BIOTECHNOLOGY AND BIOPROCESS ENGINEERING
·
2015
·Vol. 20
·期 3
·550-560
·
IF 1.113
Hao Shanhu,Yan Ying,Ren Xue,Xu Ying,Chen Lanlan,Zhang Haibo
A multifunctional polymer-drug conjugate candesartan-graft-polyethyleneimine (CD-PEI, CP) containing low molecular weight polyethyleneimine (PEI) and candesartan (CD) conjugated via an amide bond was fabricated as a co-delivery micelle of drug and siRNA for potential lung cancer therapy. Here, CD as an angiotensin II type 1 receptor blocker rich in imidazole and tetrazole rings was utilized to strengthen endosomal buffering capacity of CP and suppress tumor angiogenesis. The selfassembled CP/siRNA complexes exhibited desirable and homogenous particle size, moderate positive charges, and efficient release of drug and siRNA in vitro . In addition, CD and siRNA could readily detached from nanovectors in tumor cells via an amidase-responsive mechanism and they achieved synergistic anti-angiogenesis efficacy by effectively downregulating the expression of vascular endothelial growth factor (VEGF) mRNA and protein via different pathways in vitro. In vivo investigation on nude mice bearing A549 tumor xenografts revealed that CP/siRNA complexes possessed strong antitumor activity. These findings suggested that CP could be an ideal nanovector for simultaneous transfer of drug and siRNA, and a multifunctional CP/siRNA co-delivery system with enhanced endosomal buffering capacity, amidase-responsive drug release and synergistic anti-angiogenesis efficacy might be a new promising strategy for effective lung cancer therapy.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2015
·Vol. 76
·期 3
·482-491
·
IF 1.532
Liu Hongjing,Liu Benxue,Wang Xinqiang,Zhu Luyi,Feng Cong,Zhang Guanghui,Xu Dong
Abstract Polycrystalline zirconia fibers with dense surface and good flexibility were achieved from polyaceticzirconium (abbreviated as PEZ) precursor fibers followed by steam pretreatment and post-calcination.
PEZ was synthesized via a one-pot solid–liquid reaction between basic zirconium carbonate and glacial acetic acid in methanol. Rheological behavior of the precursor sol with different concentrations was investigated, the power law model was used to describe the rheological behavior more accurately, and the relationship between the rheology and the spinnability of sol was discussed particularly. For the polymeric structure of PEZ, acetic acid was used as chelating agent and the carboxyl group was acted as a bidentate bridging ligand, which was speculated by FT-IR analysis. The effect of the pretreatment atmosphere on the evolution of the precursor fibers and the microstructure of the final fibers was discussed. The acetate group was removed in the form of molecules, and the final fibers preheated under steam atmosphere had better densification and flexibility than those were not. In addition, crystallization process, phase composition and thermal decomposition were investigated by XRD, Raman spectra and TG/DSC. Graphical Abstract The preheated atmosphere exerts an important influence on the densification and flexibility of zirconia fibers. Under steam atmosphere, acetate group in the precursor fibers is removed in the form of molecules and zirconia fibers sintered at 1050 °C for 2 h have a dense surface. However, zirconia fibers not subjected to the steam pretreatment have a large number of voids on the surface due to the decomposition of the organics. Furthermore, the fibers preheated under steam atmosphere have better flexibility than those were not. Therefore, pretreatment under steam atmosphere is essential for the preparation of the dense and flexible fibers.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2015
·Vol. 17
·期 4
·1-11
·
IF 2.184
Zeng Xianghua,Yan Shunjun,Cui Jieya,Liu Hongfei,Dong Jing,Xia Weiwei,Zhou Min,Chen Haitao
Typical morphology substrates can improve the efficiency
of surface-enhanced Raman scattering; the need for SERS substrates of controlled morphology requires an extensive study. In this paper, one-dimensional ZnS:Al nanostructures with the width of approximately 300 nm and the length of
tens um, and micro-scale structures with the width of several um and the length of tens um were synthesized via thermal evaporation on Au-coated silicon substrates and were used to study their size effects on Raman scattering and photoluminescent spectra. The photoluminescence spectra reveal the strongest green emission at a 5 at% Al source, which originates from the Al-dopant emission. The Raman spectra reveal that the size and morphology of the ZnS:Al nanowires greatly influences the Raman scattering, whereas the Al-dopant concentration has a lesser effect on the Raman scattering. The observed Raman scattering intensity of the saw-like ZnS:Al nanowires with the width of tens nm was eight times larger than that of the bulk sample. The enhanced Raman scattering can be regarded as multiple scattering and weak exciton—phonon coupling. The branched one-dimensional nanostructure can be used as an ideal substrate to enhance Raman scattering.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2015
·Vol. 33
·期 6
·857-868
·
IF 1.835
Du Chun-hui,Ma Xu-min,Wu Chun-jin,Cai Mei-qiang,Hu Meng-xin,Wang Ting
Polymerizable ionic liquid copolymer P(MMA- co -BVIm-Br) was synthesized by radical polymerization technique, and characterized by Fourier transform infrared spectrometry (FTIR), 1 H Nuclear magnetic resonance ( 1 H-NMR) and gel permeation chromatography (GPC). The resulting copolymer was used to prepare poly(vinylidene fluoride) (PVDF) blend membranes via a phase inversion method. The effects of the copolymer on the polymorphism, surface wettability and zeta potential ( ζ ) of the blend membranes were investigated by ATR-FTIR, contact angle instrument and zeta potential analyzer. Scanning electron microscopy (SEM and SEM-EDS) was also applied to investigate the morphology and the surface element changes of the fabricated membranes. The results indicated that P(MMA- co -BVIm-Br) copolymer existed on the surface of the membrane which made the blend membrane have a positive surface during the experimental pH range. The copolymer was also in favor of the formation of β crystal phase in PVDF membranes. The contact angle experiment indicated that P(MMA- co -BVIm-Br) copolymer could switch the wettability of the blend membranes from hydrophilic to hydrophobic by exchanging Br − anion with PF 6
− . Compared with pure PVDF membranes, the water flux and water recovery flux of the blend membranes were enhanced obviously. The results from the flux recovery ratio (FR) and total fouling ratio ( R
t ) all suggested that the blend membranes had good anti-fouling properties.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2014
·Vol. 50
·期 5
·2239-2246
·
IF 2.305
Hu Lei,Cheng Xinjian,Zhang Aiqing
It is of importance to prepare self-healing materials using reversible covalent bonding within polymers. In this work, we introduced ethyl 4-aminocinnamate (EA) to polyphosphazenes to prepare a novel self-healing elastomer via the reversible photochemical [2+2] cycloaddition. Linear polymer, poly[( n -butylamino)
x
(ethyl 4-aminocinnamate)
y
] phosphazene, was synthesized firstly via the ring-opening polymerization, and then substitution reaction was conducted to introduce EA as side groups. Consequently, the damaged polyphosphazenes were re-healed by being exposed to UV light. Their structures were characterized by 1 H-NMR, 31 P-NMR, FTIR, and GPC; thermal properties were tested by TGA and DMA. The [2+2] cycloaddition reaction and retro-[2+2] cycloaddition were investigated by UV–vis. The results showed that the broken polyphosphazenes could be self-healed by the UV light irradiation at 365 nm. The damaged polyphasphozene could be re-healed almost completely within about half an hour.
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2013
·Vol. 180
·期 7
·695-702
·
IF 3.434
Zhang Ting,Ma Chao,Wu Mei,Ye Yong,Chen Huaixia,Huang Jianlin
We report on an organic–inorganic hybrid material that was double imprinted with the insecticide carbaryl and the anti-inflammatory drug naproxen by a single-step method and that can serve for selective microextraction of the two analytes. The materials, in the form of monolithic columns, were characterized by scanning electron microscopy and Fourier transform IR spectra. A simple, rapid and sensitive method was then developed for the simultaneous determination of carbaryl and naproxen in lettuce and river water using these columns for microextraction, HPLC for separation, and a diode array for UV detection. The limits of detection (at S/N = 3) and quantification (at S/N = 10) are in the ranges of 2.5 – 8.8 μg kg −1 and 2.3 – 8.0 μg L −1 for lettuce and Yangtze River water, respectively. The recoveries of this method range from 93.0 to 108 % (in case of analyzing lettuce and river water), and relative standard deviations are <8.9 %.
An organic–inorganic hybrid carbaryl and naproxen imprinted monolithic column was synthesized, characterized and applied. The derivated double-template imprinted polymer showed high selectivity and enrichment ability for templates. It can be used as an alternative technique for extracting carbaryl and naproxen from complex samples.
✓ 已验证
产品关联
DOI
高影响因子
CHROMATOGRAPHIA
·
2013
·Vol. 76
·期 7
·409-417
·
IF 1.437
Li Chenyu,Chen Ligang
A simple and fast method based on magnetic separation for extraction of pyrethroid pesticides including beta-cyfluthrin, cyhalothrin and cyphenothrin from environmental water samples has been established. Magnetic titanium dioxide was used as sorbent, which was synthesized by coating TiO 2 on Fe 3 O 4 in liquid-state co-precipitation method. The sorbent has been characterized by scanning electron microscopy and Fourier-transform infrared spectrometry, and the magnetic properties were investigated with physical property measurement system. Various parameters affecting the extraction efficiency were evaluated to achieve optimal condition and decrease ambiguous interactions. The analytes desorbed from the sorbent were detected by high performance liquid chromatography. Under the optimal condition, the linearity of the method is in the range of 25–2,500 ng L −1 . The detection limits and quantification limits of pyrethroid pesticides are in the range of 2.8–6.1 ng L −1 and 9.3–20.3 ng L −1 , respectively. The relative standard deviations of intra- and inter-day tests ranging from 2.5 to 7.2 % and from 3.6 to 9.1 % were obtained. In all three spiked levels (25, 250 and 2,500 ng L −1 ), the recoveries of pyrethroid pesticides were in the range of 84.5–94.1 %. The proposed method was successfully applied to determine pyrethroids in three water samples. Cyphenothrin was found in one river water near farmlands, and its concentration was 52 ng L −1 .
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2012
·Vol. 15
·期 1
·1-11
·
IF 3.287
Wang Yuanfeng,Xu Feng,Zhang Lei,Wei Xinlin
A one-step strategy for the facile synthesis of polyethyleneimine-functionalized Fe 3 O 4 (Fe 3 O 4 -PEI) composite is presented in this study. We also investigated the effects of reaction time and NaAc on the composite sizes. The composite with good dispersion, wonderful crystallization, and excellent magnetism was obtained through one-pot solvothermal reaction. In the sequential presence of PEI and colloidal gold (Au) solution, plentiful Au nanoparticles with a diameter of 5 nm were assembled on the surface of Fe 3 O 4 –PEI to get Fe 3 O 4 –PEI–Au 1 –PEI–Au 2 (Fe 3 O 4 /Au) composite. In-depth characterization of the composite formation process was performed using transmission electron microscopy, scanning electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer, and UV–Visible spectroscopy. The Fe 3 O 4 /Au composite was obtained with an average diameter of 150 nm, and the absorption peak was red-shifted to 580 nm. The synthesized Fe 3 O 4 /Au composite, the saturation magnetization of which was 40.4 emu/g, presented good magnetic property. Moreover, the composite could easily combine with up to 890 μg antibodies per mg, and the antibodies still kept good immunocompetence after immobilization. These advantages suggest its great potential for applications in vitro, such as separation and immunoassay.
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2014
·Vol. 182
·期 5
·1071-1077
·
IF 3.719
Dong Yajuan,Su Ming,Chen Peiyun,Sun Hanwen
Aqueous solutions of carbon dots (C-dots) were prepared by microwave-assisted thermal carbonization of poly(ethylene glycol). They were investigated by transmission electron microscopy, absorption and fluorescence spectra. It is shown that diperiodato-nicklate(IV), a strong oxidant, induces the chemiluminescence (CL) of C-dots in strongly alkaline solution without use of an additional reagent. A mechanism for this reaction is suggested. It is also found that the CL of the system is quenched by paracetamol, L-cysteine and glutathione. Under the optimized conditions, the calibration plot is linear with a correlation coefficient (r) of >0.995. The limits of detection are 90, 8, and 60 µg L- 1 for paracetamol, L-cysteine, and glutathione, respectively. Spiked urine and serum samples were analyzed and gave recoveries in the range from 84.38 to 116.0 %, with an RSD of 1.2–2.7 %.
Use of diperiodato-nickelate(IV) induces the chemiluminescence of carbon dots in alkaline solution without use of an additional reagent. And using inhibitory effect of the target analyte on the CL achieved the determination of paracetamol, L-cysteine and glutathione.
✓ 已验证
产品关联
DOI
高影响因子
BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2014
·Vol. 38
·期 5
·833-839
·
IF 1.823
Liu Zhenfeng,Shen Yanmin,Li Weiwei,Zhang Wen,Li Tao,Ren Baozeng
The synthesis of d -isoascorbyl stearate from d -isoascorbic acid and stearic acid with immobilized lipase (Novozym ® 435) as catalyst was studied. Response surface methodology and Box-Behnken design with six variables and three levels were employed to evaluate the effects of processing conditions on the conversion of d -isoascorbic acid. The results confirmed that the response surface method and statistical analysis were proved to be useful in developing optimal conditions for d -isoascorbyl stearate synthesis. The optimum conditions were predicted as follows: reaction temperature 48 °C, reaction time 17.7 h, immobilized lipase amount 50.0 % (w/w, of d -isoascorbic acid), substrate molar ratio 9:1 (stearic acid to d -isoascorbic acid), d -isoascorbic acid concentration 0.14 mol/L (based on solvent), 4A molecular sieve addition 200 g/L (based on solvent), and the optimal conversion was 90.6 %. Through the kinetics model fitting of the esterification, it was considered that the esterification conformed to a Ping–Pong bi–bi kinetic model with d -isoascorbic acid inhibition, and the obtained kinetic constants showed that the inhibition of d -isoascorbic acid and the enzyme affinity to substrate were abate with the increase of the reaction temperature.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2014
·Vol. 182
·期 3
·855-862
·
IF 3.719
Yan Fufeng,Zhang Yuanchang,Zhang Shuai,Zhao Jihong,Liu Shunli,He Linghao,Feng Xiaozhong,Zhang Hongzhong,Zhang Zhihong
We report on an efficient method for the production carboxy-modified graphene (carboxy-GR), and its application to a highly sensitive immunoassay for the livestock feed additive clenbuterol. Octadecanoic acid is shown to self-assemble on carboxy-GR via intermolecular interaction. Goat anti-mouse IgG was conjugated to 1-octadecanethiol-modified carboxy-GR and then deposited by self-assembly on a C18-modified gold surface. The resulting sensor surface was used to quantify clenbuterol by both surface plasmon resonance and electrochemical impedance spectroscopy. The assay works in the 0.01 ng∙mL −1 to 10 ng∙mL −1 concentration range and the lower detection limit is 6.57 pg∙mL −1 . It is concluded that this fairly simple method can be extended to immunoassays for other food additives.
Principle of sensor system and immunoassay. (i) Binding of ACG–IgG with the alkyl chain of 1-octadecanethiol through intermolecular force onto the gold substrate; (ii) absorbance of Ab CLB onto the surface of ACG-IgG; and (iii) detection of CLB using an immunoassay based on Ab CLB –ACG–IgG.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2014
·Vol. 21
·期 11
·1-8
·
IF 1.897
Ran Xiaoqi,Yi Shixiong,Liang Liefeng,Yang Xiao
The effect of oxygen on photodegradation of π-conjugated aromatic poly(1,3,4-oxadiazole)s (POD) was studied in detail. The results obtained by tensile test, UV-spectra and ATR-FTIR revealed that the oxygen was indispensable during photodegradation of POD. The occurrence of photodegradation of POD must be combination of UV exposure and oxygen simultaneously. The state of oxygen during photodegradation of POD was investigated by nitrotetrazolium blue chloride (NBT) method. The result illustrated that the oxygen was transformed into superoxide anion radical through accepting one electron during UV exposure. Results of tensile tests and UV-spectra further proved that the superoxide anion radical could combine with excited POD to form an unstable product that lead to occurrence of photodegradation. Singlet oxygen was also investigated and the result showed that POD appeared to be stable to singlet oxygen.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）