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1.
J Nanosci Nanotechnol ; 20(2): 673-679, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383062

RESUMO

A proper soft tissue seal between implants and gingiva is critical for success of dental implants. Implant surface modification is an important approach for achieving ideal host-implant integration. In this study, we used a new and simple oxidation method to generate a rough surface on implants at the nano scale, which oxidized titanium nano-foveolae (TiNF) surface. We further analyzed the surface topography and tested its effects on biological activities of human gingival fibroblasts. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) examination demonstrated that TiNF disks displayed uniform rough surfaces, with average TiNF diameters of approximately 60 nm and 100 nm respectively. However, the surfaces of smooth samples were highly irregular, and cell adhesion and proliferation rates on TiNF surfaces were significantly higher than those of the smooth surfaces. Extracellular matrix synthesis was also increased in the cells that interacted with oxidized TiNF surfaces. Altogether, these results suggest that the TiNF implant surfaces perform better for human gingival fibroblast biological activities compared to traditional smooth surfaces. Therefore, the TiNF implant surfaces may serve as ideal interface to facilitate implant-host integration.

2.
Sci Rep ; 9(1): 9818, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31285493

RESUMO

The combustible gas produced by coal pyrolysis can be used as a clean fuel to reduce environmental pollution caused by coal combustion. In order to improve the efficiency of coal pyrolysis to prepare flammable gases, Ni-Co supported pyrolysis catalysts were prepared by equal volume impregnation method using the pyrolysis coke of different pyrolysis final temperatures as the carrier in this study. The effects of different pyrolysis final temperatures and different metal loadings on pyrolysis products were studied. The cracking mechanism of the catalysts was characterized by BET, XRD, XPS and SEM. The results show that: (1) the catalytic efficiency of pyrolysis coke catalyst is mainly related to the metal type and loading of the additive. (2) The optimum preparation conditions for the supported catalyst are: use pyrolysis coke with 750 °C final pyrolysis temperature as the carrier, the loading amount of Ni is 5%, and the loading amount of Co is 8%.

3.
Cell Signal ; 62: 109348, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31233841

RESUMO

The neuropeptide orexin-A (OXA) has a neuroprotective effect, acting as an anti-apoptotic factor in response to multiple stimuli. Apoptosis induced by endoplasmic reticulum stress (ERS) underlies oxygen-glucose deprivation and reoxygenation (OGD/R)-induced cell damage, an in vitro model of ischemia/reperfusion injury. However, that OXA inhibits ERS-induced apoptosis in the OGD/R model has not been reported. In the present study, we investigated the neuroprotective effect of OXA (0.1 µM) on OGD/R-induced damage in the human neuroblastoma cell line SH-SY5Y. After OXA treatment following 4 h oxygen-glucose deprivation (OGD) and then 4 h reoxygenation (R), cell morphology, viability, and apoptosis were analyzed by histology, Cell Counting Kit-8 assay, and flow cytometry, respectively. Western blotting was used to measure expression levels of ERS- and apoptosis-related proteins. To determine signaling pathways involved in OXA-mediated neuroprotection, the Gi pathway inhibitor pertussis toxin (PTX; 100 ng/mL) and PI3K inhibitor LY294002 (LY; 10 µM) were added. In addition, in order to prove the specificity of these characteristics, the OXA antagonist Suvorexant (DORA; Ki of 0.55 nM and 0.35 nM for OX1R and OX2R) was used for intervention. Our results showed that OGD/R induced cell damage, manifested as morphological changes and a significant decrease in viability. Furthermore, Western blotting detected an increase in ERS-related proteins GRP78, p-IRE1α, p-JNK, and Cleaved caspase-12, as well as apoptosis-related proteins Cleaved caspase-3 and Bax, and a decrease in the anti-apoptosis factor Bcl-2. OXA intervention alleviated the degree of cellular damage, and protein expression was also reversed. In addition, the protective effect of OXA was reduced by adding PTX and LY. Meanwhile, after the use of DORA, changes in the expression of related proteins were detected, and it was found that the protective effect of OXA was weakened. Collectively, our results indicate that OXA has a neuroprotective effect on OGD/R-induced cell damage by inhibiting ERS-induced apoptosis through the combined action of Gi and PI3K signaling pathways. These findings help to clarify the mechanism underlying the neuroprotective action of OXA, which should aid the development of further candidate drugs, and provide a new therapeutic direction for the treatment of ischemic stroke.

4.
Cell Prolif ; 52(3): e12586, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30997713

RESUMO

OBJECTIVES: This study aimed at investigating cellular uptake pathways of carbon dots (CDs) in human adenoid cystic carcinoma cell line ACC-2. MATERIALS AND METHODS: We synthesized CDs using a hydrothermal method with citric acid and polyethylenimine (PEI, Mw = 25 000). The CDs incubated with the ACC-2 cells showed their bioimaging capabilities using a confocal microscopy test. Flow cytometry was used to analyse cellular uptake pathways of CDs in ACC-2 cells. RESULTS: Our findings indicated that CDs possessed good biocompatibility in ACC-2 cells. CDs were endocytosed mainly via micropinocytosis and energy-dependent pathways. CONCLUSIONS: In general, these findings suggested that CDs had excellent biomedical imaging properties for ACC-2 cells and there was a potential opportunity to develop biomedical applications.


Assuntos
Carbono , Carcinoma Adenoide Cístico/fisiopatologia , Endocitose , Nanopartículas , Neoplasias das Glândulas Salivares/fisiopatologia , Transporte Biológico Ativo , Carcinoma Adenoide Cístico/diagnóstico por imagem , Linhagem Celular Tumoral , Humanos , Cinética , Microscopia Confocal , Neoplasias das Glândulas Salivares/diagnóstico por imagem
5.
Sci Rep ; 9(1): 5659, 2019 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-30948734

RESUMO

A series of Ti/Li/Al ternary layered double hydroxides (TiLiAl-LDHs) with different Ti:Li:Al molar ratios were prepared by a coprecipitation method for photocatalytic CO2 reduction. It was demonstrated that the contents of anions between the layers of Ti/Li/Al-LDHs greatly determined the photocatalytic activity for CO2 reduction. With Ti:Li:Al molar ratios optimized to be 1:3:2, the largest contents of [Formula: see text]- anion and hydroxyl group were obtained for the Ti1Li3Al2-LDHs sample, which exhibited the highest photocatalytic activity for CO2 reduction, with CH4 production rate achieving 1.33 mmol h-1 g-1. Moreover, the theoretical calculations show that Ti1Li3Al2-LDHs is a p-type semiconductor with the narrowest band gap among all the obtained TiLiAl-LDHs. After calcined at high temperatures such as 700 °C, and the obtained TiLiAl-700 sample showed much increased photocatalytic activity for CO2 reduction, with CH4 production rate reaching about 1.59 mmol h-1 g-1. This calcination induced photocatalytic enhancement should be related to the cystal structure transformation from hydrotalcite to mixed oxides containing high reactive oxygen species for more efficient CO2 reduction.

6.
Small ; 15(32): e1900772, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30977981

RESUMO

Artificial photosynthesis for solar water splitting and CO2 reduction to produce hydrogen and hydrocarbon fuels has been considered as one of the most promising ways to solve increasingly serious energy and environmental problems. As a well-documented metal-free semiconductor, polymeric carbon nitride (PCN) has been widely used and intensively investigated for photocatalytic water splitting and CO2 reduction, owing to its physicochemical stability, visible-light response, and facile synthesis. However, PCN as a photocatalyst still suffers from the fast recombination of electron-hole pairs and poor water redox reaction kinetics, greatly restricting its activity for artificial photosynthesis. Among the various modification approaches developed so far, decorating PCN with metals in different existences of nanoparticles, single atoms and molecular complexes, has been evidently very effective to overcome these limitations to improve photocatalytic performances. In this Review article, a systematic introduction to the state-of-the-art metal/PCN photocatalyst systems is given, with metals in versatility of nanoparticles, single atoms, and molecular complexes. Then, the recent processes of the metal/PCN photocatalyst systems in the applications of artificial photosynthesis, e.g., water splitting and CO2 reduction, are reviewed. Finally, the remaining challenges and opportunities for the development of high efficiency metal/PCN photocatalyst systems are presented and prospected.

7.
J Zhejiang Univ Sci B ; 20(3): 287-290, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30829016

RESUMO

To further enrich the genetic data of the Chinese Xinjiang Mongolian group, the genetic distribution and forensic parameters of 19 autosomal short tandem repeats (STRs) were investigated. Altogether, 249 alleles were observed in these 19 STRs. The mean values of the polymorphism information content (PIC), match probability (MP), discrimination power (DP), and probability of exclusion (PE) for these 19 STRs were 0.7775, 0.0699, 0.9301, and 0.6085, respectively. Additionally, the cumulative DP and PE values obtained in the Mongolian group were 0.999 999 999 999 999 999 999 995 67 and 0.999 999 992 163, respectively. Furthermore, population genetic analysis of the Mongolian group and 20 published populations was conducted based on the population data of 15 overlapping STRs. Genetic distances indicated that the Mongolian group had closer genetic similarities with the Uyghur, Xibe, and other Chinese populations rather than the other continental populations. Multidimensional scaling analysis further revealed that the Mongolian group possessed similar genetic distributions as most Chinese populations. To sum it all up, these STRs could be used as an extremely efficient tool for forensic applications in the Xinjiang Mongolian group.


Assuntos
Grupo com Ancestrais do Continente Asiático/genética , Marcadores Genéticos , Repetições de Microssatélites , Alelos , China , Impressões Digitais de DNA , Bases de Dados Genéticas , Grupos Étnicos/genética , Frequência do Gene , Genética Populacional , Genoma Humano , Humanos , Desequilíbrio de Ligação , Mongólia , Polimorfismo Genético , Análise de Componente Principal , Probabilidade , Software
8.
Cell Prolif ; 51(5): e12488, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30039515

RESUMO

OBJECTIVES: Carbon dots (CDs) are one of the most promising carbon-based materials in bioimaging and drug/gene delivery applications. In this study, we have attempted to study the drug carrying capacity of highly fluorescent CDs for delivery of doxorubicin (DOX) and investigate the therapeutic activity of the CDs-DOX drug delivery system. MATERIALS AND METHODS: Carbon dots were synthesized by means of a hydrothermal approach with mixing citric acid and ethylenediamine. The properties of CDs were characterized in respects of spectral property, zeta potential, particle morphology and chemical composition. The drug loading efficiency (DLE) and release profile of CDs-DOX were determined by a fluorescence spectrophotometer. We investigated the cellular toxicity and pharmaceutical activity of CDs and CDs-DOX in L929 cells and MCF-7 cells by the CCK-8 assay. We also studied the cellular uptake of CDs-DOX with the methods of confocal microscopy and flow cytometry. In addition, the effect of CDs-DOX on cell apoptosis was assessed by flow cytometry. RESULTS: The obtained CDs possessed good biocompatibility and showed a potential capacity of promoting proliferation. DOX was successfully conjugated to CDs through electrostatic interaction, and the results of the DLE and loading content (DLC) suggested a relatively high drug loading capacity of CDs. Compared with free DOX, the CDs-DOX complex had a higher cellular uptake and better anti-tumour efficacy on MCF-7 cells. CONCLUSIONS: The results of this study indicated that the CDs-DOX drug delivery system had a potential value in cancer chemotherapeutic application.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Carbono/farmacologia , Doxorrubicina/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/métodos , Feminino , Corantes Fluorescentes/farmacologia , Humanos , Células MCF-7
9.
Sci Rep ; 8(1): 11054, 2018 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-30038288

RESUMO

In recent years, deletion and insertion polymorphisms (DIPs) were treated as a novel complementary tool with huge potential for forensic applications. In this study, we utilized 30 DIP loci to make a comprehensive research of allele frequency distribution and compute forensic parameters to evaluate the efficiency of forensic applications in the 295 unrelated healthy individuals of Kyrgyz group, and in addition, infer the genetic relationships between Kyrgyz group and 24 other previously studied groups. No significant departures from Hardy-Weinberg equilibrium and linkage disequilibrium were observed at these 30 DIP loci. The combined power of discrimination and the combined probability of exclusion for all 30 DIP loci in Kyrgyz group were 0.9999999999989 and 0.9939, respectively. Furthermore, the results of the interpopulation differentiations, phylogenetic reconstruction, population genetic structure and principal component analyses suggested that Kyrgyz group had relatively close genetic relationships with Kazakh and Uygur groups. However, it was also important to stress that 15 loci were selected out from these 30 DIP loci using the method of selecting ancestry markers, which could be utilized for further ancestry inference study relatively.

10.
Int J Legal Med ; 132(3): 729-731, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29134366

RESUMO

Allelic frequencies and genetic polymorphisms of 19 short tandem repeats loci were investigated so as to provide more genetic data for forensic applications in Chinese Uzbek group; besides, we evaluated phylogenetic relationships of Uzbek group with other populations. All loci were observed to conform to Hardy-Weinberg equilibrium after Bonferroni's correction. Two hundred and nine alleles were identified in 212 unrelated healthy Uzbek individuals and their allelic frequencies ranged from 0.0024 to 0.5259. The cumulative discrimination power and cumulative probability of exclusion were 0.999999999999999999999996501 and 0.999999998759, respectively. The results of population differentiation comparison, principal component analysis, and phylogenetic tree revealed that Uzbek group had close relationships with Uyghur and Kazakh groups.


Assuntos
Grupos Étnicos/genética , Genética Populacional , China/etnologia , Impressões Digitais de DNA , Frequência do Gene , Humanos , Repetições de Microssatélites , Filogenia , Polimorfismo Genético
11.
Oncotarget ; 8(43): 73837-73845, 2017 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-29088750

RESUMO

We investigated the allelic frequencies and forensic descriptive parameters of 23 autosomal short tandem repeat loci in a randomly selected sample of 1218 unrelated healthy Uyghur individuals residing in the Xinjiang Uyghur Autonomous Region, northwest China. A total of 281 alleles at these loci were identified and their corresponding allelic frequencies ranged from 0.0004 to 0.5390. The combined match probability and combined probability of exclusion of all loci were 5.192 × 10-29 and 0.9999999996594, respectively. The results of population genetic study manifested that Uyghur had close relationships with those contiguous populations, such as Xibe and Hui groups. In a word, these autosomal short tandem repeat loci were highly informative in Uyghur group and the multiplex PCR system could be used as a valuable tool for forensic caseworks and population genetic analysis.

12.
Oncotarget ; 8(34): 56651-56658, 2017 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-28915619

RESUMO

In the present study, we assessed the genetic diversities of the Chinese Kazak ethnic group on the basis of 30 well-chosen autosomal insertion and deletion loci and explored the genetic relationships between Kazak and 23 reference groups. We detected the level of the expected heterozygosity ranging from 0.3605 at HLD39 locus to 0.5000 at HLD136 locus and the observed heterozygosity ranging from 0.3548 at HLD39 locus to 0.5283 at HLD136 locus. The combined power of discrimination and the combined power of exclusion for all 30 loci in the studied Kazak group were 0.999999999999128 and 0.9945, respectively. The dataset generated in this study indicated the panel of 30 InDels was highly efficient in forensic individual identifcation but may not have enough power in paternity cases. The results of the interpopulation differentiations, PCA plots, phylogenetic trees and STRUCTURE analyses showed a close genetic affiliation between the Kazak and Uigur group.

13.
Bioorg Med Chem ; 25(15): 4123-4132, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28629630

RESUMO

As a continuous research for the discovery of coumarin-based targeted anticancer agents, we designed and synthesized a series of novel histone deacetylases (HDAC) inhibitors using the 8-ethoxy-3-nitro-2H-chromene as the surface binding or cap group, linear dicarboxylic acid or ω-amino acid moiety with different length as the linking motif, ortho-aminoanilides, amides or α-aminoamides as the zinc binding group and the internal cavity motifs. Most of these 3-nitro-2H-chromene derivatives exhibited good growth inhibitory activity against K562, A549, MCF-7, PC3 and Hela cells and were more potent than the reference drug SAHA and MS-275. At the concentration of 10µM, the ortho-aminoanilide series and the d-Phe derived α-aminoamide derivatives 16a and 16b displayed more potent activity toward HADC1 over HADC2, and only moderate to weak activity over HADC6. In contrast, the amide ZBG analogues, 12a and 12b, 14 and 15, were only moderate HDAC6 inhibitors, but more selective over HDAC1 and HDAC2. The ortho-aminoanilides 9b, 9c, 10b, 10c, 11b, and the α-aminoamides 16a and 16b were potent HADC1 inhibitors with the IC50 values in the nanomolar ranges. The ortho-aminoanilides 10b and10c with a phenyl internal cavity motif were more potent than MS-275 as HADC1 inhibitors and more selective over HADC2.


Assuntos
Benzopiranos/química , Benzopiranos/farmacologia , Desenho de Drogas , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/farmacologia , Benzopiranos/síntese química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores de Histona Desacetilases/síntese química , Humanos , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray
14.
DNA Cell Biol ; 35(12): 787-794, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27828728

RESUMO

In recent years, Insertion/Deletion (InDel) polymorphisms have become a hot area of forensic research. In this study, 30 InDel loci were selected to investigate the genetic polymorphisms of Tibetan groups, which are from Tibet Autonomous Region and Qinghai province of China, and explore the genetic relationships between Tibetan groups and other groups. Allele frequencies of the 30 InDel loci ranged from 0.1219 (HLD111) to 0.5609 (HLD57) in the Tibet Tibetan group and 0.1639 (HLD118) to 0.5655 (HLD124) in the Qinghai Tibetan group. The combined power of discrimination, matching probability, and power of exclusion were 0.999999999986, 0.999999988, and 0.9913 in the Tibet Tibetan group, respectively, and 0.99999999999204, 0.9999999796, and 0.9862 in the Qinghai Tibetan group. The results of principal component analysis, phylogenetic tree, and population structure demonstrated that the four Tibetan groups (Tibetan1, Tibetan2, Tibet, and Qinghai Tibetan groups) clustered together and had relatively close genetic relationships with nine Asian groups and then European and Amerindian groups.


Assuntos
Grupo com Ancestrais do Continente Asiático/genética , Grupos Étnicos/genética , Loci Gênicos , Genoma Humano , Mutação INDEL , Filogenia , Alelos , China , Genética Forense , Frequência do Gene , Humanos , Filogeografia , Polimorfismo Genético
15.
PLoS One ; 11(9): e0158233, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27662186

RESUMO

During eating, the teeth usually endure the sharply temperature changes because of different foods. It is of importance to investigate the heat transfer and heat dissipation behavior of the dentino-enamel junction (DEJ) of human tooth since dentine and enamel have different thermophysical properties. The spatial and temporal temperature distributions on the enamel, dentine, and pulpal chamber of both the human tooth and its discontinuous boundaries, were measured using infrared thermography using a stepped temperature increase on the outer boundary of enamel crowns. The thermal diffusivities for enamel and dentine were deduced from the time dependent temperature change at the enamel and dentine layers. The thermal conductivities for enamel and dentine were calculated to be 0.81 Wm-1K-1 and 0.48 Wm-1K-1 respectively. The observed temperature discontinuities across the interfaces between enamel, dentine and pulp-chamber layers were due to the difference of thermal conductivities at interfaces rather than to the phase transformation. The temperature gradient distributes continuously across the enamel and dentine layers and their junction below a temperature of 42°C, whilst a negative thermal resistance is observed at interfaces above 42°C. These results suggest that the microstructure of the dentin-enamel junction (DEJ) junction play an important role in tooth heat transfer and protects the pulp from heat damage.

16.
Bioorg Med Chem Lett ; 23(11): 3314-9, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23601711

RESUMO

The small chemical compound 8-ethoxy-2-(4-fluorophenyl)-3-nitro-2H-chromene (S14161) was recently identified as an inhibitor of the phosphoinositide 3-kinase (PI3K). In the present study, we designed a novel synthesis of S14161 and prepared a series of its analogues via the oxa-Michael-Henry reaction in the presence of catalytic amounts of l-proline and triethylamine. Further structural simplification led to the identification of 6-bromo-8-ethoxy-3-nitro-2H-chromene (BENC-511) that exhibited potent antiproliferative activities against a panel of 12 tumor cell lines. Compared with S14161, BENC-511 was more potent in blocking the AKT phosphorylation and inducing cancer cell apoptosis. BENC-511 also displayed more potent effects on human umbilical vein epithelial cells (HUVEC) migration, suggesting its anti-angiogenesis activity.


Assuntos
Antineoplásicos/síntese química , Benzopiranos/química , Benzopiranos/síntese química , Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Antineoplásicos/química , Antineoplásicos/toxicidade , Benzopiranos/farmacologia , Sítios de Ligação , Catálise , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais , Células Endoteliais da Veia Umbilical Humana , Humanos , Simulação de Acoplamento Molecular , Neovascularização Fisiológica/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Piperazinas/química , Prolina/química , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-akt/metabolismo
17.
Curr Med Chem ; 20(15): 1997-2016, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23317165

RESUMO

Rheumatoid arthritis (RA) and other chronic inflammatory diseases are always the major therapeutic challenges. Recent research efforts provided new insights into the molecular basis of these diseases and new opportunities for developing improved anti-inflammatory drugs. The p38 mitogen-activated protein (MAP) kinase plays a central role in the regulation of the biosynthesis and release of several proinflammatory cytokines including tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1ß). Hence, inhibition of the p38 MAP kinase is regarded as a promising therapeutic strategy for controlling inflammatory diseases. A diverse range of p38α MAP kinase inhibitors have been developed as potential anti-inflammatory agents, and some of them have entered the phase II clinical trials. The imidazole derivatives are known as competitive inhibitors at the ATP binding site of the p38α MAP kinase. Modifications on the imidazole scaffold have led to a large amount of potent p38α MAP kinase inhibitors. This review will summarize the developments of small molecule p38α MAP kinase inhibitors based on the imidazole core scaffolds in recent 10 years. Variations at the N1, C2, C4 and C5 positions of imidazole were introduced, and the structure-activity relationships of these imidazole inhibitors were also discussed.


Assuntos
Anti-Inflamatórios/química , Artrite Reumatoide/tratamento farmacológico , Imidazóis/química , Proteína Quinase 14 Ativada por Mitógeno/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Bibliotecas de Moléculas Pequenas/química , Animais , Anti-Inflamatórios/farmacologia , Artrite Reumatoide/enzimologia , Descoberta de Drogas , Humanos , Imidazóis/farmacologia , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Relação Estrutura-Atividade
18.
Colloids Surf B Biointerfaces ; 79(1): 291-7, 2010 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-20462745

RESUMO

To investigate the effect of protein surface-density gradient on the motility of endothelial cells, we developed a novel approach for the fabrication of a collagen density gradient onto poly(d, l-lactic acid) (PDLLA) films in this study. The approach involves a sequential alkali hydrolysis of PDLLA films to produce a density gradient of -COOH moieties onto the films, which were activated and then covalently linked with collagen. A collagen surface-density gradient onto PDLLA films was thus generated by this approach. Contact angle measurement and confocal laser scanning microscopy (CLSM) were employed to confirm the formation of -COOH gradient and collagen gradient, respectively. All results proved the feasibility of the fabrication of a collagen density gradient onto PDLLA films via the approach. Endothelial cells cultured on the gradient areas with low and moderate collagen surface-densities displayed a strong motility tendency, with the values such as net displacement, total distance, chemotactic index, migration rate and cell trajectories in parallel to the gradient. However, endothelial cells grew on the gradient area with high collagen density demonstrated a reverse response to the collagen gradient clue. These results suggest that cell motility is regulated by the collagen gradient with a surface-density dependent manner. This study provides an alternative for the fabrication of protein surface-density gradient onto biodegradable substrates to investigate chemical stimuli induced cell directional motility. It is potentially important for understanding the controlled angiogenesis for implantation of tissue-engineered constructs.


Assuntos
Movimento Celular/fisiologia , Colágeno/química , Células Endoteliais/fisiologia , Ácido Láctico/química , Polímeros/química , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Colágeno/metabolismo , Citoesqueleto/metabolismo , Células Endoteliais/citologia , Feminino , Humanos , Membranas Artificiais , Microscopia Confocal , Poliésteres , Propriedades de Superfície , Veias Umbilicais/citologia
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