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1.
Opt Express ; 30(3): 4424-4433, 2022 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-35209680

RESUMO

High performance and cost-effective solar absorbers are crucial for various optical applications, such as solar collection and thermophotovoltaic devices. This study designs and experimentally demonstrates a wide-angle and broadband solar absorber. The proposed absorber is composed of tapered polyimide substrate and Al-Cr-SiO2-Cr-SiO2 thin-film based on the optical interference of the multilayer thin film and excited magnetic resonance of light-trapping structures. The composite process of the colloidal lithography method and magnetron sputtering is employed for efficient fabrication in a large area. The average absorbance is more than 93% from 300 nm to 2500 nm and shows an angular tolerance of up to 60°. The high efficiency and large-area fabrication capability demonstrated by the proposed solar absorber presents future application potential in flexible solar collection devices.

2.
Mol Biol Rep ; 49(1): 341-349, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34727292

RESUMO

BACKGROUND: Hepatic ischemia-reperfusion injury (I/R) is an important factor affecting the prognosis of patients undergoing liver surgery. This study aimed to explore the value of intravenous immunoglobulin (IVIG) in hepatic I/R and its mechanism in a rat model. MATERIALS AND METHODS: Forty eight adult male Sprague-Dawley (SD) rats were divided into six groups randomly: (1-2) treated with normal saline (NS) without ischemia or reperfusion; (3-4) treated with NS + 30 min ischemia; (5-6) treated with IVIG + 30 min ischemia. Rats of group 1/3/5 were euthanized at 12 h after operation (sham + NS + 12 h, I/R + NS + 12 h, I/R + IVIG + 12 h group) while group 2/4/6 were euthanized at 24 h (sham + NS + 24 h, I/R + NS + 24 h, I/R + IVIG + 24 h group). Interleukin 10 (IL-10), interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) were quantified as well as serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Hepatic pathological changes were observed while nuclear factor kappa B p65 (NF-κB p65), Inhibitory Subunit of NF Kappa B Alpha (IKB-alpha) and cleaved caspase-3 were detected. CONCLUSION: ALT, AST, IL-6, TNF-alpha, NF-κB p65 and cleaved caspase-3 were increased by I/R whereas IL-10 and IKB-alpha were decreased. However, IVIG pretreatment reduced ALT, AST, IL-6, TNF-alpha, NF-κB p65 and cleaved caspase-3, but increased IL-10 and IKB-alpha. IVIG treatment attenuates the infiltration of inflammatory cell and cell apoptosis which were observed in I/R groups. IVIG may alleviate hepatic I/R in rats by inhibiting the classical NF-κB signaling pathway, reducing IL-6, TNF-alpha, promoting IL-10, and inhibiting cell apoptosis.


Assuntos
Anti-Infecciosos/administração & dosagem , Imunoglobulinas Intravenosas/administração & dosagem , Hepatopatias/tratamento farmacológico , Traumatismo por Reperfusão/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Alanina Transaminase/sangue , Animais , Anti-Infecciosos/farmacologia , Aspartato Aminotransferases/sangue , Regulação da Expressão Gênica/efeitos dos fármacos , Imunoglobulinas Intravenosas/farmacologia , Interleucina-10/sangue , Interleucina-6/sangue , Hepatopatias/sangue , Hepatopatias/etiologia , Hepatopatias/imunologia , Masculino , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/sangue , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/imunologia , Resultado do Tratamento , Fator de Necrose Tumoral alfa/sangue
3.
Int J Mol Sci ; 23(9)2022 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-35563669

RESUMO

BACKGROUND: Capsaicin, the hot pepper agent, produces burning followed by desensitization. To treat localized itch or pain with minimal burning, low capsaicin concentrations can be repeatedly applied. We hypothesized that alternatively controlled release of capsaicin from poly(lactic-co-glycolic acid) (PLGA) nanoparticles desensitizes superficially terminating nociceptors, reducing burning. METHODS: Capsaicin-loaded PLGA nanoparticles were prepared (single-emulsion solvent evaporation) and characterized (size, morphology, capsaicin loading, encapsulation efficiency, in vitro release profile). Capsaicin-PLGA nanoparticles were applied to murine skin and evaluated in healthy human participants (n = 21) for 4 days under blinded conditions, and itch and nociceptive sensations evoked by mechanical, heat stimuli and pruritogens cowhage, ß-alanine, BAM8-22 and histamine were evaluated. RESULTS: Nanoparticles (loading: 58 µg capsaicin/mg) released in vitro 23% capsaicin within the first hour and had complete release at 72 h. In mice, 24 h post-application Capsaicin-PLGA nanoparticles penetrated the dermis and led to decreased nociceptive behavioral responses to heat and mechanical stimulation (desensitization). Application in humans produced a weak to moderate burning, dissipating after 3 h. A loss of heat pain up to 2 weeks was observed. After capsaicin nanoparticles, itch and nociceptive sensations were reduced in response to pruritogens cowhage, ß-alanine or BAM8-22, but were normal to histamine. CONCLUSIONS: Capsaicin nanoparticles could be useful in reducing pain and itch associated with pruritic diseases that are histamine-independent.


Assuntos
Capsaicina , Nanopartículas , Animais , Capsaicina/farmacologia , Glicóis , Histamina , Temperatura Alta , Humanos , Camundongos , Dor/tratamento farmacológico , Prurido/induzido quimicamente , Prurido/tratamento farmacológico , beta-Alanina
4.
Adv Funct Mater ; 30(14)2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32440263

RESUMO

Breast cancer brain metastases (BCBMs) represent a major cause of morbidity and mortality among patients with breast cancer. Chemotherapy, which is widely used to treat tumors outside of the brain, is often ineffective on BCBMs due to its inability to efficiently cross the blood-brain barrier (BBB). Although the BBB is partially disrupted in tumor lesions, it remains intact enough to prevent most therapeutics from entering the brain. Here, we report a nanotechnology approach that can overcome the BBB through synthesis of lexiscan-loaded, AMD3100-conjugated, shrinkable NPs, or LANPs. LANPs respond to neutrophil elastase-enriched tumor microenvironment by shrinking in size and disrupt the BBB in tumors through lexiscan-mediated modulation. LANPs recognize tumor cells through the interaction between AMD3100 and CXCR4, which are expressed in metastatic tumor cells. We demonstrate that the integration of tumor responsiveness, tumor targeting, and BBB penetration enables LANPs to penetrate metastatic lesions in the brain with high efficiency, and, when doxorubicin was encapsulated, LANPs effectively inhibited tumor growth and prolonged the survival of tumor-bearing mice. Due to their high efficiency in penetrating the BBB for BCBMs treatment, LANPs have the potential to be translated into clinical applications for improved treatment of patients with BCBMs.

5.
Mol Pharm ; 17(4): 1343-1351, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32150416

RESUMO

Breast cancer is the most common type of cancer in women. About 12% of all women in the United States will be diagnosed with breast cancer over their lifetimes. At the same time, incidences of brain metastases (BMs) are increasing and represent an emerging health threat. However, there is no effective chemotherapy for breast cancer brain metastases (BCBMs), which is largely due to lack of efficient delivery of antitumor drugs or drug combinations to the brain. In this study, oleanolic acid (OA), a natural pentacyclic triterpenoid compound with excellent antitumor activity, was found to form nanoparticles (NPs) and efficiently penetrate the brain for BCBMs treatment. On the basis of these findings, we developed a synergistic combinatorial chemotherapeutic regimen by formulating paclitaxel (PTX) into OA NPs and demonstrated that the resulting PTX-OA NPs effectively inhibited primary breast cancer and BCBMs in mouse xenografts. Collectively, this study introduces a new direction to treat primary breast cancer and BCBMs through noninvasive combination chemotherapy.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias da Mama/tratamento farmacológico , Nanopartículas/química , Ácido Oleanólico/farmacologia , Paclitaxel/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Linhagem Celular Tumoral , Sinergismo Farmacológico , Feminino , Humanos , Camundongos , Camundongos Nus
6.
Int J Mol Sci ; 19(10)2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30336592

RESUMO

Flower and fruit colors are of vital importance to the ecology and economic market value of plants. The mechanisms of flower and fruit coloration have been well studied, especially among ornamental flower plants and cultivated fruits. As people pay more attention to exocarp coloration, the endocarp coloration in some species has often been ignored. Here, we report on the molecular mechanism of endocarp coloration in three development stages of Euscaphis konishii. The results show that endocarp reddening is closely related to anthocyanin accumulation, and a total of 86,120 unigenes were assembled, with a mean length of 893 bp (N50 length of 1642 bp). We identified a large number of differentially expressed genes associated with endocarp coloration, including anthocyanin biosynthesis, carotenoid biosynthesis, and chlorophyll breakdown. The genes participating in each step of the anthocyanin biosynthesis were found in the transcriptome dataset, but a few genes were found in the carotenoid biosynthesis and chlorophyll breakdown. In addition, the candidate R2R3-MYB transcription factors and candidate glutathione S-transferase transport genes, which likely regulate the anthocyanin biosynthesis, were identified. This study offers a platform for E. konishii functional genomic research and provides a reference for revealing the regulatory mechanisms of endocarp reddening.


Assuntos
Frutas/genética , Malvaceae/genética , Pigmentação/genética , Análise de Sequência de RNA , Transcriptoma/genética , Antocianinas/biossíntese , Carotenoides/biossíntese , Clorofila/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Genes de Plantas , Anotação de Sequência Molecular , Família Multigênica , Mapas de Interação de Proteínas/genética , Reprodutibilidade dos Testes , Fatores de Transcrição/metabolismo
7.
Adv Funct Mater ; 27(46)2017 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-29755309

RESUMO

Due to its simplicity, versatility, and high efficiency, the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 technology has emerged as one of the most promising approaches for treatment of a variety of genetic diseases, including human cancers. However, further translation of CRISPR/Cas9 for cancer gene therapy requires development of safe approaches for efficient, highly specific delivery of both Cas9 and single guide RNA to tumors. Here, novel core-shell nanostructure, liposome-templated hydrogel nanoparticles (LHNPs) that are optimized for efficient codelivery of Cas9 protein and nucleic acids is reported. It is demonstrated that, when coupled with the minicircle DNA technology, LHNPs deliver CRISPR/Cas9 with efficiency greater than commercial agent Lipofectamine 2000 in cell culture and can be engineered for targeted inhibition of genes in tumors, including tumors the brain. When CRISPR/Cas9 targeting a model therapeutic gene, polo-like kinase 1 (PLK1), is delivered, LHNPs effectively inhibit tumor growth and improve tumor-bearing mouse survival. The results suggest LHNPs as versatile CRISPR/Cas9-delivery tool that can be adapted for experimentally studying the biology of cancer as well as for clinically translating cancer gene therapy.

8.
J Chem Phys ; 144(17): 174502, 2016 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-27155640

RESUMO

Scrutinizing critical thermodynamic and kinetic factors for glass formation and the glass stability of materials would benefit the screening of the glass formers for the industry of glassy materials. The present work aims at elucidating the factors that contribute to the glass formation by investigating medium-sized molecules of pharmaceuticals. Glass transition related thermodynamics and kinetics are performed on the pharmaceuticals using calorimetric, dielectric, and viscosity measurements. The characteristic thermodynamic and kinetic parameters of glass transition are found to reproduce the relations established for small-molecule glass formers. The systematic comparison of the thermodynamic and kinetic contributions to glass formation reveals that the melting-point viscosity is the crucial quantity for the glass formation. Of more interest is the finding of a rough correlation between the melting-point viscosity and the entropy of fusion normalized by the number of beads of the pharmaceuticals, suggesting the thermodynamics can partly manifest its contribution to glass formation via kinetics.


Assuntos
Química Farmacêutica , Vidro/química , Termodinâmica , Estabilidade de Medicamentos , Cinética , Tamanho da Partícula
9.
Nanomedicine ; 12(7): 1833-1842, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27039220

RESUMO

Ischemic stroke is a leading cause of disability and death worldwide. Current drug treatment for stroke remains inadequate due to the existence of the blood-brain barrier. We proposed an innovative nanotechnology-based autocatalytic targeting approach, in which the blood-brain barrier modulator lexiscan is encapsulated in nanoparticles to enhance blood-brain barrier permeability and autocatalytically augment the brain stroke-targeting delivery efficiency of chlorotoxin-anchored nanoparticles. The nanoparticles efficiently and specifically accumulated in the brain ischemic microenvironment and the targeting efficiency autocatalytically increased with subsequent administrations. When Nogo-66 receptor antagonist peptide NEP1-40, a potential therapeutic agent for ischemic stroke, was loaded, nanoparticles significantly reduced infarct volumes and enhanced survival. Our findings suggest that the autocatalytic targeting approach is a promising strategy for drug delivery to the ischemic microenvironment inside the brain. Nanoparticles developed in this study may serve as a new approach for the clinical management of stroke.


Assuntos
Agonistas do Receptor A2 de Adenosina/administração & dosagem , Isquemia Encefálica/tratamento farmacológico , Nanopartículas , Purinas/administração & dosagem , Pirazóis/administração & dosagem , Acidente Vascular Cerebral/tratamento farmacológico , Animais , Barreira Hematoencefálica , Sistemas de Liberação de Medicamentos , Humanos , Masculino , Camundongos Endogâmicos C57BL
10.
J Chem Phys ; 143(16): 164501, 2015 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26520521

RESUMO

The glass transition and dynamics of benzene are studied in binary mixtures of benzene with five glass forming liquids, which can be divided into three groups: (a) o-terphenyl and m-xylene, (b) N-butyl methacrylate, and (c) N,N-dimethylpropionamide and N,N-diethylformamide to represent the weak, moderate, and strong interactions with benzene. The enthalpies of mixing, ΔH(mix), for the benzene mixtures are measured to show positive or negative signs, with which the validity of the extrapolations of the glass transition temperature T(g) to the benzene-rich regions is examined. The extrapolations for the T(g) data in the mixtures are found to converge around the point of 142 K, producing T(g) of pure benzene. The fragility m of benzene is also evaluated by extrapolating the results of the mixtures, and a fragility m ∼ 80 is yielded. The obtained T(g) and m values for benzene allow for the construction of the activation plot in the deeply supercooled region. The poor glass formability of benzene is found to result from the high melting point, which in turn leads to low viscosity in the supercooled liquid.

11.
J Chem Phys ; 142(21): 214505, 2015 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-26049506

RESUMO

The dielectric relaxations in six primary and secondary alkoxy alcohols with varying molecular size and different separation between -O- and hydroxyl group are studied at temperatures around glass transition. The analyses of the apparent full width at half maximum of the main relaxations of the alkoxy alcohols reveal minima in the temperature dependence of the relaxation dispersions. The stretching exponents for the main relaxations of the alkoxy alcohols are also found not to follow the empirical correlations with other dynamic quantities established for generic liquids. A comparison of the relaxation dispersions in the alkoxy alcohols with those in Debye and non-Debye (generic) liquids is presented. The impacts of the ß-relaxations on the apparent main relaxation widths are reviewed for molecular glass formers.

12.
Org Biomol Chem ; 12(29): 5365-74, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24874918

RESUMO

A newly designed, dual-functional probe based on intracellular activation has been successfully developed for the detection of cancer cells. The probe is nearly non-fluorescent in buffer due to its highly efficient FRET quenching, but it can be specifically activated with dramatic fluorescence enhancement upon intracellular cathepsin B cleavage in target cancer cells after selective internalization via folate receptor-dependent endocytosis. Therefore, this probe enables "turn-on" visualization of cancer cells with desirable specificity and contrast enhancement. This targeted, intracellularly activatable probe exhibits low fluorescence-quenched background when compared with "always-on" probes and avoids non-specific activation by non-specifically expressed enzymes in normal tissue, which normally occurs when using common "turn on" probe design strategies. Therefore, this probe can be potentially applied in intraoperative inspection during clinical cancer surgery with higher contrast and sensitivity.


Assuntos
Corantes Fluorescentes , Espaço Intracelular/metabolismo , Imagem Molecular/métodos , Neoplasias/diagnóstico , Animais , Catepsina B , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão , Citometria de Fluxo , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Ácido Fólico/metabolismo , Humanos , Camundongos , Microscopia Confocal , Células NIH 3T3 , Neoplasias/patologia , Plasma/metabolismo , Reprodutibilidade dos Testes , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Temperatura , Fatores de Tempo
13.
Eur Phys J E Soft Matter ; 37(6): 7, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24965151

RESUMO

The calorimetric determination of the fragility m-index is compared using the T f and T g-onset methods for typical metallic and molecular glass forming systems of Pd39Ni10Cu30P21, glycerol, triacetin and propylene carbonate. The results are evaluated by referring to the standard m-values determined from the kinetic measurements of the viscosity or structural relaxation time in the supercooled liquid regimes. The m-indexes derived from the T f method are found to generally agree well with the kinetic measurements for all the systems. However, a large deviation is shown between the m-indexes calculated with the T g-onset method and the kinetic results for the fragile liquids of triacetin and propylene carbonate, indicating the calorimetric determination of the fragility m-indexes in terms of the T f method produces less uncertainty.

14.
Phys Chem Chem Phys ; 16(8): 3586-92, 2014 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-24413254

RESUMO

A quantitative evaluation of the contribution of mixing thermodynamics to glass transition is performed for a binary eutectic benzil and m-nitroaniline system. The microcalorimetric measurements of the enthalpy of mixing give small and positive values, typically ~200 J mol(-1) for the equimolar mixture. The composition dependence of the glass transition temperature, T(g), is found to show a large and negative deviation from the ideal mixing rule. The Gordon-Taylor and Couchman-Karasz models are subsequently applied to interpret the T(g) behavior, however, only a small fraction of the deviation is explained. The analyses of the experimental results manifest quantitatively the importance of the mixing thermodynamics in the glass transition in miscible systems.

15.
J Chem Phys ; 141(10): 104506, 2014 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-25217936

RESUMO

The glass transition and relaxation dynamics in the binary mixtures of a Debye liquid, N-ethylacetamide, with water, monoalcohol, and amine are studied by calorimetric and dielectric measurements in the highly viscous regimes near the glass transition. Calorimetric measurements show the glass transition temperature in the N-ethylacetamide-water mixtures is remarkably enhanced as water is added as high as 70 mol. % before crystallization is detected. A similar increase is also observed in the N-ethylacetamide-rich mixtures with the non-Debye 1,2-propanediamine. However, the dielectric measurements show that the main relaxation in the N-ethylacetamide-water mixtures with water fraction up to 60 mol. % reproduces the dynamic characters of the mixtures constituted by two Debye liquids, N-ethylacetamide and 2-ethyl-1-butanol. The comparison of the calorimetric and dielectric features for the three mixing systems suggests that the Debye relaxation persists in the N-ethylacetamide-water mixtures within the experimentally studied compositions.

16.
Tissue Cell ; 86: 102261, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37951061

RESUMO

OBJECTIVE: To construct a new diethylnitrosamine (DEN)-induced rat hepatocellular carcinoma (HCC) model with short induction time, high incidence, and survival rate. METHODS: 60 male Sprague-Dawley rats were randomly divided into 4 groups: the control group, the model A (MA) group, the model B (MB) group, and the model C (MC) group. The control group was intraperitoneally injected with 0.9% saline for 6 weeks. The MA group was injected with the DEN solution at 30 mg/kg three times a week for 6 weeks. The MB group was injected with the DEN solution at 30 mg/kg three times a week for 6 weeks, and discontinued the induction for 2 weeks. The MC group was injected with the DEN solution at 30 mg/kg three times a week for 8 weeks. The levels of albumin (ALB), alanine transaminase (ALT), and aspartate aminotransferase (AST) in serum were assayed. Meanwhile, the pathological conditions, apoptosis of hepatocytes, expression of NF-κBp65, and the reactive oxygen species level were detected. RESULTS: All rats in the control group and the MA group survived, and none of the rats occurred HCC. HCC occurred in rats of the MB group and the MC group. The serum ALB level in the MB group was higher than that in the MC group. The serum ALT and AST levels and the number of proliferating and apoptotic hepatocyte cells in the MB group were lower than those in the MC group. The expression of ROS- and NF-κBp6- positive cells in the MA group, MB group, and MC group were significantly higher than that of the control group. CONCLUSION: This study developed a new DEN-induced rat HCC model with short induction time, high incidence, and survival rate. NF-κB pathway may be one of the main pathways involved in the development of this model.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Ratos , Masculino , Animais , Carcinoma Hepatocelular/patologia , Fígado/patologia , Neoplasias Hepáticas/patologia , Ratos Sprague-Dawley , Dietilnitrosamina/toxicidade , Dietilnitrosamina/metabolismo
17.
Med Phys ; 51(8): 5351-5360, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38758744

RESUMO

BACKGROUND: In laparoscopic liver surgery, accurately predicting the displacement of key intrahepatic anatomical structures is crucial for informing the doctor's intraoperative decision-making. However, due to the constrained surgical perspective, only a partial surface of the liver is typically visible. Consequently, the utilization of non-rigid volume to surface registration methods becomes essential. But traditional registration methods lack the necessary accuracy and cannot meet real-time requirements. PURPOSE: To achieve high-precision liver registration with only partial surface information and estimate the displacement of internal liver tissues in real-time. METHODS: We propose a novel neural network architecture tailored for real-time non-rigid liver volume to surface registration. The network utilizes a voxel-based method, integrating sparse convolution with the newly proposed points of interest (POI) linear attention module. POI linear attention module specifically calculates attention on the previously extracted POI. Additionally, we identified the most suitable normalization method RMSINorm. RESULTS: We evaluated our proposed network and other networks on a dataset generated from real liver models and two real datasets. Our method achieves an average error of 4.23 mm and a mean frame rate of 65.4 fps in the generation dataset. It also achieves an average error of 8.29 mm in the human breathing motion dataset. CONCLUSIONS: Our network outperforms CNN-based networks and other attention networks in terms of accuracy and inference speed.


Assuntos
Fígado , Redes Neurais de Computação , Fígado/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador/métodos , Fatores de Tempo , Tamanho do Órgão , Tomografia Computadorizada por Raios X , Imageamento Tridimensional/métodos
18.
Mater Today Bio ; 28: 101234, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39309165

RESUMO

Magnesium (Mg)-based scaffolds are garnering increasing attention as bone repair materials owing to their biodegradability and mechanical resemblance to natural bone. Their effectiveness can be augmented by incorporating surface coatings to meet clinical needs. However, the limited bonding strength and unclear mechanisms of these coatings have impeded the clinical utility of scaffolds. To address these issues, this study introduces a composite coating of high-bonding-strength polydopamine-microarc oxidation (PDA-MHA) on Mg-based scaffolds. The results showed that the PDA-MHA coating achieved a bonding strength of 40.56 ± 1.426 MPa with the Mg scaffold surface, effectively enhancing hydrophilicity and controlling degradation rates. Furthermore, the scaffold facilitated bone regeneration by influencing osteogenic markers such as RUNX-2, OPN, OCN, and VEGF. Transcriptomic analyses further demonstrated that the PDA-MHA/Mg scaffold upregulated carboxypeptidase Z expression and activated the Wnt-4/ß-catenin signaling pathway, thereby promoting bone regeneration. Overall, this study demonstrated that PDA can synergistically enhance bone repair with Mg scaffold, broadening the application scenarios of Mg and PDA in the field of biomaterials. Moreover, this study provides a theoretical underpinning for the application and clinical translation of Mg-based scaffolds in bone tissue engineering endeavors.

19.
J Virol ; 86(3): 1421-32, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22090132

RESUMO

For retroviruses such as HIV-1 and murine leukemia virus (MLV), active receptor recruitment and trafficking occur during viral entry. However, the underlying mechanisms and cellular factors involved in the process are largely uncharacterized. The viral receptor for ecotropic MLV (eMLV), a classical model for retrovirus infection mechanisms and pathogenesis, is mouse cationic amino acid transporter 1 (mCAT-1). Growth factor receptor-bound protein 2 (GRB2) is an adaptor protein that has been shown to couple cell surface receptors, such as epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor, to intracellular signaling events. Here we examined if GRB2 could also play a role in controlling infection by retroviruses by affecting receptor function. The GRB2 RNA interference (RNAi)-mediated suppression of endogenous GRB2 resulted in a consistent and significant reduction of virus binding and membrane fusion. The binding between eMLV and cells promoted increased GRB2-mCAT-1 interactions, as detected by immunoprecipitation. Consistently, the increased colocalization of GRB2 and mCAT-1 signals was detected by confocal microscopy. This association was time dependent and paralleled the kinetics of cell-virus membrane fusion. Interestingly, unlike the canonical binding pattern seen for GRB2 and growth factor receptors, GRB2-mCAT-1 binding does not depend on the GRB2-SH2 domain-mediated recognition of tyrosine phosphorylation on the receptor. The inhibition of endogenous GRB2 led to a reduction in surface levels of mCAT-1, which was detected by immunoprecipitation and by a direct binding assay using a recombinant MLV envelope protein receptor binding domain (RBD). Consistent with this observation, the expression of a dominant negative GRB2 mutant (R86K) resulted in the sequestration of mCAT-1 from the cell surface into intracellular vesicles. Taken together, these findings suggest a novel role for GRB2 in ecotropic MLV entry and infection by facilitating mCAT-1 trafficking.


Assuntos
Canais de Cálcio/metabolismo , Proteína Adaptadora GRB2/metabolismo , Vírus da Leucemia Murina/fisiologia , Fusão de Membrana , Canais de Cátion TRPV/metabolismo , Animais , Linhagem Celular , Citometria de Fluxo , Proteína Adaptadora GRB2/genética , Humanos , Vírus da Leucemia Murina/metabolismo , Camundongos , Fosforilação , Ligação Proteica , Interferência de RNA , RNA Interferente Pequeno
20.
J Chem Phys ; 139(16): 164504, 2013 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-24182046

RESUMO

The dielectric relaxation of two long-chain glass forming monohydroxy alcohols, 2-butyl-1-octanol and 2-hexyl-1-decanol, is studied at low temperature. Remarkable broadening from the pure Debye relaxation is identified for the slowest dynamics, differing from the dielectric spectra of short-chain alcohols. The broadening of the Debye-like relaxation in the two liquids develops as temperature increases, and the approaching of the Debye-like and structural relaxation widths is shown. Similar results are observed in the dielectric spectra of dilute 2-ethyl-1-hexanol in either 2-hexyl-1-decanol or squalane. The results of the liquids and mixtures reveal a correlation between the broadening and the Debye-like relaxation strength. Molecular associations in monohydroxy alcohols are discussed with the modification of the Debye relaxation.

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