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Novel core–shell poly(acrylamide) magnetic nanogels with controllable particle size produced via photochemical method in emulsion-free aqueous system at room temperature have been developed for the first time. After Hoffmann elimination of carbonyl, the nanogels with amino groups, or poly(acrylamide-vinyl amine) magnetic nanogels, were also obtained. Particle size, size distributions and zeta potential of the magnetic nanogels before and after Hoffmann elimination were measured by photo correlation spectroscopy (PCS). Structure and morphology of the magnetic nanogels were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The higher dispersibility and stability of the magnetic nanogels suggest promising potential applications in targeted radiopharmaceuticals carrier for cancer therapy, and in biological and medical studies as well. [ABSTRACT FROM AUTHOR]

Although the efficacy and the health care advantages of Chinese herbal medicine (CHM) have become increasingly recognized worldwide, the potential side effects and toxicity still restrict its broader application. This study established and applied an integrated platform anchored on automatic patch clamp system to screen and evaluate a collection of CHM extracts, compositions and monomeric compounds for in vitro cardiac toxicity. Of 1036 CHM samples screened, 2.79% significantly inhibited hERG channel activity. Among them, Strychnine was identified for the first time as a potent hERG inhibitor with an IC 5 0 of 6. 6 5 ± 1. 0 4 μ M in comparison to that of Dofetilide at 1. 8 0 ± 0. 2 4 μ M and Quinidine at 7. 4 2 ± 0. 5 4 μ M. Langendorff-perfusion experiments confirmed that strychnine increased QT interphase from 7 1. 6 9 ± 5. 3 4 ms to 9 8. 6 1 ± 5. 5 4 ms and decreased heart rates from 2 2 7. 6 5 ± 5. 4 0 bmp to 1 6 2. 9 1 ± 1 4. 7 0 bmp in isolated rat hearts. The cardiac toxicity effect of strychnine appears to be specific to hERG channel since an in vitro multiplex imaging analysis showed that it did not affect cellular phenotypes such as cell vitality, nucleus area, mitochondria mass and function, nor intracellular calcium in rat primary myocytes. This integrated high-throughput hERG patch clamp and high-content multi-parameter imaging cardiac toxicity screen approach should be useful for large-scale preclinical evaluation of complex Chinese herbal medicine. [ABSTRACT FROM AUTHOR]

Fluorescence microscopy has become an essential tool for biologists, to visualize the dynamics of intracellular structures with specific labeling. Quantitatively measuring the dynamics of moving objects inside the cell is pivotal for understanding of the underlying regulatory mechanism. Protein-containing vesicles are involved in various biological processes such as material transportation, organelle interaction, and hormonal regulation, whose dynamic characteristics are significant to disease diagnosis and drug screening. Although some algorithms have been developed for vesicle tracking, most of them have limited performance when dealing with images with low resolution, poor signal-to-noise ratio (SNR) and complicated motion. Here, we proposed a novel deep learning-based method for intracellular vesicle tracking. We trained the U-Net for vesicle localization and motion classification, with demonstrates great performance in both simulated datasets and real biological samples. By combination with fan-shaped tracker (FsT) we have previously developed, this hybrid new algorithm significantly improved the performance of particle tracking with the function of subsequently automated vesicle motion classification. Furthermore, its performance was further demonstrated in analyzing with vesicle dynamics in different temperature, which achieved reasonable outcomes. Thus, we anticipate that this novel method would have vast applications in analyzing the vesicle dynamics in living cells. [ABSTRACT FROM AUTHOR]