Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
J Environ Manage ; 252: 109647, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31600685

RESUMO

This research built up a continuous dynamic flow filter membrane to treat diluted textile wastewater and basically investigated dynamic membrane fouling mechanism. By pre-depositing particles activated carbon (PAC) on membrane support material (MSM), a thin layer was formed on its surface, which showed excellent results in removing organic pollutants from diluted textile wastewater. Experimental data were regressed by the Langmuir, Freundlich, Temkin, Dubinin-Radushkevich (D-R) and Sips isotherm models. The three two-parameter isotherms (Temkin, D-R and Freundlich) were the models that best fitted, with respectively 0.977, 0.975 and 0.973 regression coefficients. D-R model has registered the maximum calculated adsorption capacity Qmd, cal. = 45.499 mg/g and the mean energy which was required to adsorb 1 mol of MB dye by the DM layer E = 4.249 kJ/mol; indicating the energy distribution onto heterogeneous surface of a physical adsorption process. Furthermore, kinetic models results showed that MB adsorption onto PAC at different initial concentrations follows the pseudo-second order. The obtained results also indicated that a flexible DM layer with different thickness can be formed from different amount of PAC pre-deposited on MSMs, which demonstrated that it was convenient to adjust the required DM thickness to filtrate a known initial concentration for >99% organic pollutants removal efficiency rate. However, DM fouling occurred on small pores MSMs; which resulted in an increase of the filtration pressure what have affected the filtration performance. PAC and MSMs surface morphology and texture structure, before and after filtration, were visualized respectively by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infra-Red and Attenuated Total Reflectance (FTIR/ATR). From these experimental results, a sustainable flux (>6.85 × 10-5 m/s) was established to discriminate no fouling from fouling conditions based on flux and TMP trends variance.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Humanos , Cinética , Membranas Artificiais , Têxteis , Águas Residuárias
2.
Chemistry ; 23(42): 10215-10221, 2017 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-28682004

RESUMO

Drug delivery carriers with a high drug loading capacity and biocompatibility, especially for controlled drug release, are urgently needed due to the side effects and frequently dose in the traditional therapeutic method. In our work, a Zr-based metal-organic framework named ZJU-801, which is isoreticular with NU-801, has been designed and further demonstrated as an excellent drug delivery system (DDS) with a high drug loading of 41.7 %. Such a high drug loading capacity may be ascribed to the appropriate match of the size and the large pore volume of this kind of Zr MOF material. Compared with DS@NU-801, this DDS has successfully achieved on-command heating-activated drug release, which was probably attributed to the bulkier ligand, the better stability, and the intense π-π interaction between ZJU-801 and diclofenac sodium (DS) demonstrated comprehensively by SEM, powder X-ray diffraction (PXRD), FTIR and 13 C solid-state NMR spectroscopy as well as computer simulations. It is worth noting that premature drug release was avoided effectively without any complicated post-modifications. The low cytotoxicity and good biocompatibility of our DDS were certificated by the in vitro favorable results from an MTT assay, a WST-1 assay, and confocal microscopy imaging.


Assuntos
Materiais Biocompatíveis/química , Diclofenaco/química , Portadores de Fármacos/química , Estruturas Metalorgânicas/química , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Diclofenaco/metabolismo , Portadores de Fármacos/toxicidade , Liberação Controlada de Fármacos , Espectroscopia de Ressonância Magnética , Estruturas Metalorgânicas/toxicidade , Microscopia Confocal , Microscopia Eletrônica de Varredura , Células PC12 , Porosidade , Ratos , Espectroscopia de Infravermelho com Transformada de Fourier , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Difração de Raios X , Zircônio/química
3.
Acta Pharmacol Sin ; 38(6): 764-781, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28552910

RESUMO

Conjugated polymer nanomaterials (CPNs), as optically and electronically active materials, hold promise for biomedical imaging and drug delivery applications. This review highlights the recent advances in the utilization of CPNs in theranostics. Specifically, CPN-based in vivo imaging techniques, including near-infrared (NIR) imaging, two-photon (TP) imaging, photoacoustic (PA) imaging, and multimodal (MM) imaging, are introduced. Then, CPN-based photodynamic therapy (PDT) and photothermal therapy (PTT) are surveyed. A variety of stimuli-responsive CPN systems for drug delivery are also summarized, and the promising trends and translational challenges are discussed.


Assuntos
Sistemas de Liberação de Medicamentos , Nanoestruturas/química , Polímeros/química , Nanomedicina Teranóstica , Fotoquimioterapia
4.
BMC Infect Dis ; 15: 495, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26530702

RESUMO

BACKGROUND: Hand, foot, and mouth disease (HFMD) is an infectious disease caused by a group of enteroviruses, including Coxsackievirus A16 (CVA16) and Enterovirus A71 (EV-A71). In recent decades, Asian countries have experienced frequent and widespread HFMD outbreaks, with deaths predominantly among children. In several Asian countries, epidemics usually peak in the late spring/early summer, with a second small peak in late autumn/early winter. We investigated the possible underlying association between the seasonality of HFMD epidemics and meteorological variables, which could improve our ability to predict HFMD epidemics. METHODS: We used a time series analysis composed of a spectral analysis based on the maximum entropy method (MEM) in the frequency domain and the nonlinear least squares method in the time domain. The time series analysis was applied to three kinds of monthly time series data collected in Wuhan, China, where high-quality surveillance data for HFMD have been collected: (i) reported cases of HFMD, (ii) reported cases of EV-A71 and CVA16 detected in HFMD patients, and (iii) meteorological variables. RESULTS: In the power spectral densities for HFMD and EV-A71, the dominant spectral lines were observed at frequency positions corresponding to 1-year and 6-month cycles. The optimum least squares fitting (LSF) curves calculated for the 1-year and 6-month cycles reproduced the bimodal cycles that were clearly observed in the HFMD and EV-A71 data. The peak months on the LSF curves for the HFMD data were consistent with those for the EV-A71 data. The risk of infection was relatively high at 10 °C ≤ t < 15 °C (t, temperature [°C]) and 15 °C ≤ t < 20 °C, and peaked at 20 °C ≤ t < 25 °C. CONCLUSION: In this study, the HFMD infections occurring in Wuhan showed two seasonal peaks, in summer (June) and winter (November or December). The results obtained with a time series analysis suggest that the bimodal seasonal peaks in HFMD epidemics are attributable to EV-A71 epidemics. Our results suggest that controlling the spread of EV-A71 infections when the temperature is approximately 20-25 °C should be considered to prevent HFMD infections in Wuhan, China.


Assuntos
Doença de Mão, Pé e Boca/epidemiologia , Criança , Pré-Escolar , China/epidemiologia , Doenças Transmissíveis/epidemiologia , Surtos de Doenças , Enterovirus/patogenicidade , Infecções por Enterovirus/epidemiologia , Humanos , Lactente , Recém-Nascido , Análise dos Mínimos Quadrados , Modelos Teóricos , Estações do Ano , Temperatura , Tempo (Meteorologia)
5.
Int J Pharm ; 659: 124247, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38782153

RESUMO

There is a growing and urgent need for developing novel biomaterials and therapeutic approaches for efficient wound healing. Microneedles (MNs), which can penetrate necrotic tissues and biofilm barriers at the wound and deliver active ingredients to the deeper layers in a minimally invasive and painless manner, have stimulated the interests of many researchers in the wound-healing filed. Among various materials, polymeric MNs have received widespread attention due to their abundant material sources, simple and inexpensive manufacturing methods, excellent biocompatibility and adjustable mechanical strength. Meanwhile, due to the unique properties of nanomaterials, the incorporation of nanomaterials can further extend the application range of polymeric MNs to facilitate on-demand drug release and activate specific therapeutic effects in combination with other therapies. In this review, we firstly introduce the current status and challenges of wound healing, and then outline the advantages and classification of MNs. Next, we focus on the manufacturing methods of polymeric MNs and the different raw materials used for their production. Furthermore, we give a summary of polymeric MNs incorporated with several common nanomaterials for chronic wounds healing. Finally, we discuss the several challenges and future prospects of transdermal drug delivery systems using nanomaterials-based polymeric MNs in wound treatment application.


Assuntos
Sistemas de Liberação de Medicamentos , Nanoestruturas , Agulhas , Polímeros , Cicatrização , Cicatrização/efeitos dos fármacos , Humanos , Polímeros/química , Animais , Nanoestruturas/administração & dosagem , Administração Cutânea , Microinjeções/métodos
6.
Biomater Sci ; 9(24): 8386-8395, 2021 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-34787601

RESUMO

Methotrexate (MTX) as an anti-inflammatory drug for the treatment of rheumatoid arthritis (RA) through oral and injectable administration is still problematic in the clinic. Herein, a MTX-loaded thermal-responsible flexible liposome (MTFL) incorporated within a carbomer-based gel was prepared as a novel transdermal agent (MTFL/Gel) for effective treatment of RA. It was found that MTFL had an average size of approximately 90 nm, which could rapidly release the drug under thermal conditions. The prepared MTFL/Gel could remarkably increase the MTX skin permeation as compared with free MTX, which was possibly due to the deformable membrane of flexible liposomes. Moreover, the results suggested MTFL/Gel could lead to a remarkably enhanced RA treatment when in combination with microwave hyperthermia. The superior ability of MTFL/Gel to alleviate RA response was attributed to the excellent skin permeation, thermal-responsible drug release, and synergistic anti-arthritic effect of MTX chemotherapy and microwave-induced hyperthermia therapy. Overall, the MTFL/Gel with dual deformable and thermal-responsible performances could be used as a novel promising transdermal agent for enhanced treatment of RA.


Assuntos
Artrite Reumatoide , Hipertermia Induzida , Artrite Reumatoide/tratamento farmacológico , Humanos , Lipossomos , Metotrexato , Micro-Ondas
7.
Dalton Trans ; 47(44): 15882-15887, 2018 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-30362496

RESUMO

A biocompatible metal-organic framework Zn-GA comprising zinc ions and the bio-friendly molecule l-glutamic acid (GA) is synthesized as a drug delivery system, and controlled drug release triggered by pH and thermal stimuli without premature delivery is realized. The anticancer drug methotrexate (MTX) is selected to be encapsulated into the crystal which possesses one-dimensional channels along the a axis. The on-command drug carrier shows superior biocompatibility, extremely low toxicity, satisfactory loading capabilities and excellent dual-responsiveness, indicating its practical application as an efficient drug carrier with controlled release.


Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Materiais Biocompatíveis/química , Portadores de Fármacos/química , Estruturas Metalorgânicas/química , Metotrexato/administração & dosagem , Temperatura , Animais , Antimetabólitos Antineoplásicos/química , Antimetabólitos Antineoplásicos/farmacologia , Materiais Biocompatíveis/síntese química , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Portadores de Fármacos/síntese química , Ensaios de Seleção de Medicamentos Antitumorais , Ácido Glutâmico/química , Ácido Glutâmico/farmacologia , Concentração de Íons de Hidrogênio , Estruturas Metalorgânicas/síntese química , Metotrexato/química , Metotrexato/farmacologia , Modelos Moleculares , Imagem Óptica , Células PC12 , Ratos , Células Tumorais Cultivadas , Zinco/química , Zinco/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA