Design of polyglycidol-containing microspheres for biomedical applications

The paper presents a short review on the synthesis, characterisation and selected medical applications of poly(styrene/α-tert-butoxy-ω-vinylbenzyl-polyglycidol) (P(S/PGL)) microspheres. The soap-free emulsion-polymerisation of styrene and α-tert-butoxy-ω-vinylbenzyl-polyglycidol macromonomer (PGL) in water yielded core-shell microspheres with a low particle-diameter dispersity (ratio of the weight average particle diameter and the number average particle diameter). The interfacial fraction of PGL units, estimated by XPS, was in the range of 0–42 mole % depending on the concentration of the macromonomer in the polymerisation feed. The studies of adsorption of model proteins showed that the surface fraction of adsorbed protein was significantly reduced when the PGL interfacial fraction was higher than 40 mole %. The P(S/PGL) particles with covalently immobilised proteins were used for the preparation of photonic crystal assemblies suitable for applications in optical biosensors and the medical diagnostic test for the detection of Helicobacter pylori antibodies in the blood serum.     

Facile and Practical Synthesis of (R)‐6‐Br‐2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl

A new enantiopure 6‐monobromo‐substituted BINAP has been prepared via a one‐step nickel‐catalyzed coupling reaction in moderate yield. It is an important intermediate for asymmetric 2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl (BINAP) derivatives. Its structure was elucidated by NMR spectral and elemental analysis.     

Urinary metabonomic study using a CUMS rat model of depression

Chronic unpredictable mild stress (CUMS) is a well‐validated model of depression. In this study, a urinary metabonomics method based on the NMR spectrometry was used to study the metabolic perturbation in CUMS‐induced rat depression model. With pattern recognition analysis, a clear separation of CUMS rats and healthy controls was achieved, and nine endogenous metabolites contributing to the separation were identified. CUMS‐treated rats were characterized by the increase of glycine, pyruvate, glutamine, and asparagines, as well as the decrease of 2‐oxoglutarate, dimethylglycine, citrate, succinate, and acetate. The urinary biochemical changes related to the metabolic disturbance in CUMS induced depression, and the possible correlations with live qi stagnation in traditional Chinese medicine are discussed. The work shows that CUMS is a reliable model for studying depression, and the noninvasive urinary metabolomic method is a valuable tool to investigate the biochemical pertubations in depression as an early diagnostic means. Copyright © 2012 John Wiley & Sons, Ltd.     

Fabrication of a sol–gel derived microporous zirconia membrane for nanofiltration

This paper reports the fabrication and nanofiltration properties of a sol–gel derived microporous zirconia membrane. Effects of synthesis parameters, including hydrolysis time, hydrolysis temperature, hydrolysis ratio and chelating agent dopant, on the state and size of polymeric zirconia sol, were investigated. Highly reproducible and stable zirconia sol after refluxing at 40 °C for 180 min, with an average particle size of approximately 8.6 nm, was synthesized with a recipe of [Zirconium n-propoxide]: [Diethanolamine]: [1-propanol]: [H₂O] being 1: 2.2: 28.7: 9.4 (in molar ratio). The sol was subsequently used for the fabrication of microporous ZrO₂ membranes onto alumina supported mesoporous γ-Al₂O₃ layers. ZrO₂ membranes with molecular weight cut-off (MWCO) of 354, 1,195, corresponding to the pore size of 0.94 and 1.75 nm, were successfully fabricated. Ionic retention properties of such ZrO₂ membranes with respect to electrolyte solutions, like MgCl₂, CaCl₂, NaCl and Na₂SO₄, were also determined. Effects of parameters such as concentration of salt solutions and trans-membrane pressure on retention rates of microporous ZrO₂ membranes were studied in detail. Results showed that zirconium n-propoxide derived microporous ZrO₂ membranes exhibited comparatively high retention rates towards divalent ions like Mg²⁺ and Ca²⁺, while much lower retention rates were observed for mono-valent ion (Na⁺) in the present study, which are the characteristics of nanofiltration membranes.     

Exceptional Blueshifted and Enhanced Aggregation‐Induced Emission of Conjugated Asymmetric Triazines and Their Applications in Superamplified Detection of Explosives

A novel conjugated asymmetric donor–acceptor (CADA) strategy for preventing the redshift in photoluminescence, as well as preserving the merits of donor–acceptor architectures, was proposed and demonstrated for two triazine derivatives, which showed highly efficient, narrow, and blueshifted ultraviolet light emission in solid films along with special aggregation‐induced emission behavior. A mechanism of aggregation‐induced locally excited‐state emission by suppressing the twisted intramolecular charge‐transfer emission for the spectacular optoelectronic phenomena of these CADA molecules was suggested on the basis of both experimental measurements and theoretical calculations. By taking advantage of this special CADA architecture, fluorescent probes based on aggregates of conjugated asymmetric triazines in THF/water for the detection of explosives show superamplified detection of picric acid with high quenching constants (>1.0×10⁷ M ^?1) and a low detection limit of 15 ppb.     

氯乙酸缓冲体系在稀土测定中的应用研究

研究了氯乙酸/氢氧化钠缓冲体系在分光光度法测定稀土中的应用。以偶氮胂Ⅲ(0.5 g·L-1)为显色剂,比较了氯乙酸/氢氧化钠、甲酸/氢氧化钠、乙酸/乙酸纳缓冲体系灵敏度的差异,考察了pH值、偶氮胂Ⅲ对摩尔吸光系数的影响。并在氯乙酸/氢氧化钠体系下确定了测定单一稀土元素的最佳条件(缓冲溶液为氯乙酸/氢氧化钠,加入量为2 mL;显色剂为偶氮胂Ⅲ,加入量为2 mL),找到了测定每种稀土元素的最佳pH值。分光光度法与ICP-AES法测试基本吻合,可以简捷快速地测定稀土元素总量。     

Stabilization of zeylenone in rat plasma by the presence of esterase inhibitors and its LC‐MS/MS assay for pharmacokinetic study

Six esterase inhibitors, namely EDTA·2Na⁺, NaF, phenylmethanesulfonyl fluoride, dichlorvos, bis‐nitrophenyl phosphate (BNPP) and thenoyltrifluoroacetone, and the mixture of NaF and BNPP, were evaluated for the stabilization of labile benzoate containing zeylenone in rat plasma. The mixture appeared to exhibit the most effectively stabilizing effect with the degraded content of zeylenone decreasing from >60% (in the absence of inhibitors) to <6%. Following the stabilization by the addition of NaF (5 mm ) and BNPP (5 mm ), the analytes in rat plasma were acidified by formic acid and extracted into ethyl acetate at 0°C. After chromatographic separation, the detection of zeylenone was performed on a 3200 Q‐Trap with positive ion electrospray mode, monitoring the ion transition m/z 383.2 → 105.0. The method was validated over the range from 2.68 to 1340 ng/mL with inter‐ and intra‐run precision for the quality control samples being less than 6.8%. The assay accuracy was within 100 ± 7.0%. The validated method was successfully applied to a pharmacokinetic study in rats after the intratracheal administration of zeylenone in free drug or polymeric micellar solutions. The results showed that the pulmonary absorption of zeylenone loaded in micelles was significantly retarded compared with that of free drug solutions. Copyright © 2012 John Wiley & Sons, Ltd.     

Telaprevir fragments as organocatalysts in asymmetric direct aldol reactions of aldehydes

We have demonstrated that the fragments of Telaprevir can act as organocatalysts for asymmetric aldol reactions between aromatic aldehydes and acetone under mild conditions. The reaction conditions have been optimized in terms of the catalyst nature, choice of temperature, solvent, additive, and the catalyst loading. Under proper conditions, fairly good yield and enantioselectivity have been achieved.