Association between fetal growth restriction and maternal exposure to polybrominated diphenyl ethers.

Humans are exposed to polybrominated diphenyl ethers (PBDEs) via ingestion of food, dust inhalation, and dermal absorption. Exposure to PBDEs via the placenta and breast milk is a special and important pathway in infants. This nested case-control study aimed to investigate the levels of PBDEs in maternal serum and colostrum, and to assess the association between the occurrence of fetal growth restriction (FGR) and prenatal exposure to PBDEs. We recruited 293 mother-newborn pairs, including 98 FGR cases and 195 healthy controls in Wenzhou, China. Maternal serum and colostrum samples were collected during pregnancy and after delivery, respectively, and the levels of PBDEs were measured by gas chromatography-tandem mass spectrometry. The total levels of PBDEs in maternal serum and colostrum were found to be in equilibrium, but congener profiles of PBDEs in these matrices were different. Increased BDE-207, BDE-209, ∑BDE196-209 and ∑PBDEs levels in maternal serum and BDE-99, ∑BDE17-154 and ∑PBDEs levels in colostrum were correlated with decreased birth weight Z score. Increased concentrations of higher brominated BDEs in maternal serum (odds ratio (OR) = 1.010, 95%CI = 1.003-1.018) and low-to moderately brominated BDEs in colostrum (OR = 1.004, 95%CI = 1.000-1.009) were associated with increased risk of FGR, which showed an exposure-response relationship. In addition, infants with FGR were more exposed to PBDEs in colostrum after birth than healthy infants. Longitudinal birth cohort studies are needed to determine the prolonged effect of PBDEs exposure on the growth of FGR infants in the future.

The hypoglycemic and antioxidant effects of polysaccharides from the petioles and pedicels of Euryale ferox Salisb. on alloxan-induced hyperglycemic mice.

The present study investigated the potential hypoglycemic and antioxidant effects of polysaccharides extracted from the petioles and pedicels of Euryale ferox Salisb. (EFPP) on alloxan-induced hyperglycemic mice. The EFPP had a total carbohydrate of 65.72 ± 2.81%, uronic acid of 4.56 ± 0.62% and protein of 0.58 ± 0.12%, with an average molecular weight from 1.02 kDa to 11.45 kDa and monosaccharide composition of Man, GlcA, Rha, Glc, Gal and Ara at a molar ratio of 0.12 : 0.01 : 9.57 : 0.41 : 1.00 : 0.24. Administration with EFPP, especially high dose EFPP, was beneficial to reverse body weight loss, reduce blood glucose levels, enhance serum insulin levels, improve oral glucose tolerance, increase hepatic glycogen content and GCK activity, and modulate the mRNA expression of GCK in the liver. Meanwhile, EFPP had protective effects against alloxan-induced oxidative injury in mice, via increasing the activities of SOD, CAT and GSH-Px and decreasing the MDA contents in the liver and kidney of the mice. EFPP ameliorated the damage in pancreas, kidney and liver tissues, which was confirmed by histopathological observation. The results suggested that EFPP possess hypoglycemic and antioxidant activities, and could be a potential source of natural hypoglycemic and antioxidant agents for functional foods or complementary medicines.

[Influence of different drying methods on the quality of Sparganii rhizoma based on multi-index evaluation].

OBJECTIVE: To study the influence of different drying methods on the quality of Sparganii Rhizoma and obtain the optimal one. METHODS: Based on multi-index evaluation technology, Sparganii Rhizoma was processed using five drying methods including drying in the shade, drying in the sun, drying in the oven, infrared drying and microwave drying. The contents of the functional ingredients such as seven phenolic compounds including p-hydroxybenzaldehde, vanillic acid,p-coumaric acid, ferulic acid, rutin, kaempferol and formononetin, polysaccharide, total saponins and total polyphenols were determined by the validated procedures of HPLC and ultraviolet spectrophotometry. RESULTS: The contents of seven phenolic compounds, polysaccharide and total polyphenols were the highest using microwave drying, while the content of the total saponins was the highest by drying in the oven. CONCLUSION: Different drying methods have significant influence on the quality of Sparganii Rhizoma.

Au@Ag/Au nanoparticles assembled with activatable aptamer probes as smart "nano-doctors" for image-guided cancer thermotherapy.

Although nanomaterial-based theranostics have increased positive expectations from cancer treatment, it remains challenging to develop in vivo "nano-doctors" that provide high-contrast image-guided site-specific therapy. Here we designed an activatable theranostic nanoprobe (ATNP) via self-assembly of activatable aptamer probes (AAPs) on Au@Ag/Au nanoparticles (NPs). As both quenchers and heaters, novel Au@Ag/Au NPs were prepared, showing excellent fluorescence quenching and more effective near-infrared photothermal therapy than Au nanorods. The AAP comprised a thiolated aptamer and a fluorophore-labeled complementary DNA; thus, the ATNP with quenched fluorescence in the free state could realize signal activation through target binding-induced conformational change of the AAP, and then achieve on-demand treatment under image-guided irradiation. By using S6 aptamer as the model, in vitro and in vivo studies of A549 lung cancer verified that the ATNP greatly improved imaging contrast and specific destruction, suggesting a robust and versatile theranostic strategy for personalized medicine in future.

Extraction optimization, isolation, preliminary structural characterization and antioxidant activities of the cell wall polysaccharides in the petioles and pedicels of Chinese herbal medicine Qian (Euryale ferox Salisb.).

Cell wall polysaccharides in the petioles and pedicels of Qian (Euryale ferox Salisb.) (EFPP) were extracted using ultrasound-assisted technique. Response surface methodology (RSM) based on Box-Behnken design (BBD) was employed to optimize extraction parameters for the maximum purity of polysaccharides. The results showed that the optimum extraction conditions were extraction temperature of 80 °C, extraction time of 32 min, ultrasonic power of 270W and liquid-to-solid ratio of 40 mL/g. Under the optimal conditions, the experimental purity of polysaccharides was 62.57% ± 1.68%, which was very close to the predicted. The crude EFPP were isolated using DEAE-52 column and four major fractions (EFPP-1, EFPP-2, EFPP-3 and EFPP-4) were obtained. Typical functional groups of polysaccharides were characteristic for EFPP-1, EFPP-3 and EFPP-4 from FT-IR spectrum. Furthermore, the crude EFPP and three fractions (EFPP-1, EFPP-3 and EFPP-4) possessed appreciable in vitro antioxidant effects on α,α-diphenyl-ß-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl radical scavenging and reducing powers. Then, the crude EFPP and EFPP-4 could effective against H2O2-induced injury on HUVEC and VSMC through enhancement of T-AOC, SOD and CAT activities and decrease of MDA content.

Poly(thymine)-templated fluorescent copper nanoparticles for ultrasensitive label-free nuclease assay and its inhibitors screening.

Noble-metal fluorescent nanoparticles have attracted considerable interest on account of their excellent properties and potential applicable importance in many fields. Particularly, we recently found that poly(thymine) (poly T) could template the formation of fluorescent copper nanoparticles (CuNPs), offering admirable potential as novel functional biochemical probes. However, exploration of poly T-templated CuNPs for application is still at a very early stage. We report herein for the first example to develop a novel ultrasensitive label-free method for the nuclease (S1 nuclease as a model system) assay, and its inhibitors screening using the poly T-templated fluorescent CuNPs. In this assay, the signal reporter of poly T of 30 mer (T30) kept the original long state in the absence of nuclease, which could effectively template the formation of fluorescent CuNPs. In the presence of nuclease, poly T was digested to mono- or oligonucleotide fragments with decrease of fluorescence. The proposed method was low-cost and simple in its operation without requirement for complex labeling of probe DNA or sophisticated synthesis of the fluorescent compound. The assay process was very rapid with only 5 min for the formation of fluorescent CuNPs. The capabilities for target detection from complex fluids and screening of nuclease inhibitors were verified. A high sensitivity exhibited with a detectable minimum concentration of 5 × 10(-7) units µL(-1) S1 nuclease, which was about 1-4 orders of magnitude more sensitive than the developed approaches.

[Study on quality evaluation of Sparganii rhizoma by biopotency determination method].

OBJECTIVE: To establish a method for determining anticoagulation potency of Sparganii Rhizoma, and evaluate the effect of Sparganii Rhizoma herbs from different producing areas on promoting blood circulation and removing blood stasis; and study the material basis of Sparganii Rhizoma through the correlation analysis on its anticoagulation potency, ferulic acid and total flavonoid content. METHOD: The anticoagulation time of Sparganii Rhizoma from different producing areas with activeated partial thromboplastin time for their active extracts. Their biopotency was calculated by using the method of "parallel lines of dose effect" (3, 3). The degree of correlation between their anticoagulation potency and chemical constituents were calculated by using Pearson correlational analysis method. RESULT: Sparganii Rhizoma and is control drugs had a good linear relationship between dose and effect (Y = 172.76X - 193.39, R2 = 0.9955). The method had better accuracy (RSD 4.7%), repeatability (RSD 2.3%) and intermediate precision (RSD 5.4%), finding that the biopotency of Sparganii Rhizoma from different producing areas ranged between 52.33-238.58 U x g(-1), and all of them passed the test on reliability. The results of correlation analysis showed no remarkable relationship between the anticoagulation potency of Sparganii Rhizoma and the contents of the two chemical constituents. CONCLUSION: This biopotency determination method established in the experiment can be used as one of approaches for qulaity evaluation on Sparganii Rhizoma.

Biosynthesis of gold nanoparticles using catclaw buttercup (Radix Ranunculi Ternati) and evaluation of its colloidal stability.

The biosynthesis of gold nanoparticles using catclaw buttercup (Radix Ranunculi Ternati) and their stability have been reported in this paper. The aqueous catclaw buttercup was used as mild reducing agent for gold nanoparticles synthesis from HAuCl4 solutions. The influence of reaction time, temperature and mass ratio of HAuCl4/catclaw buttercup were evaluated to investigate their effects on gold nanoparticles synthesis. Under the optimized reaction parameters, the gold nanoparticles obtained are characterized by UV-vis spectrum, X-ray diffraction (XRD), EDAX technique (EDX), high resolution transmission electron microscopy (HRTEM), FTIR spectrum, anthrone-sulfuric colorimetric method, and plus Improved-Lowry Protein Assay Kit. The HRTEM images showed that the biosynthesized gold nanoparticles are mostly spherical with size range from 9-24 nm. Furthermore, it was found that the biosynthesized gold nanoparticles possessed outstanding colloid stability in aqueous solutions as a function of category and concentration of monovalent salt and pH value of the solution when compared with chemosynthetic ones with the similar size. Anthrone-sulfuric colorimetric method revealed that there is no sugar in the biosynthesized gold colloid. While Improved-Lowry tests results demonstrated that the existence of much protein in the biosynthesized gold colloid, which may played an important role in stabilization of it. Owing to their stability, biocompatibility, lower cost and so on, gold nanoparticles synthesized by this biosynthesis method show potential application prospect in optoelectronic and biomedicine.

pH induced protein-scaffold biosynthesis of tunable shape gold nanoparticles.

In this paper, a pH-inductive protein-scaffold biosynthesis of shape-tunable crystalline gold nanoparticles at room temperature has been developed. By simple manipulation of the reaction solution's pH, anisotropic gold nanoparticles including spheres, triangles and cubes could be produced by incubating an aqueous solution of sodium tetrachloroaurate with Dolichomitriopsis diversiformis biomasses after immersion in ultrapure Millipore water overnight. A moss protein with molecular weight of about 71 kDa and pI of 4.9 was the primary biomolecule involved in the biosynthesis of gold nanoparticles. The secondary configuration of the proteins by CD spectrum implied that the moss protein could display different secondary configurations including random coil, α-helix and intermediate conformations between random coil and α-helix for the experimental pH solution. The growth process of gold nanoparticles further showed that the moss protein with different configurations provided the template scaffold for the shape-controlled biosynthesis of gold nanoparticles. The constrained shape of the gold nanoparticles, however, disappeared in boiled moss extract. The gold nanoparticles with designed morphology were successfully reconstructed using the moss protein purified from the gold nanoparticles. Structural characterizations by SEM, TEM and SAED showed that the triangular and cubic gold nanoparticles were single crystalline.

Electrochemical detection of nicotinamide adenine dinucleotide based on molecular beacon-like DNA and E. coli DNA ligase.

An electrochemical method for nicotinamide adenine dinucleotide (NAD(+)) detection with high sensitivity and selectivity has been developed by using molecular beacon (MB)-like DNA and Escherichia coli DNA ligase. In this method, MB-like DNA labeled with 5'-SH and 3'-biotin was self-assembled onto a gold electrode in its duplex form by means of facile gold-thiol chemistry, which resulted in blockage of electronic transmission. It was eT OFF state. In the presence of NAD(+), E. coli DNA ligase was activated, and the two nucleotide fragments which were complementary to the loop of the MB-like DNA could be ligated by the NAD(+)-dependent E. coli DNA ligase. Hybridization of the ligated DNA with the MB-like DNA induced a large conformational change in this surface-confined DNA structure, which in turn pushed the biotin away from the electrode surface and made the electrons exchange freely with the electrode. Then the generated electrochemical signals can be measured by differential pulse voltammetry (DPV). Under optimized conditions, a linear response to logarithmic concentration of NAD(+) range from 3 nM to 5 µM and a detection limit of 1.8 nM were obtained. Furthermore, the proposed strategy had sufficient selectivity to discriminate NAD(+) from its analogues.

A sensitive ligase-based ATP electrochemical assay using molecular beacon-like DNA.

A sensitive and selective ligase-based signal-on electrochemical sensing method for adenosine-5'-triphosphate (ATP) detection had been developed using molecular beacon (MB)-like DNA. In this method, the biotin-tagged MB-like DNA was self-assembled onto a gold electrode to form a stem-loop structure by means of facile gold-thiol chemistry, which resulted in blockage of electronic transmission. It was eT OFF state. In the presence of ATP, two nucleotide fragments which were complementary to the loop of the MB-like DNA could be ligated by the ATP-dependent T4 DNA ligase. Hybridization of the ligated DNA with the MB-like DNA induced a significant conformational change in this surface-confined DNA structure, which in turn released the biotin from the surface allowing free exchange of electrons with the electrode generating a measurable electrochemical signal (eT ON). The resulting change in electron transfer efficiency was readily measured by differential pulse voltammetry at target ATP concentrations as low as 0.05 nM and with linear response range from 0.1 to 1000 nM. Moreover, it was also able to discriminate ATP from its analogues. The proposed method had been successfully applied to the determination of ATP in the Escherichia coli O157:H7 extracts of water samples, and the linear response was found between the concentrations of 10(3) and 10(7) cfu/mL.

Barbated Skullcup herb extract-mediated biosynthesis of gold nanoparticles and its primary application in electrochemistry.

The design, synthesis, characterization and application of biologically synthesized nanomaterials have become an important branch of nanotechnology. In this paper, we report the extracellular synthesis of gold nanoparticles using Barbated Skullcup (BS) herb (a dried whole plant of Scutellaria barbata D. Don) as the reducing agent. After exposing the gold ions to BS herb extract, rapid reduction of gold ions is observed leading to the formation of gold nanoparticles in solution. UV-vis spectrum of the aqueous medium containing gold nanoparticles showed a peak at around 540 nm. Transmission electron microscopy (TEM) micrograph analysis of the gold nanoparticles indicated that they were well-dispersed and ranged in size 5-30 nm. When the gold nanoparticles were modified on the glassy carbon electrode (GCE), it could enhance electronic transmission rate between the electrode and the p-nitrophenol.

Pharmaceutical applications of dendrimers: promising nanocarriers for drug delivery.

Dendrimers are new artificial macromolecules which have the structure like a tree. They are hyperbranched and monodisperse three-dimensional molecules with defined molecular weights, large numbers of functional groups on the surface and well-established host-guest entrapment properties. Recently, dendrimers have successfully proved themselves as promising nanocarriers for drug delivery because they can render drug molecules a greater water-solubility, bioavailability, and biocompatibility. In this review, recent progress in the pharmaceutical applications of dendrimers as delivery systems for drugs, particularly, the non-steroidal anti-inflammatory, anti-microbial/anti-viral and potent anti-cancer drugs is discussed. Three possible interaction mechanisms between dendrimers and drug molecules are presented. In addition, the pharmacodynamic and pharmacokinetic properties of both dendrimer/drug complex and dendrimer-drug conjugation after their administration to animals are evaluated.

Characterization of different sequences of DNA on si substrate by atomic force microscopy and gold nanoparticle labeling.

In this paper, different sequences of single-strand DNA modified on Si substrate were studied taking advantages of the high resolution of atomic force microscopy (AFM) and signal enhancement of gold nanoparticles. Two sequences of single-strand DNA, as a model, were immobilized on Si substrate and hybridized with their sequence-complementary DNA molecules modified respectively with two sizes of gold nanoparticles. The surface of Si substrate was characterized through detecting the size and coverage of gold nanoparticles by AFM. Results demonstrated that different sizes of gold nanoparticles represented different sequences of DNA immobilized on the substrate. Density and distribution of DNA on Si substrate can be investigated by AFM imaging using gold nanoparticles as topographic markers. Compared to other sensitive methods such as fluorescence energy transfer, X-ray photoelectron, and radiolabeling experiments, this approach is advantageous in terms of high spatial resolution in sub-micrometer scale. This new method will be beneficial in the characterization of DNA immobilized on chip surfaces.