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1.
Chin Med ; 18(1): 157, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38037150

RESUMO

BACKGROUND: Acute-on-chronic liver failure (ACLF) is a refractory disease with high mortality, which is characterized by a pathophysiological process of inflammation-related dysfunction of energy metabolism. Jieduan-Niwan formula (JDNWF) is a eutherapeutic Chinese medicine formula for ACLF. However, the intrinsic mechanism of its anti-ACLF effect still need to be studied systematically. PURPOSE: This study aimed to investigate the mechanism of JDNWF against ACLF based on altered substance metabolic profile in ACLF the expression levels of related molecules. MATERIALS AND METHODS: The chemical characteristics of JDNWF were characterized using ultra performance liquid chromatography (UPLC) coupled with triple quadrupole mass spectrometry. Wistar rats subjected to a long-term CCL4 stimulation followed by a combination of an acute attack with LPS/D-GalN were used to establish the ACLF model. Liver metabolites were analyzed by LC-MS/MS and multivariate analysis. Liver function, coagulation function, histopathology, mitochondrial metabolic enzyme activity and mitochondrial damage markers were evaluated. The protein expression of mitochondrial quality control (MQC) was investigated by western blot. RESULTS: Liver function, coagulation function, inflammation, oxidative stress and mitochondrial enzyme activity were significantly improved by JDNWF. 108 metabolites are considered as biomarkers of JDNWF in treating ACLF, which were closely related to TCA cycle. It was further suggested that JDNWF alleviated mitochondrial damage and MQC may be potential mechanism of JDNWF improving mitochondrial function. CONCLUSIONS: Metabolomics revealed that TCA cycle was impaired in ACLF rats, and JDNWF had a regulatory effect on it. The potential mechanism may be improving the mitochondrial function through MQC pathway, thus restoring energy metabolism.

2.
Sci Rep ; 12(1): 14052, 2022 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-35982134

RESUMO

Acute-on-chronic liver failure (ACLF) is a critical and refractory disease and a hepatic disorder accompanied by immune dysfunction. Thus, it is essential to explore key immune-related genes of ACLF and investigate its mechanisms. We used two public datasets (GSE142255 and GSE168048) to perform various bioinformatics analyses, including WGCNA, CIBERSORT, and GSEA. We also constructed an ACLF immune-related protein-protein interaction (PPI) network to obtain hub differentially expressed genes (DEGs) and predict corresponding miRNAs. Finally, an ACLF rat model was established to verify the results. A total of 388 DEGs were identified in ACLF, including 162 upregulated and 226 downregulated genes. The enrichment analyses revealed that these DEGs were mainly involved in inflammatory-immune responses and biosynthetic metabolic pathways. Twenty-eight gene modules were obtained using WGCNA and the coral1 and darkseagreen4 modules were highly correlated with M1 macrophage polarization. As a result, 10 hub genes and 2 miRNAs were identified to be significantly altered in ACLF. The bioinformatics analyses of the two datasets presented valuable insights into the pathogenesis and screening of hub genes of ACLF. These results might contribute to a better understanding of the potential molecular mechanisms of ACLF. Finally, further studies are required to validate our current findings.


Assuntos
Insuficiência Hepática Crônica Agudizada , MicroRNAs , Insuficiência Hepática Crônica Agudizada/genética , Animais , Biologia Computacional/métodos , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , MicroRNAs/metabolismo , Ratos
3.
Artigo em Inglês | MEDLINE | ID: mdl-35873636

RESUMO

Jieduan-Niwan (JDNW) formula is a traditional Chinese medicine compound created by the famous Chinese medicine expert Professor Qian Ying, and has been used clinically for decades to treat acute-on-chronic liver failure (ACLF) and exhibits remarkable efficacy. However, the exact mechanism remains to be discovered. As an important hepatocyte damage-associated molecular patterns (DAMP) factor, high mobility group box 1 (HMGB1) is a potential therapeutic target as an accelerator of ACLF in the pathogenesis. Therefore, the present study investigated whether JDNW inhibits the overexpression and cytoplasmic translocation of HMGB1 in ACLF liver tissue and alleviates its mediated oxidative stress and apoptosis. In vivo, an immune-induced ACLF rat model was established, and then treated with JDNW for 5, 10, and 15 d. The results showed that a large number of cytoplasmic translocations of HMGB1 occurred in the ACLF group. And there was an increase in the expression of HMGB1 in the M-5 d group. After the intervention of JDNW, the overexpression and translocation of HMGB1 were inhibited. In vitro, D-GaLN caused an increase in the expression and translocation of HMGB1 in L02 cells. Similar to the inhibitor of HMGB1, JDNW serum alleviated this kind of increase. Further tests showed that JDNW attenuated ACLF-related oxidative stress and apoptosis, and the inhibition was associated with the regulation of TLR-4/NF-κB signaling pathway. In conclusion, our present findings suggest that the therapeutic effect of JDNW on ACLF was associated with the inhibition of high expression and cytoplasmic translocation of HMGB1 during the acute injury phase, thus, attenuating oxidative stress injury and apoptosis induced by HMGB1/TLR-4/NF-κB pathway.

4.
Artigo em Inglês | MEDLINE | ID: mdl-34904016

RESUMO

BACKGROUND: Acute on chronic liver failure (ACLF) is a syndrome of acute liver failure that occurs on the basis of chronic liver disease, which is characterized by a rapid deterioration in a short period and high mortality. High mobility group box 1 (HMGB1) may be involved in the pathological process of ACLF; its specific role remains to be further elucidated. Our previous studies have shown that quercetin (Que) exerts anti-oxidant and anti-apoptotic effects by inhibiting HMGB1 in vitro. The present study aimed to investigate the effect of Que on liver injury in ACLF rats. METHODS: The contents of ALT, AST, TBiL, and PT time of rats in each group were observed. HE staining was used to detect liver pathology. The levels of oxidative stress indicators such as MDA, GSH, and 4-HNE in the rat liver were detected. TUNEL assay was used to detect apoptosis in rat hepatocytes. Immunofluorescence and western blot analysis were performed to explore the protective effect of Que on ACLF rats and the underlying mechanism. RESULTS: The results showed that Que could reduce the increase of serum biochemical indices, improve liver pathology, and reduce liver damage in ACLF rats. Further results confirmed that Que reduced the occurrence of oxidative stress and apoptosis of hepatocytes, and these reactions may aggravate the progress of ACLF. Meanwhile, the results of immunofluorescence and western blotting also confirmed that the expression of HMGB1 and extranuclear translocation in ACLF rat hepatocytes were significantly increased, which was alleviated by the treatment of Que. In addition, when cotreated with glycyrrhizin (Gly), an inhibitor of HMGB1, the inhibition of Que on HMGB1 and its translocation, apoptosis and oxidative stress, and the related proteins of HMGB1-mediated cellular pathway have been significantly enhanced. CONCLUSION: Thus, Que alleviates liver injury in ACLF rats, and its mechanism may be related to oxidative stress and apoptosis caused by HMGB1 and its translocation.

5.
Front Pharmacol ; 12: 693701, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34512330

RESUMO

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease in China. Sinisan (SNS) is a traditional Chinese medicine formula that has been widely used in treating chronic liver diseases, including NAFLD. However, its underlying biological mechanisms are still unclear. In this study, we employed a network pharmacology approach consisting of overlapped terms- (genes or pathway terms-) based analysis, protein-protein interaction (PPI) network-based analysis, and PPI clusters identification. Unlike the previous network pharmacology study, we used the shortest path length-based network proximity algorithm to evaluate the efficacy of SNS against NAFLD. And we also used random walk with restart (RWR) algorithm and Community Cluster (Glay) algorithm to identify important targets and clusters. The screening results showed that the mean shortest path length between genes of SNS and NAFLD was significantly smaller than degree-matched random ones. Six PPI clusters were identified and ten hub targets were obtained, including STAT3, CTNNB1, MAPK1, MAPK3, AGT, NQO1, TOP2A, FDFT1, ALDH4A1, and KCNH2. The experimental study indicated that SNS reduced hyperlipidemia, liver steatosis, and inflammation. Most importantly, JAK2/STAT3 signal was inhibited by SNS treatment and was recognized as the most important signal considering the network pharmacology part. This study provides a systems perspective to study the relationship between Chinese medicines and diseases and helps to discover potential mechanisms by which SNS ameliorates NAFLD.

6.
Drug Des Devel Ther ; 15: 3845-3862, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34526765

RESUMO

BACKGROUND: Acute-on-chronic liver failure (ACLF) is a severe, complicated human disease. E2F1-mediated apoptosis plays an important role in ACLF development. Jieduan-Niwan (JDNW) formula, a traditional Chinese medicine (TCM), has shown remarkable clinical efficacy in ACLF treatment. However, the hepatoprotective mechanisms of the formula are barely understood. PURPOSE: This study aimed to investigate the mechanisms of JDNW formula in ACLF treatment by specifically regulating E2F1-mediated apoptotic signaling pathways in rats. METHODS: The JDNW components were determined by high-performance liquid chromatography (HPLC) analysis. The ACLF rat model was established using human serum albumin immune-induced liver cirrhosis, followed by D-galactosamine and lipopolysaccharide joint acute attacks. The ACLF rat was treated with JDNW formula. Prothrombin time activity was measured to investigate the coagulation function. Liver pathological injury was observed by hematoxylin-eosin (HE) and reticular fiber staining. The hepatocyte apoptosis index and apoptosis rate were determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and flow cytometry, respectively. Additionally, the expression of key genes and proteins that regulate E2F1-mediated apoptosis was analyzed by quantitative real-time PCR and Western blot. RESULTS: Seven major components of JDNW formula were detected. The formula ameliorated the coagulation function, decreased the hepatocyte apoptosis index and apoptosis rate, and alleviated liver pathological damage in ACLF rats. The down-regulation of the expression of genes and proteins from p53-dependent and non-p53-dependent apoptosis pathways and the up-regulation of the expression of genes from blocking anti-apoptotic signaling pathways indicated that JDNW formula inhibited excessive hepatocyte apoptosis in ACLF rats via E2F1-mediated apoptosis signaling pathways. CONCLUSION: The findings indicate that JDNW formula protects livers of ACLF rats by inhibiting E2F1-mediated apoptotic signaling pathways, implying that these pathways might be a potential therapeutic target for ACLF treatment.


Assuntos
Insuficiência Hepática Crônica Agudizada/tratamento farmacológico , Apoptose/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Hepatócitos/efeitos dos fármacos , Animais , Cromatografia Líquida de Alta Pressão , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/química , Fator de Transcrição E2F1/metabolismo , Citometria de Fluxo , Hepatócitos/patologia , Marcação In Situ das Extremidades Cortadas , Masculino , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos
7.
J Inflamm Res ; 14: 7295-7313, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34992418

RESUMO

BACKGROUND: Acute-on-chronic liver failure (ACLF) is a critical disease with a high fatality rate. Immune dysfunction and inflammatory responses are key risk factors in ACLF. Pyroptosis is a form of programmed cell death characterized by the release of inflammatory cytokines, which causes the strong inflammatory responses. High mobility group box-1 (HMGB1) could induce pyroptosis and is closely related to ACLF. However, the role of HMGB1-induced hepatocyte pyroptosis in ACLF has never been proposed; whether HMGB1-induced hepatocyte pyroptosis participates in the development of ACLF and the mechanisms involved are barely understood. PURPOSE: This study aimed to clarify the roles of HMGB1-induced hepatocyte pyroptosis in ACLF and the molecular mechanisms involved. METHODS: Wistar rats were randomly divided into five groups, viz.: Normal, ACLF model, HMGB1 inhibitor, Caspase-1 inhibitor, and HMGB1 inhibitor+Caspase-1 inhibitor groups. The ACLF rat model was established using 40% carbon tetrachloride-induced liver fibrosis, followed by D-galactosamine and lipopolysaccharide joint acute attacks. The liver function, coagulation function and pathological damage of rats in each group were evaluated. The biological mechanisms of HMGB1-induced pyroptosis and the release of inflammatory cytokines were investigated using Western blot, quantitative real-time PCR (RT-qPCR), immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. RESULTS: The liver function and coagulation function of ACLF rats were seriously impaired; liver tissue showed massive or submassive necrosis, accompanied by inflammatory cell infiltration; the percentage of pyroptotic hepatocytes significantly increased, and a large number of inflammatory cytokines were released. The expression levels of pyroptosis-related genes and proteins in liver tissues and serum significantly increased. But these phenomenons were improved by the inhibition of HMGB1, and the dual inhibition of HMGB1 and Caspase-1 showed a stronger effect. CONCLUSION: The findings indicate, for the first time, that pyroptosis is a crucial pathophysiological event of ACLF involved in its pathogenesis, and HMGB1-induced hepatocyte pyroptosis expands inflammatory responses to aggravate ACLF, suggesting that it may be a potential therapeutic target for ACLF treatment.

8.
Front Pharmacol ; 11: 608, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32431618

RESUMO

High mobility group box-1 (HMGB1) plays an important role in various liver injuries. In the case of acute liver injury, it leads to aseptic inflammation and other reactions, and also regulates specific cell death responses in chronic liver injury. HMGB1 has been demonstrated to be a good therapeutic target for treating liver failure. Quercetin (Que), as an antioxidant, is a potential phytochemical with hepatocyte protection and is also considered to be an inhibitor of HMGB1. However, the mechanism of its hepatoprotective effects remains to be characterized. The present study explored whether the hepatoprotective effect of Que antagonizes HMGB1, and subsequent molecular signaling events. Our results indicated that Que protects L02 cells from d-galactosamine (d-GaLN)-induced cellular damage by reducing intracellular reactive oxygen species (ROS) production and apoptotic responses in the mitochondrial pathway. Immunofluorescence and Western blot assays showed that HMGB1 was involved in d-GaLN-induced L02 cell damage. Further research showed that after transfection with HMGB1 short hairpin RNA (shRNA), cell viability was improved, and intracellular ROS production and apoptosis were suppressed. When co-treated with Que, the expression of HMGB1 was decreased significantly, the expression of proteins in the corresponding signal pathway were further reduced, and the production of ROS and apoptosis were further suppressed. Molecular docking also indicated the binding of Que and HMGB1. Taken together, these results indicate that Que significantly improves d-GaLN-induced cellular damage by inhibiting oxidative stress and mitochondrial apoptosis via inhibiting HMGB1.

9.
Artigo em Inglês | MEDLINE | ID: mdl-33456481

RESUMO

BACKGROUND: Acute-on-chronic liver failure (ACLF) is a clinical syndrome with acute jaundice and coagulation dysfunction caused by various inducements on the basis of chronic liver disease. Western medical treatment is limited. Previous studies have confirmed that Jieduan-Niwan Formula (JDNW Formula), an empirical prescription for the treatment of ACLF, can inhibit inflammation and resist hepatocyte apoptosis. However, potential targets and mechanisms still need to be explored. METHODS: In this study, network pharmacological analysis was performed to investigate the key components and potential mechanisms of JDNW Formula treating ACLF. Firstly, we predicted the potential active ingredients of JDNW Formula and the corresponding potential targets through TCMSP, BATMAN-TCM platform, and literature supplement. Then, the ACLF targets database was built using OMIM, DisGeNET, and GeneCard database. Based on the matching targets between JDNW Formula and ACLF, the PPI network was constructed for MCODE analysis and common targets were enriched by Metascape. Furthermore, the ACLF rat model was used to verify the potential mechanism of JDNW Formula in treating ACLF. RESULTS: 132 potential bioactive components of JDNW Formula and 168 common targets were obtained in this study. The enrichment analysis shows that the AMPK signaling pathway was associated with the treating effects of JDNW Formula. Quercetin was hypothesized to be the key bioactive ingredient in JDNW Formula and has a good binding affinity to AMPK based on molecular docking verification. JDNW Formula and quercetin were verified to treat ACLF by regulating the AMPK/PGC-1α signaling pathway as a prediction. CONCLUSION: The study predicted potential mechanisms of JDNW Formula in the treatment of ACLF, involving downregulation of inflammatory factor expression, antioxidant stress, and inhibition of hepatocyte apoptosis. JDNW Formula may improve mitochondrial quality in ACLF via the AMPK signaling pathway, which serves as a guide for further study.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31827563

RESUMO

Acute-on-chronic liver failure (ACLF) is a serious and complicated disease that threatens human health because its pathogenesis is unclear, and the outcome of the current therapies has been less than satisfactory. A national famous doctor of traditional Chinese medicine, Qian Ying, created the Jieduan-Niwan Formula (JDNW), based on his long-term clinical experience. However, despite the good clinical outcome, the biological mechanism by which it works is unknown. In the current study, we established an ACLF rat model by administering human serum albumin (HSA) combined with D-galactosamine (D-GalN) and lipopolysaccharide (LPS) to explore the potential mechanism of JDNW in treating ACLF. The rats were treated with JDNW by administration of the model substances and sacrificed after 4, 8, and 12 h. Then we divided the rats into normal group, model at 4 h, model at 8 h, model at 12 h, JDNW at 4 h, JDNW at 8 h, and JDNW at 12 h. Biochemical and histopathological examinations were performed to compare the rats in different groups. Compared with the ACLF model group, expression levels of alanine transaminase, aspartate aminotransferase, total bilirubin, and TNF-α and IL-6 proteins were reduced in the JDNW group at the corresponding time points, the survival rates of rats were increased, and the pathological condition of the liver was improved. In addition, JDNW treatment improved the ultrastructure of hepatocytes and mitochondria and decreased the hepatocyte apoptosis index. E2F1, P53, P73, Apaf-1, p14ARF, caspase-3, caspase-6, and caspase-7 levels in the JDNW group were distinctly lower than those in the untreated rats. Moreover, Bcl-2 and Mcl-1 levels increased. Thus, JDNW decreases ACLF-induced mortality in rats by modulating the E2F1-mediated intrinsic apoptotic pathway.

11.
Nanomedicine ; 13(3): 783-793, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28003120

RESUMO

Contrast agent-enhanced magnetic resonance (MR) imaging is critical for the diagnosis and monitoring of a number of diseases, including cancer. Certain clinical applications, including the detection of liver tumors, rely on both T1 and T2-weighted images even though contrast agent-enhanced MR imaging is not always reliable. Thus, there is a need for improved dual mode contrast agents with enhanced sensitivity. We report the development of a nanodiamond-manganese dual mode contrast agent that enhanced both T1 and T2-weighted MR imaging. Conjugation of manganese to nanodiamonds resulted in improved longitudinal and transverse relaxivity efficacy over unmodified MnCl2 as well as clinical contrast agents. Following intravenous administration, nanodiamond-manganese complexes outperformed current clinical contrast agents in an orthotopic liver cancer mouse model while also reducing blood serum concentration of toxic free Mn2+ ions. Thus, nanodiamond-manganese complexes may serve as more effective dual mode MRI contrast agent, particularly in cancer.


Assuntos
Meios de Contraste/análise , Neoplasias Hepáticas/diagnóstico por imagem , Fígado/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Manganês/análise , Nanodiamantes/análise , Animais , Linhagem Celular , Meios de Contraste/administração & dosagem , Meios de Contraste/farmacocinética , Feminino , Humanos , Manganês/administração & dosagem , Manganês/farmacocinética , Camundongos , Nanodiamantes/administração & dosagem
12.
ACS Nano ; 8(12): 12151-66, 2014 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-25437772

RESUMO

Chemoresistance is a primary cause of treatment failure in cancer and a common property of tumor-initiating cancer stem cells. Overcoming mechanisms of chemoresistance, particularly in cancer stem cells, can markedly enhance cancer therapy and prevent recurrence and metastasis. This study demonstrates that the delivery of Epirubicin by nanodiamonds is a highly effective nanomedicine-based approach to overcoming chemoresistance in hepatic cancer stem cells. The potent physical adsorption of Epirubicin to nanodiamonds creates a rapidly synthesized and stable nanodiamond-drug complex that promotes endocytic uptake and enhanced tumor cell retention. These attributes mediate the effective killing of both cancer stem cells and noncancer stem cells in vitro and in vivo. Enhanced treatment of both tumor cell populations results in an improved impairment of secondary tumor formation in vivo compared with treatment by unmodified chemotherapeutics. On the basis of these results, nanodiamond-mediated drug delivery may serve as a powerful method for overcoming chemoresistance in cancer stem cells and markedly improving overall treatment against hepatic cancers.


Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Epirubicina/química , Epirubicina/farmacologia , Neoplasias Hepáticas/patologia , Nanodiamantes/química , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Transporte Biológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Epirubicina/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Modelos Moleculares , Conformação Molecular , Células-Tronco Neoplásicas/metabolismo , Tamanho da Partícula , Proteínas/química , Propriedades de Superfície
13.
Mol Pharm ; 11(8): 2683-91, 2014 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-24867631

RESUMO

Chemoresistance is a prevalent issue that accounts for the vast majority of treatment failure outcomes in metastatic cancer. Among the mechanisms of resistance that markedly decrease treatment efficacy, the efflux of drug compounds by ATP-binding cassette (ABC) transporter proteins can impair adequate drug retention by cancer cells required for therapeutic cytotoxic activity. Of note, ABC transporters are capable of effluxing several classes of drugs that are clinical standards, including the anthracyclines such as doxorubicin, as well as anthracenediones such as mitoxantrone. To address this challenge, a spectrum of nanomaterials has been evaluated for improved drug retention and enhanced efficacy. Nanodiamonds (NDs) are emerging as a promising nanomaterial platform because they integrate several important properties into a single agent. These include a uniquely faceted truncated octahedral architecture that enables potent drug binding and dispersibility in water, scalably processed ND particles with uniform diameters of approximately 5 nm, and a demonstrated ability to improve drug tolerance while delaying tumor growth in multiple preclinical models, among others. This work describes a ND-mitoxantrone complex that can be rapidly synthesized and mediates marked improvements in drug efficacy. Comprehensive complex characterization reveals a complex with favorable drug delivery properties that is capable of improving drug retention and efficacy in an MDA-MB-231-luc-D3H2LN (MDA-MB-231) triple negative breast cancer cell line that was lentivirally transduced for resistance against mitoxantrone. Findings from this study support the further evaluation of ND-MTX in preclinical dose escalation and safety studies toward potentially clinical validation.


Assuntos
Sistemas de Liberação de Medicamentos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Mitoxantrona/química , Nanodiamantes/química , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Sobrevivência Celular , Feminino , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Luz , Mitoxantrona/administração & dosagem , Proteínas de Neoplasias/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Espalhamento de Radiação , Solubilidade
14.
J Colloid Interface Sci ; 362(2): 629-32, 2011 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-21774943

RESUMO

Polyethylene films were prepared with phase separation at lower temperatures. The wettability of such films varied from hydrophobicity to superhydrophobicity as the processing temperature decreased owing to the increase of surface roughness. Storing the as-prepared films at subzero temperature (-15 °C), it was found that the water contact angle of the film decreased obviously, and the decrease depended on the corresponding roughness. Further keeping the as-prepared films at room temperature for 30 min, the water contact angle would return to the normal value, which indicated that the reversible switching of surface wettability can be controlled by the environmental temperature.

15.
Langmuir ; 25(12): 6875-9, 2009 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-19388630

RESUMO

Hydrophilic titania (TiO(2)) nanoparticles were dispersed in solutions of polystyrene (PS), and the suspensions were cast on glass surfaces. The effect of drying temperature on the hydrophobic character of PS/TiO(2) was investigated: the static water contact angle increased with the drying temperature, and the as-prepared coating could be adjusted from superhydrophilicity to superhydrophobicity just by controlling the drying temperature. Moreover, the superhydrophobic coating turning into a superhydrophilic one (CA < 5 degrees ) after UV illumination, which can be recovered through being heated.

16.
J Colloid Interface Sci ; 333(1): 400-3, 2009 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-19232634

RESUMO

A stable polytetrafluoroethylene superhydrophobic surface is prepared with filter paper which is first used as a template. Scanning electron microscope image shows a lotus-leaf like structure appears on the polytetrafluoroethylene surface. Altering the sintering temperature, the microstructure of the as-prepared surface also varied. After treating 12 h in acid, alkali or organic solvents, the as-prepared surface still retains superhydrophobicity and shows excellent stability.

17.
J Colloid Interface Sci ; 327(1): 120-4, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18755474

RESUMO

A polypropylene/methyl-silicone superhydrophobic surface was prepared using a simple casting method. Varying the ratio of polypropylene and methyl-silicone results in different surface microstructure. The wetting behavior of the as-prepared surface was investigated. A polypropylene monolithic material was also prepared. Its superhydrophobicity still retains when the material was cut or abraded. The as-prepared material can also be used to separate some organic solvents from water.

18.
J Colloid Interface Sci ; 316(1): 206-9, 2007 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17714723

RESUMO

A SiO(2)-polystyrene (PS) nanocomposite surface was prepared with a simple method. The wetting behavior of the as-prepared surface was investigated. It was found that the as-prepared surface could be varied from superhydrophilicity to superhydrophobicity just by controlling the drying temperature and the content of SiO(2) nanoparticles in the system. In addition, a transition from the Wenzel regime to the Cassie regime was observed.

19.
Langmuir ; 23(19): 9695-8, 2007 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-17691747

RESUMO

A methylsilicone/phenolic resin/silica composite surface was prepared by a casting method. The wetting behavior of the surface was investigated. It was found that the as-prepared surface can be varied from superhydrophilicity to superhydrophobicity as the drying temperature increased. Methylsilicone/silica and phenolic resin/silica composite surfaces were also prepared as comparisons. Both of them cannot achieve superhydrophobicity. A mechanism was proposed to explain this phenomenon.

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