Fabrication of chitosan microcapsules via layer-by-layer assembly for loading and in vitro release of heparin

The heparin-loaded microcapsules were successfully prepared by layer-by-layer deposition of chitosan (CHI) and heparin (Hep). Film growth was confirmed by the reversal of ζ-potentials during polysaccharide deposition. Both scanning electron microscopy and transmission electron microscope evidenced the integrity of (CHI/Hep)₅ capsules after the removal of cores. By assembling the carriers with chitosan that are inherently degradable, the capsules were engineered to degrade specifically in the presence of lysozyme. It was demonstrated that the loaded heparin was released from the capsules over a long period of time when being incubated in lysozyme solution. With these results, such CHI/Hep capsules may have a great potential as controlled release carrier for heparin.     

Determination of 20(S)-protopanaxadiol in rat plasma by LC-MS/MS and its application to the pharmacokinetic study: A comparative study of its solution and two oral formulations

A high-performance liquid chromatography — tandem mass spectrometry method was used in a comparative pharmacokinetic study on 20(S)-protopanaxadiol in its solution, pharmacosomes and hydroxy-propyl-β-cyclodextrin inclusion compound. The calibration linearity range was 2.5–5000 ng/mL and the limit of quantification was 2.5 ng/mL. The intra- and inter-assay coefficients of variation were less than 7% and the recoveries were 67.4, 63.3 and 69.6% at 5, 250 and 4500 ng/mL. In contrast to 20(S)-protopanaxadiol solution, its pharmacosomes and hydroxypropyl-β-cyclodextrin inclusion compound improved the oral bioavailability to different extent and meanwhile were much safer in clinical use.     

Mild and Efficient Syntheses of 1-Aryl-3,4-dihydroisoquinolines and 1-Aryl-3,4-dihydro-β-carbolines via Regiospecific β-Eliminations of the Corresponding N-Tosyl-1,2,3,4-tetrahydroisoquinolines and N-Tosyl-1,2,3,4-tetrahydro-β-carbolines

Treatment of N-tosyl-1-aryl-1,2,3,4-tetrahydro-isoquinolines or N-tosyl-1-aryl-1,2,3,4-tetrahydro-β-carbolines with a strong base such as NaOH or KOH at 70 °C in dimethylsulfoxide (DMSO) produced 1-aryl-3,4-dihydroisoquinolines or 1-aryl-3,4-dihydro-β-carbolines in good yields via mild and regiospecific β-eliminations. A dramatic solvent effect was observed, DMSO was crucial for the reactions. The temperature is also crucial for the reactions and should be kept between 60 and 80 °C.     

Direct Blue 71 staining as a destaining‐free alternative loading control method for Western blotting

In Western blotting, a suitable loading control is indispensable for correcting errors in the total amount of loaded protein. Immunodetection of housekeeping proteins and total protein staining have traditionally been used as loading control methods. Direct Blue 71 (DB71) staining—a novel, sensitive, dye‐binding staining method compatible with immunodetection—may offer advantages over these traditional loading control methods. Three common neuroscientific samples (human plasma, human oligodendrocytes, and rat brain) were employed to assess DB71 staining as a loading control method for Western blotting. DB71, CBB, one traditional housekeeping protein, and one protein of interest were comparatively assessed for reliability and repeatability and linear dynamic range over 2.5–40 μg of protein loaded. DB71's effect on the reliability and repeatability and linear dynamic range of immunoreaction were also assessed. Across all three sample types, DB71 was either equivalent or superior to CBB and housekeeping protein‐based methods in terms of reliability and repeatability and linear dynamic range. Across all three sample types, DB71 staining did not impair the reliability and repeatability or linear dynamic range of immunoreaction. Our results demonstrate that the DB71 staining can be used as a destaining‐free alternative loading control method for Western blotting.     

Improvement in Uranium Adsorption Properties of Amidoxime-Based Adsorbent Through Cografting of Amine Group

Amidoxime (AO)/amine co-functionalized polypropylene fiber adsorbents were prepared. The all-polymeric structures were characterized by using Fourier transform infrared spectroscopy (FTIR), optical microscope, contact angle meter and electron spin resonance (ESR) analysis methods, confirming the grafting, modification, and amidoximation stages gravimetrically, spectroscopically, and visually. The properties for the removal of uranyl(VI) from aqueous solutions were investigated. For amidoxime (AO) fiber, high adsorption rate was observed within the first 30 minutes and the plateau value of 40.6% uranium loading (0.0812 mg/g) was reached at around 30 minutes. The adsorption equilibrium for AO/amine fiber was attained within 20 minutes, resulting in the adsorption of 92.6% uranium loading (0.185 mg/g). The percentage of adsorption increases with increasing pH value (2–6), reaches a maximum at pH 6.0 and then remains almost constant for AO/amine fiber, whereas reduces slightly for AO fiber.     

Microfluidic-directed assembly of uniform fluorescent supraballs from CdTe nanocrystals-loaded acrylosilane microemulsion

We report herein a facile approach of fabricating fluorescent supraballs from CdTe nanocrystals (NCs)-loaded acrylosilane microemulsion by a simple microfluidic strategy. Initially, core–shell acrylosilane microemulsion with poly(methylmethacrylate-co-butylacrylate-co-vinyltri(isopropoxy)silane) (poly (MMA-co-BA-co-VPS)) as the core and poly(methylmethacrylate-co-butylacrylate-co-vinyltri(isopropoxy)silane-co-acrylamide) (poly(MMA-co-BA-co-VPS-co-AM)) as the shell were synthesized by differential microemulsion polymerization. Subsequently, CdTe NCs were assembled with these acrylosilane microemulsion particles in the presence of N′-(ethylcarbonimidoyl)-N, N-dimethylpropane-1, 3-diaminemonohydrochloride. Eventually, we fabricated uniformly distributed fluorescent supraballs using the as-prepared CdTe-loaded acrylosilane microemulsion as the discontinuous phase, and methylsilicone oil as the continuous phase by means of a microfluidic device. These fluorescent supraballs display unique colors and favorable fluorescence, which might be useful in optoelectronic applications, such as fluorescent switches, light-emitting diode displays, and illuminations.     

Validity of Inorganic Nanosheets as an Efficient Planar Substituent To Enhance the Enantioselectivity of Transition‐Metal‐Catalyzed Asymmetric Synthesis

Effectively enhancing the enantioselectivity is a persistent challenge in heterogeneous asymmetric catalysis. Here, the validity of a layered double hydroxides (LDH) nanosheet as an efficient planar substituent to enhance the enantioselectivity has been investigated theoretically; first in vanadium‐catalyzed asymmetric epoxidation of allylic alcohols, and then in zinc‐catalyzed direct asymmetric aldol addition. The computational predication is further confirmed experimentally in zinc‐catalyzed direct asymmetric aldol addition by controlling the location of catalytic sites.     

Two Coordination Polymers Constructed from 5‐(4‐Pyridyl)‐1H‐tetrazole Ligands with Different Organic Carboxylates: Structure and Luminescence Properties

Two coordination polymers (CPs), namely, [Cu(Hptz)₂(Hhba)₂]_n ( 1 ) [Hptz = 5‐(4‐pyridyl)‐1H‐tetrazole, H₂hba = 2‐hydroxybenzoic acid] and [Zn₃(ptz)₂(hpa)₂]_n ( 2 ) (H2hpa = 2‐hydroxy‐2‐phenylacetic acid), were synthesized by solvothermal reactions. Both complexes were characterized by elemental analysis, infrared spectroscopy, powder X‐ray diffraction, thermogravimetric analysis, and single‐crystal X‐ray diffraction analysis. Compound 1 exhibits a 2D (4,4) network, where each layer connects to four adjacent layers to construct a 3D supramolecular framework. Compound 2 has a 3D framework structure composed of 1D SUBs, which are formed by both carboxyl and tetrazole groups. The complexes represent two rare examples of CPs constructed from Hptz and organic carboxyl acid ligands. Complex 2 exhibits intense, red‐shifted emissions in the visible region at room temperature.