Comparison of the binding behavior of FCCP with HSA and HTF as determined by spectroscopic and molecular modeling techniques

The interaction of carbonylcyanide p‐(trifluoromethoxy) phenylhydrazone (FCCP) with human serum albumin (HSA) and human transferrin (HTF) was investigated using multiple spectroscopy, molecular modeling, zeta‐potential and conductometry measurements of aqueous solutions at pH 7.4. The fluorescence, UV/vis and polarization fluorescence spectroscopy data disclosed that the drug–protein complex formation occurred through a remarkable static quenching. Based on the fluorescence quenching, two sets of binding sites with distinct affinities for FCCP existed in the two proteins. Steady‐state and polarization fluorescence analysis showed that there were more affinities between FCCP and HSA than HTF. Far UV‐CD and synchronous fluorescence studies indicated that FCCP induced more structural changes on HSA. The resonance light scattering (RLS) and zeta‐potential measurements suggested that HTF had a greater resistance to drug aggregation, whereas conductometry measurements expressed the presence of free ions improving the resistance of HSA to aggregation. Thermodynamic measurements implied that a combination of electrostatic and hydrophobic forces was involved in the interaction between FCCP with both proteins. The phase diagram plots indicated that the presence of second binding site on HSA and HTF was due to the existence of intermediate structures. Site marker competitive experiments demonstrated that FCCP had two distinct binding sites in HSA which were located in sub‐domains IIA and IIIA and one binding site in the C‐lobe of HTF as confirmed by molecular modeling. The obtained results suggested that both proteins could act as drug carriers, but that the HSA potentially had a higher capacity for delivering FCCP to cancerous tissues. Copyright © 2013 John Wiley & Sons, Ltd.     

Mechanical and In Vitro Biological Performance of Graphene Nanoplatelets Reinforced Calcium Silicate Composite

Calcium silicate (CaSiO₃, CS) ceramic composites reinforced with graphene nanoplatelets (GNP) were prepared using hot isostatic pressing (HIP) at 1150°C. Quantitative microstructural analysis suggests that GNP play a role in grain size and is responsible for the improved densification. Raman spectroscopy and scanning electron microscopy showed that GNP survived the harsh processing conditions of the selected HIP processing parameters. The uniform distribution of 1 wt.% GNP in the CS matrix, high densification and fine CS grain size help to improve the fracture toughness by ∼130%, hardness by ∼30% and brittleness index by ∼40% as compared to the CS matrix without GNP. The toughening mechanisms, such as crack bridging, pull-out, branching and deflection induced by GNP are observed and discussed. The GNP/CS composites exhibit good apatite-forming ability in the simulated body fluid (SBF). Our results indicate that the addition of GNP decreased pH value in SBF. Effect of addition of GNP on early adhesion and proliferation of human osteoblast cells (hFOB) was measured in vitro. The GNP/CS composites showed good biocompatibility and promoted cell viability and cell proliferation. The results indicated that the cell viability and proliferation are affected by time and concentration of GNP in the CS matrix.     

甾体1，4-脱氢和11α-羟基化反应的两种不同微生物转化

Two kinds of micro-organism, Arthrobacter sp. AX86(1,4-dehdrogenator)and Absidia sp. A28(11α-hydroxylator) were used in this experiment. Two different fermentation techniques were performed to accomplish the multiple conversional reactions for producing 16β-methyl-11α, 17α, 21-trihydroxy-1,4-pregnadiene-3,20-dione (Ⅲ) from 16β-methyl-3β, 17α,21-trihydroxy-5α-pregnane-20-one-21-acetate(1) 1)To produce product(Ⅲ)by means of a two-step fermentation method which were independently performed first by Arthrobacter and next by Abslaia, and 2)the product was obtained by a sequential fermentation system of aforesaid two micro-organisms in a single fermentor without isolation of the intermediates from the mixture. Our results showed that in both fermentation systems high yield of product was obtained. However, according to the technical simplicity, shorter duration of fermentation cycle and efficient yield of product, the second method is better than the first one.     

地塞美松中间体的C1,4脱氢和11α-羟基化

地塞美松 (Ｄｅｘａｍｅｔｈａｓｏｎｅ)为高效肾上腺皮质激素药物 ,临床上广泛使用。开拓用梯可吉宁 (Ｔｉｇｏｇｅｎｉｎ)为起始原料生产从化学结构和合成技术上讲较为合理 ,而且适合于资源综合利用[1] 。在合成过程中 ,除了Ａ环需引入Ｃ1,2 和Ｃ4 ,5两个双键 (含Ｃ-3 羟基氧化 )外 ,还需用微生物法在Ｃ-11位引入羟基。国外常采用化学法脱氢 ,然后再用霉菌 11α 羟基化[2 ,3 ] 。本文报道用两类微生物菌种 ,节杆菌 (Ａｒｔｈｒｏｂａｃｔｅｒｓｐ .)ＡＸ86和绿僵菌 (Ｍｅｔａｒｈｉｚｉｕｍｓｐ .)Ｍ 88,混合转化一步完成脱氢和羟基化反应…     

High Concentration of Fluoride Can Be Increased Risk of Abortion

The presence of fluoride in drinking water can be either beneficial or harmful for human health, depending on its concentration. Most adverse effects of fluoride are observed at high concentrations (above 1.5 mg/L). This study was aimed to evaluate the effect of fluoride concentrations in drinking water on spontaneous abortion in two regions: one with low fluoride concentration and another with high fluoride concentration. The results showed that there is a relationship between the concentration of fluoride in drinking water and abortion, so that the risk of abortion increased at high concentrations of fluoride. However, further studies are needed to clarify this relationship due to the small area and population in this study.     

Methyl jasmonate effects on volatile oil compounds and antioxidant activity of leaf extract of two basil cultivars under salinity stress

Basil (Ocimum basilicum L.) as an economic and culinary herb is used in traditional medicine. In this research, a pot experiment was conducted, as factorial based on randomized completely design with three replications, to examine the influence of methyl jasmonate (MeJA) on volatile substances and chemical components as well as antioxidant activity of leaf’s extract from two commercial cultivars (Genove and Rubi) of sweet basil under salinity stress. The treatments were comprised MeJA (0 and 0.5 mM) and salinity stresses (0, 30, 60, and 90 mM). Using MeJA foliarly meaningfully raised the essential oil content in the Rubi cultivar at 0 and 30 mM of salinity and in the Genove cultivar just on 30 mM of salinity. MeJA treatment increased the essential oil content and also showed noticeable effects on the main components of the oils. The foliar application of MeJA raised the percentages of linalool and 1,8-cineole, whereas reduced the percentages of α-cadinol, α-bergamotene, β-maaliene, and eugenol in the extracted oil. In both basil cultivars, the MeJA significantly enhanced the antioxidant activity. The highest antioxidant activities in the Rubi and Genove cultivars were obtained at 0 mM (control) and 60 mM of salinity with the MeJA application, respectively. In conclusion, the foliar application of MeJA caused to different responses in the cultivars and reduced the negative effects of salt stress.     

Apolipoprotein A-II Plus Lipid Emulsion Enhance Cell Growth via SR-B1 and Target Pancreatic Cancer In Vitro and In Vivo

Background

Apolipoprotein A-II (ApoA-II) is down regulated in the sera of pancreatic ductal adenocarcinoma (PDAC) patients, which may be due to increase utilization of high density lipoprotein (HDL) lipid by pancreatic cancer tissue. This study examined the influence of exogenous ApoA-II on lipid uptake and cell growth in pancreatic cancer (PC) both in vitro and in vivo.

Methods

Cryo transmission electron microscopy (TEM) examined ApoA-II’s influence on morphology of SMOFLipid emulsion. The influence of ApoA-II on proliferation of cancer cell lines was determined by incubating them with lipid+/-ApoA-II and anti-SR-B1 antibody. Lipid was labeled with the fluorophore, DiD, to trace lipid uptake by cancer cells in vitro by confocal microscopy and in vivo in PDAC patient derived xenograft tumours (PDXT) by fluorescence imaging. Scavenger receptor class B type-1(SR-B1) expression in PDAC cell lines and in PDAC PDXT was measured by western blotting and immunohistochemistry, respectively.

Results

ApoA-II spontaneously converted lipid emulsion into very small unilamellar rHDL like vesicles (rHDL/A-II) and enhanced lipid uptake in PANC-1, CFPAC-1 and primary tumour cells as shown by confocal microscopy. SR-B1 expression was 13.2, 10.6, 3.1 and 2.3 fold higher in PANC-1, MIAPaCa-2, CFPAC-1 and BxPC3 cell lines than the normal pancreatic cell line (HPDE6) and 3.7 fold greater in PDAC tissue than in normal pancreas. ApoA-II plus lipid significantly increased the uptake of labeled lipid and promoted cell growth in PANC-1, MIAPaCa-2, CFPAC-1 and BxPC3 cells which was inhibited by anti SR-B1 antibody. Further, ApoA-II increased the uptake of lipid in xenografts by 3.4 fold.

Conclusion

Our data suggest that ApoA-II enhance targeting potential of lipid in pancreatic cancer which may have imaging and drug delivery potentialities.