Read by QxMD icon Read

Mesoporous silica

Aurelia Vasile, Maria Ignat, Mirela Fernanda Zaltariov, Liviu Sacarescu, Iulian Stoleriu, Dan Draganescu, Mihai Dumitras, Lacramioara Ochiuz
The present study reports the first time use of MCM-41 mesoporous silica as highly efficient carrier for bexarotene - an antineoplastic agent specific for cutaneous T-cell lymphoma treatment. Bexarotene is highly toxic and poor-water soluble, having low bioavailability in the conventional pharmaceutical forms. Comparative uptake of bexarotene on amino-functionalized silica host at various functionalization degrees is discussed in details taking into account all structural features, of matrix as well as properties of the drug molecules...
March 2018: Acta Chimica Slovenica
Subhasis Das, Manideepa Sengupta, Arijit Bag, Mumtaj Shah, Ankur Bordoloi
A synergistic approach was made to develop a highly stable and carbon resistant catalyst system based on cobalt and nickel supported over modified mesoporous silica for the dry reforming of methane (DRM). Modified mesoporous silica is prepared by a hydrothermal method, and the total Co & Ni composition is taken at around 5% by using the deposition-precipitation technique. CO2 reforming with methane was performed at 400-800 °C under atmospheric pressure as well as at a pressure of 1 MPa, keeping the CH4/CO2 ratio equal to unity...
March 21, 2018: Nanoscale
Eduardo Guisasola, Laura Asín, Lillianne Beola, Jesús M De La Fuente, Alejandro Baeza, María Vallet Regí
This work presents an innovation in the tumor treatment in vivo mediated by magnetic mesoporous silica nanoparticles (MMSNs). This device was built with iron oxide magnetic nanoparticles embedded in a mesoporous silica matrix and coated with an engineered thermoresponsive polymer. The magnetic nanoparticles act as internal heating sources under an alternating magnetic field (AMF) that increase the temperature of the surroundings, provoking the polymer transition and consequently the release of a drug trapped inside the silica pores...
March 21, 2018: ACS Applied Materials & Interfaces
Juan L Paris, Miguel Manzano, M Victoria Cabañas, María Vallet-Regí
A novel smart hierarchical ultrasound-responsive mesoporous silica nanocarrier for cancer therapy is presented here. This dynamic nanosystem has been designed to display different surface characteristics during its journey towards tumor cells. Initially, the anticancer-loaded nanocarriers are shielded with a polyethylene glycol layer. Upon exposure to high frequency ultrasound, the polymer shell detaches from the nanoparticles, exposing a positively charged surface. This favors the internalization in human osteosarcoma cells, where the release of topotecan takes place, drastically enhancing the cytotoxic effect...
March 21, 2018: Nanoscale
Frédéric A Perras, Kasuni C Boteju, Igor I Slowing, Aaron D Sadow, Marek Pruski
We utilize direct 17O DNP for the characterization of non-protonated oxygens in heterogeneous catalysts. The optimal sample preparation and population transfer approach for 17O direct DNP experiments performed on silica surfaces is determined and applied to the characterization of Zr- and Y-based mesoporous silica-supported single-site catalysts.
March 21, 2018: Chemical Communications: Chem Comm
Meng Tian, Yu Long, Dan Xu, Shuoyun Wei, Zhengping Dong
Nowadays, chemical catalytic methods for the treatment of organic wastes are attracting more and more research attention. In the current research, novel catalysts with palladium nanoparticles (Pd NPs) supported on the hollow mesoporous silica nanotubes (h-mSiO2 ) were synthesized for the catalytic reduction of 4-nitrophenol (4-NP) and hydrodechlorination (HDC) of 4-chlorophenol (4-CP). The key point for the fabrication of the catalysts is that a certain thickness of the silica shell was wrapped on the multiwalled carbon nanotubes (MWNTs) or Pd/MWNTs through biphase stratification approach, and then the samples were calcined to remove the MWNTs...
March 14, 2018: Journal of Colloid and Interface Science
Huang Zhou, Daping He, Amiinu Ibrahim Saana, Jinlong Yang, Zhe Wang, Jian Zhang, Qirui Liang, Shuai Yuan, Jiawei Zhu, Shichun Mu
Carbon materials, with a controllable structure, derived from metal-organic frameworks (MOFs) have emerged as a new class of electrocatalysts in renewable energy devices. However, efficient conversion of MOFs to small diameter doped carbon nanotubes in inert gases at high temperatures (>600 °C) remains a significant challenge. In this study, we first report the growth of small diameter cobalt and nitrogen co-doped carbon nanotubes (Co/N-CNTs) from mesoporous silica (mSiO2)-coated Co-based MOFs (ZIF-67)...
March 20, 2018: Nanoscale
Dongsheng Zhang, Weixiang Li, Zhanfang Ma
An improved sandwich-type electrochemical immunosensor based on the novel signal amplification strategy was developed. Methylene blue (MB) loaded mesoporous silica nanoparticles (MSN) with polydopamine coating (PDA) were employed as "smart" labels, while phytic acid doped polyaniline hydrogel (PANI) with high adsorption capacity was acted as substrate. In this strategy, amount of redox species (MB) encapsulated in MSN by PDA will be released under acidic condition and then absorbed stably by PANI...
March 13, 2018: Biosensors & Bioelectronics
Ziyang Zhang, Haiyan Li, Huijuan Liu
In order to study the influences of functionalized groups onto the adsorption of tetracycline, we prepared a series of amino and amino-Fe3+ complex mesoporous silica adsorbents with diverse content of amino and Fe3+ groups (named N,N-SBA15 and Fe-N,N-SBA15). The resulting mesoporous silica adsorbents were fully characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectrometer (FTIR) and N2 adsorption/desorption isotherms. Furthermore, the effects of functionalized groups on the removal of TC were investigated...
March 2018: Journal of Environmental Sciences (China)
Bin Li, Yaqing Liu, Changjin Wan, Zhiyuan Liu, Ming Wang, Dianpeng Qi, Jiancan Yu, Pingqiang Cai, Meng Xiao, Yi Zeng, Xiaodong Chen
Memristive synapses based on resistive switching are promising electronic devices that emulate the synaptic plasticity in neural systems. Short-term plasticity (STP), reflecting a temporal strengthening of the synaptic connection, allows artificial synapses to perform critical computational functions, such as fast response and information filtering. To mediate this fundamental property in memristive electronic devices, the regulation of the dynamic resistive change is necessary for an artificial synapse. Here, it is demonstrated that the orientation of mesopores in the dielectric silica layer can be used to modulate the STP of an artificial memristive synapse...
March 15, 2018: Advanced Materials
Jiahui Kou, Lin-Bing Sun
Due to their diverse structure, high porosity, and tunable functionality, metal-organic frameworks (MOFs) are of great inter-est for diverse applications including catalysis. However, the poor hydrostability of most reported MOFs hinders their cata-lytic applications seriously. In addition, the development of an effective method to improve the catalytic activity of MOFs is another challenge. Here, we report for the first time the development of a double-solvent strategy to fabricate MOFs inside silica nanopores...
March 14, 2018: ACS Applied Materials & Interfaces
Yang Li, Yanhong Duo, Jiangang Bi, Xiaowei Zeng, Lin Mei, Shiyun Bao, Lisheng He, Aijun Shan, Yue Zhang, Xiaofang Yu
Introduction: MicroRNA-155 (miR-155) is an oncogenic microRNA, which is upregulated in many human cancers including colorectal cancer (CRC). Overexpression of miR-155 has been found to regulate several cancer-related pathways, and therefore, targeting miR-155 may be an effective strategy for cancer therapy. However, effective and safe delivery of anti-miR-155 to tumors remains challenging for the clinical applications of anti-miR-155-based therapeutics. Methods: In this study, we explored the expression of miR-155 and the transcription factor nuclear factor kappa B (NF-κB) in CRC tissues and cell lines, and the possible relationship between miR-155 and NF-κB...
2018: International Journal of Nanomedicine
Nhat Tri Vo, Astam Kumar Patra, Dukjoon Kim
The new class of silica nanoparticles with unprecedented structural morphology is synthesized by hydrolysis of tetraethyl orthosilicate (TEOS) in the presence of cetyltrimethylammonium bromide (CTAB), L-arginine, and ammonium metatungstate (AMT) composite template, all in aqueous ethanol. The morphology of the synthesized mesoporous silica nanoparticles (MSNs) can be tuned from a spherical to a hollow dough-nut shape through a hollow sphere by controlling the concentration of AMT in the composite template. The formation mechanism of the hol-low doughnut shaped MSNs (hd-MSNs) is well explored by means of zeta potential, high resolution transmission electron microscopy (HRTEM) with elemental mapping analysis, and X-ray photoelectron spectroscopy...
March 13, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Hagit Sade, Jean-Paul Lellouche
Two tungsten disulfide (WS₂)-based core-shell nanocomposites were fabricated using readily available reagents and simple procedures. The surface was pre-treated with a surfactant couple in a layer-by-layer approach, enabling good dispersion of the WS₂ nanostructures in aqueous media and providing a template for the polymerization of a silica (SiO₂) shell. After a Stöber-like reaction, a conformal silica coating was achieved. Inspired by the resulting nanocomposite, a second one was prepared by reacting the surfactant-modified WS₂ nanostructures with aniline and an oxidizing agent in an aqueous medium...
March 10, 2018: Nanomaterials
Heran Li, Haiting Li, Chen Wei, Jia Ke, Jing Li, Lu Xu, Hongzhuo Liu, Yangyang, Sanming Li, Mingshi Yang
In this study, spherical shaped chiral mesoporous silica nanoparticles (CMS) was biomimetic synthesized using histidine derivatives (C16 -L-histidine) as template via the sol-gel reaction and employed as poorly water-soluble drug nimodipine (NMP) carrier. Characteristics of CMS and its application as drug carrier were intensively investigated and compared with MCM41. Then NMP was respectively loaded into CMS and MCM41 with the drug: carrier weight ratio of 2:1. Structural features of NMP before and after drug loading were systemically characterized...
March 9, 2018: European Journal of Pharmaceutical Sciences
Joshua A Hammons, Fan Zhang, Jan Ilavsky
HYPOTHESIS: Many applications of deep eutectic solvents (DES) rely on exploitation of their unique yet complex liquid structures. Due to the ionic nature of the DES components, their diffuse structures are perturbed in the presence of a charged surface. We hypothesize that it is possible to perturb the bulk DES structure far (>100 nm) from a curved, charged surface with mesoscopic dimensions. EXPERIMENTS: We performed in situ, synchrotron-based ultra-small angle X-ray scattering (USAXS) experiments to study the solvent distribution near the surface of charged mesoporous silica particles (MPS) (≈0...
March 3, 2018: Journal of Colloid and Interface Science
Raheel Akram, Muhammad Aizaz Ud Din, Sami Ullah Dar, Anila Arshad, Wei Liu, Zhanpeng Wu, Dezhen Wu
A hierarchical excavated iron-nitrogen codoped mesoporous carbon (Ex-FeN-MC) electrocatalyst has been successfully synthesized by pyrolysis of the unique ureidopyrimidinone containing organic precursor MAMIS by using silica as the mesoporous template and iron nitrate as the source of iron. The selected organic precursor has multifunctionalities with diverse distribution of nitrogen and oxygen species which constitute interesting features to prepare the Ex-FeN-MC electrocatalyst. The as-prepared Ex-FeN-MC material shows unexpectedly higher catalytic activities towards ORR/OER performances with an overpotential of 250 mV for OER in alkaline solution at a current density of 10 mA cm-2 , while the ORR activity is almost similar to that of commercial Pt/C...
March 12, 2018: Nanoscale
Philip D Hopkins, Tara Mastren, Justyna Florek, Roy Copping, Mark Brugh, Kevin D John, Meiring F Nortier, Eva R Birnbaum, Freddy Kleitz, Michael E Fassbender
The separation of Th, Pa, and U is of high importance in many applications including nuclear power, nuclear waste, environmental and geochemistry, nuclear forensics and nuclear medicine. Diglycolamide (DGA)-based resins have shown the ability to separate many elements, however, these resins consist of non-covalent impregnation of the DGA molecules on the resin backbone resulting in co-elution of the extraction molecule during separation cycles, therefore limiting their long-term and repeated use. Covalently binding the DGA molecules onto silica is one way to overcome this issue...
March 12, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Fuat Topuz, Tamer Uyar
Mesoporous silica nanoparticles (MSNs) have sparked considerable interest in drug/gene delivery, catalysis, adsorption, separation, sensing, antireflection coatings and bioimaging because of their tunable structural properties. The shape, size and pore structure of MSNs are greatly influenced by the type of additives used, e.g., solvent and pore-templating agent. Here, we studied the influence of cyclodextrin (CD) molecules on the formation of MSNs. The nanoparticles over 100 nm in diameter were synthesized by surfactant-templated, hydrolysis-polycondensation reactions in the presence of pristine CD (β-CD) or hydroxypropyl-functionalized CDs (HP-γ-CD and HP-β-CD)...
2018: Beilstein Journal of Nanotechnology
Seyyed Javad Mousavi, Mehdi Parvini, Mohsen Ghorbani
In the present study, new generation of silica-based mesoporous adsorbents were introduced for the removal of heavy metals with the aim of developing new adsorption technologies in water treatment. The magnetic nanoadsorbent, prepared by modification of SBA-15 with [3-(2-Aminoethylamino) propyl] trimethoxysilane (AEAPTMS)-functionalized chitosan, was applied for the removal of Zn2+ from aqueous solution. The synthesized Fe2 O3 @SBA-15-CS-AEAPTMS nanoadsorbent was thoroughly characterized using XRD, TEM, FTIR and BET analysis...
May 15, 2018: Carbohydrate Polymers
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"