All-in-One Strategy for Downstream Molecular Profiling of Tumor-Derived Exosomes

Buoyant Metal-Organic Framework Corona-Driven Fast Isolation and Ultrasensitive Profiling of Circulating Extracellular Vesicles

Accurately assaying tumor-derived circulating extracellular vesicles (EVs) is fundamental in noninvasive cancer diagnosis and therapeutic monitoring but limited by challenges in efficient EV isolation and profiling. Here, we report a bioinspired buoyancy-driven metal-organic framework (MOF) corona that leverages on-bubble coordination and dual-encoded surface-enhanced Raman scattering (SERS) nanotags to streamline rapid isolation and ultrasensitive profiling of plasma EVs in a single assay for cancer diagnostics. This integrated bubble-MOF-SERS EV assay (IBMsv) allows barnacle-like high-density adhesion of MOFs on a self-floating bubble surface to enable fast isolation (2 min, near 90% capture efficiency) of tumor EVs via enhanced EV-MOF binding. Also, IBMsv harnesses four-plexed SERS nanotags to profile the captured EV surface protein markers at a single-particle level. Such a sensitive assay allows multiplexed profiling of EVs across five cancer types, revealing heterogeneous EV surface expression patterns. Furthermore, the IBMsv assay enables cancer diagnosis in a pilot clinical cohort (n = 55) with accuracies >95%, improves discrimination between cancer and noncancer patients via an algorithm, and monitors the surgical treatment response from hepatocellular carcinoma patients. This assay provides a fast, sensitive, streamlined, multiplexed, and portable blood test tool to enable cancer diagnosis and response monitoring in clinical settings.

Lewis Acidic Metal-Organic Framework Assisted Ambient Liquid Extraction Mass Spectrometry Imaging for Enhancing the Coverage of Poorly Ionizable Lipids in Brain Tissue

The spatial distribution of lipidomes in tissues is of great importance in studies of living processes, diseases, and therapies. Mass spectrometry imaging (MSI) has become a critical technique for spatial lipidomics. However, MSI of low-abundance or poorly ionizable lipids is still challenging because of the ion suppression from high-abundance lipids. Here, a metal-organic framework (MOF) Zr6O4(OH)4(1,3,5-Tris(4-carboxyphenyl) benzene)2(triflate)6(Zr6OTf-BTB) was prepared and used for selective on-tissue adsorption of phospholipids to reduce ion suppression from them to poorly ionizable lipids. The results show that Zr6OTf-BTB with strong Lewis acidic sites and a large specific surface area (647.9 m2·g-1) could selectively adsorb phospholipids under 1% FA-MeOH. Adsorption efficiencies of phospholipids are 88.4-144.9 times higher than those of other neutral lipids. Moreover, the adsorption capacity and the adsorption kinetic rate constant of the new material to phospholipids are higher than those of Zr6-BTB (242.72 vs 73.96 mg·g-1, 0.0442 vs 0.0220 g·mg-1·min-1). A Zr6OTf-BTB sheet was prepared by a lamination technique for on-tissue phospholipid adsorption from brain tissue. Then, the tissue section on the Zr6OTf-BTB sheet was directly imaged via ambient liquid extraction-MSI with 1% FA-MeOH as the sampling solvent. The results showed that phospholipids could be 100% removed directly on tissue, and the detection coverage of the Zr6OTf-BTB-enhanced MSI method to ceramides (Cers) and hexosylceramides (HexCers) was increased by 5-26 times compared with direct tissue MSI (26 vs 1 and 17 vs 3). The new method provides an efficient and convenient way to eliminate the ion suppression from phospholipids in MSI, largely improving the detection coverage of low-abundance and poorly ionizable lipids.

Spatially Confined Nanoreactors Designed for Biological Applications

The applications of nanoreactors in biology are becoming increasingly significant and prominent. Specifically, nanoreactors with spatially confined, due to their exquisite design that effectively limits the spatial range of biomolecules, attracted widespread attention. The main advantage of this structure is designed to improve reaction selectivity and efficiency by accumulating reactants and catalysts within the chambers, thus increasing the frequency of collisions between reactants. Herein, the recent progress in the synthesis of spatially confined nanoreactors and their biological applications is summarized, covering various kinds of nanoreactors, including porous inorganic materials, porous crystalline materials with organic components and self-assembled polymers to construct nanoreactors. These design principles underscore how precise reaction control could be achieved by adjusting the structure and composition of the nanoreactors to create spatial confined. Furthermore, various applications of spatially confined nanoreactors are demonstrated in the biological fields, such as biocatalysis, molecular detection, drug delivery, and cancer therapy. These applications showcase the potential prospects of spatially confined nanoreactors, offering robust guidance for future research and innovation.

Proteomic Research of Extracellular Vesicles in Clinical Biofluid

Extracellular vesicles (EVs), the lipid bilayer membranous structures of particles, are produced and released from almost all cells, including eukaryotes and prokaryotes. The versatility of EVs has been investigated in various pathologies, including development, coagulation, inflammation, immune response modulation, and cell-cell communication. Proteomics technologies have revolutionized EV studies by enabling high-throughput analysis of their biomolecules to deliver comprehensive identification and quantification with rich structural information (PTMs, proteoforms). Extensive research has highlighted variations in EV cargo depending on vesicle size, origin, disease, and other features. This fact has sparked activities to use EVs for diagnosis and treatment to ultimately achieve clinical translation with recent endeavors summarized and critically reviewed in this publication. Notably, successful application and translation require a constant improvement of methods for sample preparation and analysis and their standardization, both of which are areas of active research. This review summarizes the characteristics, isolation, and identification approaches for EVs and the recent advances in EVs for clinical biofluid analysis to gain novel knowledge by employing proteomics. In addition, the current and predicted future challenges and technical barriers are also reviewed and discussed.

MoS2 QDs-MXene heterostructure-based ECL sensor for the detection of miRNA-135b in gastric cancer exosomes

Exosomes play an important role in the proliferation, adhesion and migration of cancer cells. In this study, we have developed a novel electrochemiluminescence (ECL) sensor based on MoS₂ QDs-MXene heterostructure and Au NPs@biomimetic lipid layer to detect exosomal miRNA. MoS₂ QDs-MXene heterostructure had been prepared as the luminescence probe. Ti₃C₂T_x MXene nanosheets possessed the large specific surface area, excellent flexibility and superior conductivity. MoS₂ QDs on the MXene nanosheets worked as the radiation center to generate strong ECL signal. Meanwhile, Au NPs with biomimetic lipid layer have been modified on the electrode, which retained the lipid dynamics and excellent antifouling property. When miRNA-135b was recognized on the Au NPs@biomimetic lipid layer, MoS₂ QDs-MXene heterostructure was linked on the electrode and further extended the outer Helmholtz plane. As a result, the self-luminous Faraday cage-mode sensing system has been used to detect miRNA-135b from 30 fM to 20 nM with a detection limit of 10 fM. Furthermore, gastric cancer exosomal miRNA in the ascites of clinical patients has been detected successfully. The sensing system can be served as a versatile platform with huge application potential in the field of exosome detection.