamers.

Construction of a 3D Quantum Dot Nanoassembly with Two-Step FRET for One-Step Sensing of Human Telomerase RNA in Breast Cancer Cells and Tissues

Telomerase is an important biomarker for early diagnosis of cancers, but current telomerase assays usually rely on measuring the extension products of telomerase substrates, which increases the assay complexity. More evidence indicates that human telomerase RNA (hTR), as a core component of telomerase, is positively correlated with the telomerase activity. Herein, we demonstrate the development of a duplex-specific nuclease (DSN)-propelled 3D quantum dot (QD) nanoassembly with two-step Föster resonance energy transfer (FRET) for the one-step sensing of hTR in breast cancer cells and tissues. This assay involves only one hairpin probe modified with a Cy5 at the sixth base from the 5'-biotin end and a BHQ2 at the 3'-terminus, which integrates three functions of target recognition, target recycling amplification, and signal readout. The anchoring of the hairpin probe on the 605QD surface results in the formation of a 3D 605QD-Cy5-probe-BHQ2 nanoassembly in which two-step FRET occurs among the 605QD, Cy5, and BHQ2 quencher. Notably, the formation of 605QD-Cy5-probe-BHQ2 nanoassembly facilitates the reduction of background signal and the increase of signal-to-background ratio due to its dense, highly oriented nucleic acid shell-induced steric hindrance effect. This assay can achieve one-step and rapid detection of hTR with a detection limit of 2.10 fM, which is the simplest and most rapid hTR assay reported so far. Moreover, this assay can efficiently distinguish single-base mismatched sequences, and it can discriminate the hTR level between breast cancer patients and healthy donors with a high accuracy of 100%, with great prospects for early diagnosis of cancers.

Liquid biopsy techniques and lung cancer: diagnosis, monitoring and evaluation

Lung cancer stands as the most prevalent form of cancer globally, posing a significant threat to human well-being. Due to the lack of effective and accurate early diagnostic methods, many patients are diagnosed with advanced lung cancer. Although surgical resection is still a potential means of eradicating lung cancer, patients with advanced lung cancer usually miss the best chance for surgical treatment, and even after surgical resection patients may still experience tumor recurrence. Additionally, chemotherapy, the mainstay of treatment for patients with advanced lung cancer, has the potential to be chemo-resistant, resulting in poor clinical outcomes. The emergence of liquid biopsies has garnered considerable attention owing to their noninvasive nature and the ability for continuous sampling. Technological advancements have propelled circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), extracellular vesicles (EVs), tumor metabolites, tumor-educated platelets (TEPs), and tumor-associated antigens (TAA) to the forefront as key liquid biopsy biomarkers, demonstrating intriguing and encouraging results for early diagnosis and prognostic evaluation of lung cancer. This review provides an overview of molecular biomarkers and assays utilized in liquid biopsies for lung cancer, encompassing CTCs, ctDNA, non-coding RNA (ncRNA), EVs, tumor metabolites, TAAs and TEPs. Furthermore, we expound on the practical applications of liquid biopsies, including early diagnosis, treatment response monitoring, prognostic evaluation, and recurrence monitoring in the context of lung cancer.

Controllable Assembly of a Quantum Dot-Based Aptasensor Guided by CRISPR/Cas12a for Direct Measurement of Circulating Tumor Cells in Human Blood

Accurate and sensitive analysis of circulating tumor cells (CTCs) in human blood provides a non-invasive approach for the evaluation of cancer metastasis and early cancer diagnosis. Herein, we demonstrate the controllable assembly of a quantum dot (QD)-based aptasensor guided by CRISPR/Cas12a for direct measurement of CTCs in human blood. We introduce a magnetic bead@activator/recognizer duplex core-shell structure to construct a multifunctional platform for the capture and direct detection of CTCs in human blood, without the need for additional CTC release and re-identification steps. Notably, the introduction of magnetic separation ensures that only a target-induced free activator can initiate the downstream catalysis, efficiently avoiding the undesired catalysis triggered by inappropriate recognition of the activator/recognizer duplex structure by crRNAs. This aptasensor achieves high CTC-capture efficiency (82.72%) and sensitive detection of CTCs with a limit of detection of 2 cells mL-1 in human blood, holding great promise for the liquid biopsy of cancers.

DNA-Modulated and Mechanoresponsive Excitonic Couplings Reveal Chiroptical Correlation of Conformation, Tension, and Dynamics of DNA Self-Assembly

Study of the conformational and mechanical behaviors of biomolecular assemblies is vital to the rational design and realization of artificial molecular architectures with biologically relevant functionality. Here, we revealed DNA-modulated and mechanoresponsive excitonic couplings between organic chromophores and verified strong correlations between the excitonic chiroptical responses and the conformational and mechanical states of DNA self-assemblies irrespective of fluorescence background interference. Besides, the excitonic chiroptical effect allowed sensitive monitoring of DNA self-assembled nanostructures due to small molecule bindings or DNA strand displacement reactions. Moreover, we developed a new chiroptical reporter, a DNA-templated dimer of an achiral cyanine5 and an intrinsically chiral BODIPY, that exhibited unique multiple-split spectral line shape of exciton-coupled circular dichroism, largely separated response wavelengths, and enhanced anisotropy dissymmetry factor (g-factor). These results shed light on a promising chiroptical spectroscopic tool for studying biomolecular recognition and binding, conformation dynamics, and soft mechanics in general.