MATERIALS LETTERS
·
2015
·
IF 2.489
Zhang Leilei,Li Hejun,Li Kezhi,Liu Shoujie,Zhang Yulei,Yao Pei,Zhang Wenqi,Chen Guanzheng
A multi-layer coating composed of SiC inner-layer and Mg and F co-substituted hydroxyapatite/chitosan hybrid out-layer for carbon fibers has been synthesized using a combination method of chemical vapor deposition , electrochemical deposition and ion exchange method. The morphology, microstructure and in-vitro bioactivity of the multi-layer coating are analyzed. The results show that the SiC inner-layer exhibits a squamous shape. Mg and F co-substituted hydroxyapatite/chitosan hybrid out-layer covers the SiC inner-layer coated carbon fiber entirely and uniformly with a flat structure. The multi-layer coating could induce the precipitation of particle-shaped apatite crystals with Ca/P molar ratios of 1.34–1.51 on its surface in simulated body fluid. The multi-layer SiC/Mg and F co-substituted hydroxyapatite/chitosan coated carbon fibers should have potential application for tissue engineering.
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APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Kaihang Chen,Zuguang Shen,Jiwen Luo,Xiaoying Wang,Runcang Sun
There is an urgent need to develop a highly sensitive detection system for detecting trace amounts of food contaminants. In this study, optimal synthesis of silver nanoparticles (Ag NPs) with stable and narrow size distribution in the range of 15–25 nm was performed under microwave irradiation, using quaternized chitosan (QCS) as reducing and stabilizing agent. The results showed that the ratio of QCS to [Ag(NH 3 ) 2 ] + , reaction temperature, irradiation time, the degree of substitution ( DS ) and molecular weight ( Mw ) of QCS had obvious effects on the formation, particle size and size distribution of Ag NPs. In addition, utilizing QCS/Ag NPs composite as SERS substrate, tricyclazole and Sudan I could be rapidly and sensitively detected with the limit of detection (LOD) as low as 50 ppb and 10 ppm, respectively. Compared with previously reported works, our detection system are of great stability and operability. The QCS was coated on the surface of Ag core, avoiding aggregation of Ag NPs and creating hot spots, in turn, providing superior amplification of SERS. Thus, it is believed that the QCS/Ag NPs composite could be considered as an ideal SERS-active substrate for detection of food contaminants.
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POLYMER DEGRADATION AND STABILITY
·
2015
·
IF 3.163
Mingguang Li,Hongjun Zang,Jiaxuan Feng,Qing Yan,Nianqin Yu,Xiaolong Shi,Bowen Cheng
A new process for the efficient conversion of chitosan into 5-hydroxymethylfurfural (5-HMF) has been developed. Chitosan was hydrolyzed in the presence of acidic ionic liquids (ILs), with N-methyl imidazolium hydrogen sulfate ([MIM]HSO 4 ) giving the best results. The effects of reaction time, temperature and quantity of water and IL were investigated in detail. The optimal reaction conditions were found to be 4wt % IL ([MIM]HSO 4 ) aqueous solution under hydrothermal condition, 180 °C and a reaction time of 5 h. A yield of 29.5 mol% 5-HMF was obtained from 100 mg chitosan. Furthermore, chitosan with different molecular weight could be directly converted into 5-HMF in good yields under these conditions. More importantly, [MIM]HSO 4 could be recovered by simple post-processing and exhibited constant activity over 5 cycles.
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BIOMACROMOLECULES
·
2015
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IF 5.75
Xiaojie Song,Hao Wu,Shen Li,Yanfang Wang,Xiaojun Ma,Mingqian Tan
Nanocarriers play an important role in improving the photo- and thermal-stability of photosensitizers to gain better pharmacokinetics behavior in tumor photothermal therapy. Herein, PEGylated chitosan (CG-PEG; PEG: polyethylene glycol) nanoparticles with ultrasmall size (∼5 nm) were prepared through a water-in-oil reverse microemulsion method using genipin as a cross-linker. Particle size and zeta-potential can be tuned by varying the molar ratio between chitosan amino groups and genipin. CG-PEG-ICG (ICG: indocyanine green) nanoparticles were fabricated by adding ICG to CG-PEG aqueous solution through a self-assembly method via electrostatic interaction. The resultant CG-PEG-ICG nanoparticles exhibited improved photo- and thermal-stability, good biocompatibility, and low toxicity. When irradiated with a laser, the cells incubated with CG-PEG-ICG nanoparticles showed very low cell viability (15%), indicating the CG-PEG-ICG nanoparticles possess high in vitro photothermal toxicity. Moreover, the CG-PEG nanocarriers can significantly alter the biodistribution and prolong the retention time of ICG in the mice body after intravenous injection. In vivo photothermal study of tumors injected with CG-PEG-ICG nanoparticles containing ICG at a concentration greater than 100 μg·mL–1 (100 μL) induced irreversible tissue damage. The growth of U87 tumors was dramatically inhibited by CG-PEG-ICG nanoparticles, demonstrating that the CG-PEG nanoparticles may act as potential ICG nanocarriers for effective in vivo tumor photothermal therapy.
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高影响因子
COLLOID AND POLYMER SCIENCE
·
2015
·Vol. 294
·期 3
·629-637
·
IF 1.865
Zhang Liping,Xi Lin,Shi Gang,Zhu Changping,Ni Caihua
Stimuli-responsive nanoparticles as drug carriers have promising applications in chemotherapy. To increase stability of nanogels in the bloodstream and to enhance intracellular drug uptake, reduction-responsive zwitterionic nanogels were prepared using carboxymethyl chitosan as a material. The preparation included modification of carboxymethyl chitosan and crosslinking by of N , N -Bis(acryloyl) cystamine. The nanogels possessed zwitterions of carboxyl and amino groups, and showed excellent non-fouling behavior against protein adsorption. In the presence of a reduction agent such as glutathione (GSH), the nanogels were dissociated due to scission of disulfide bonds in the crosslinking structure, leading to drug release in tumor cells. The nanogels were non-cytotoxic, biocompatible, biodegradable, and would be potentially used as anticancer drug delivery carriers in controlled release for enhancing cellular drug uptake.
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BIOMATERIALS
·
2014
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IF 8.312
Xiaoying Wang,Yihang Chen,Fatima Zohra Dahmani,Lifang Yin,Jianping Zhou,Jing Yao
An amphiphilic carboxymethyl chitosan-quercetin (CQ) conjugate was designed and synthesized for oral delivery of paclitaxel (PTX) to improve its oral bioavailability by increasing its water solubility and bypassing the P-gp drug efflux pumps . CQ conjugate had low critical micelle concentration (55.14 μg/mL), and could self assemble in aqueous condition to form polymeric micelles (PMs). PTX-loaded CQ PMs displayed a particle size of 185.8 ± 4.6 nm and polydispersity index (PDI) of 0.134 ± 0.056. The drug-loading content (DL) and entrapment efficiency (EE) were 33.62 ± 1.34% and 85.63 ± 1.26%, respectively. Moreover, PTX-loaded CQ PMs displayed similar sustained-release profile in simulated gastrointestinal fluids (pH 1.2/pH 6.8) and PBS (pH 7.4). In situ intestinal absorption experiment showed that PTX-loaded CQ PMs significantly improved the effective permeability of PTX as compared to verapamil ( P < 0.01). Likewise, PTX-loaded CQ PMs significantly enhanced the oral bioavailability of PTX, resulting in strong antitumor efficacy against tumor xenograft models with better safety profile as compared to Taxol ® and Taxol ® with verapamil. Overall, the results implicate that CQ PMs are promising vehicles for the oral delivery of water-insoluble anticancer drugs.
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BIOLOGICAL TRACE ELEMENT RESEARCH
·
2017
·Vol. 184
·期 1
·60-74
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IF 2.399
Tao Ran,Wang Chengzhang,Zhang Changwei,Li WenJun,Zhou Hao,Chen Hongxia,Ye Jianzhong
The structure and bioactivity of Ginkgo biloba leaves polyprenol (GBP) are similar to that of dolichol which widely exists in human and mammalian organs. GBP possesses potential pharmacological activities against cancer. This study involved oil-in-water type nanoemulsion (NE) loading GBP was prepared by dissolving polyprenol in nanoemulsion of sodium tripolyphosphate (TPP)/TiO 2 solution, Triton X-100, and 1-octanol by inversed-phase emulsification (EIP) and ultrasonic emulsification (UE) method. Folic acid (FA)-coupled chitosan (CS) nanoparticles (NPs), GBP-FA-CS-NPs and GBP-TiO 2 -FA-CS-NPs, were fabricated by ionic cross-linking of positively charged FA-CS conjugates and negatively charged nanoemulsion with TPP/TiO 2 . And characterizations of them were investigated by TEM, SEM, FTIR, particle size, and zeta potential. The cytotoxic and genotoxic effects of GBP-TiO 2 -FA-CS-NP treatment were higher than GBP-NE, GBP-FA-CS-NPs, TiO 2 -NE, GBP-TiO 2 -NE, TiO 2 -FA-CS-NPs, and GBP-TiO 2 -FA-CS-NP treatment at the same tested concentrations in HepG2 cells. GBP-TiO 2 -FA-CS-NPs at low TiO 2 concentration (from 1 to 2.5 μg/ml) showed good inhibition capacity on HepG2 cells and low cytotoxic and genotoxic effects on HL-7702 cells. The possible mechanism of cytotoxicity on GBP-TiO 2 -FA-CS-NPs against HepG2 cells is by preventing excessive intracellular Ca 2+ into extracellular spaces via inhibiting Ca 2+ -ATPase and Ca 2+ /Mg 2+ -ATPase.
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Nanoscale Research Letters
·
2017
·Vol. 12
·期 1
·1-8
·
IF 2.833
Cai Limei,Yu Rufen,Hao Xi,Ding Xiangcui
In this study, novel folic acid-conjugated chitosan nanoparticle was formulated for specific delivery of bioflavonoid, Genistein (GEN), to the cervical cancer cells. The prepared GEN-loaded chitosan nanoparticles (GCN) and folic acid-conjugated GCN (FGCN) showed smaller size with a controlled drug release profile. FGCN exhibited enhanced internalization potential in HeLa cells than that of GCN. The specific internalization of FGCN was mainly due to the affinity of folic acid (FA) with FRs-α which is present in large numbers in HeLa cells. The results revealed that FGCN has a specific affinity towards HeLa cells that will contribute to the better treatment. Folic acid-tagged nanoformulations exhibited a superior cytotoxic effect compared to that of non-targeted formulations. Consistently, IC50 value of GEN decreased from 33.8 to 14.6 μg/ml when treated with FGCN after 24 h incubation. The apoptosis studies indicated that the FGCN nanoparticles were then either GCN or free GEN in terms of anticancer activity. Overall, results revealed that folate conjugation to the delivery system might have great effect on the survival of cervical cancers that will be beneficial for overall cancer treatment.
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Marine Drugs
·
2017
·Vol. 15
·期 7
·223
·
IF 3.503
Na Li,Huanhuan Wang,Xiaosai Qu,Yu Chen
ROMP is an effective method for preparing functional polymers due to its having characteristics of “living” polymerization and rapid development of catalysts. In the present work, poly(norbornene-methylamine), a mimic of chitosan, was synthesized via ROMP reaction. The amino-protected product, 5-norbornene-2-(N-methyl)-phthalimide, was prepared by a reaction of 5-norbornene-2-methylamine with phthalic anhydride, which was then subjected to the ROMP reaction in the presence of Hoveyda-Grubbs 2nd catalyst to afford poly(norbornene-(N-methyl)-phthalimide). The target product, poly(norbornene-methylamine), was obtained by deprotection reaction of poly(norbornene-(N-methyl)-phthalimide). The products in each step were characterized by FTIR and1H-NMR, and their thermal stabilities were determined by TG analysis. The effects of molar ratio between monomer ([M]/[I]) and catalyst on the average relative molecular weight (Mn¯) and molecular weight distribution of the produced polymer products were determined by gel permeation chromatography (GPC). It was found that theMn¯of poly(norbornene-(N-methyl)-phthalimide) was controllable and exhibited a narrow polydispersity index (PDI) (~1.10). The synthesis condition of 5-norbornene-2-(N-methyl)-phthalimide was optimized by determining the yields at different reaction temperatures and reaction times. The highest yield was obtained at a reaction temperature of 130 °C and a reaction time of 20 min. Our work provides a new strategy to synthesize polymers with controllable structures and free –NH2groups via ROMP.Keywords:ROMP;poly(norbornene-methylamine);controllable;living polymerization;chitosan
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INTERNATIONAL JOURNAL OF MINERAL PROCESSING
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2017
·
IF 1.561
Cheng Zhang,Cheng Liu,Qiming Feng,Yanfei Chen
Utilization of N -carboxymethyl chitosan (N-CMCh) to limit the detrimental effect of serpentine on the flotation of pyrite is presented in this work. Flotation results show that the presence of hydrophilic serpentine slimes results in lower recoveries of the valuable pyrite. Utilization of N -carboxymethyl chitosan can limit the detrimental effect of serpentine on the flotation of pyrite. Zeta potential measurements illustrate that N-CMCh is with negative charge and the electrostatic interaction between serpentine and N-CMCh is occurred at pH 8.5, then the serpentine zeta potential will be changed from positive to negative, the electro-steric attraction converts into electro-steric repulsion between pyrite and serpentine and the pyrite recovery is improved.
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CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Minghua Lai,Jingnan Wang,Jiayun Tan,Jiahao Luo,Li-Ming Zhang,David Y.B. Deng,Liqun Yang
To improve the small intestinal absorption efficacy of Astragalus polysaccharides (APS) through oral administration, amphiphilic chitosan derivatives conjugated with deoxycholic acid residues in the absence and presence of vitamin B 12 residues (DA-Chit and VB 12 -DA-Chit, respectively) were synthesized and characterized by FTIR and NMR spectroscopy. APS and the amphiphilic chitosan derivatives formed the nano-complexes with positive zeta potentials in the size of 100–150 nm observed using scanning electron microscopy. To investigate the fluorescent properties of APS, a Congo red residue-conjugated APS derivative (CR-APS) was synthesized. Fluorescence spectroscopy and resonance light scattering spectroscopy confirmed the formation of the CR-APS/DA-Chit nano-complex as a result of electrostatic interaction. The APS/DA-Chit and APS/VB 12 -DA-Chit nano-complexes were not toxic against the human colon adenocarcinoma (Caco-2) cells. The APS/VB 12 -DA-Chit nano-complex exhibited high permeation through intestinal enterocytes using the Caco-2 cell model, which could be beneficial to small intestinal absorption of humans.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2016
·
IF 3.138
Haiye Wang,Xinzhen Zhao,Chunju He
A novel zwitterionic surface of PVDF membrane with significantly improved antifouling properties was prepared though pressure-assisted layer by layer self-assembly method based on the electrostatic interactions of chitosan (CS), sodium alginate (SA) and polyfunctional lysine. For the modified C-S-C-S-L membrane, the contact angle decreased to 35°, the bovine serum albumin (BSA) adsorption mass of static fouling on the membrane surface decreased to 10 μg/cm 2 , and the secondary water flux recovery rate (FRR) of dynamic fouling of BSA and humic acid (HA) pollutants increased to 98% and 99%, respectively, exhibiting excellent antifouling performance. The results demonstrated that using charged bio-macromolecules and amino acids to build zwitterionic surface was effective and convenient to change the interface properties of the separation membrane through the pressure-assisted self-assembly modification method, and provided a new way for the industrial scale hydrophilic modification of hydrophobic porous membrane materials.
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