[Comparative study on anti-inflammatory effect of Lonicerae Japonicae Flos and Lonicerae Flos].

The aim of this paper was to observe the anti-inflammatory action and mechanism of Lonicerae Japonicae Flos extract and Lonicerae Flos extract in xylene-induced ear swelling experiment and lipopolysaccharide(LPS)-induced RAW264.7 cell inflammatory model. In vivo, xylene-induced mouse auricle swelling model was used to detect the auricle swelling degree and swelling inhibition rate of Lonicerae Japonicae Flos extract and Lonicerae Flos extract; the pathological changes of mice auricle were observed by hematoxylin eosin(HE) staining. In vitro, RAW264.7 inflammatory cell model was induced by LPS, where the cytotoxic effects of Lonicerae Japonicae Flos extract and Lonicerae Flos extract on RAW264.7 cells were detected by CCK-8 method; Griess method was used to detect the effect of Lonicerae Japonicae Flos extract and Lonicerae Flos extract on nitric oxide(NO) production, and ELISA method was used to detect the content of inflammatory factors interleukin-6(IL-6), IL-1ß, and tumor necrosis factor-α(TNF-α). At last, Western blot was used to detect the protein changes of cyclooxygenase 1(COX1), COX2 and inducible nitric oxide synthetase(iNOS) for RAW264.7 cells. The results showed that both Lonicerae Japonicae Flos extract and Lonicerae Flos extract could significantly inhibit the degree of auricle swelling caused by xylene in mice and the inhibition rate was positively correlated with the drug dose. Furthermore, both of them could reduce the infiltration of lymphocytes and neutrophils in mouse ear tissues. For in vitro experiments, both Lonicerae Japonicae Flos extract and Lonicerae Flos extract inhibited NO secretion in RAW264.7 cells, down-regulated the release of IL-1ß, IL-6 and TNF-α, and down-regulated iNOS protein and COX2, NF-κB p65 protein content. In conclusion, both Lonicerae Japonicae Flos extract and Lonicerae Flos extract have good anti-inflammatory effect, and the mechanism may be related with the inhibition of NF-κB signaling pathway.

Adsorption Behaviour of Cr(VI) from Ternary Mesoporous Mg/Fe/Al Oxide Using Glucose as a Soft Template.

The ternary mesoporous MgFeAl oxide (MgFeAlO) material was designed and prepared using glucose as a soft template by calcination of its MgFeAl hydrotalcite precursor. The MgFeAlO showed significantly better Cr(VI) adsorption performance than binary MgAlO. The effect of Fe3+ on Cr(VI) removal in simulated wastewater was studied by researching the microstructure, adsorption properties and mechanism of the material. The results showed that the addition of Fe3+ affected the microstructure of MgAlO, where the partial substitution of Al3+ by Fe3+ into the host layers resulted in an increase in the interlayer region and specific area (SBET) as well as an enlargement in mesoporous feature into the MgFeAlO. The Cr(VI) adsorption process, taking place by the reconstruction of the MgFeAlO oxide with water (memory effect) companying with the intercalation of CrO2-4 anions, was much more efficient than that occurring in the binary MgAlO. MgFeAlO's adsorption of Cr(VI) follows the pseudo-second-order model and it is controlled by intra particle diffusion. The adsorption isotherm was better fitted by the Langmuir model, suggesting that the Cr(VI) adsorption was a monolayer adsorption onto the homogeneous support surface. All thermodynamic and kinetic calculations suggested that the Cr(VI) adsorption process on the MgFeAlO was of chemisorption nature, in which activation energy (Ea) and enthalpy change (ΔH) were 30.01 and 193.58 kJ·mol-1, respectively.

Fabrication of green alginate-based and layered double hydroxides flame retardant for enhancing the fire retardancy properties of polypropylene.

An efficient and bio-based alginate pillared hydrotalcite (SA@LDHs) was fabricated via calcination-reconstruction manner with sodium alginate (SA) and hydrotalcite (LDHs-C), and used as novel flame retardant for polypropylene (PP). The morphologies and combustion properties of SA@LDHs and its hybrid with PP composites (PP/SA@LDHs) had been characterized by SEM, TGA, cone calorimetry, LOI and UL-94 measurements. With 30 wt% loading, the SA@LDHs achieved a LOI value of 30.9 % and a UL-94 V-0 rating, whereas the LDHs-C exhibited only LOI value of 27.6 % and a UL-94 V-1 rating. The peak heat release rate, total heat release and total smoke production of PP/SA@LDHs were 260.8 kW m-2, 61.3 MJ m-2 and 8.2 m2, respectively, which presented declines of 69.2 %, 42.8 % and 32.2 % compared with those of Neat PP. These improvements could be attributed to the presence of the radical-trapping effect of SA, which leading to promote PP chains to participate in the carbonization process.

Fabrication of Ag2O/Ag decorated ZnAl-layered double hydroxide with enhanced visible light photocatalytic activity for tetracycline degradation.

The photocatalytic performance of layered double hydroxides (LDH) is usually confined to the slow interface mobility and high recombination rate of photogenerated electron-hole pairs in material. To overcome the low photocatalytic efficiency, novel Ag2O/Ag decorated LDH (LDH-Ag2O/Ag) was successfully synthesized by depositing Ag2O on the surface of LDH and then converted to Ag° nanoparticles in the right position after heat treatment. The as-synthesized LDH-Ag2O/Ag composites were characterized by Powder X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectra (UV-vis DRS), photoluminescence spectra (PL) and transient photocurrent (TPC) analysis. Compared with virgin LDH, the photocatalytic activities of LDH-Ag2O/Ag composites were enhanced significantly. The optimum photocatalytic efficiency of LDH-Ag10 (0.0184 min-1) was nearly 46 times higher than that of virgin LDH (0.0004 min-1). The result of active species trapping experiments indicated that •OH, h+, and •O2- have an effect on the TC degradation, where •OH played the predominant role during the photocatalytic process. The possible photocatalytic mechanisms involving the charge transfer pathway and reactive species generation during the process of TC degradation were also discussed. The improved photocatalytic activity of LDH-Ag2O/Ag could be attributed to the synergetic effect between LDH and Ag2O/Ag that extended visible light range and reduced photogenerated charge carriers recombination.

Facile Preparation of Modifying Layered Double Hydroxide Nanoparticles for Drug Delivery.

Mg-Al-NO3 hydrotalcite (p-LDH) was employed as a carrier for the controlled release of 5-Fluorouracil (5-FU). The p-LDH was pretreated by acid-pretreatment to gain a more stable material (a-LDH) in acid medium for oral administration. It demonstrated that the a-LDH had smaller crystal size, particle sizes and higher permanent charge density (σp) compared with that of the p-LDH by means of XRD, SEM, FT-IR, UV-vis DRS, TG-DSC, BET/BJH and other techniques. The FU/a-LDH and FU/p-LDH delivery systems were obtained using anion-exchange method. The in vitro 5-FU drug release studies showed that no burst release phenomenon was observed at the beginning of release tests. The in vitro 5-FU release behaviors of the delivery systems at initial pH 4.6 and 7.5 were studied which could be described by first-order and Bhaskas models. Combined with the XRD and FT-IR analyses of the solid residues of the FU/a-LDH and FU/p-LDH after the release, it was found that the dissolution mechanism was mainly responsible for the release behavior of the FU/p-LDH at initial 4.6, while the anion-exchange between intercalated 5-FU and phosphate anions mechanism was responsible for the FU/a-LDH at pH 4.6 and 7.5 as well as FU/p-LDH at pH 7.5. It is concluded that the hydrotalcites could be used as the basis of a tunable drug delivery carrier for 5-FU.