11 research outputs found

    Nanozymatic Antioxidant System Based on MoS<sub>2</sub> Nanosheets

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    The enzymatic antioxidant system (EAS) protects aerobic cells from oxidative stress. However, it is brittle and susceptible of inactivation of reactive oxygen species (ROS) immoderate production. Here, we demonstrated that MoS<sub>2</sub> nanosheets (few-layer MoS<sub>2</sub>), as a multifunctional nanozyme, possess intrinsic activity of mimicking enzymes of superoxide dismutases (SODs), catalases (CATs), and peroxidases (PODs) under physiological conditions (pH 7.4, 25 °C). Further, MoS<sub>2</sub> nanosheets showed POD-like activity by transferring electrons instead of generating ROS. Similar to EAS, a defense termed nanozymatic antioxidant system (NAS) was developed by MoS<sub>2</sub> nanosheets, for regulation of oxidative stress. Surprisingly, this NAS can effectively scavenge other free radicals including hydroxyl radicals (<sup>•</sup>OH), nitrogen-centered free radicals (<sup>•</sup>DPPH), and nitric oxide (<sup>•</sup>NO). To evaluate these unique properties of MoS<sub>2</sub>-based NAS in vivo, Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and A549 cell models were established, respectively. These results showed MoS<sub>2</sub> nanosheets superiorly protect bacteria and cells against oxidative injury caused by H<sub>2</sub>O<sub>2</sub>. This work makes MoS<sub>2</sub> nanosheets promising antioxidants in the pathological processes and expands their application in biocatalysis and nano-biomedicine

    Single-Exosome-Counting Immunoassays for Cancer Diagnostics

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    Exosomes shed by tumor cells have been recognized as promising biomarkers for cancer diagnostics due to their unique composition and functions. Quantification of low concentrations of specific exosomes present in very small volumes of clinical samples may be used for noninvasive cancer diagnosis and prognosis. We developed an immunosorbent assay for digital qualification of target exosomes using droplet microfluidics. The exosomes were immobilized on magnetic microbeads through sandwich ELISA complexes tagged with an enzymatic reporter that produces a fluorescent signal. The constructed beads were further isolated and encapsulated into a sufficient number of droplets to ensure only a single bead was encapsulated in a droplet. Our droplet-based single-exosome-counting enzyme-linked immunoassay (droplet digital ExoELISA) approach enables absolute counting of cancer-specific exosomes to achieve unprecedented accuracy. We were able to achieve a limit of detection (LOD) down to 10 enzyme-labeled exosome complexes per microliter (∼10<sup>–17</sup> M). We demonstrated the application of the droplet digital ExoELISA platform in quantitative detection of exosomes in plasma samples directly from breast cancer patients. We believe our approach may have the potential for early diagnosis of cancer and accelerate the discovery of cancer exosomal biomarkers for clinical diagnosis

    Additional file 8: of Metabolic reprogramming-based characterization of circulating tumor cells in prostate cancer

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    Figure S3. The pairwise comparison matrix used in the AHP model. The weighting coefficients of the criteria layer were calculated on the basis of the maximum eigenvalue using the sum-product method. (TIF 481 kb

    Additional file 5: of Metabolic reprogramming-based characterization of circulating tumor cells in prostate cancer

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    Figure S1. Migration and invasion assays of the five PCa cell lines. (A–B) Representative images and statistical comparison between PC-3 M 2B4 and PC-3 M 1E8 cells in wound healing (A, 100×) and Transwell (B, 200×) assays. (C–D) Representative images and statistical comparison among LNCAP, PC-3, and DU145 cells by wound healing (C, 100×) and Transwell (D, 200×) assays. ***P < 0.001; Scale bar = 150 μm. (TIF 19013 kb