Facile fabrication of carbon nanotube hollow microspheres as a fiber coating for ultrasensitive solid-phase microextraction of phthalic acid esters in tea beverages.

The efficient extraction of phthalic acid esters (PAEs) is challenging due to their extremely low concentration, complicated matrices and hydrophilicity. Herein, hollow microspheres, as an ideal coating, possess significant potential for solid-phase microextraction (SPME) due to their fascinating properties. In this study, multiwalled carbon nanotube hollow microspheres (MWCNT-HMs) were utilized as a fiber coating for the SPME of PAEs from tea beverages. MWCNT-HMs were obtained by dissolving the polystyrene (PS) cores with organic solvents. Interestingly, MWCNT-HMs well maintain the morphology of the MWCNTs@PS precursors. The layer-by-layer (LBL) assembly of MWCNTs on PS microsphere templates was achieved through electrostatic interactions. Six PAEs, di-ethyl phthalate (DEP), di-iso-butyl phthalate (DIBP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP) and di-n-octyl phthalate (DOP), were selected as target analytes for assessing the efficiency of the coating for SPME. The stirring rate, sample solution pH and extraction time were optimized by using the Box-Behnken design. Under optimal working conditions, the proposed MWCNT-HMs/SPME was coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS) to achieve high enrichment factors (118-2137), wide linearity (0.0004-10 µg L-1), low limits of detection (0.00011-0.0026 µg L-1) and acceptable recovery (80.2-108.5%) for the detection of PAEs. Therefore, the MWCNT-HM coated fibers are promising alternatives in the SPME method for the sensitive detection of PAEs at trace levels in tea beverages.

[Active components and mechanism of Jinwugutong Capsules in treatment of osteoporosis: a study based on UPLC-Q-Exactive-MS/MS combined with network pharmacology].

UPLC-Q-Exactive-MS/MS and network pharmacology were employed to preliminarily study the active components and mechanism of Jinwugutong Capsules in the treatment of osteoporosis. Firstly, UPLC-Q-Exactive-MS/MS was employed to characterize the chemical components of Jinwugutong Capsules, and network pharmacology was employed to establish the "drug-component-target-pathway-disease" network. The key targets and main active components were thus obtained. Secondly, AutoDock was used for the molecular docking between the main active components and key targets. Finally, the animal model of osteoporosis was established, and the effect of Jinwugutong Capsules on the expression of key targets including RAC-alpha serine/threonine-protein kinase(AKT1), albumin(ALB), and tumor necrosis factor-alpha(TNF-α) was determined by enzyme-linked immunosorbent assay(ELISA). A total of 59 chemical components were identified from Jinwugutong Capsules, among which coryfolin, 8-prenylnaringenin, demethoxycurcumin, isobavachin, and genistein may be the main active components of Jinwugutong Capsules in treating osteoporosis. The topological analysis of the protein-protein interaction(PPI) network revealed 10 core targets such as AKT1, ALB, catenin beta 1(CTNNB1), TNF, and epidermal growth factor receptor(EGFR). The Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment showed that Jinwugutong Capsules mainly exerted the therapeutic effect by regulating the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT) signaling pathway, neuroactive ligand-receptor interaction, mitogen-activated protein kinase(MAPK) signaling pathway, Rap1 signaling pathway and so on. Molecular docking showed that the main active components of Jinwugutong Capsules well bound to the key targets. ELISA results showed that Jinwugutong Capsules down-regulated the protein levels of AKT1 and TNF-α and up-regulated the protein level of ALB, which preliminarily verified the reliability of network pharmacology. This study indicates that Jinwugutong Capsules may play a role in the treatment of osteoporosis through multiple components, targets, and pathways, which can provide reference for the further research.

[Preparation of triptolide-loaded dissolving microneedles and its transdermal penetration].

Triptolide(TP), the main active and toxic component of Tripterygium wilfordii, has the limitations of low bioavailability, poor absorption, low concentration in plasma, and small lethal dose. Microneedle(MN), the hybrid of hypodermic needle and transdermal patch, is a physical penetration-enhancing system. Dissolving microneedles(DMNs) can be tailored to specific needs of degradation rate. In this study, the TP-loaded DMNs(DMNs-TP) were prepared with the two-step centrifugation method. The optimal ratio of PVA to PVP K30, water content in matrix solution, demoulding method, and plasticizer for preparing DMNs were investigated with the indexes of formability and mechanical strength. The drug loading capacity was determined by HPLC and morphological characteristics were observed under an optical microscope. The mechanical properties were investigated by H&E staining and Franz diffusion cell was used to detect the in vitro skin permeation characteristics. Through the experiment, we confirmed that the optimal backing material should be PVA and PVP K30(3∶1) and the optimal ratio of matrix material to water should be 3∶4. The prepared DMNs-TP were pyramidal with smooth surface and length of approximately 550 µm. Each patch(2.75 cm~2) had the drug loading capacity of(153.41±2.29) µg, and TP was located in the upper part of the needle. The results of in vitro skin permeation assay demonstrated that the cumulative penetration of TP in DMNs-TP reached 80% in 24 h, while little TP solution penetrated the skin, which proved that DMNs promoted the transdermal delivery of TP.