Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Nat Sci Sleep ; 16: 573-583, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38827393

RESUMEN

Purpose: This investigation sought to elucidate the genetic underpinnings that connect obesity indicators, circulating blood lipid levels, adipokines levels and obstructive sleep apnea syndrome (OSAS), employing a bidirectional two-sample Mendelian randomization (MR) analysis that utilizes data derived from extensive genome-wide association studies (GWAS). Methods: We harnessed genetic datasets of OSAS available from the FinnGen consortium and summary data of four obesity indices (including neck circumference), seven blood lipid (including triglycerides) and eleven adipokines (including leptin) from the IEU OpenGWAS database. We primarily utilized inverse variance weighted (IVW), weighted median, and MR-Egger methods, alongside MR-PRESSO and Cochran's Q tests, to validate and assess the diversity and heterogeneity of our findings. Results: After applying the Bonferroni correction, we identified significant correlations between OSAS and increased neck circumference (Odds Ratio [OR]: 3.472, 95% Confidence Interval [CI]: 1.954-6.169, P= 2.201E-05) and decreased high-density lipoprotein (HDL) cholesterol levels (OR: 0.904, 95% CI: 0.858-0.952, P= 1.251E-04). Concurrently, OSAS was linked to lower leptin levels (OR: 1.355, 95% CI: 1.069-1.718, P= 0.012) and leptin receptor levels (OR: 0.722, 95% CI: 0.530-0.996, P= 0.047). Sensitivity analyses revealed heterogeneity in HDL cholesterol and leptin indicators, but further multiplicative random effects IVW method analysis confirmed these correlations as significant (P< 0.05) without notable heterogeneity or horizontal pleiotropy in other instrumental variables. Conclusion: This investigation compellingly supports the hypothesis that OSAS could be a genetic predisposition for elevated neck circumference, dyslipidemia, and adipokine imbalance. These findings unveil potential genetic interactions between OSAS and metabolic syndrome, providing new pathways for research in this domain. Future investigations should aim to delineate the specific biological pathways by which OSAS impacts metabolic syndrome. Understanding these mechanisms is critical for developing targeted prevention and therapeutic strategies.

2.
Int Immunopharmacol ; 126: 111234, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-37977071

RESUMEN

Obstructive sleep apnea (OSA), a state of sleep disruption, is characterized by recurrent apnea, chronic intermittent hypoxia (CIH) and hypercapnia. Previous studies have showed that CIH-induced neuroinflammatory plays a crucial role in cognitive deficits. Pseudoginsenoside GQ (PGQ) is a new oxytetracycline-type saponin formed by the oxidation and cyclization of the 20(S) Rg3 side chain. Rg3 has been found to afford anti-inflammatory effects, while whether PGQ plays a role of anti-neuroinflammatory remains unclear. The purpose of this study was to investigate whether PGQ attenuates CIH-induced neuroinflammatory and cognitive impairment and the possible mechanism it involves. We found that PGQ significantly ameliorated CIH-induced spatial learning deficits, and inhibited microglial activation, pro-inflammatory cytokine release, and neuronal apoptosis in the hippocampus of CIH mice. In addition, PGQ pretreatment promoted microglial M1 to M2 phenotypic transition in IH-induced BV-2 microglial, as well as indirectly inhibited IH-induced neuronal injury via modulation of microglia polarization. Furthermore, we noted that activation of HMGB1/TLR4/NF-κB signaling pathway induced by IH was inhibited by PGQ. Molecular docking results revealed that PGQ could bind to the active sites of HMGB1 and TLR4. Taken together, this work supports that PGQ inhibits M1 microglial polarization via the HMGB1/TLR4/NF-κB signaling pathway, and indirectly exerts neuroprotective effects, suggesting that PGQ may be a potential therapeutic strategy for cognitive impairment accompanied OSA.


Asunto(s)
Proteína HMGB1 , Apnea Obstructiva del Sueño , Ratones , Animales , Microglía , FN-kappa B/metabolismo , Proteína HMGB1/metabolismo , Inflamación/tratamiento farmacológico , Receptor Toll-Like 4/metabolismo , Simulación del Acoplamiento Molecular , Hipoxia/metabolismo , Apnea Obstructiva del Sueño/metabolismo , Cognición
3.
Biomater Sci ; 11(13): 4549-4556, 2023 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-37159049

RESUMEN

As an emerging anti-tumor strategy, chemodynamic therapy (CDT) utilizes a Fenton/Fenton-like reaction to generate highly toxic hydroxyl radicals to kill tumor cells. However, the efficiency of CDT is still hindered by the low Fenton/Fenton-like reaction rate. Herein, we report the combination of ion interference therapy (IIT) and chemodynamic therapy (CDT) via an amorphous iron oxide (AIO) nanomedicine with encapsulated EDTA-2Na (EDTA). Iron ions and EDTA are released from the nanomedicine in acidic tumors and chelate to form iron ion-EDTA, which improves the efficiency of CDT and promotes the generation of reactive oxygen species (ROS). In addition, EDTA can disrupt the homeostasis of Ca2+ in tumor cells by chelating with Ca2+ ions, which induces the separation of tumor cells and affects normal physiological activities. Both in vitro and in vivo experiments show that the nano chelating drugs exhibit significant improvement in Fenton reaction performance and excellent anti-tumor activity. This study based on chelation provides a new idea for designing efficient catalysts to enhance the Fenton reaction and provides more revelations on future research on CDT.


Asunto(s)
Nanopartículas , Neoplasias , Humanos , Ácido Edético/uso terapéutico , Neoplasias/tratamiento farmacológico , Radical Hidroxilo/uso terapéutico , Nanopartículas/uso terapéutico , Hierro , Línea Celular Tumoral , Peróxido de Hidrógeno , Microambiente Tumoral
4.
Exp Gerontol ; 171: 112037, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36436758

RESUMEN

BACKGROUND: The excessive activation of the microglia leads to the release of inflammatory factors that contribute to neuronal cell loss and neurodegeneration in Parkinson's Disease (PD). Mesencephalic astrocyte-derived neurotrophic factor (MANF) that belongs to a newly found neurotrophic factors (NTFs) family has been reported to promote neuronal survival in the PD models. However, the effects of the MANF on neuroinflammation in PD remain unclear. METHODS: AAV8-MANF virus was constructed to determine whether the high expression of MANF can protect the neuroinflammation-induced dopaminergic neurodegeneration in rats with 6-OHDA-induced PD. Rotarod performance test, immunofluorescent staining and western bolt were employed to evaluate the behavioral dysfunction, dopaminergic neurodegeneration, microglia activation, and signal activation. 6-OHDA treated SH-SY5Y cells and LPS treated BV-2 cells were used as the in vitro model for MANF neuroprotective and neuroinflammation mechanisms. Cell vitality and apoptosis were evaluated with MTT, CCK-8 and flow cytometric analysis. The AKT/GSK3ß-Nrf2 signaling and the TNF-α/IL6 expression were measured by Western Blot. RESULTS: Our findings indicated that the elevated MANF expression by the AAV8-MANF administration ameliorated the motor dysfunction and protected the dopaminergic neurons in the 6-OHDA treated rats. The upregulated CD11b in the rat SN caused by the 6-OHDA administration was significantly attenuated by the pretreatment of the AAV8-MANF. Furthermore, the levels of p-AKT, p-GSK3ß, BCL-2, and Nrf-2 were upregulated by the high expression of the MANF. Under the oxidative stress of the 6-OHDA, the MANF significantly reduced the apoptotic effect of the TNF-α on the SH-SY5Y cells. In the LPS treated BV-2 cells, the MANF reduced the production of the TNF-α and IL-6, via enhancing the Nrf-2, p-Akt, p-GSK3ß, and p-NF-κß level. CONCLUSIONS: These results suggested that the MANF prevented the dopaminergic neurodegeneration caused by the microglia activation in PD via activation of the AKT/GSK3ß-Nrf-2 signaling axis.


Asunto(s)
Neuroblastoma , Enfermedad de Parkinson , Humanos , Ratas , Animales , Factor de Necrosis Tumoral alfa , Factores de Crecimiento Nervioso/farmacología , Oxidopamina , Dopamina/metabolismo , Neuronas Dopaminérgicas
5.
Front Aging Neurosci ; 14: 891644, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35813950

RESUMEN

Background: Exercise plays an essential role in improving motor symptoms in Parkinson's disease (PD), but the underlying mechanism in the central nervous system remains unclear. Methods: Motor ability was observed after 12-week treadmill exercise on a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. RNA-sequencing on four brain regions (cerebellum, cortex, substantia nigra (SN), and striatum) from control animals, MPTP-induced PD, and MPTP-induced PD model treated with exercise for 12 weeks were performed. Transcriptional networks on the four regions were further identified by an integrative network biology approach. Results: The 12-week treadmill exercise significantly improved the motor ability of an MPTP-induced mouse model of PD. RNA-seq analysis showed SN and striatum were remarkably different among individual region's response to exercise in the PD model. Especially, synaptic regulation pathways about axon guidance, synapse assembly, neurogenesis, synaptogenesis, transmitter transport-related pathway, and synaptic regulation genes, including Neurod2, Rtn4rl2, and Cd5, were upregulated in SN and striatum. Lastly, immunofluorescence staining revealed that exercise rescued the loss of TH+ synapses in the striatal region in PD mice, which validates the key role of synaptic regulation pathways in exercise-induced protective effects in vivo. Conclusion: SN and striatum are important brain regions in which critical transcriptional changes, such as in synaptic regulation pathways, occur after the exercise intervention on the PD model.

6.
Oxid Med Cell Longev ; 2022: 7925686, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35847585

RESUMEN

Progressive accumulation of misfolded SNCA/α-synuclein is key to the pathology of Parkinson's disease (PD). Drugs aiming at degrading SNCA may be an efficient therapeutic strategy for PD. Our previous study showed that mesencephalic astrocyte-derived neurotrophic factor (MANF) facilitated the removal of misfolded SNCA and rescued dopaminergic (DA) neurons, but the underlying mechanisms remain unknown. In this study, we showed that AAV8-MANF relieved Parkinsonian behavior in rotenone-induced PD model and reduced SNCA accumulation in the substantia nigra. By establishing wildtype (WT) SNCA overexpression cellular model, we found that chaperone-mediated-autophagy (CMA) and macroautophagy were both participated in MANF-mediated degradation of SNCAWT. Nuclear factor erythroid 2-related factor (Nrf2) was activated to stimulating macroautophagy activity when CMA pathway was impaired. Using A53T mutant SNCA overexpression cellular model to mimic CMA dysfunction situation, we concluded that macroautophagy rather than CMA was responsible to the degradation of SNCAA53T, and this degradation was mediated by Nrf2 activation. Hence, our findings suggested that MANF has potential therapeutic value for PD. Nrf2 and its role in MANF-mediated degradation may provide new sights that target degradation pathways to counteract SNCA pathology in PD.


Asunto(s)
Enfermedad de Parkinson , alfa-Sinucleína , Autofagia/fisiología , Neuronas Dopaminérgicas/metabolismo , Humanos , Factor 2 Relacionado con NF-E2/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Enfermedad de Parkinson/tratamiento farmacológico , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo
7.
Mol Cell Biol ; 42(7): e0055921, 2022 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-35708320

RESUMEN

Charcot-Marie-Tooth type 4D (CMT4D) is an autosomal recessive demyelinating form of CMT characterized by progressive motor and sensory neuropathy. N-myc downstream regulated gene 1 (NDRG1) is the causative gene for CMT4D. Although more CMT4D cases have been reported, the comprehensive molecular mechanism underlying CMT4D remains elusive. Here, we generated a novel knockout mouse model in which the fourth and fifth exons of the Ndrg1 gene were removed. Ndrg1-deficient mice develop early progressive demyelinating neuropathy and limb muscle weakness. The expression pattern of myelination-related transcriptional factors, including SOX10, OCT6, and EGR2, was abnormal in Ndrg1-deficient mice. We further investigated the activation of the ErbB2/3 receptor tyrosine kinases in Ndrg1-deficient sciatic nerves, as these proteins play essential roles in Schwann cell myelination. In the absence of NDRG1, although the total ErbB2/3 receptors expressed by Schwann cells were significantly increased, levels of the phosphorylated forms of ErbB2/3 and their downstream signaling cascades were decreased. This change was not associated with the level of the neuregulin 1 ligand, which was increased in Ndrg1-deficient mice. In addition, the integrin ß4 receptor, which interacts with ErbB2/3 and positively regulates neuregulin 1/ErbB signaling, was significantly reduced in the Ndrg1-deficient nerve. In conclusion, our data suggest that the demyelinating phenotype of CMT4D disease is at least in part a consequence of molecular defects in neuregulin 1/ErbB signaling.


Asunto(s)
Enfermedad de Charcot-Marie-Tooth , Enfermedad de Refsum , Animales , Enfermedad de Charcot-Marie-Tooth/genética , Enfermedad de Charcot-Marie-Tooth/metabolismo , Receptores ErbB , Ratones , Neurregulina-1/genética , Neurregulina-1/metabolismo , Fenotipo , Enfermedad de Refsum/genética , Enfermedad de Refsum/metabolismo , Células de Schwann/metabolismo
8.
Ear Nose Throat J ; 101(5): NP199-NP202, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32921173

RESUMEN

Basaloid squamous cell carcinoma and large cell neuroendocrine carcinoma are not common in head and neck, these tumors rarely occur in the larynx but both have highly aggressive clinical behavior and a high mortality rate. The diagnosis is complicated by these tumors' atypical clinical and pathological features. This case details a coexistence of basaloid squamous cell carcinoma and large cell neuroendocrine carcinoma of a woman in the larynx. The patient underwent endoscopy- and coblation-assisted transoral microsurgery to achieve hyoid horizontal epiglottidectomy and has no recurrence after 12 months of follow-up.


Asunto(s)
Carcinoma Neuroendocrino , Carcinoma de Células Escamosas , Laringe , Carcinoma Neuroendocrino/complicaciones , Carcinoma Neuroendocrino/diagnóstico , Carcinoma Neuroendocrino/cirugía , Carcinoma de Células Escamosas/complicaciones , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/cirugía , Femenino , Humanos , Laringe/patología
9.
Biosci Rep ; 2020 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-33245101

RESUMEN

Early stage diagnosis of Parkinson's disease (PD) is challenging without significant motor symptoms. The identification of effective molecular biomarkers as a hematological indication of PD may help improve the diagnostic timeliness and accuracy. In this paper, we analyzed and compared the blood samples of PD and control (CTR) patients to identify the disease-related changes and determine the putative biomarkers for PD diagnosis. Based on the RNA sequencing analysis, differentially expressed genes (DEGs) were identified, and the co-expression network of DEGs was constructed using the weighted correlation network analysis (WGCNA). The analysis leads to the identification of 87 genes that were exclusively regulated in the PD group, whereas 66 genes were significantly increased and 21 genes were significantly decreased in contrast to the control group. The results indicate that the core lncRNA-mRNA co-expression network greatly changes the immune response in PD patients. Specifically, the results showed that PWAR6, LINC00861, AC83843.1, IRF family, IFIT family and CaMK4 may play important roles in the immune system of PD. Based on the findings from this the present study, future research aims at identify novel therapeutic strategies for PD.

10.
Oxid Med Cell Longev ; 2020: 8951907, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32566108

RESUMEN

Parkinson's disease (PD) is a neurodegenerative disease characterized by the gradual loss of dopaminergic (DA) neurons in the substantia nigra (SN) and the formation of intracellular Lewy bodies (LB) in the brain, which aggregates α-synuclein (α-Syn) as the main component. The interest of flavonoids as potential neuroprotective agents is increasing due to its high efficiency and low side effects. Baicalin is one of the flavonoid compounds, which is a predominant flavonoid isolated from Scutellaria baicalensis Georgi. However, the key molecular mechanism by which Baicalin can prevent the PD pathogenesis remains unclear. In this study, we used bioinformatic assessment including Gene Ontology (GO) to elucidate the correlation between oxidative stress and PD pathogenesis. RNA-Seq methods were used to examine the global expression profiles of noncoding RNAs and found that C/EBPß expression was upregulated in PD patients compared with healthy controls. Interestingly, Baicalin could protect DA neurons against reactive oxygen species (ROS) and decreased C/EBPß and α-synuclein expression in pLVX-Tet3G-α-synuclein SH-SY5Y cells. In a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced PD mouse model, the results revealed that treatment with Baicalin improved the PD model's behavioral performance and reduced dopaminergic neuron loss in the substantia nigra, associated with the inactivation of proinflammatory cytokines and oxidative stress. Hence, our study supported that Baicalin repressed C/EBPß via redox homeostasis, which may be an effective potential treatment for PD.


Asunto(s)
Antioxidantes/farmacología , Proteína beta Potenciadora de Unión a CCAAT/metabolismo , Flavonoides/farmacología , Enfermedad de Parkinson/metabolismo , 1-Metil-4-fenil-1,2,3,6-Tetrahidropiridina , Animales , Línea Celular , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/metabolismo , Neuronas Dopaminérgicas/patología , Flavonoides/química , Ontología de Genes , Humanos , Inflamación/patología , Masculino , Ratones Endogámicos C57BL , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Anotación de Secuencia Molecular , Actividad Motora/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Neurotoxinas/toxicidad , Oxidación-Reducción , Estrés Oxidativo/efectos de los fármacos , Enfermedad de Parkinson/patología , Enfermedad de Parkinson/fisiopatología , alfa-Sinucleína/metabolismo
11.
Transl Cancer Res ; 9(10): 6505-6515, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35117258

RESUMEN

NUT carcinoma (NC) is a rare, highly invasive and fatal tumor and often misdiagnosed. It typically arises from the mediastinum and midline organs and has complicated pathogenesis and poor outcome. Genetically, its pathogenesis is related to a chromosomal rearrangement involving the NUTM1 gene. In most cases, the main oncoprotein is BRD4-NUT with a translocation between NUTM1 and BRD4 genes, but in a few cases, the oncoprotein is BRD3-NUT, or NSD3-NUT. Studies have shown that the histone hyperacetylation and BRD4 hyperphosphorylation may lead to the activation of cancer circuits. Abnormal production of microRNA, inactivation of tumor suppressor genes and abnormal activation of several signaling pathways are proposed as potential mechanisms underlying the pathogenesis of NC. Currently, there is no consensus on its standard treatment for NC. Extent of surgical resection with negative margins, initial radiotherapy and part of chemotherapy regimens may significantly associated with the improvement of progression-free survival (PFS) rate and overall survival (OS) rate. Some bromodomain and extraterminal inhibitors (BETis) have shown encouraging results in the clinical trials on NC, but delayed drug resistance is still an important issue that needs to be resolved. Histone deacetylase inhibitors are also found to possess the potential in the treatment of NC. Herein, we summarize recent advances in the pathogenesis and treatment of NC.

12.
Front Neurol ; 10: 1389, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-32047471

RESUMEN

Parkinson's disease (PD) is a common neurodegenerative disease with movement and balance impairments. Although studies have reported improvement of motor symptoms with physical exercise, the mechanisms by which exercise is beneficial remains poorly understood. Our study addresses the exercise-induced changes to peripheral immune cells by interrogating the transcriptome of blood-derived leukocytes in PD patients before and after exercise. Patients attended 1 h exercise classes twice a week for 12 weeks. Leukocytes were collected at the beginning and end of the study for gene expression analysis by RNA-seq or quantitative real-time PCR. We correlated differentially expressed genes after exercise with clinical measures and analyzed the potential functions of gene changes with Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology analysis. Exercise improved measures of movement and balance when compared with scores before the exercise program. Among the gene changes, Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analysis suggests that T-cell receptor signaling, T-cell activation, and T-cell migration pathways were downregulated, while the T-cell receptor signaling pathway was the most significantly correlated with clinical measures. To further investigate T-cell-related changes in PD leukocytes, we reanalyzed the differentially expressed genes from publicly available microarray data and found that genes in the T-cell activation, differentiation, and migration pathways were upregulated in PD samples compared to controls in a time-dependent manner. Together, our findings suggest that exercise rehabilitation may improve movement and balance in PD patients by reversing the upregulated T-cell activation pathways associated with PD. This study was registered with the Chinese Clinical Trial Registry under ChiCTR-TRC-14004707. Registered on May 27, 2014.

13.
Exp Gerontol ; 100: 77-86, 2017 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-29079145

RESUMEN

Oxidative stress and apoptosis are thought to be broadly involved in the pathogenesis of Parkinson's disease. We previously reported that Mesencephalic astrocyte-derived neurotrophic factor (MANF) possesses anti-oxidation and anti-apoptotic effects against 6-OHDA-induced neurotoxicity, but the specific molecular mechanism remains unclear. In this study, we showed that MANF up-regulates the expression of nuclear factor erythroid 2-related factor (Nrf2) and promotes its translocation into the nucleus. The anti-oxidation and anti-apoptotic effects of MANF could be partially blocked by inhibitor or shRNA-mediated knockdown of Nrf2. Furthermore, MANF activated phospoinositide-3-kinase (PI3K)/Akt signaling and suppressed glycogen synthase kinase (GSK3ß) activation. PI3K inhibitor (LY49002) abolished effects of MANF on AKT phosphorylation, GSK3ß inactivation, Nrf2 nuclear translocation and subsequently abrogated MANF-mediates cytoprotection. Collectively, our findings indicated that MANF-mediated protection against 6-OHDA-induced cytotoxicity by potentiating the Nrf2-related survival mechanism through the PI3K/Akt/GSK3ß pathway.


Asunto(s)
Apoptosis , Factor 2 Relacionado con NF-E2/metabolismo , Factores de Crecimiento Nervioso/farmacología , Fármacos Neuroprotectores/farmacología , Estrés Oxidativo/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Línea Celular Tumoral , Citoprotección , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Humanos , Factor 2 Relacionado con NF-E2/genética , Oxidopamina , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo
14.
Artículo en Chino | MEDLINE | ID: mdl-27373039

RESUMEN

OBJECTIVE: To assess the effect of CPAP therapy on sleep quality and quality of life in patients with moderate or severe OSAHS. METHOD: Seventy-two patients diagnosed as OSAHS by polysomnography (PSG) were assigned to receive CPAP therapy for 3 months. At baseline and three months after treatment patients underwent polysomnography (PSG). Analyze the results of PSG, sleep quality, excessive daytime sleepiness, quality of life and the general well-being. RESULT: The lowest average oxygen saturation and the average blood oxygen saturation improved significantly after CPAP therapy, and the longest sleep apnea time and AHI decreased obviously (P < 0.01). Except body pain, the other seven dimensions of SF-36 improved obviously (P < 0.01); ESS, PSQI and GWB also improved (P < 0.05). CONCLUSION: For patients with moderate or severe OSAHS, CPAP therapy can obviously improve the sleep quality, excessive daytime sleepiness, improve patients' life quality and the general well-being.


Asunto(s)
Presión de las Vías Aéreas Positiva Contínua , Calidad de Vida , Apnea Obstructiva del Sueño/terapia , Humanos , Oximetría , Polisomnografía
15.
Langmuir ; 28(25): 9451-9, 2012 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-22621226

RESUMEN

Well-controlled polymerization of N-vinylpyrrolidone (NVP) on Au surfaces by surface-initiated atom transfer radical polymerization (SI-ATRP) was carried out at room temperature by a silanization method. Initial attempts to graft poly(N-vinylpyrrolidone) (PVP) layers from initiators attached to alkanethiol monolayers yielded PVP films with thicknesses less than 5 nm. The combined factors of the difficulty in the controllable polymerization of NVP and the instability of alkanethiol monolayers led to the difficulty in the controlled polymerization of NVP on Au surfaces. Therefore, the silanization method was employed to form an adhesion layer for initiator attachment. This method allowed well-defined ATRP polymerization to occur on Au surfaces. Water contact angle, X-ray photoelectron spectroscopy (XPS), and reflectance Fourier transform infrared (reflectance FTIR) spectroscopy were used to characterize the modified surfaces. The PVP-modified gold surface remained stable at 130 °C for 3 h, showing excellent thermal stability. Thus, postfunctionalization of polymer brushes at elevated temperatures is made possible. The silanization method was also applied to modify SPR chips and showed potential applications in biosensors and biochips.


Asunto(s)
Oro/química , Polimerizacion , Povidona/química , Povidona/síntesis química , Temperatura , Adsorción , Técnicas de Química Sintética , Proteínas/química , Silanos/química , Compuestos de Sulfhidrilo/química , Resonancia por Plasmón de Superficie , Propiedades de Superficie , Agua/química
16.
Colloids Surf B Biointerfaces ; 96: 37-43, 2012 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-22510455

RESUMEN

A new method for the modification of poly(dimethylsiloxane) (PDMS) elastomer surfaces with hydrophilic poly(N-vinylpyrrolidone) (PVP) has been developed. PVP chains were grafted from the PDMS surface by surface-initiated atom transfer radical polymerization (SI-ATRP). The resulting surfaces were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM) and water contact angle measurements. It was shown that the modified surfaces were strongly hydrophilic, indicating that the PVP grafts dominate the surface and define its properties. The anti-fouling properties of the grafted surfaces were demonstrated in protein adsorption and cell adhesion experiments. Both protein adsorption and cell adhesion were inhibited significantly on the PVP-modified PDMS surfaces compared to unmodified controls. It is concluded that modification by SI-ATRP grafting of PVP is an effective method for the preparation of anti-biofouling PDMS materials.


Asunto(s)
Incrustaciones Biológicas/prevención & control , Dimetilpolisiloxanos/química , Elastómeros/farmacología , Polímeros/química , Pirrolidinonas/química , Adsorción , Animales , Proteínas Sanguíneas/química , Proteínas Sanguíneas/farmacocinética , Western Blotting , Adhesión Celular/efectos de los fármacos , Línea Celular Tumoral , Elastómeros/química , Humanos , Microscopía de Fuerza Atómica , Modelos Químicos , Estructura Molecular , Espectroscopía de Fotoelectrones , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Propiedades de Superficie
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...