65 research outputs found
Synthesis of Cyclen-Functionalized Ethenylene-Based Periodic Mesoporous Organosilica Nanoparticles and Metal-Ion Adsorption Studies
The preparation of two cyclens both possessing two triethoxysilyl groups through click chemistry is described. These two cyclens were incorporated into bis(triethoxysilyl)ethenylene-based periodic mesoporous organosilica nanoparticles (PMO NPs) at different proportions of bis(triethoxysilyl)ethenylene/cyclens (90/10, 75/25). The obtained nanorods were analyzed with different techniques and showed high specific surface areas at low proportion of cyclens. The nanorods containing free amino groups of cyclen were then used for Ni(II) and Co(II) removal from model solutions. The kinetics and isotherms of adsorption of Ni(II) and Co(II) were determined, and the materials showed high uptake of metals (up to 3.9 mmol . g(-1)). They demonstrated pronounced selectivity in separation of rare earth elements from late transition metals, e. g. Ni(II) and Co(II) by adsorption and even more so by controlled desorption
Influence of the synthetic method on the properties of two-photon-sensitive mesoporous organosilica nanoparticles
International audienceHerein we report the modulation of the properties of mesoporous silica nanoparticles (NPs) via various synthetic approaches. Three types of elaborations were compared, one in aqueous media at 25 °C, and the other two at 80 °C in water or in a waterâethanol mixture. For all these methods, an alkoxysilylated two-photon photosensitizer (2PS) was co-condensed with tetraethylorthosilicate (TEOS) in the presence of cetyltrimethylammonium bromide (CTAB), leading to five two-photon-sensitive mesoporous silica (M2PS) NPs. The M2PS NP porous structure could be tuned from radial to worm-like and MCM-41 types of organization. Besides, the 2PS precursor spatial dispersion was found to be highly dependent on both the 2PS initial concentration and the elaboration process. As a result, two-photon properties were modulated by the choice of the synthesis, the best results being found in aqueous media at 25 or 80 °C. Finally, the M2PS NPs were used for in vitro two-photon imaging of cancer cells
Optimisation des déclarations des effets indésirables en onco-hématologie à l'hÎpital Paul Brousse au Centre régional de pharmacovigilance par une étude des comptes-rendus de sortie
CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF
Bionanocomposite-Textbookâ-WILEY and Sons Eds, 2017Carole AimĂ© and Thibaud Coradin
International audienc
Two-Photon-Excited Silica and Organosilica Nanoparticles for Spatiotemporal Cancer Treatment
International audienceCoherent twoâphotonâexcited (TPE) therapy in the nearâinfrared (NIR) provides safer cancer treatments than current therapies lacking spatial and temporal selectivities because it is characterized by a 3D spatial resolution of 1 ”m3 and very low scattering. In this review, the principle of TPE and its significance in combination with organosilica nanoparticles (NPs) are introduced and then studies involving the design of pioneering TPEâNIR organosilica nanomaterials are discussed for bioimaging, drug delivery, and photodynamic therapy. Organosilica nanoparticles and their rich and wellâestablished chemistry, tunable composition, porosity, size, and morphology provide ideal platforms for minimal sideâeffect therapies via TPEâNIR. Mesoporous silica and organosilica nanoparticles endowed with high surface areas can be functionalized to carry hydrophobic and biologically unstable twoâphoton absorbers for drug delivery and diagnosis. Currently, most lightâactuated clinical therapeutic applications with NPs involve photodynamic therapy by singlet oxygen generation, but low photosensitizing efficiencies, tumor resistance, and lack of spatial resolution limit their applicability. On the contrary, higher photosensitizing yields, versatile therapies, and a unique spatial resolution are available with engineered twoâphotonâsensitive organosilica particles that selectively impact tumors while healthy tissues remain untouched. Patients suffering pathologies such as retinoblastoma, breast, and skin cancers will greatly benefit from TPEâNIR ultrasensitive diagnosis and therapy
Unexpected Coordination Chemistry of Bisphenanthroline Complexes within Hybrid Materials: A Mild Way to Eu2+ Containing Materials with Bright Yellow Luminescence
International audienceA hybrid organic-inorganic material containing bisphenanthroline units forming tetrahedral cavities was prepared. We show that these cavities not only allow the incorporation of Cu2+ and Eu3+ ions but also induce the reduction of these ions in Cu+ and Eu2+, respectively. The Eu2+ containing material shows an extremely bright yellow luminescence and might be therefore a candidate for future applications
Preparation and Characterization of Novel Mixed Periodic Mesoporous Organosilica Nanoparticles
International audienceWe report herein the preparation of mixed periodic mesoporous organosilica nanoparticles (E-Pn 75/25 and 90/10 PMO NPs) by sol-gel co-condensation of E-1,2-bis(triethoxysilyl)ethylene ((E)-BTSE or E) with previously synthesized disilylated tert-butyl 3,5-dialkoxybenzoates bearing either sulfide (precursor P1) or carbamate (precursor P2) functionalities in the linker. The syntheses were performed with cetyltrimethylammonium bromide (CTAB) as template in the presence of sodium hydroxide in water at 80 °C. The nanomaterials have been characterized by Transmission Electron Microscopy (TEM), nitrogen-sorption measurements (BET), Dynamic Light Scattering (DLS), zetapotential, Thermogravimetric Analysis (TGA), FTIR, 13 C CP MAS NMR and small angle X-ray diffraction (p-XRD). All the nanomaterials were obtained as mesoporous rodlike-shape nanoparticles. Remarkably, E-Pn 90/10 PMO NPs presented high specific surface areas ranging from 700 to 970 m 2 g-1 , comparable or even higher than pure E PMO nanorods. Moreover, XRD analyses showed an organized porosity for E-P1 90/10 PMO NPs typical for a hexagonal 2D symmetry. The other materials showed a worm-like mesoporosity
Synthesis of triethoxysilylated cyclen derivatives, grafting on magnetic mesoporous silica nanoparticles and application to metal ion adsorption
The synthesis through click chemistry of triethoxysilylated cyclen derivative-based ligands is described. Different methods were used such as the copper catalyzed Huisgen's reaction, or thiol-ene reaction for the functionalization of the cyclen scaffold with azidopropyltriethoxysilane or mercaptopropyltriethoxysilane, respectively. These ligands were then grafted on magnetic mesoporous silica nanoparticles (MMSN) for extraction and separation of Ni(ii) and Co(ii) metal ions from model solutions. The bare and ligand-modified MMSN materials revealed high adsorption capacity (1.0-2.13 mmol g(-1)) and quick adsorption kinetics, achieving over 80% of the total capacity in 1-2 hours
Attachment of trianglamines to silicon wafers, chiral recognition by chemical force microscopy
International audienc
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