Integration of ion-mobility high-resolution liquid chromatography/mass spectrometry-based untargeted metabolomics and desorption electrospray ionization-mass spectrometry imaging to unveil the ginsenosides variation induced by steaming for Panax ginseng, P. quinquefolius and P. notoginseng

The raw and steamed products of ginseng exhibit different efficacy, and elucidation of the underlying chemical transformation is significant for their rational application and quality control. This work was designed to holistically depict the chemical variation of Panax ginseng (PG), P. quinquefolius (PQ), and P. notoginseng (PN) induced by the steaming, and to unveil the steaming-associated markers diagnostic for differentiating between the raw and processed products, following a three-step strategy: 1) systematic ginsenosides characterization by hybrid scan (namely HDDIDDA) available on the Vion™ ion mobility-quadrupole time-of-flight mass spectrometer coupled with reversed-phase ultra-high performance liquid chromatography; 2) holistic depiction of the chemical variation and discovery of potential markers by the pattern recognition untargeted metabolomics analysis; and 3) construction of steaming-induced transformation network combined with desorption electrospray ionization-mass spectrometry imaging (DESI-MSI). Consequently, 542 ginsenosides were characterized from the raw and processed PG/PQ/PN. Steaming at 1–10 h could cause significant chemical variation, and separately 26, 28, and 18 potential markers were found for the steaming of PG, PQ, and PN. Steaming-induced transformation network mainly involved hydration of the malonyl group, hydrolysis of the glycosyl moiety, and dehydration at C-20. DESI-MSI further revealed spatial distribution of marker saponins in the cork layer, phloem, and xylem, and primarily confirmed the hydrolysis reactions occurring to ginseng steaming. Conclusively, the established strategy is practical to unveil the holistic ginsenosides variation of ginseng induced by the processing, which is useful in the quality control of both the herbal medicines and foods

Magnetic Upconversion Luminescent Nanocomposites with Small Size and Strong Super-Paramagnetism: Polyelectrolyte-Mediated Multimagnetic-Beads Embedding

The incorporation of magnetic and upconversion luminescent properties into one single nanostructure is highly desirable in nanomedicine for contrast agents and/or nanotheranostic platforms. Current magnetic upconversion luminescent nanocomposites generally suffer from relatively large size and/or low magnetization, which might induce unsatisfactory colloidal stability, reticuloendothelial system clearance, and limit their applications in biolabeling, sensing, imaging, bioseparation, magnetic targeting, and so on. Herein, we constructed multimagnetic-beads-embedded Fe₃O₄/NaYF₄: Yb, Er nanocomposites to overcome these problems. Polyelectrolyte was introduced as an organic intermediate layer to offset the crystal lattice mismatch between Fe₃O₄ and NaYF₄: Yb, Er. It also acted as the ligand to direct the growth of NaYF₄: Yb, Er on the surface of Fe₃O₄. So-prepared nanocomposites exhibited an average size of 33.8 nm, much smaller than those with magnetic nanoparticle clusters as the core. The saturation magnetization of the nanocomposites is 17.8 emu/g, higher than those following current single magnetic nanoparticle embedded approach. To demonstrate their application potential in bioimaging and theranostics, magnetic field-assisted sensitive upconversion luminescence cell imaging is presented

Near-Infrared Triggered Upconversion Polymeric Nanoparticles Based on Aggregation-Induced Emission and Mitochondria Targeting for Photodynamic Cancer Therapy

Photodynamic therapy (PDT) is an auspicious strategy for cancer therapy by yielding reactive oxygen species (ROS) under light irradiation. Here, we have developed near-infrared (NIR) triggered polymer encapsulated upconversion nanoparticles (UCNPs) based on aggregation-induced emission (AIE) characteristics and mitochondria target ability for PDT. The coated AIE polymer as a photosensitizer can be photoactivated by the up-converted energy of UCNPs upon 980 nm laser irradiation, which could generate ROS efficiently in mitochondria and induce cell apoptosis. Moreover, a “sheddable” poly­(ethylene glycol) (PEG) layer was easily conjugated at the surface of NPs. The pH-responsive PEG layer shields the surface positive charges and shows stronger protein-resistance ability. In the acidic tumor environment, PEGylated NPs lose the PEG layer and show the mitochondria-targeting ability by responding to tumor acidity. A cytotoxicity study indicated that these NPs have good biocompatibility in the dark but exert severe cytotoxicity to cancer cells, with only 10% cell viability, upon being irradiated with an NIR laser. The AIE nanoparticles are a good candidate for effective mitochondria targeting photosensitizer for PDT

Characterization of ginsenosides from Panax japonicus var. major (Zhu-Zi-Shen) based on ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry and desorption electrospray ionization-mass spectrometry imaging

Abstract Background Panax japonicus var. major (PJM) belongs to the well-known ginseng species used in west China for hundreds of years, which has the effects of lung tonifying and yin nourishing, and exerts the analgesic, antitussive, and hemostatic activities. Compared with the other Panax species, the chemical composition and the spatial tissue distribution of the bioactive ginsenosides in PJM have seldom been investigated. Methods Ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/QTOF-MS) and desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) were integrated for the systematic characterization and spatial tissue distribution studies of ginsenosides in the rhizome of PJM. Considering the great difficulty in exposing the minor saponins, apart from the conventional Auto MS/MS (M1), two different precursor ions list-including data-dependent acquisition (PIL-DDA) approaches, involving the direct input of an in-house library containing 579 known ginsenosides (M2) and the inclusion of the target precursors screened from the MS1 data by mass defect filtering (M3), were developed. The in situ spatial distribution of various ginsenosides in PJM was profiled based on DESI-MSI with a mass range of m/z 100–1500 in the negative ion mode, with the imaging data processed by the High Definition Imaging (HDI) software. Results Under the optimized condition, 272 ginsenosides were identified or tentatively characterized, and 138 thereof were possibly not ever reported from the Panax genus. They were composed by 75 oleanolic acid type, 22 protopanaxadiol type, 52 protopanaxatriol type, 16 octillol type, 19 malonylated, 35 C-17 side-chain varied, and 53 others. In addition, the DESI-MSI experiment unveiled the differentiated distribution of saponins, but the main location in the cork layer and phloem of the rhizome. The abundance of the oleanolic acid ginsenosides was high in the rhizome slice of PJM, which was consistent with the results obtained by UHPLC/QTOF-MS. Conclusion Comprehensive characterization of the ginsenosides in the rhizome of PJM was achieved, with a large amount of unknown structures unveiled primarily. We, for the first time, reported the spatial tissue distribution of different subtypes of ginsenosides in the rhizome slice of PJM. These results can benefit the quality control and further development of PJM and the other ginseng species

<i>In vivo</i> tactile stimulation induced Ca²⁺ elevation in <i>C</i>. <i>elegans</i> AMsh cell.

<p>(A) An example of intracellular Ca²⁺ elevation in an AMsh cell induced by a train of tactile stimuli (20 μm, 2 Hz, 5 s). Sample times are indicated in seconds. *, cell body of the AMsh cell. (B) Fluorescence intensities in the cell body of an AMsh cell. (C) Ratio changes in the cell bodies of the AMsh cells. (D) Ratio changes in the process and cell body of an AMsh cell. The Ca²⁺ wave was propagated from the process to the cell body.</p

<i>In vivo</i> patch-clamp recording of touch-induced currents from the <i>C</i>. <i>elegans</i> AMsh glial cells.

<p>(A) Diagram of the morphologies of the AMsh cell and the ASH neuron [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117114#pone.0117114.ref005" target="_blank">5</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117114#pone.0117114.ref013" target="_blank">13</a>]. Tactile stimuli were delivered to the nose tip of the worm using a ∼ 5μm glass probe. (B) Representative currents in an AMsh cell evoked by a pair of tactile stimuli (500 ms). Inset shows the period of tactile stimulation in expanded time scale. (C) I-V curve of the touch-induced currents in the AMsh cells. Displacement,10 μm; mean ± s.e.m, n≥5 animals; Voltage clamped at-70 mV.</p

Sensitivities of the AMsh cell and the ASH neuron to stimulus strength.

<p>Tactile stimuli of varying displacements were applied to the nose tip of the worm. (A) Touch-induced currents in an AMsh cell evoked by 4, 7, and 10 μm displacements. (B) Inward currents in an ASH neuron evoked by 10, 15, and 20 μm displacement. (C) Amplitudes of touch-induced currents in the AMsh cells and the ASH neurons. A displacement of 4μm was able to evoke currents in the AMsh cells, whereas a displacement <10μm failed to evoke currents in the ASH neurons. (D) Rise-times of currents evoked by a 15 μm displacement. (E) Decay-times of touch-induced currents evoked by a 15 μm displacement. The decay time is measured as the time elapsed for the current to fully recover from the peak. (F) Latencies of touch-induced currents in the AMsh cells evoked by 4, 7, 10, and 15 μm displacement and ASH neurons evoked by 15 and 20 μm displacement. Mean ± s.e.m, n≥4 animals; Voltage clamped at-70 mV.</p

<i>In Vivo</i> Tactile Stimulation-Evoked Responses in <i>Caenorhabditis elegans</i> Amphid Sheath Glia

<div><p>Glial cells are important components of the nervous system. However, how they respond to physiological stimuli <i>in vivo</i> remains largely unknown. In this study, we investigated the electrophysiological activities and Ca²⁺ responses of the <i>C. elegans</i> amphid sheath glia (AMsh glia) to tactile stimulation <i>in vivo</i>. We recorded robust inward currents and Ca²⁺ elevation in the AMsh cell with the delivery of tactile stimuli of varying displacements to the nose tip of the worm. Compared to the adjacent mechanoreceptor ASH neuron, the AMsh cell showed greater sensitivity to tactile stimulation. Amiloride, an epithelial Na⁺ channel blocker, blocked the touch-induced currents and Ca²⁺ signaling in the ASH neuron, but not those in the AMsh cell. Taken together, our results revealed that AMsh glial cells actively respond to <i>in vivo</i> tactile stimulation and likely function cell-autonomously as mechanoreceptors.</p></div