7 results on '"An, Zhiguo"'
Search Results
2. Hybrid mesoporous silica nanospheres modified by poly (NIPAM-co-AA) for drug delivery
- Author
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Yuhong Zhang, Zhiguo Wang, Dong Zhou, Peixin He, and Keju Zhang
- Subjects
Materials science ,Biocompatibility ,Cell Survival ,Surface Properties ,Drug Compounding ,Nanoparticle ,Bioengineering ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Phase Transition ,Cell Line, Tumor ,Specific surface area ,Humans ,General Materials Science ,Particle Size ,Electrical and Electronic Engineering ,Acrylamides ,Drug Carriers ,Antibiotics, Antineoplastic ,Mechanical Engineering ,General Chemistry ,Silanes ,Mesoporous silica ,Silicon Dioxide ,021001 nanoscience & nanotechnology ,Controlled release ,0104 chemical sciences ,Drug Liberation ,Kinetics ,Acrylates ,Chemical engineering ,Doxorubicin ,Mechanics of Materials ,Drug delivery ,Nanoparticles ,0210 nano-technology ,Mesoporous material ,Drug carrier ,Porosity ,HeLa Cells - Abstract
The synthesis of drug delivery systems based on surface-modified mesoporous silica hollow structures remains a huge challenge. In this paper, we have obtained hollow mesoporous silica nanoparticles (MSNs) by surfactant directed sol-gel assisted hydrothermal treatment. The MSNs have the inorganic-organic hybrid frameworks with uniform diameter distribution (260 nm), and their specific surface area, mesoporous size and pore volume are 540 m2 g-1, 3.7 nm, 0.58 cm3 g-1, respectively. It was proved that the preparation of hollow ethane-bridged nanospheres with two silicon source was due to the high crosslinking of the silicone interface and hydrothermal treatment, providing a new approach for the study of drug-loaded and controlled release behavior. Based on the synthesis of MSNs, MSNs were modified by methacryloxy propyl trimethoxyl silane (MPS) on the surface of MSNs. Then N-isopropylacryamide (NIPAM) and acrylic acid (AA) were grafted onto the surface of modified MSNs. The hollow ethane-bridged PNA-MSNs (poly (NIPAM-co-acrylic acid)-MSNs) with two silicon source were prepared successfully. Due to their distinctive hollow structure, PNA-MSNs demonstrated high drug encapsulation efficiency (70.4% ± 2.9%). The experiment results proved that the modified hollow nanoparticles not only had good biocompatibility and stability, but also possessed pH-/thermal-dual responsiveness in drug release.
- Published
- 2019
3. Ni Nanoparticles Decorated NiFe Layered Double Hydroxide as Bifunctional Electrochemical Catalyst.
- Author
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Xiangyun Gao, Xia Long, Han Yu, Xiaoyang Pan, and Zhiguo Yi
- Subjects
NANOPARTICLES ,ELECTROCATALYSIS ,HYDROXIDES - Abstract
Reducing overpotential and increasing current density remain a great challenge for promoting the application of transition metals-based layered double hydroxides (LDHs). Herein, Ni nanoparticles (~10 nm) decorated NiFe LDH ultrathin (thickness: ~2 nm) nanosheets (Ni NP/NiFe LDH) were successfully synthesized which exhibited advanced electrocatalytic activity and long-term stability on both oxygen evolution reaction (OER) and urea oxidation reaction (UOR). The onset potentials for OER and UOR are 1.50 V and 1.34 V, respectively, both are lower than NiFe LDH under the same conditions. Moreover, the peak current density of UOR was 300 mA/cm², which is much larger than reported precious-metal free UOR catalysts. The excellent catalytic performance of Ni NP/NiFe LDH composite for OER and UOR is proposed to result from the abundant exposed active sites, small charge transfer resistance, and the synergistic effects between NiFe LDH and anchored Ni nanoparticles. This work provides inspiring ideas and helpful guidelines in design of low-cost but highly efficient electrochemical catalysts. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
4. Aqueous synthesis of Cu-doped ZnCdS/ZnS core/shell nanocrystals with a new and highly reactive sulfur source.
- Author
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Zeng, Ruosheng, Shen, Rongan, Zhao, Yunqiang, Li, Xingsheng, Sun, Zhiguo, and Shen, Yayun
- Subjects
NANOCRYSTALS ,DOPING agents (Chemistry) ,NANOPARTICLES ,PHOTOLUMINESCENCE ,X-ray diffraction ,ABSORPTION spectra ,TRANSMISSION electron microscopy - Abstract
A new sulfur precursor with a highly reactive chemical nature was prepared with S powder and NaBH
4 at the high temperature of 180 °C in a closed autoclave and made it possible to carry out the synthesis of high quality metal sulfide nanocrystals (NCs) with diverse composition and structure. Using this new sulfur source, we demonstrated aqueous synthesis of colloidal Cu-doped ZnCdS NCs (d-dots) with pure, color-tunable photoluminescence (PL) in a wide spectral range (from 517 to 650 nm) based on the ‘co-nucleation doping’ strategy. The influences of the various experimental variables, including Cd/Zn ratio, Cu-doping concentration, pH value and amount of mercaptopropionic acid (MPA), on the optical properties of Cu-doped ZnCdS NCs were systematically investigated. Furthermore, highly efficient and stable dopant emission from Cu:ZnCdS/ZnS core/shell d-dots with PL quantum yield as high as 40% was achieved by the deposition of a ZnS shell around the bare Cu:ZnCdS cores; this is the highest reported to date for aqueous doped NCs. The optical properties and structure of the d-dots were characterized by UV–vis absorption spectra, PL spectra, x-ray photoelectron spectroscopy, powder x-ray diffraction, and transmission electron microscopy. The experimental results indicated that this facile synthesis route would provide a versatile approach for the preparation of other water-soluble sulfide NCs. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
5. NIR stimulus-responsive core–shell type nanoparticles based on photothermal conversion for enhanced antitumor efficacy through chemo-photothermal therapy.
- Author
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Kai Sun, Chaoqun You, Senlin Wang, Zhiguo Gao, Hongshuai Wu, W Andy Tao, Xiaoli Zhu, and Baiwang Sun
- Subjects
NANOPARTICLES ,DOXORUBICIN ,INDOCYANINE green - Abstract
A novel core–shell type nanoparticle (CSNP) was designed here to target co-delivery of doxorubicin (DOX) and photosensitizer indocyanine green (ICG) to tumor sites by the aid of NIR induced photothermal conversion effect for the purpose of synergistic chemo-photothermal cancer therapy. The electrostatically self-assembled CSNPs were prepared by amino-functionalized mesoporous silica nanoparticles (MSN-NH
2 ) as the positive inner core and DSPE-PEG2000 -COOH and DSPE-PEG2000 -FA modified lecithin as the negative outer shell. The obtained CSNPs were nanospheres with a uniform size of 47 nm, which were kept stable at 4 °C in PBS (pH = 7). Research on the release of NIR stimulus (808 nm, 1.54 W cm−2 , 6 min) manifested that the release property of the CSNPs was controllable under low pH conditions. In addition, specific concentration (40 μg ml−1 ) ICG-loaded CSNPs, achieving an appropriate temperature up to 45 °C, indicated a desired photothermal conversion efficiency. For targeting the folate receptor, the folate modified CSNPs enabled us to reach a higher cellular uptake by the mean fluorescence intensity. In vitro cell assay, the prepared CSNPs showed outstanding inhibitory efficiency (2.07% cell viability and 91.8% cell apoptosis) on MCF-7 cells for 24 h when irradiated by an 808 nm laser with a power of 1.54 W cm−2 for 6 min. Our research highlights that the prepared nanoparticles hold potential promise for cancer treatment based on photothermal conversion performance and FA-targeted delivery. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
6. Co-delivery of cisplatin and CJM-126 via photothermal conversion nanoparticles for enhanced synergistic antitumor efficacy.
- Author
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Chaoqun You, Hongshuai Wu, Mingxin Wang, Zhiguo Gao, Xiangyang Zhang, and Baiwang Sun
- Subjects
TARGETED drug delivery ,CISPLATIN ,NANOMEDICINE ,DRUG delivery systems ,PHOTOTHERMAL conversion ,NANOPARTICLES ,ANTINEOPLASTIC agents ,BENZOTHIAZOLE - Abstract
Polymeric biomaterials that can be smartly disassembled through the cleavage of the covalent bonds in a controllable way upon an environmental stimulus such as pH change, redox, special enzymes, temperature, or ultrasound, as well as light irradiation, but are otherwise stable under normal physiological conditions have attracted great attention in recent decades. The 2-(4-aminophenyl) benzothiazole molecule (CJM-126), as one of the benzothiazole derivatives, has exhibited a synergistic effect with cisplatin (CDDP) and restrains the bioactivities of a series of human breast cancer cell lines. In our study, novel NIR-responsive targeted binary-drug-loaded nanoparticles encapsulating indocyanine green (ICG) dye were prepared as a new co-delivery and combined therapeutic vehicle. The prepared drug-loaded polymeric nanoparticles (TNPs/CDDP-ICG) are stable under normal physiological conditions, while burst drugs release upon NIR laser irradiation in a mild acidic environment. The results further confirmed that the designed co-delivery platform showed higher cytotoxicity than the single free CDDP due to the synergistic treatment of CJM-126 and CDDP in vitro. Taken together, the work might provide a promising approach for effective site-specific antitumor therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
7. Adsorption of chitosan onto carbonaceous surfaces and its application: atomic force microscopy study.
- Author
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Shengnan Tan, Zhiguo Liu, Yuangang Zu, Yujie Fu, Zhimin Xing, Lin Zhao, Tongze Sun, and Zhen Zhou
- Subjects
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ADSORPTION (Chemistry) , *CHITOSAN , *ATOMIC force microscopy , *HYDROGEN-ion concentration , *NANOPARTICLES , *DNA - Abstract
The adsorption of chitosan onto highly ordered pyrolytic graphite(HOPG) surfaces and its applications have been studied by atomic force microscopy (AFM). The results indicated that chitosan topography formed on the HOPG surface significantly depends on the pH conditions and its concentration for the incubation. Under strongly acidic conditions (pH < 3.5) and at a concentration of 1 mg ml [?] 1, chitosan formed into uniform network structures composed of fine chains. When the solution pH was changed from 3.5 to 6.5, chitosan tends to form a thicker film. Under neutral and basic conditions, chitosan changed into spherical nanoparticles, and their sizes were increased with increasing pH. Dendritic structures have been observed when the chitosan concentration was increased up to 5 mg ml [?] 1. In addition, the chitosan topography can also be influenced by ionic strength and the addition of different metal ions. When 0.1 M metal ions Na + , Mg2 + , Ca2 + and Cu2 + were added into the chitosan solution at pH 3.0 for the incubation, network structures, branched chains, block structures and dense networks attached with many small particles were observed, respectively. The potential applications of these chitosan structures on HOPG have been explored. Preliminary results characterized by AFM and XPS indicated that the chitosan network formed on the HOPG surface can be used for AFM lithography, selective adsorption of gold nanoparticles and DNA molecules. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
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