Notes

Asymmetric misfit nanotubes: Chemical substance thanks outwits your entropy at high-temperature solid-state tendencies.
Recent developments in the field of polymer vesicles, i.e. polymersomes, have demonstrated that disrupting the equilibrium conditions of the milieu could lead to shape transformation into stable non-spherical morphologies, bringing on-demand shape control to reality and bearing great promise for cell mimicry and a variety of biomedical applications. Here, we studied the self-assembly behavior of glassy amphiphilic triblock copolymers, poly(ethylene glycol)-block-polystyrene-stat-poly(coumarin methacrylate)-block-poly(ethylene glycol) (PEG-b-P(S-stat-CMA)-b-PEG), and their response to various stimuli. By changing the respective molecular weights of both the hydrophobic P(S-stat-CMA) and the hydrophilic PEG blocks, we varied the hydrophobic volume fraction thereby accessing a range of morphologies from spherical and worm-like micelles, as well as polymersomes. learn more For the latter, we observed that slow osmotic pressure changes induced by dialysis led to a decrease in size while rapid osmotic pressure changes by addition of a PEG fusogen led to morphological transformations into rod-like and tubular polymersomes. We also found out that chemically crosslinking the vesicles before inducing osmotic pressure changes led to the vesicles exhibiting hypotonic shock, atypical for glassy polymersomes. We believe that this approach combining the robustness of triblock copolymers and light-based transformations will help expand the toolbox to design ever more complex biomimetic constructs.Using a regular CMOS sensor as a template, we are able to fabricate a simple but highly effective superhydrophobic SERS substrate. Specifically, we decorated the microlens layer of the sensor with 7 μm polystyrene beads to obtain a PDMS patterned replica. The process resulted in a uniform pattern of voids in the PDMS (denoted nanobowls) that are intercalated with a few larger voids (denoted here microbowls). The voids act as superhydrophobic substrates with analyte concentration capabilities in bigger bowl-like structures. Silver nanoparticles were directly grown on the patterned PDMS substrate inside both the nano- and microbowls, and serve as strong electromagnetic field enhancers for the SERS substrate. After systematic characterization of the fabricated SERS substrate by atomic force microscopy and scanning electron microscopy, we demonstrated its SERS performance using 4-aminothiophenol as a reporter molecule. Finally, we employed this innovative substrate to concentrate and analyze extracellular vesicles (EVs) isolated from an MC65 neural cell line in an ultralow sample volume. This substrate can be further exploited for the investigation of various EV biomarkers for early diagnosis of different diseases using liquid biopsy.The viscosity of lysosomes plays a significant role in modulating biological processes and reflects the status and function of this kind of organelle, e.g., locations, morphologies, and components. Herein, we constructed a novel near-infrared (NIR) lysosome-targeting viscosity probe, Lyso-cy, for monitoring viscosity changes in biological systems. The Lyso-cy probe showed very strong fluorescence emission at around 710 nm in viscous media. The fluorescence intensity of Lyso-cy increased 122-fold from when in water to when in 95% glycerol. Moreover, Lyso-cy proved to be an ideal lysosome-targeting tracer for monitoring fluctuations in the viscosity of a living cell with high spatial and temporal resolution under laser confocal microscopy.Nitric oxide (NO) is an important signaling molecule involved in various physiological and pathological processes. The effects of NO depend on its concentration, and the spatial and temporal constraints of the cell microenvironment. Meanwhile, NO can react with some biomolecules such as biothiols, leading to a short biological lifetime. Thus, it is very crucial to establish a real-time visualization method for monitoring NO levels. In this work, we have developed a fluorescent probe, RBA, for NO, with a 3-extended BODIPY as a fluorophore and a secondary amine as the active site. The probe RBA can quickly sense NO (∼10 s) in aerobic solutions to generate a fluorescent N-nitrosamine (RBA-NO, Φf = 0.87) due to blocking of the photoinduced electron transfer (PET) process from the secondary amine to the BODIPY core. This sensing reaction displays high sensitivity (LOD = 10 nM) and high selectivity for NO over relevant analytes except some reducing reagents including biothiols, and a remarkable interference effect is observed ascribed to a competitive reaction with biothiols. Furthermore, the exo- and endogenous detection of NO in live cells and zebra fish was achieved, and it was demonstrated that glutathione (GSH) weakens drastically the fluorescence response by cell-imaging experiments. These results imply that the colorimetric and fluorescence response of the chemosensor for NO depends on the levels of both NO and GSH in environments.Bacteria-induced infections have always been associated with various medical devices. The construction of an intelligent antimicrobial surface is an important challenge. In this study, we report the construction of a zwitterionic surface with good biocompatibility under physiological conditions and which shows an anti-adhesion effect on the original bacteria. Once the bacteria multiply, the acidic environment initiated by the bacteria will cause the amide bond on the surface to break, and the zwitterionic surface can be rapidly converted to a cationic bactericidal surface. Confocal laser scanning (CLSM) and scanning electron microscopy (SEM) show that the zwitterionic surface has efficient antibacterial activity with an anti-adhesion property while the pH-responsive transition to quaternary ammonium compounds with a germicidal surface in the acidic environment of bacterial metabolism aids the activity. Thus, the pH-responsive zwitterionic-to-cationic transition antibacterial design opens up new ideas for the efficient and safe application of cationic bactericides in clinical medical antibacterial materials.Homogeneous cationic gold(i) catalysis emerged as a preferred avenue for the activation of alkenes and alkynes towards reactions with weak nucleophiles, especially in cyclization reactions. Here we report an intramolecular carboalkoxylation reaction of electron-rich benzyl ethers of 2-ethynylaryl phenols catalysed by a digold(i)-NHC complex. The reaction proceeds efficiently with low catalyst loading and the resulting 2,3-disubstituted benzofurans form in moderate to good yields. Based on the results of a cross-over experiment, spectroscopic data, and DFT calculations, we propose a mechanism that accounts for the observed chemo- and regioselectivity.
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