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1.
Environ Sci Technol ; 57(48): 19956-19964, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37948508

RESUMO

Pd/SSZ-13 has been proposed as a passive NOx adsorber (PNA) for low-temperature NOx adsorption. However, it remains challenging for Pd/SSZ-13 to work efficiently when suffering from phosphorus poisoning. Herein, we report a simple and efficient strategy to regenerate the phosphorus-poisoned Pd/SSZ-13 based on the cooperation between hydrothermal aging treatment and Na cocations. It was found that hydrothermal aging treatment enabled the redispersion of Pd and P-containing species in phosphorus-poisoned Pd/SSZ-13. Meanwhile, the presence of Na cocations significantly reduced the formation of AlPO4 and retained more paired Al sites for highly dispersed Pd2+ ions, which was of great importance for the recovery of adsorption performance. To our satisfaction, the restoration ratio of the adsorption capacity of poisoned Pd/SSZ-13 was >90% after regeneration. Strikingly, the NOx adsorption activities of phosphorus-poisoned Pd/SSZ-13 with phosphorus loadings of 0.2 and 0.4 mmol g-1 almost completely recovered upon regeneration. This study demonstrates the promoting effect of Na cocations on the regeneration of phosphorus-poisoned Pd/SSZ-13 by hydrothermal aging treatment, which provides useful guidance for the design of PNA materials with excellent durability for cold-start application.


Assuntos
Fósforo , Venenos , Adsorção , Íons
2.
ACS Appl Mater Interfaces ; 10(35): 29314-29324, 2018 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-30091897

RESUMO

A smart supramolecular nanosystem integrating targeting, chemotherapy, and photothermal therapy was constructed based on carboxylatopillar[5]arene (CP[5]A)-functionalized CuS nanoparticles (CuS@CP NPs). CuS@CP NPs with good monodispersibility and strong near-infrared absorption were synthesized in aqueous solution through a facile one-pot supramolecular capping method, followed by surface installation of a liver cancer-targeted galactose derivative through host-guest binding interaction. The resulting smart supramolecular nanosystem, namely, CuS@CPG, exhibited excellent photothermal ablation capability to HepG2 cells upon irradiation with laser at 808 nm. Chemotherapeutic drug, doxorubicin hydrochloride (DOX), was further loaded on CuS@CPG via electrostatic interactions between positively charged DOX and negatively charged CP[5]A to give CuS@CPG-DOX with a high drug-loading capacity up to 48.4%. The weakening of DOX-CP[5]A interactions in an acidic environment promoted the pH-responsive drug release from CuS@CPG-DOX. Significantly, this multifunctional supramolecular nanosystem showed a remarkably enhanced therapeutic effect through the combination of targeted chemotherapy and photothermal therapy upon in vitro cell study. Moreover, preliminary in vivo study demonstrated that CuS@CPG and CuS@CPG-DOX had good biocompatibility and excellent tumor inhibition effects upon near-infrared laser irradiation.


Assuntos
Cobre/classificação , Tratamento Farmacológico , Nanopartículas/química , Fototerapia , Compostos de Amônio Quaternário/química , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Liberação Controlada de Fármacos
3.
Angew Chem Int Ed Engl ; 57(22): 6486-6490, 2018 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-29532573

RESUMO

Extra-large-pore zeolites have attracted much interest because of their important applications for processing larger molecules. Although great progress has been made in academic science and industry, it is challenging to synthesize these materials. A new extra-large-pore zeolite SYSU-3 (Sun Yat-sen University no. 3) has been synthesized by using a novel sophoridine derivative as an organic structure-directing agent (OSDA). The framework structure was solved and refined using continuous rotation electron diffraction (cRED) data from nanosized crystals. SYSU-3 exhibits a new zeolite framework topology, which has the first 24×8×8-ring extra-large-pore system and a framework density (FD) as low as 11.4 T/1000 Å3 . The unique skeleton of the OSDA plays an essential role in the formation of the distinctive zeolite structure. This work provides a new perspective for developing new zeolitic materials by using alkaloids as cost-effective OSDAs.


Assuntos
Medicina Tradicional Chinesa , Silicatos/química , Zeolitas/química , Modelos Moleculares , Conformação Molecular , Silicatos/síntese química , Estereoisomerismo , Zeolitas/síntese química
4.
ACS Appl Mater Interfaces ; 10(15): 12155-12163, 2018 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-29261277

RESUMO

A novel multifunctional drug delivery system has been constructed by assembling per-6-thio-ß-cyclodextrin-modified ultrasmall CuS nanoparticles (CD-CuS) onto fluorescent AIEgen-containing mesoporous silica nanoparticles (FMSN). The CD-CuS nanoparticles are anchored on the surface of benzimidazole-grafted FMSN, acting as a gatekeeper and photothermal agent. The prepared blue-emitting nanocomposite (FMSN@CuS) exhibits good biocompatibility and cell imaging capability. Anticancer drug doxorubicin hydrochloride (DOX) molecules are loaded into FMSN@CuS, and zero prerelease at physiological pH (7.4) and on-demand drug release at an acidic environment can be achieved due to the pH-responsive gate-opening of CD-CuS only at an acidic condition. The FMSN@CuS nanocomposite can generate obvious thermal effect after the exposure of 808 nm laser, which can also accelerate the DOX release. Meanwhile, the fluorescence intensity of DOX-loaded FMSN@CuS increases with the release of DOX, and the intracellular drug release process can be tracked according to the change of luminescence intensity. More importantly, DOX-loaded FMSN@CuS displays efficient anticancer effects in vitro upon 808 nm laser irradiation, demonstrating a good synergistic therapeutic effect via combining enhanced chemotherapy and photothermal therapy.


Assuntos
Dióxido de Silício/química , Cobre , Ciclodextrinas , Doxorrubicina , Humanos , Hipertermia Induzida , Nanopartículas , Neoplasias , Fototerapia
5.
Zhong Yao Cai ; 28(4): 304-6, 2005 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-16104506

RESUMO

The effect of theaflavins (TFs) on the adhesion between monocyte and endothelial cells induced by oxidized low density lipoprotein was studied. The experiments of cells-adhesion,the cells ELISA were applied. The results showed that TFs could significantly inhibit the adhesion between monocyte and endothelial cells, and the expression of cell adhesion molecule (ICAM-1) and vascular cell adhesion molecule (VCAM-1). That maybe one of the mechanisms in antiatheroclerosis and antiadhesion between monocyte and endothelial cells.


Assuntos
Antioxidantes/farmacologia , Biflavonoides/farmacologia , Catequina/farmacologia , Endotélio Vascular/fisiologia , Monócitos/fisiologia , Chá/química , Adesão Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Humanos , Molécula 1 de Adesão Intercelular/biossíntese , Lipoproteínas LDL , Monócitos/efeitos dos fármacos , Molécula 1 de Adesão de Célula Vascular/biossíntese
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