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Clay Jonassen posted an update 6 months, 4 weeks ago
Microfluidics-based technologies for single-cell analysis are becoming increasingly important tools in biological studies. With the increasing sophistication of microfluidics, cellular barcoding techniques, and next-generation sequencing, a more detailed picture of cellular subtype is emerging. Unfortunately, the majority of the methods developed for single-cell analysis are high-throughput and not suitable for rare cell analysis as they require a high input cell number. Here, we report a low-cost and reproducible method for rare single-cell analysis using a highly hydrophobic surface and nanosized static droplets. Our method allows rapid and efficient on-chip single-cell lysis and subsequent collection of genetic materials in nanoliter droplets using a micromanipulator or a laboratory pipette before subsequent genetic analysis. We show precise isolation of single cancer cells with high purity using two different strategies (i- cytospin and ii- static droplet array) for subsequent RNA analysis using droplet digital polymerase chain reaction (PCR) and real-time PCR. Our highly controlled isolation method opens a new avenue for the study of subcellular functional mechanisms, enabling the identification of rare cells of potential functional or pathogenic consequence.It remains challenging to achieve efficient and air-stable photon upconversion (UC) in rigid, technologically valuable transparent films. Here, we report the first example of epoxy resins that show an air-stable and efficient triplet-triplet annihilation (TTA)-based UC. Epoxy resins are thermally cross-linked polymers widely used as coating and sealing materials in actual devices. To achieve efficient TTA-UC in rigid epoxy films, it is essential to execute both the triplet sensitization and triplet exciton diffusion processes without relying on molecular diffusion. This requires homogeneously dispersing emitter molecules without aggregation in three-dimensionally cross-linked rigid polymer networks at a high concentration (ca. 1000 mM) such that the inter-emitter distance is less than 1 nm, where dexter energy transfer can occur. This difficult requirement is solved by employing an ionic liquid emitter that consists of 9,10-diphenylanthracene sulfonate and lipophilic phosphonium ions bearing long alkyl chains. The obtained epoxy resins show a high TTA-UC efficiency (ηUC = 3.8%) and low threshold excitation intensity (Ith = 40 mW cm-2) in air. These UC parameters are achieved by virtue of a very high sensitizer-to-emitter triplet energy-transfer efficiency (92.8%) and a significantly long emitter triplet lifetime (17.8 ms) that reflect the high emitter concentration and the rigid chromophore environment, respectively. The bulk transparent upconverting resins can be prepared in air and function in air, which opens a new avenue toward a wide range of real-world applications.Titania (TiO2) nanoparticles are active photocatalysts, and isoprene (C5H8) is a biogenic volatile organic compound that contributes crucially to global particulate matter generation. Herein, the direct photooxidation of isoprene by titanium oxide cluster anions with dimensions up to a nanosize by both ultraviolet (UV) and visible (Vis) light excitations has been successfully identified through mass spectrometric experiments combined with quantum chemistry calculations. The potential role of “dry” titania in atmospheric isoprene oxidation has been revealed, and a clear picture of the photooxidation mechanism on titanium oxide nanoparticles has been provided explicitly at the molecular level. The adsorption of isoprene on the atomic oxygen radicals (O•-) of titanium oxide clusters leads to the formation of the crucial interfacial state (IS) within the band gap of titanium oxides. This IS is demonstrated to be the significant factor in delivering the electron from the π orbital of C5H8 to the Ti3d orbital in the photooxidation process (C5H8 + Ti4+-O•- → C5H8O + Ti3+) and creating photoactivity in the Vis region. It is revealed that after the photogeneration of the O•- radicals by UV excitation on the TiO2 particle surface, the subsequent reactions can be induced by Vis excitation through the IS. This multicolor strategy in both the UV and Vis regions can enhance the efficiency of solar energy harvesting and improve the product yield of the photocatalysis on TiO2 nanoparticles. New insights have been provided into both the atmospheric chemistry of isoprene and the photochemistry of TiO2 nanoparticles.Lipoprotein lipase (LPL) is the key enzyme that hydrolyzes triglycerides from triglyceride-rich lipoproteins. Angiopoietin-like proteins (ANGPTL) 3, 4, and 8 are well-characterized protein inhibitors of LPL. ANGPTL8 forms a complex with ANGPTL3, and the complex is a potent endogenous inhibitor of LPL. However, the nature of the structural interaction between ANGPTL3/8 and LPL is unknown. To probe the conformational changes in LPL induced by ANGPTL3/8, we found that HDX-MS detected significantly altered deuteration in the lid region, ApoC2 binding site, and furin cleavage region of LPL in the presence of ANGPTL3/8. Supporting this HDX structural evidence, we found that ANGPTL3/8 inhibits LPL enzymatic activities and increases LPL cleavage. ANGPTL3/8-induced effects on LPL activity and LPL cleavage are much stronger than those of ANGPTL3 or ANGPTL8 alone. ANGPTL3/8-mediated LPL cleavage is blocked by both an ANGPTL3 antibody and a furin inhibitor. Knock-down of furin expression by siRNA significantly reduced ANGPT3/8-induced cleavage of LPL. Our data suggest ANGPTL3/8 promotes furin-mediated LPL cleavage.Glucose oxidase (GOx) is regarded as an ideal endogenous natural enzyme for tumor starvation therapy and photothermal therapy (PTT) is a promising strategy for the ablation of primary tumor. In this work, Cu-doped cobalt oxide and porous carbon nanocomposites (CuCo(O)@PCNs) were synthesized from double-layered ZIF-8@ZIF-67 and GOx was loaded in the porous carbon to form a CuCo(O)/GOx@PCNs hybrid nanozyme. CuCo(O) was characterized as the Cu0.3Co2.7O4 phase through X-ray diffraction analysis and it can react with H2O2 to generate O2 and alleviate tumor hypoxia, resulting in the recovered enzymatic activity of GOx and the enhanced starvation therapy. selleck The porous nanocarbon can ablate the primary tumor because of its high photothermal conversion efficiency of 40.04%. The three-in-one functions of oxygen supply, glucose consumption, and photothermal conversion were realized in the ZIFs-derived CuCo(O)/GOx@PCNs nanozyme and the starvation therapy effect was improved by PTT and oxygen supplement. Furthermore, the inhibition effect of CuCo(O)/GOx@PCNs on metastatic tumor is similar to combined therapy of the nanozyme and the immune checkpoint-blocking antibody, α-PD-1.
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