Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Chem Asian J ; 19(3): e202301023, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38158585

RESUMO

Over the past few decades, Janus materials have drawn much interest owing to the combination of two different functionalities on the opposite sides. Janus nano-objects (JNOs) with asymmetric polymer brushes are one unique material of them, which consist of a polymeric or inorganic core and asymmetric polymer chains coated on the core. Combining the properties of nanomaterials, asymmetric structures and flexible polymer brushes, hairy JNOs have shown great potential in interfacial compatibilization, interfacial catalysis, oil-water separation and drug delivery. This review summarizes recent progress in the preparation strategies of JNOs with asymmetric polymer brushes via self-assembly or grafting strategies, as well as their applications in interfacial engineering, biomedicine and other aspects. Finally, the outlook and challenges of this direction are discussed.

2.
Front Pharmacol ; 14: 1105405, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37033634

RESUMO

Globally, metabolic diseases are becoming a major public health problem. Herbal medicines are medicinal materials or preparations derived from plants and are widely used in the treatment of metabolic diseases due to their good curative effects and minimal side effects. Recent studies have shown that gut microbiota plays an important role in the herbal treatment of metabolic diseases. However, the mechanisms involved are still not fully understood. This review provides a timely and comprehensive summary of the interactions between herbal medicines and gut microbiota in metabolic diseases. Mechanisms by which herbal medicines treat metabolic diseases include their effects on the gut microbial composition, the intestinal barrier, inflammation, and microbial metabolites (e.g., short-chain fatty acids and bile acids). Herbal medicines can increase the abundance of beneficial bacteria (e.g., Akkermansia and Blautia), reduce the abundance of harmful bacteria (e.g., Escherichia-Shigella), protect the intestinal barrier, and alleviate inflammation. In turn, gut microbes can metabolize herbal compounds and thereby increase their bioavailability and bioactivity, in addition to reducing their toxicity. These findings suggest that the therapeutic effects of herbal medicines on metabolic diseases are closely related to their interactions with the gut microbiota. In addition, some methods, and techniques for studying the bidirectional interaction between herbal medicines and gut microbiota are proposed and discussed. The information presented in this review will help with a better understanding of the therapeutic mechanisms of herbal medicines and the key role of gut microbiota.

3.
Adv Sci (Weinh) ; 9(25): e2202394, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35780503

RESUMO

Mesoporous carbon microparticles (MCMPs) with anisotropic shapes and ordered structures are attractive materials that remain challenging to access. In this study, a facile yet versatile route is developed to prepare anisotropic MCMPs by combining neutral interface-guided 3D confined self-assembly (3D-CSA) of block copolymer (BCP) with a self-templated direct carbonization strategy. This route enables pre-engineering BCP into microparticles with oblate shape and hexagonal packing cylindrical mesostructures, followed by selective crosslinking and decorating of their continuous phase with functional species (such as platinum nanoparticles, Pt NPs) via in situ growth. To realize uniform in situ growth, a "guest exchange" strategy is proposed to make room for functional species and a pre-crosslinking strategy is developed to preserve the structural stability of preformed BCP microparticles during infiltration. Finally, Pt NP-loaded MCMPs are derived from the continuous phase of BCP microparticles through selective self-templated direct carbonization without using any external carbon source. This study introduces an effective concept to obtain functional species-loaded and N-doped MCMPs with oblate shape and almost hexagonal structure (p6mm), which would find important applications in fuel cells, separation, and heterogeneous catalysis.


Assuntos
Carbono , Nanopartículas Metálicas , Carbono/química , Catálise , Nanopartículas Metálicas/química , Platina/química , Polímeros/química
4.
Macromol Rapid Commun ; 43(14): e2100845, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35032147

RESUMO

Generally, nanostructured polymer particles are prepared by 3D confined self-assembly (3D-CSA) of block copolymers (BCPs), while micelles are obtained through self-assembly of BCPs in dilute solutions. Herein, a facile yet robust strategy is developed to regulate the assembled structures of BCP, poly(styrene-block-4-vinylpyridine) (PS-b-P4VP), from nanostructured particles to micelles. The assemblies are prepared by an emulsion-solvent diffusion-induced self-assembly route, which is conducted by dialysis. A key feature of this strategy is that a P4VP-selective solvent (e.g., ethanol) is added to the dialysate to tune the interfacial behavior of the droplets and assembled structures of PS-b-P4VP. The authors' results reveal that in the presence of slight ethanol, the surface and internal structural transitions of nanostructured particles are caused by changes in the interfacial selectivity and packing parameter. Interestingly, interfacial instability, which results in the formation of micelles, is observed when the dialysate contains 50 vol% ethanol or more. The reason can be ascribed to the decreased interface tension, which is induced by the increase in ethanol and enhanced solubility of P4VP. This facile strategy provides a new opportunity to bridge the gap between traditional 3D-CSA and solution self-assembly of BCPs, offering a promising route to engineer morphologies and nanostructures of polymeric assemblies.


Assuntos
Micelas , Polímeros , Soluções para Diálise , Emulsões , Etanol , Polímeros/química , Solventes/química
5.
Mycopathologia ; 185(4): 717-726, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32647906

RESUMO

Talaromyces marneffei is an important opportunistic pathogen mainly afflicting the HIV-infected patients, in rare instance, it could cause infection in non-HIV-infected individuals. We report a 51-year-old Chinese woman who, with histories of SLE for 14 years and disseminated talaromycosis for 4 years, occurred partial intestinal obstruction that was demonstrated to be caused by Talaromyces marneffei infection. The randomly amplified polymorphic DNA results of paraffin-embedded tissues from both the present episode and the previous infection suggested that the present infection was a recurrent. The patient was performed excision of involved intestine and treated with oral itraconazole at a daily dose of 400 mg for 3 months, leading to an excellent response. However, she died with unknown reason more than a year later. We also reviewed the literature on Talaromyces marneffei infection associated with SLE as well as intestinal talaromycosis alone.


Assuntos
Obstrução Intestinal , Lúpus Eritematoso Sistêmico , Micoses , Talaromyces , Feminino , Humanos , Obstrução Intestinal/microbiologia , Lúpus Eritematoso Sistêmico/complicações , Pessoa de Meia-Idade , Micoses/diagnóstico , Recidiva
6.
Oncol Lett ; 5(2): 702-706, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23420417

RESUMO

The aim of this study was to study the effects of killing C6 glioma cells induced by hematoporphyrin monomethyl ether (HMME)-mediated sonodynamic therapy combined with photodynamic therapy (SPDT). In the SPDT group, the cells were treated with sonication at an intensity of 0.5 W/cm(2) and a frequency of 1 MHz, followed by different doses of light irradiation. The growth inhibition rate following treatment was determined by MTT assay. The apoptotic rate was examined by a flow cytometry. Cleavage of caspase 3, 8 and 9 was investigated by immunoblotting. Reactive oxygen species (ROS) were measured by a fluorescence microplate reader. The effect of SPDT on the glioma cells was also studied in the absence or presence of various ROS scavengers. The growth inhibition rate of C6 glioma cells treated with SPDT was significantly higher compared with sonodynamic therapy (SDT) or photodynamic therapy (PDT) alone at light doses <200 J/cm(2). The growth inhibition rate of C6 glioma cells treated with SPDT did not rise significantly when the light dose increased to >120 J/cm(2). The apoptosis rate was the highest in the SPDT group, when the light dose was at 80 J/cm(2). A greater amount of ROS were generated in the SPDT group than in the groups treated with SDT or PDT alone. The addition of NaN(3) or mannitol resulted in a decrease in the growth inhibition rate with SPDT. In conclusion, our data indicate that SPDT powerfully kills C6 glioma cells in vitro through the synergistic effects of SDT and PDT. The pathway of PDT inducing C6 glioma cell apoptosis includes both the mitochondrial and death receptor pathways. Furthermore, ROS may play an important role in SPDT.

7.
Int J Radiat Biol ; 87(10): 1061-6, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21961969

RESUMO

PURPOSE: Our aim was to study calcium overload-induced apoptosis and its relation to reactive oxygen species (ROS) in rat C6 glioma cells after sonodynamic treatment (SDT). MATERIALS AND METHODS: Hematoporphyrin monomethyl ether (HMME) was used as the sonosensitizer. The concentration of intracellular Ca(2+) ([Ca(2+)](i)) was measured by fluorometry. Apoptosis and necrosis rates were evaluated by a flow cytometry. Moreover, sarcoplasmic reticulum Ca(2+) -ATPase (SERCA(2)), cytochrome c (cyto-c) and cleaved caspase-3 were investigated by immunoblotting. RESULTS: Our study indicated that [Ca(2 +)](i) and ROS increased in cells of SDT group, the apoptosis rate, quantity of cyto-c and cleaved caspase-3 markedly increased after SDT. Furthermore, N-Acetyl-L-cysteine (NAC) or 1,2-bisethane-N,N,N',N'-tetraacetic acid tetrakis ester (BAPTA-AM) could decrease the apoptosis rate, the release of cyto-c and cleaved caspase-3 in SDT group, SERCA(2) degradation was found in SDT group and could also be prevented by the addition of NAC. CONCLUSIONS: Our results show that HMME-SDT can induce C6 cell death through both necrosis and apoptosis. ROS in C6 cells play a decisive role in HMME-SDT-induced cell death. The endoplasmic reticulum (ER) may be a major target of HMME-SDT, ROS can induce SERCA(2) degradation, causing the elevation of [Ca(2+)](i).


Assuntos
Apoptose/efeitos da radiação , Cálcio/metabolismo , Glioma/radioterapia , Hematoporfirinas/uso terapêutico , Terapia por Ultrassom/métodos , Acetilcisteína/farmacologia , Animais , Apoptose/efeitos dos fármacos , Cálcio/química , Caspase 3/metabolismo , Citocromos c/metabolismo , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Fluorometria , Glioma/induzido quimicamente , Glioma/metabolismo , Hematoporfirinas/farmacologia , Immunoblotting , Membranas Intracelulares/química , Membranas Intracelulares/metabolismo , Necrose/metabolismo , Necrose/patologia , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Ratos , Espécies Reativas de Oxigênio/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Células Tumorais Cultivadas
8.
Chemotherapy ; 57(2): 128-33, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21430380

RESUMO

PURPOSE: It was the aim of our study to evaluate the in vitro activities of tetracycline (TET), erythromycin (ERY) and levofloxacin (LVX) alone and in dual combinations against ureaplasmas. METHODS: The minimum inhibitory concentrations (MICs) of 51 ureaplasmal strains were determined by microdilution assay. RESULTS: TET was the most active when the antibiotics were used alone. The combinations resulted in significantly decreased MICs for every agent compared with the use of single antibiotics (p < 0.05, respectively), except for ERY in the ERY-LVX pair (p > 0.05), and decreased the MICs more significantly in the strains with an MIC ≥4 mg/l compared with MIC <4 mg/l, except for the TET-ERY pair. The ERY-LVX pair increased ERY MICs significantly in the MIC <4 mg/l group (p < 0.05). The combinations resulted in more beneficial MICs in strains where both agents had an MIC ≥4 mg/l compared with those where either had an MIC ≥4 mg/l, as well as in strains where either agent had an MIC <4 mg/l compared with those where both had an MIC <4 mg/l. CONCLUSIONS: Drugs in dual combinations always give more beneficial MICs against ureaplasmas than one agent alone. Combinational benefits prefer strains with a higher initial MIC.


Assuntos
Antibacterianos/farmacologia , Eritromicina/farmacologia , Levofloxacino , Ofloxacino/farmacologia , Tetraciclina/farmacologia , Ureaplasma/efeitos dos fármacos , Combinação de Medicamentos , Quimioterapia Combinada , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Infecções por Ureaplasma/tratamento farmacológico , Infecções por Ureaplasma/microbiologia
9.
Artigo em Chinês | MEDLINE | ID: mdl-15650790

RESUMO

OBJECTIVE: To study the genome sequence of hepatitis A virus L-A-1 strain which has been applied for live attenuated vaccine production in China, to compare with other HAV strains, to understand some characteristics of L-A-1 strain, and to find the mechanism of attenuation and cell adaptation. METHODS: Genome fragments were prepared by antigen-capture PCR from infected cell (2BS), PCR products were cloned into T vector, sequenced and analyzed by using bioinformatics program. RESULTS: Analysis of the genomic sequences(nt 25-7,418) showed that the open reading frame contains 6,675 nucleotides in length encoding 2,225 amino acids. Sequence homology comparison showed 98.00% and 94.00% homology at nucleotide level, and 98.51% and 98.65% homology at amino acid level with international strains MBB and HM 175, respectively. Through comparison with other attenuated, cell adapted and cytopathic effect (CPE) strains, L-A-1 strain had mutation at nt 152, 591, 646, 687 and insertion at nt 180-181 in 5?NTR and had mutation at nt 3,889 (aa 1 052-Val) in 2B region, these mutations and insertion are molecular basis for cell adaptation; mutation at nt 4,185 (aa 1 152-Lys) in 2C region should be attenuated marker; deletion in 3A region (nt 5,020-5,025) that caused two amino acids deletion is virus fast growth basis. CONCLUSION: Through analyzing L-A-1 strain genomic sequence, certain sites related to cell adaptation and attenuation were found.


Assuntos
Genoma Viral , Vacinas contra Hepatite A/genética , Vírus da Hepatite A/genética , Fases de Leitura Aberta/genética , Adaptação Biológica/genética , Sequência de Aminoácidos , Sequência de Bases , Deleção de Genes , Vírus da Hepatite A/crescimento & desenvolvimento , Mutação , Homologia de Sequência , Vacinas Atenuadas/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...