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1.
Small ; 20(10): e2305076, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37909382

RESUMEN

Chronic diabetic wounds remain a worldwide challenge for both the clinic and research. Given the vicious circle of oxidative stress and inflammatory response as well as the impaired angiogenesis of the diabetic wound tissues, the wound healing process is disturbed and poorly responds to the current treatments. In this work, a nickel-based metal-organic framework (MOF, Ni-HHTP) with excellent antioxidant activity and proangiogenic function is developed to accelerate the healing process of chronic diabetic wounds. The Ni-HHTP can mimic the enzymatic catalytic activities of antioxidant enzymes to eliminate multi-types of reactive species through electron transfer reactions, which protects cells from oxidative stress-related damage. Moreover, this Ni-based MOF can promote cell migration and angiogenesis by activating transforming growth factor-ß1 (TGF-ß1) in vitro and reprogram macrophages to the anti-inflammatory phenotype. Importantly, Ni-HHTP effectively promotes the healing process of diabetic wounds by suppressing the inflammatory response and enhancing angiogenesis in vivo. This study reports a versatile and promising MOF-based nanozyme for diabetic wound healing, which may be extended in combination with other wound dressings to enhance the management of diabetic or non-healing wounds.


Asunto(s)
Diabetes Mellitus Experimental , Estructuras Metalorgánicas , Animales , Especies Reactivas de Oxígeno , Estructuras Metalorgánicas/farmacología , Níquel , Angiogénesis , Cicatrización de Heridas/fisiología , Antioxidantes , Hidrogeles
2.
J Am Chem Soc ; 144(11): 4799-4809, 2022 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-35192770

RESUMEN

Chemodrug resistance is a major reason accounting for tumor recurrence. Given the mechanistic complexity of chemodrug resistance, molecular inhibitors and targeting drugs often fail to eliminate drug-resistant cancer cells, and sometimes even promote chemoresistance by activating alternative pathways. Here, by exploiting biochemical fragility of high-level but dynamically balanced cellular redox homeostasis in drug-resistant cancer cells, we design a nanosized copper/catechol-based metal-organic framework (CuHPT) that effectively disturbs this homeostasis tilting the balance toward oxidative stress. Within drug-resistant cells, CuHPT starts disassembly that is triggered by persistent consumption of cellular glutathione (GSH). CuHPT disassembly simultaneously releases two structural elements: catechol ligands and reductive copper ions (Cu+). Both of them cooperatively function to amplify the production of intracellular radical oxidative species (ROS) via auto-oxidation and Fenton-like reactions through exhausting GSH. By drastically heightening cellular oxidative stress, CuHPT exhibits selective and potent cytotoxicity to multiple drug-resistant cancer cells. Importantly, CuHPT effectively inhibits in vivo drug-resistant tumor growth and doubles the survival time of tumor-bearing mice. Thus, along with CuHPT's good biocompatibility, our biochemical, cell biological, preclinical animal model data provide compelling evidence supporting the notion that this copper-based MOF is a predesigned smart therapeutic against drug-resistant cancers through precisely deconstructing their redox homeostasis.


Asunto(s)
Estructuras Metalorgánicas , Neoplasias , Animales , Catecoles/farmacología , Línea Celular Tumoral , Cobre/química , Resistencia a Antineoplásicos , Glutatión/metabolismo , Homeostasis , Estructuras Metalorgánicas/metabolismo , Estructuras Metalorgánicas/farmacología , Ratones , Neoplasias/tratamiento farmacológico , Oxidación-Reducción
4.
J Agric Food Chem ; 72(18): 10218-10226, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38666644

RESUMEN

In this work, a series of pyrrolidinone-containing 2-phenylpyridine derivatives were synthesized and evaluated as novel protoporphyrinogen IX oxidase (PPO, EC 1.3.3.4) inhibitors for herbicide development. At 150 g ai/ha, compounds 4d, 4f, and 4l can inhibit the grassy weeds of Echinochloa crus-galli (EC), Digitaria sanguinalis (DS), and Lolium perenne (LP) with a range of 60 to 90%. Remarkably, at 9.375 g ai/ha, these compounds showed 100% inhibition effects against broadleaf weeds of Amaranthus retroflexus (AR) and Abutilon theophrasti (AT), which were comparable to the performance of the commercial herbicides flumioxazin (FLU) and saflufenacil (SAF) and better than that of acifluorfen (ACI). Molecular docking analyses revealed significant hydrogen bonding and π-π stacking interactions between compounds 4d and 4l with Arg98, Asn67, and Phe392, respectively. Additionally, representative compounds were chosen for in vivo assessment of PPO inhibitory activity, with compounds 4d, 4f, and 4l demonstrating excellent inhibitory effects. Notably, compounds 4d and 4l induced the accumulation of reactive oxygen species (ROS) and a reduction in the chlorophyll (Chl) content. Consequently, compounds 4d, 4f, and 4l are promising lead candidates for the development of novel PPO herbicides.


Asunto(s)
Diseño de Fármacos , Inhibidores Enzimáticos , Herbicidas , Simulación del Acoplamiento Molecular , Malezas , Protoporfirinógeno-Oxidasa , Pirrolidinonas , Protoporfirinógeno-Oxidasa/antagonistas & inhibidores , Protoporfirinógeno-Oxidasa/química , Protoporfirinógeno-Oxidasa/metabolismo , Herbicidas/farmacología , Herbicidas/química , Herbicidas/síntesis química , Malezas/efectos de los fármacos , Malezas/enzimología , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/síntesis química , Relación Estructura-Actividad , Pirrolidinonas/química , Pirrolidinonas/farmacología , Pirrolidinonas/síntesis química , Proteínas de Plantas/química , Proteínas de Plantas/antagonistas & inhibidores , Piridinas/química , Piridinas/farmacología , Piridinas/síntesis química , Amaranthus/efectos de los fármacos , Amaranthus/química , Echinochloa/efectos de los fármacos , Echinochloa/enzimología , Digitaria/efectos de los fármacos , Digitaria/enzimología , Digitaria/química , Lolium/efectos de los fármacos , Lolium/enzimología , Estructura Molecular
5.
Pest Manag Sci ; 80(9): 4450-4458, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38662600

RESUMEN

BACKGROUND: Potato virus Y (PVY) is a prominent representative of plant viruses. It can inflict severe damage upon Solanaceae plants, leading to global dissemination and substantial economic losses. To discover new antiviral agents, a class of planar chiral thiourea molecules through the key step of N-heterocyclic carbene-catalyzed nitrile formation reaction was synthesized with excellent optical purities for antiviral evaluations against plant virus PVY. RESULTS: The absolute configurations of the planar chiral compounds exhibited obvious distinctions in the anti-PVY activities. Notability, compound (S)-4u exhibited remarkable curative activities against PVY, with a half maximal effective concentration (EC50) of 349.3 µg mL-1, which was lower than that of the ningnanmycin (NNM) (EC50 = 400.8 µg mL-1). Additionally, The EC50 value for the protective effects of (S)-4u was 146.2 µg mL-1, which was superior to that of NNM (276.4 µg mL-1). Furthermore, the mechanism-of-action of enantiomers of planar chiral compound 4u was investigated through molecular docking, defensive enzyme activity tests and chlorophyll content tests. CONCLUSION: Biological mechanism studies have demonstrated that the configuration of planar chiral target compounds plays a crucial role in the molecular interaction with PVY-CP, enhancing the activity of defense enzymes and affecting chlorophyll content. The current study has provided significant insights into the roles played by planar chiralities in plant protection against viruses. This paves the way for the development of novel green pesticides bearing planar chiralities with excellent optical purities. © 2024 Society of Chemical Industry.


Asunto(s)
Antivirales , Potyvirus , Tiourea , Tiourea/farmacología , Tiourea/análogos & derivados , Tiourea/química , Antivirales/farmacología , Antivirales/síntesis química , Antivirales/química , Potyvirus/efectos de los fármacos , Simulación del Acoplamiento Molecular , Diseño de Fármacos , Estereoisomerismo
6.
J Agric Food Chem ; 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38593435

RESUMEN

In order to discover novel protoporphyrinogen oxidase (PPO) inhibitors with excellent herbicidal activity, a series of structurally novel 6-(pyridin-2-yl) benzothiazole derivatives were designed based on the scaffold hopping strategy. The in vitro experiments demonstrated that the newly synthesized compounds exhibited noteworthy inhibitory activity against Arabidopsis thaliana PPO (AtPPO), with IC50 values ranging from 0.06 to 1.36 µM. Preliminary postemergence herbicidal activity tests and crop safety studies indicated that some of our compounds exhibited excellent herbicidal activity and crop safety. For instance, compound (rac)-7as exhibited superior herbicidal activities to commercially available flumioxazin (FLU) and saflufenacil (SAF) at all the tested concentrations and showed effective herbicidal activities even at a dosage as low as 18.75 g ai/ha. Meanwhile, compound (rac)-7as showed good crop safety for wheat at a dosage as high as 150 g of ai/ha. Although the absolute configuration of compound 7as has no obvious effect on its herbicidal activity, compound (R)-7as showed a slightly higher crop safety than compound (S)-7as. Molecular simulation studies of Nicotiana tabacum PPO (NtPPO) and our candidate compounds showed that the benzothiazole moiety of compounds (R)-7as or (S)-7as formed multiple π-π stacking interactions with FAD, and the pyridine ring generated π-π stacking with Phe-392. Our finding proved that the pyridyl-benzothiazol hybrids are promising scaffolds for the development of PPO-inhibiting herbicides.

7.
J Agric Food Chem ; 72(5): 2501-2511, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38270648

RESUMEN

To discover protoporphyrinogen oxidase (PPO) inhibitors with robust herbicidal activity and crop safety, three types of substituted 3-(pyridin-2-yl)phenylamino derivatives bearing amide, urea, or thiourea as side chain were designed via structure splicing strategy. Postemergence herbicidal activity assessment of 33 newly prepared compounds revealed that many of our compounds such as 6a, 7b, and 8d exhibited superior herbicidal activities against broadleaf and monocotyledon weeds to commercial acifluorfen. In particular, compound 8d exhibited excellent herbicidal activities and high crop safety at a dosage range of 37.5-150 g ai/ha. PPO inhibitory studies supported our compounds as typical PPO inhibitors. Molecular docking studies revealed that compound 8d provided effective interactions with Nicotiana tabacum PPO (NtPPO) via diverse interaction models, such as π-π stacking and hydrogen bonds. Molecular dynamics (MD) simulation studies and degradation studies were also conducted to gain insight into the inhibitory mechanism. Our study indicates that compound 8d may be a candidate molecule for the development of novel herbicides.


Asunto(s)
Herbicidas , Herbicidas/química , Simulación del Acoplamiento Molecular , Malezas , Nicotiana , Relación Estructura-Actividad , Inhibidores Enzimáticos/química , Protoporfirinógeno-Oxidasa
8.
Acta Biomater ; 159: 312-323, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36708854

RESUMEN

As a controllable, simple method with few side effects, near-infrared (NIR) light-based photothermal therapy (PTT) has been proven an effective cancer therapeutic approach. However, PTT-induced inflammation is a potential negative factor. And the overexpressed heat shock proteins (HSPs) by cancer cells can protect them from hyperthermia during PTT. In this work, small-size Ti3C2Tx MXene nanosheets with high photothermal conversion efficiency in the region of NIR, high cargo loading capability and good free radical scavenging capability were chosen for cancer PTT and anti-inflammation. And (-)-epigallocatechin gallate (EGCG) was applied to form EGCG/Fe metal-polyphenol nanodots on the nanosheets. EGCG being released in acid cancer cells could reduce the expression of HSPs and could be used for anti-inflammation. As a result, the complex nanosheets named MXene@EGCG could achieve enhanced cancer PTT and be anti-inflammatory. Both in vitro and in vivo studies proved the good photothermal ability of MXene@EGCG and demonstrated that it could inhibit the expression of HSPs in tumor cells and relieve PTT-induced inflammation. Therefore, the nanosheets show good results in tumor ablation with a low level of inflammation, which provides another possibility for cancer therapy. STATEMENT OF SIGNIFICANCE: Photothermal therapy (PTT)-induced inflammation plays an essential role in some important stages of tumor development and is unfavorable for cancer treatment. And hyperthermia leads to the overexpression of heat shock proteins (HSPs) in cancer cells, which limits the therapeutic effect of PTT. Therefore, we coated small-size Ti3C2Tx MXene nanosheets with (-)-epigallocatechin gallate (EGCG)/Fe metal-polyphenol nanodots and named them as MXene@EGCG. This system shows a good photothermal conversion efficiency at 808 nm. And it can release EGCG in cancer cells to inhibit the expression of HSPs, thus achieving an enhanced cancer PTT. Both MXene and EGCG can also diminish the PTT-trigged inflammation. Both in vitro and in vivo studies prove the good anti-cancer PTT effect and anti-inflammation capability of MXene@EGCG.


Asunto(s)
Hipertermia Inducida , Neoplasias , Humanos , Fototerapia/métodos , Terapia Fototérmica , Hipertermia Inducida/métodos , Titanio , Neoplasias/patología , Antiinflamatorios , Proteínas de Choque Térmico , Línea Celular Tumoral
9.
ACS Biomater Sci Eng ; 6(6): 3375-3387, 2020 06 08.
Artículo en Inglés | MEDLINE | ID: mdl-33463161

RESUMEN

The purpose of developing novel anticancer drug delivery systems (DDSs) is to efficiently carry and release drugs into cancer cells and minimize side effects. In this work, based on hollow mesoporous silica nanoparticle (HMSN) and the charge-reversal property, a pH/GSH-dual-sensitive DDS named DOX@HMSN-SS-PLL(cit) was reported. HMSN encapsulated DOX with high efficacy and was then covered by the "gatekeeper" ß-cyclodextrin (ß-CD) through the glutathione (GSH)-sensitive disulfide bond. Thereafter, adamantine-blocked citraconic-anhydride-functionalized poly-l-lysine (PLL(cit)-Ad) was decorated on the surface of the particles via host-guest interaction. The negatively charged carriers were stable in the neutral environment in vivo and could be effectively transported to the tumor site. The surface charge of the nanoparticles could be reversed in the weakly acidic environment, which increased the cellular uptake ability of the carriers by the cancer cells. After cellular internalization, ß-CD can be removed by breakage of the disulfide bond in the presence of a high concentration of GSH, leading to DOX release. The preparation process of the carriers was monitored. The charge-reversal capability and the controlled drug-release behavior of the carriers were also investigated. In vitro and in vivo experiments demonstrated the excellent cancer therapy effect with low side effects of the carriers. It is expected that dual-sensitive DOX@HMSN-SS-PLL(cit) could play an important role in cancer therapy.


Asunto(s)
Nanopartículas , Neoplasias , Doxorrubicina/uso terapéutico , Sistemas de Liberación de Medicamentos , Glutatión/uso terapéutico , Humanos , Concentración de Iones de Hidrógeno , Neoplasias/tratamiento farmacológico , Porosidad , Dióxido de Silicio/uso terapéutico
10.
J Colloid Interface Sci ; 573: 263-277, 2020 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-32283415

RESUMEN

The integration of diagnostic and therapeutic functions in a nanoplatform has been a rapidly emerging method in the management of cancer. The application of imaging technology paves the way to track the pharmacokinetics of the nanoplatforms, to guide the treatment, and to monitor the therapeutic processes and outcomes. Herein, we reported a novel type of monodisperses mesoporous silica-coated superparamagnetic iron oxide-based multifunctional nanoplatform (DOX@MMSN-SS-PEI-cit) for the diagnosis and treatment of cancer. The fabrication process included the surface modification of monodisperses mesoporous silica nanoparticle (MMSN) with branched polyethyleneimine (PEI) via disulfide bonds and the further coupling of citraconic anhydride to PEI. Typically, the hydrolysis of amide bonds in the tumor microenvironment (TME) could lead to a negative-to-positive charge reversion, which can enhance the endosomal escape of the resulting nanoplatform. The rapid release of doxorubicin hydrochloride (DOX) directly killed the cancer cells. Due to the superparamagnetic iron oxide-based high-resolution T2-weighted MR imaging contrast agents, this novel multifunctional nanoplatform successfully realized MR imaging, targeted drug delivery and controlled release in one system, and achieved significant improvement in tumor diagnosis and therapy. In summary, the therapeutic nanoplatform is a promising option in precise cancer treatment.


Asunto(s)
Antibióticos Antineoplásicos/farmacología , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/tratamiento farmacológico , Doxorrubicina/farmacología , Imagen por Resonancia Magnética , Nanopartículas/química , Animales , Antibióticos Antineoplásicos/síntesis química , Antibióticos Antineoplásicos/química , Doxorrubicina/química , Femenino , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Células MCF-7 , Ratones , Ratones Endogámicos BALB C , Oxidación-Reducción , Tamaño de la Partícula , Porosidad , Dióxido de Silicio/química , Propiedades de Superficie , Células Tumorales Cultivadas
11.
Int J Biol Macromol ; 146: 363-373, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-31911174

RESUMEN

In this paper, a targeting hyaluronic acid (HA)/mesoporous silica nanoparticle (MSN) based drug delivery system (DDS) with dual-responsiveness was prepared for cancer therapy. To avoid the side reaction between the anti-cancer drug doxorubicin hydrochloride (DOX) and HA, host-guest interaction was applied to fabricate the DDS named DOX@MSN-SS-N=C-HA. The "nanocontainer" MSN was modified with benzene ring via both pH-sensitive benzoic imine bond and redox-sensitive disulfide linkage. When DOX was loaded in the pores of MSN, the channels were then capped by the "gatekeeper" ß-CD grafted HA (HA-g-CD) through host-guest interaction between ß-CD and benzene. HA endowed the drug carriers with the targeting capability in CD44 over-expressed cancer cells. After cellular uptake, the carriers could rapidly release DOX for cell apoptosis due to both the hydrolysis of benzoic imine bond at low pH and the cleavage of disulfide bond at a high concentration of glutathione (GSH) intracellular. In vitro drug release studies and in vitro cytotoxicity studies were taken to investigate the dual-responsiveness of the carriers. And the CD44-receptor mediated cancer cell targeting capability was investigated as well. In conclusion, the targeted dual-responsive complex DDS fabricated through host-guest interaction has promising potential in cancer therapy.


Asunto(s)
Doxorrubicina , Portadores de Fármacos , Ácido Hialurónico , Nanopartículas , Neoplasias/tratamiento farmacológico , Dióxido de Silicio , Línea Celular Tumoral , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacología , Doxorrubicina/química , Doxorrubicina/farmacología , Portadores de Fármacos/química , Portadores de Fármacos/farmacología , Humanos , Ácido Hialurónico/química , Ácido Hialurónico/farmacología , Concentración de Iones de Hidrógeno , Nanopartículas/química , Nanopartículas/uso terapéutico , Neoplasias/metabolismo , Neoplasias/patología , Porosidad , Dióxido de Silicio/química , Dióxido de Silicio/farmacología
12.
Mitochondrial DNA B Resour ; 4(2): 3628-3629, 2019 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-33366115

RESUMEN

We report the complete mitogenome of Hydrophis curtus, which is 17,702 bp in size and includes 13 protein-coding (PCGs), two rRNA genes, 22 tRNA genes, and two control regions. PCGs, with 13 genes, are 11,261 bp in length. All PCGs use as the start codon ATN except ND1 (CTA) and COX1 (GTG); ATP8, ATP6, ND4L, ND5, and Cytb use the typical stop codon TAA; but COX2 and ND4 with a single T-. Phylogeny recon-structed using the Bayesian inference (BI) method with 13 PCGs indicates that H. curtus at the root of Laticaudinae.

13.
Colloids Surf B Biointerfaces ; 181: 461-469, 2019 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-31176118

RESUMEN

Negative-to-positive charge-reversal strategy employed in anti-cancer drug delivery systems (DDSs) can improve the utilization of the drugs as well as reduce their side effects efficiently. In this article, a complex DDS named DOX@MSN-ZnO-PLL-PLL(DMA) was prepared. Doxorubicin hydrochloride (DOX) was loaded in mesoporous silica nanoparticles (MSNs), which were then covered by ZnO in situ. Poly-L-lysine (PLL) and 2,3-dimethylmaleic anhydride functionalized PLL (PLL(DMA)) were finally coated on the nanoparticles through a Layer-by-Layer (LbL) assembly process with PLL(DMA) outside to obtain the carriers. The negative charged PLL(DMA) avoided the unspecific uptake of the carriers by normal cells at pH 7.4. While the charge-reversal property could reverse the zeta-potential of the carriers to positive in weakly acidic tumor tissues at pH 6.5, which promoted the cytophagy of the carriers by cancer cells. ZnO which blocked the pores of MSNs could be dissolved intracellular due to the more acidic environment in endosome/lysosome, and resulting in drug release for cancer cell apoptosis. Zeta-potential measurements, the in vitro cellular uptake behaviors as well as cellular cytotoxicity of the carriers at different pH values were investigated to prove the charge-reversal property. The in vitro drug release studies and the cellular cytotoxicity studies were also investigated to prove the controlled DOX release behavior of the carriers. In summary, the complex DDS with charge-reversal property should be of consideration in cancer therapy.


Asunto(s)
Aminoácidos/química , Antibióticos Antineoplásicos/farmacología , Doxorrubicina/farmacología , Sistemas de Liberación de Medicamentos , Nanopartículas/química , Polímeros/química , Óxido de Zinc/química , Antibióticos Antineoplásicos/química , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/química , Liberación de Fármacos , Ensayos de Selección de Medicamentos Antitumorales , Células HeLa , Humanos , Tamaño de la Partícula , Porosidad , Dióxido de Silicio/química , Propiedades de Superficie
14.
Colloids Surf B Biointerfaces ; 167: 407-414, 2018 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-29704741

RESUMEN

Due to the difference of pH values between normal tissues, tumor tissues and intracellular environments, DOX@MSN-CD-PEG, a stepwise-acid-active organic/inorganic hybrid drug delivery system (DDS) was reported in this article. The inorganic mesoporous silica nanoparticle (MSN) was introduced for loading of doxorubicin hydrochloride (DOX). Then organic components were applied to achieve the stepwise-acid-active intracellular drug release: MSN was capped with a ß-cyclodextrine (ß-CD) based host-guest system via pH-sensitive epoxy bond. Then PEG was grafted outside of the carriers through pH-sensitive benzoic imine bond. With the protection of PEG layer, the carriers were difficult cellular uptake by normal cells but could be "acid-activated" for cytophagy by cancer cells in the slightly acidic environments in tumor tissues because of the abscission of PEG. Inside the cells, the more acidic environments could further "activate" the carriers to release DOX as the leaving of the host-guest system. The fabrication processes of DOX@MSN-CD-PEG were monitored. And the stepwise-acid-active property of which was investigated by acid-triggered PEG abscission studies and in vitro drug release studies at pH 7.4 and 6.5, respectively. The in vitro cellular cytotoxicity and cellular uptake behavior were also investigated. In summary, the stepwise-acid-active hybrid DDS should be considerable for cancer therapy.


Asunto(s)
Ácidos/química , Doxorrubicina/química , Nanopartículas/química , Dióxido de Silicio/química , beta-Ciclodextrinas/química , Antibióticos Antineoplásicos/administración & dosificación , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacocinética , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacocinética , Sistemas de Liberación de Medicamentos/métodos , Liberación de Fármacos , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Microscopía Electrónica de Transmisión , Nanopartículas/ultraestructura , Polietilenglicoles/química , Porosidad
15.
Water Res ; 37(15): 3646-51, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12867330

RESUMEN

The photocatalytic activity of the carbon-black-modified nano-TiO2) (CB-TiO2) thin films was 1.5 times higher than that of TiO2 thin films in degrading Reactive Brilliant Red X-3B. Photocatalytic oxidation and ozonation of catechol over CB-TiO2 thin films supported on Al sheet was investigated. The experiments showed that ozone concentrations had an important effect on TOC removal. The combined photocatalysis with UV irradiation and ozonation (TiO2/UV/O3) process considerably increased TOC removal rate compared to combined photocatalysis with UV irradiation and oxygen oxidation (TiO2/UV/O2) process, ozonation alone (O3) process, combined ozonation and UV irradiation (UV/O3) process. The complete mineralization of catechol followed pseudo-zero-order kinetics dependent upon ozone (oxygen) concentration and indicated catechol concentration did not affect the kinetics during UV/O3 and TiO2/UV/O3 (O2) processes. The kinetic study showed that the rate constants in the complete mineralization of catechol with TiO2/UV/O3 are 1.32-1.80 times higher than that of UV/O3 with the same concentration of ozone. The rate constants are 2.56-5.36 times higher than the maximal rate constants of TiO2/UV/O2 and 4.68-9.8 times higher than the maximal rate constants of TiO2/UV.


Asunto(s)
Carbono/química , Catecoles/aislamiento & purificación , Ozono/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Catálisis , Catecoles/química , Colorantes/química , Cinética , Fotoquímica , Titanio/química , Rayos Ultravioleta
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