Institute of Chemistry
Changchun Institute of Applied Chemistry, Chinese Academy Of SciencesNot a member yet
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Biodegradable dextran vesicles for effective haemoglobin encapsulation
No full textBiodegradable dextran vesicles were developed based on dextran and poly(L-lactide) (PLA). The amphiphilic graft copolymer dextran-g-poly(L-lactide) (dextran-g-PLA) was obtained by coupling carboxyl-terminated PLA to dextran. The copolymer was induced to self-assemble to form nanoparticles using a dialysis procedure. The morphology and size of the nanoparticles were examined by transmission electron microscopy (TEM) and dynamic light scattering (DLS). An alternative morphology could be induced by varying the relative mass ratio of dextran to PLA. The vesicles produced showed high stability. In order to encapsulate haemoglobin (Hb), the lyophilized dextran-g-PLA was dispersed in a Hb phosphate buffer solution (PBS) and free Hb removed by centrifugation. The oxygen affinity of haemoglobin vesicles (HbVs) was close to that of pure Hb, suggesting that HbVs have considerable future potential as a blood substitute
Effects of side groups on the kinetics of charge carrier recombination in dye molecule-doped multilayer organic light-emitting diodes
No full textThe carrier recombination coefficient (gamma) in dye molecule-doped multilayer organic light-emitting diodes was quantified by transient electroluminescence. It was found that gamma and device efficiency were both strongly dependent on the molecular structures of the dopants
Tunable luminescence and energy transfer properties in Ca8MgLu(PO4)(7):Ce3+,Tb3+,Mn2+ phosphors
No full textCa8MgLu(PO4)(7):Ce3+,Tb3+,Mn2+ (abbreviated as CMLP:Ce3+,Tb3+,Mn2+) phosphors were synthesized by a high-temperature solid-state method. X-ray diffraction (XRD), photoluminescence (PL) spectra, GSAS structural refinement, and absolute quantum yield and lifetimes were used to characterize the samples. Increasing the Ce3+ doping concentration in the CMLP host shifts the emission peak from 360 to 374 nm. Under UV excitation, the energy transfers (ETs) from Ce3+ to Tb3+ and from Ce3+ to Mn2+ in the CMLP host occurred mainly via a dipole-quadrupole mechanism, and the critical distances of the ion pairs (R-C) were calculated by the quenching concentration method and spectral overlap method, respectively. The emission colors of the CMLP:Ce3+,Tb3+,Mn2+ samples could be adjusted from blue to green, and eventually to orange-red by the ET between Ce3+ and Tb3+/Mn2+. Moreover, a white light emission tunable over a wide range was obtained by precisely controlling the contents of Ce3+, Tb3+ and Mn2+. Temperature dependent luminescence spectra proved the good thermal stability of the as-prepared phosphor. Based on the good PL properties and varied hues of the CMLP host achieved by adjusting the doping concentration of the activators (Ce3+, Tb3+, Mn2+), CMLP might be promising as a host material for solid-state lighting and display fields
Binary release of ascorbic acid and lecithin from core-shell nanofibers on blood-contacting surface for reducing long-term hemolysis of erythrocyte
No full textThere is an urgent need to develop blood-contacting biomaterials with long-term anti-hemolytic capability. To obtain such biomaterials, we coaxially electrospin [ascorbic acid (AA) and lecithin]/poly (ethylene oxide) (PEO) core-shell nanofibers onto the surface of styrene-b-(ethylene-co-butylene)-b-styrene elastomer (SEBS) that has been grafted with poly (ethylene glycol) (PEG) chains. Our strategy is based on that the grafted layers of PEG render the surface hydrophilic to reduce the mechanical injure to red blood cells (RBCs) while the AA and lecithin released from nanofibers on blood-contacting surface can actively interact with RBCs to decrease the oxidative damage to RBCs. We demonstrate that (AA and lecithin)/PEO core-shell structured nanofibers have been fabricated on the PEG grafted surface. The binary release of AA and lecithin in the distilled water is in a controlled manner and lasts for almost 5 days; during RBCs preservation, AA acts as an antioxidant and lecithin as a lipid supplier to the membrane of erythrocytes, resulting in low mechanical fragility and hemolysis of RBCs, as well as high deformability of stored RBCs. Our work thus makes a new approach to fabricate blood-contacting biomaterials with the capability of long-term anti-hemolysis. (C) 2014 Elsevier B.V. All rights reserved
A simple and rapid colorimetric sensor for sulfide anion detection based on redox reaction of ABTS with Au (III)
No full textA cost-effective and simple colorimetric sensor based on redox reaction of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) with Au (III) ion, has been fabricated for the determination of sulfide (S2-) anion. In the proposed method, colorless ABTS could be oxidized by Au (III) to produce bluish green oxidized ABTS (oxABTS), accompanying with a dramatic absorption band centered at 414 nm. However, in the presence of S2-, Au (III) would be reduced to Au nanoparticles (Au NPs), Au2S NPs or their mixture, inducing a bluish green color fading of ABTS-Au (III) system and a decrease of the absorbance at 414 nm because neither Au NPs nor Au2S NPs were able to oxidize ABTS. Based on this phenomenon, detection of S2- was achieved via its inhibiting effect on the ABTS-Au (III) chromogenic reaction and carried out either by visualizing the solution color change or by measuring the absorbance change of the oxABTS. A linear relationship in the S2- concentration range of 0.5-15 mu M could be acquired with a low detection limit of 0.28 mu M with the help of UV-vis spectroscopy and 1.0 mu M by naked eyes. The as-proposed sensor showed high selectivity toward S2- over other common anions and metallic ions by taking advantage of the sulfide-specific reduction of Au (III). Additionally, such sensing system featured simplicity, rapidity and flexibility, with no requirement of organic probes or nanomaterials. The proposed sensor has been successfully applied to detect S2- in lake water samples with satisfactory results, demonstrating its potential application in environmental water sample detection. (C) 2015 Elsevier B.V. All rights reserved
In situ IR spectral identification of NH4H2PO4 structural evolution during crystallization in water-ethanol mixed solvent
No full textBoth the crystallizing molecule without long-range ordered arrangement and the complex interactions between solvent, anti-solvent, and molecule crystal challenge the imaging of molecule configurations during anti-solvent crystallization. Here, the structural evolution of NH4H2PO4 during anti-solvent crystallization was tracked by in situ ATR-IR spectroscopy. The NH4H2PO4 molecule undergoes D-2d -> C-2v -> D-2d or C-2v -> D-2d during anti-solvent crystallization, depending on both V(H2O)/V(ethanol) ratio and the concentration of NH4H2PO4 aqueous solution. Moreover, IR spectroscopy can also be used to confirm the anti-solvent role of ethanol in the NH4H2PO4-H2O-ethanol crystallization system. The volatilization of ethanol has been demonstrated as an effective approach to control the dissolution process of NH4H2PO4, which can be used to study the crystallization-dissolution-recrystallization process. The present study can shed light on the anti-solvent crystallization physical and chemistry of NH4H2PO4 from a molecule-level viewpoint
In situ crosslinkable hydrogels formed from modified starch and O-carboxymethyl chitosan
No full textAn in situ hydrogel based on oxidation cholesterol starch (OCS) and O-carboxymethyl chitosan (CMCT) that is completely devoid of potentially cytotoxic small molecule cross-linkers and does not require complex manoeuvres or catalysis has been formulated and characterized. The network structure was created by Schiff base formation. The mechanical properties, internal morphology and swelling ability of the injectable hydrogel were examined. Rheological measurements demonstrated that increasing the concentration of the monomer improved the storage modulus. SEM showed that the hydrogel possessed a well-defined porous structure. In addition, the Schiff base reaction was acid sensitive. Under acid conditions, the hydrogel could hydrolyse quickly compared with high pH conditions. Doxorubicin (DOX) was used as a model drug to investigate the control and release properties of the hydrogel. The cytotoxic potential of the hydrogel was determined using an in vitro viability assay with L929 cells as a model and the results revealed that the hydrogel was non-cytotoxic
A novel metalloporphyrin-based conjugated microporous polymer for capture and conversion of CO2
No full textA novel conjugated microporous polymer was solvothermally synthesized using an aluminum porphyrin as a main building block, which had a high Brunauer-Emmett-Teller specific surface area up to 839 m(2) g(-1) and a pore volume of 2.14 cm(3) g(-1). The polymer displayed excellent capacity to capture carbon dioxide (4.3 wt%) at 273 K and 1 bar, and good catalytic activity for cyclic carbonate synthesis with TOF up to 364 h(-1)
Water-dispersible near-infrared Ag2S nanoclusters with tunable fluorescence for bioimaging application
No full textWater-dispersed NIR-emitting ultrasmall-sized Ag2S nanoclusters (NCs) are prepared directly in the aqueous phase via a facile one-step microwave synthesis. Through fine adjustment of the experimental conditions, Ag2S NCs with tunable multicolor emission are successfully realized from the visible region to the NIR region. The resultant Ag2S NCs are promising biological probes for cellular imaging
Methylsulfonylmethane-loaded electrospun poly(lactide-co-glycolide) mats for cartilage tissue engineering
No full textMethylsulfonylmethane (MSM) is popularly used for the therapy of arthritic and rheumatic diseases but seldom in tissue engineering applications for cartilage regeneration. In this study, biodegradable poly(lactide-co-glycolide) (PLGA) fibrous mats containing MSM with different doping levels were fabricated by electrospinning. The MSM-loaded mats were interconnected with smooth, uniform micro- and nano-fibers. In vitro drug release of MSM-loaded mats and the biological activity for chondrocytes were investigated. The results showed that the total MSM release of 0.01 wt%, 0.1 wt%, 1 wt% and 10 wt% MSM/PLGA mats within 48 hours were 83.5%, 80.7%, 72.2%, and 51.5%, respectively. Because of the excellent bioactivity of MSM, the MSM-loaded mats showed much better cell proliferation and ECM formation ability than that of the PLGA mat. Among them, the 0.1 wt% MSM/PLGA mat showed the best cell proliferation. More importantly, the MSM/PLGA mats, especially for the 10 wt% group, also promoted extracellular matrix (ECM) formation, the cartilage related gene expression of collagen type II, aggrecan, and collagen type I, and cartilage specific protein expression of collagen type II. Together, findings from this study have revealed that the electrospun MSM-loaded PLGA mat is a promising candidate for cartilage regeneration