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1.
Sci Rep ; 12(1): 4891, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35318437

RESUMO

Large eyelid defect after excision of malignancies or trauma is difficult to reconstruct due to special structure and function of the eyelid. In this study, we aimed to present the outcomes of subcutaneous pedicled propeller flap for reconstructing the large eyelid defect after excision of malignancies or trauma. A retrospective review of patients diagnosed with eyelid defect due to excision of malignancies or trauma, and undergoing subcutaneous pedicled propeller flap for reconstructing the large eyelid defect, was conducted at our hospital. The clinical data were collected and analyzed. A total of 15 patients were included in the cases series. Nine patients were diagnosed with basal cell carcinoma, 3 patients with epidermoid carcinoma, and 3 patients with trauma. All the defects were successfully covered with this designed flap. There was no flap necrosis in all the cases. No functional problems were observed in all of the cases. At long-term postoperative follow-up, the average score of patients' satisfaction was good. This subcutaneous pedicled propeller flap is a feasible alternative technique for reconstructing the large eyelid defect after excision of malignancies or trauma. This flap option could avoid the use of free flaps for large defect.


Assuntos
Carcinoma Basocelular , Procedimentos de Cirurgia Plástica , Neoplasias Cutâneas , Carcinoma Basocelular/cirurgia , Pálpebras/cirurgia , Humanos , Procedimentos de Cirurgia Plástica/métodos , Neoplasias Cutâneas/cirurgia , Retalhos Cirúrgicos/cirurgia
2.
Alzheimers Res Ther ; 13(1): 74, 2021 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-33827675

RESUMO

INTRODUCTION: Subjective cognitive decline (SCD) represents a cognitively normal state but at an increased risk for developing Alzheimer's disease (AD). Recognizing the glucose metabolic biomarkers of SCD could facilitate the location of areas with metabolic changes at an ultra-early stage. The objective of this study was to explore glucose metabolic biomarkers of SCD at the region of interest (ROI) level. METHODS: This study was based on cohorts from two tertiary medical centers, and it was part of the SILCODE project (NCT03370744). Twenty-six normal control (NC) cases and 32 SCD cases were in cohort 1; 36 NCs, 23 cases of SCD, 32 cases of amnestic mild cognitive impairment (aMCIs), 32 cases of AD dementia (ADDs), and 22 cases of dementia with Lewy bodies (DLBs) were in cohort 2. Each subject underwent [18F]fluoro-2-deoxyglucose positron emission tomography (PET) imaging and magnetic resonance imaging (MRI), and subjects from cohort 1 additionally underwent amyloid-PET scanning. The ROI analysis was based on the Anatomical Automatic Labeling (AAL) template; multiple permutation tests and repeated cross-validations were conducted to determine the metabolic differences between NC and SCD cases. In addition, receiver operating characteristic curves were used to evaluate the capabilities of potential glucose metabolic biomarkers in distinguishing different groups. Pearson correlation analysis was also performed to explore the correlation between glucose metabolic biomarkers and neuropsychological scales or amyloid deposition. RESULTS: Only the right middle temporal gyrus (RMTG) passed the methodological verification, and its metabolic levels were correlated with the degrees of complaints (R = - 0.239, p = 0.009), depression (R = - 0.200, p = 0.030), and abilities of delayed memory (R = 0.207, p = 0.025), and were weakly correlated with cortical amyloid deposition (R = - 0.246, p = 0.066). Furthermore, RMTG metabolism gradually decreased across the cognitive continuum, and its diagnostic efficiency was comparable (NC vs. ADD, aMCI, or DLB) or even superior (NC vs. SCD) to that of the metabolism of the posterior cingulate cortex or precuneus. CONCLUSIONS: These findings suggest that the hypometabolism of RMTG could be a typical feature of SCD, and the large-scale hypometabolism in patients with symptomatic stages of AD may start from the RMTG, which gradually progresses starting in the preclinical stage. The specificity of identifying SCD from the perspective of self-perceived symptoms is likely to be increased by the detection of RMTG metabolism.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Doença de Alzheimer/diagnóstico por imagem , Biomarcadores , Disfunção Cognitiva/diagnóstico por imagem , Fluordesoxiglucose F18 , Glucose , Humanos , Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Lobo Temporal/diagnóstico por imagem
3.
Front Aging Neurosci ; 13: 632382, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33603659

RESUMO

Objective: This study assessed the methylation of peripheral NCAPH2 in individuals with subjective cognitive decline (SCD), identified its correlation with the hippocampal volume, and explored whether the correlation is influenced by apolipoprotein E ε4 (APOE ε4) status. Methods: Cognitively normal controls (NCs, n = 56), individuals with SCD (n = 81), and patients with objective cognitive impairment (OCI, n = 51) were included from the Sino Longitudinal Study on Cognitive Decline (NCT03370744). All participants completed neuropsychological assessments, blood tests, and structural MRI. NCAPH2 methylation was compared according to the diagnostic and APOE ε4 status. Partial correlation analysis was conducted to assess the correlations between the hippocampal volume, cognitive tests, and the NCAPH2 methylation levels. Results: Individuals with SCD and patients with OCI showed significantly lower levels of NCAPH2 methylation than NCs, which were independent of the APOE ε4 status. The NCAPH2 methylation levels and the hippocampal volumes were positively correlated in the SCD APOE ε4 non-carriers but not in the OCI group. No association was found between the NCAPH2 methylation levels and the cognitive function. Conclusion: Abnormal changes in blood NCAPH2 methylation were found to occur in SCD, indicating its potential to be used as a useful peripheral biomarker in the early stage of Alzheimer's disease screening.

4.
Mech Ageing Dev ; 184: 111175, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31678325

RESUMO

Alzheimer's disease (AD) is characterized by a series of interacting pathophysiological cascades, including the aggregation of ß-amyloid plaques and the formation of neurofibrillary tangles derived from hyperphosphorylated tau proteins. AD is the cause of approximately 70 % of dementia, an irreversible and untreatable syndrome at its late stage. Hence, more efforts should be devoted to identifying at-risk or preclinical AD populations for early intervention and the improved design of drug trials. The exosome, a nanoscale subtype of extracellular vesicle that serves as a cell-to-cell communication messenger, is an emerging liquid biopsy tool for various diseases including AD. Recently, it has been discovered that brain-derived exosomes can flow through the blood-brain barrier to the peripheral blood, containing important protein and nucleic acid biomarkers that are associated with the pathogenesis and progression of AD. Other reports showed a strong involvement of exosomes in synaptic function, insulin resistance, and neuroinflammation, among others. Here, we summarize those studies and assess the value of exosomes as an emerging tool for the early detection of AD in conjunction with the current clinical diagnosis paradigm.


Assuntos
Doença de Alzheimer/diagnóstico , Diagnóstico Precoce , Vesículas Extracelulares/química , Animais , Exossomos , Humanos , Medição de Risco
5.
Artigo em Inglês | MEDLINE | ID: mdl-30836684

RESUMO

Coronary artery disease has become a major health concern over the past several decades. We aimed to explore the association of single nucleotide polymorphisms (SNPs) in the ATP-binding cassette subfamily A member 1 (ABCA1) and lifestyle factors with coronary artery disease (CAD) in dyslipidemia. This nested case-control study included 173 patients with CAD and 500 matched control individuals (1:3, case: control) from a district in southern China. We collected medical reports, lifestyle details, and blood samples of individuals with dyslipidemia and used the polymerase chain reaction-ligase detection reaction method to genotype the SNPs. The CC genotype of the additive and recessive models of rs4149339, together with regular intake of fried foods or dessert, increased the risk of CAD (adjusted odd ratio (OR) = 1.91, p = 0.030; adjusted OR = 1.97, p = 0.017; adjusted OR = 1.80, p = 0.002; adjusted OR = 1.98, p = 0.001). The AT + AA genotype of the dominant model of rs4743763 and moderate/heavy physical activity reduced the risk of CAD (adjusted OR = 0.66, p = 0.030; adjusted OR = 0.44, p = 0.001). The CT + CC genotype of the dominant model of rs2472386 reduced the risk of CAD only in males (adjusted OR = 0.36, p = 0.001). The interaction between rs4149339 and rs4743763 of ABCA1 and haplotype CTT (comprising rs4149339, rs4743763, and rs2472386) appeared to increase the risk of CAD (relative excess risk due to interaction (RERI) = 3.19, p = 0.045; OR = 1.49, p = 0.019). Polymorphisms of rs4149339, rs4743763 and rs2472386 in ABCA1 and three lifestyle factors (physical activity, fried food intake, and dessert intake) were associated with CAD in people with dyslipidemia in southern China. These results provide the theoretical basis for gene screening and the prevention of chronic cardiovascular diseases.


Assuntos
Transportador 1 de Cassete de Ligação de ATP/genética , Povo Asiático/genética , Doença da Artéria Coronariana/genética , Dislipidemias/genética , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , China/epidemiologia , Doença da Artéria Coronariana/epidemiologia , Dislipidemias/epidemiologia , Ingestão de Alimentos , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo de Nucleotídeo Único , Fatores de Risco
6.
Int J Neurosci ; 128(9): 849-853, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29447481

RESUMO

Purpose/aim: We investigated the regularity changes of the retinal nerve fiber layer (RNFL) and macular ganglion cell complex (mGCC) of the amnestic mild cognitive impairment (aMCI) patients in this prospective cohort study. MATERIALS AND METHODS: Twenty-four aMCI patients and 30 health controls, who are more than 60 years old, were recruited into the study. The RNFL and the mGCC average thickness were measured with Fourier-domain optical coherence tomography (FD-OCT). RESULTS: Compared with that in the controls, the intraocular pressure (IOP) was significantly lower in the aMCI patients. A significant decrease in RNFL thickness in superior temporal, temporal upper (TU), and temporal upper and lower (TL) (TU+TL) quadrants was found in the aMCI patients than in the controls. The average thickness of the mGCC was also significantly thinner in the aMCI patients than in the controls. CONCLUSIONS: Retinal degeneration in the aMCI patients detected by OCT together with lower IOP may indicate disease pathological progression.


Assuntos
Disfunção Cognitiva/patologia , Fibras Nervosas/patologia , Retina/patologia , Células Ganglionares da Retina/patologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Pressão Intraocular/fisiologia , Masculino , Testes de Estado Mental e Demência , Pessoa de Meia-Idade , Tomografia de Coerência Óptica
7.
Oncotarget ; 7(31): 48953-48962, 2016 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-27418146

RESUMO

Network analysis has been widely used in studying Alzheimer's disease (AD). However, how the white matter network changes in cognitive impaired patients with subjective cognitive decline (SCD) (a symptom emerging during early stage of AD) and amnestic mild cognitive impairment (aMCI) (a pre-dementia stage of AD) is still unclear. Here, structural networks were constructed respectively based on FA and FN for 36 normal controls, 21 SCD patients, and 33 aMCI patients by diffusion tensor imaging and graph theory. Significantly lower efficiency was found in aMCI patients than normal controls (NC). Though not significant, the values in those with SCD were intermediate between aMCI and NC. In addition, our results showed significantly altered betweenness centrality located in right precuneus, calcarine, putamen, and left anterior cingulate in aMCI patients. Furthermore, association was found between network metrics and cognitive impairment. Our study suggests that the structural network properties might be preserved in SCD stage and disrupted in aMCI stage, which may provide novel insights into pathological mechanisms of AD.


Assuntos
Transtornos Cognitivos/patologia , Disfunção Cognitiva/patologia , Substância Branca/patologia , Idoso , Mapeamento Encefálico , Estudos de Casos e Controles , Imagem de Tensor de Difusão , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Modelos Biológicos
8.
BMC Neurol ; 16: 64, 2016 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-27176479

RESUMO

BACKGROUND: The ε4 allele of the Apolipoprotein E gene (APOE-ε4) is a potent genetic risk factor for sporadic Alzheimer's disease (AD). Amnestic mild cognitive impairment (aMCI) is an intermediate state between normal cognitive aging and dementia, which is easy to convert to AD dementia. It is an urgent problem in the field of cognitive neuroscience to reveal the conversion of aMCI-ε4 to AD. Based on our preliminary work, we will study the neuroimaging features in the special group of aMCI-ε4 with multi-modality magnetic resonance imaging (structural MRI, resting state-fMRI and diffusion tensor imaging) longitudinally. METHODS/DESIGN: In this study, 200 right-handed subjects who are diagnosed as aMCI with APOE-ε4 will be recruited at the memory clinic of the Neurology Department, XuanWu Hospital, Capital Medical University, Beijing, China. All subjects will undergo the neuroimaging and neuropsychological evaluation at a 1 year-interval for 3 years. The primary outcome measures are 1) Microstructural alterations revealed with multimodal MRI scans including structure MRI (sMRI), resting state functional MRI (rs-fMRI), diffusion tensor imaging (DTI); 2) neuropsychological evaluation, including the World Health Organization-University of California-LosAngeles Auditory Verbal Learning Test (WHO-UCLA AVLT), Addenbrook's cognitive examination-revised (ACE-R), mini-mental state examination (MMSE), Montreal Cognitive Assessment (MoCA), Clinical Dementia Rating scale (CDR). DISCUSSION: This study is to find out the neuroimaging biomarker and the changing laws of the marker during the progress of aMCI-ε4 to AD, and the final purpose is to provide scientific evidence for new prevention, diagnosis and treatment of AD. TRIAL REGISTRATION: This study has been registered to ClinicalTrials.gov (NCT02225964, https://www.clinicaltrials.gov/ ) in August 24, 2014.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Doença de Alzheimer/genética , Doença de Alzheimer/psicologia , Apolipoproteína E4/genética , Biomarcadores , China , Disfunção Cognitiva/genética , Disfunção Cognitiva/psicologia , Imagem de Tensor de Difusão/métodos , Progressão da Doença , Seguimentos , Neuroimagem Funcional , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Testes Neuropsicológicos , Estudos Prospectivos
9.
J Chromatogr A ; 1409: 268-76, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26206627

RESUMO

A newly designed molecularly imprinted polymer (MIP) material was developed and successfully used as recognition element for enantioselective recognition by microchip electrophoresis. In this work, molecularly imprinted polymers were facilely prepared employing Fe3O4 nanoparticles (NPs) as the supporting substrate and norepinephrine as the functional monomer in the presence of template molecule in a weak alkaline solution. After extracting the embedded template molecules, the produced imprinted Fe3O4@polynorepinephrine (MIP-Fe3O4@PNE) NPs have cavities complementary to three dimensional shape of template molecules favoring high binding capacity and magnetism property for easy manipulation. The MIP-Fe3O4@PNE NPs prepared with l-tryptophan, l-valine, l-threonine, Gly-l-Phe, S-(-)-ofloxacin or S-(-)-binaphthol as template molecules were packed in the polydimethylsiloxane microchannel via magnetic field as novel stationary phase to successful enantioseparation of corresponding target analysts. The MIP-Fe3O4@PNE NPs-based microchip electrophoresis system exhibited strong recognition ability, excellent high-performance, admirable reproducibility and stability, which provided a powerful protocol for separation enantiomers within a short analytical time and opened up an avenue for multiplex chiral compound assay in various systems.


Assuntos
Nanopartículas de Magnetita/química , Impressão Molecular , Norepinefrina/química , Dimetilpolisiloxanos , Dipeptídeos/química , Eletroforese em Microchip , Ofloxacino/química , Polímeros , Reprodutibilidade dos Testes , Estereoisomerismo , Treonina/química , Triptofano/química , Valina/química
10.
J Chromatogr A ; 1362: 301-8, 2014 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-25182855

RESUMO

A facile approach for preparation of molecularly imprinted polymers was developed and successfully used as chiral stationary phase for rapid enantioseparation by open tubular capillary electrochromatography (OT-CEC). In this work, molecularly imprinted polymers were one-step prepared employing Fe3O4 nanoparticles (NPs) as the supporting substrate and dopamine as the functional monomer. By simply mixing Fe3O4 NPs with template molecules in a weak alkaline solution of dopamine, a thin adherent polydopamine (PDA) film imprinted with template molecules was formed by the self-polymerization of dopamine on the surface of Fe3O4 NPs. After extracting the embedded template molecules, the produced imprinted Fe3O4@PDA NPs are of three dimensional shape of template molecules favoring high binding capacity and magnetism property for easy manipulation. The imprinted Fe3O4@PDA NPs prepared with l-tryptophan, l-tyrosine, Gly-l-Phe or s-ofloxacin as template molecules were packed in the PDMS microchannel via magnetic field as novel stationary phase for the successful enantioseparation of corresponding target analysts. In addition, the imprinted Fe3O4@PDA NPs-based OT-CEC system exhibited excellent reproducibility, stability and repeatability, which provides a powerful protocol for separation enantiomers within a short analytical time and opens up a promising avenue for high-throughput screening of chiral compounds.


Assuntos
Eletrocromatografia Capilar/métodos , Compostos Férricos/química , Indóis/química , Impressão Molecular/métodos , Nanopartículas/química , Polímeros/química , Fenômenos Magnéticos , Nanopartículas/ultraestrutura , Reprodutibilidade dos Testes , Estereoisomerismo
11.
Electrophoresis ; 35(19): 2824-32, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25042461

RESUMO

In this work, a novel enantioselective MCE was developed employing BSA-conjugated Fe3 O4 @Au nanoparticles (Fe3 O4 @Au NPs) as stationary phase. Fe3 O4 @Au NPs with high magnetic responsively, excellent solubility, and high dispersibility in water were prepared through a sonochemical synthesis strategy. BSA was then immobilized onto the Fe3 O4 @Au NPs surfaces through the well-developed interaction between Au NPs and amine groups of BSA to form Fe3 O4 @Au NPs-BSA conjugates, which were then locally packed into PDMS microchannels with the help of magnets. The resultant Fe3 O4 @Au NPs-BSA conjugates not only have the magnetism of Fe3 O4 NPs that make them easily manipulated by an external magnetic field, but also have the larger surface and excellent biocompatibility of Au shell, which can incorporate much more biomolecules and well maintain their biological activity. In addition, the successful BSA decorations endowed Fe3 O4 @Au NPs-BSA conjugates with pH-tunable water solubility related to the pI of BSA (pI 4.7) and led to enhanced stability against high ionic strength. Compared with the native PDMS microchannel, the modified surfaces exhibited more stable and suppressed electroosmotic mobility, and less nonspecific adsorption toward analytes. Successful separation of chiral amino acids (tryptophan and threonine) and ofloxacin enantiomers demonstrate that the constructed MCE columns own ideal enantioselectivity. The results are expected to open up a new possibility for high-throughput screening of enantiomers with protein targets as well as a new application of magnetic NPs.


Assuntos
Eletroforese em Microchip/instrumentação , Nanopartículas de Magnetita/química , Nanocompostos/química , Soroalbumina Bovina/química , Estabilidade de Medicamentos , Eletroforese em Microchip/métodos , Concentração de Íons de Hidrogênio , Reprodutibilidade dos Testes , Estereoisomerismo , Triptofano/análise , Triptofano/química , Triptofano/isolamento & purificação
12.
J Chromatogr A ; 1323: 135-42, 2014 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-24331371

RESUMO

A novel chip-based enantioselective open-tubular capillary electrochromatography (OT-CEC) was developed employing bovine serum albumin (BSA) conjugated polydopamine-graphene oxide (PDA/GO) nanocomposites (PDA/GO/BSA) as stationary phase. After the poly(dimethylsiloxane) (PDMS) microfluidic chip was filled with a freshly prepared solution containing dopamine and graphene oxide, PDA/GO nanocomposites were formed and deposited on the inner wall of microchannel as permanent coating via the oxidation of dopamine by the oxygen dissolved in the solution. The PDA/GO-coated PDMS microchips not only have the adhesion of PDA that make them easily immobilized in the microchannel, but also have the larger surface and excellent biocompatibility of graphene which can incorporate much more biomolecules and well maintain their biological activity. In addition, incorporation of GO in PDA film can make surface morphology more rough, which is beneficial for enhancing the loading capacity of proteins in the microchannels and increasing sample capacity of OT-CEC columns. BSA was stably immobilized in the PDMS microchannel to fabricate a protein-stationary phase. Compared with the native PDMS microchannels, the modified surfaces exhibited much better wettability, more stable electroosmotic mobility, and less nonspecific adsorption. The efficient separation of chiral amino acids (tryptophan and threonine) and chiral dipeptide demonstrate that the constructed OT-CEC columns own ideal enantioselectivity. The presented strategy using PDA/GO coating as a versatile platform for facile conjugation of proteins may offer new processing strategies to prepare a functional surface designed on microfluidic chips.


Assuntos
Eletrocromatografia Capilar/métodos , Grafite/química , Indóis/química , Óxidos/química , Polímeros/química , Proteínas/química , Proteínas/isolamento & purificação , Adesividade , Adsorção , Dimetilpolisiloxanos/química , Dipeptídeos/química , Dipeptídeos/isolamento & purificação , Eletro-Osmose , Técnicas Analíticas Microfluídicas , Nanocompostos/química , Soroalbumina Bovina/química , Treonina/química , Treonina/isolamento & purificação , Triptofano/química , Triptofano/isolamento & purificação
13.
J Chromatogr A ; 1315: 28-35, 2013 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-24084001

RESUMO

A new strategy for facile construction of graphene oxide magnetic nanocomposites (GO/Fe3O4 MNCs)-based on-chip enzymatic microreactor and ultrasensitive pesticide detection has been proposed. GO/Fe3O4 MNCs were first prepared through an in situ chemical deposition strategy. Then, acetylcholinesterase (AChE) was adsorbed onto the GO/Fe3O4 surface to form GO/Fe3O4/AChE MNCs which was locally packed into PDMS microchannel simply with the help of external magnetic field to form an on-chip enzymatic microreactor. The constructed GO/Fe3O4/AChE MNCs-based enzymatic microreactor not only have the magnetism of Fe3O4 NPs that make them conveniently manipulated by an external magnetic field, but also have the larger surface and excellent biocompatibility of graphene which can incorporate much more AChE molecules and well maintain their biological activity. On the basis of the AChE inhibition principle, a novel on-chip enzymatic microreactor was constructed for analyzing dimethoate which is usually used as a model of organophosphorus pesticides. Under optimal conditions, a linear relationship between the inhibition rates of AChE and the concentration of dimethoate from 1 to 20 µgL(-1) with a detection limit of 0.18 µgL(-1) (S/N=3) was obtained. The developed electrophoretic and magnetic-based chip exhibited excellent reproducibility and stability with no decrease in the activity of enzyme for more than 20 repeated measurements over one week period, which provided a new and promising tool for the analysis of enzyme inhibitors with low cost and excellent performance.


Assuntos
Acetilcolinesterase/metabolismo , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Óxido Ferroso-Férrico/química , Nanocompostos/química , Resíduos de Praguicidas/análise , Acetilcolinesterase/química , Estabilidade Enzimática , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Grafite/química , Limite de Detecção , Compostos Organofosforados/análise , Compostos Organofosforados/química , Compostos Organofosforados/metabolismo , Óxidos/química , Resíduos de Praguicidas/química , Resíduos de Praguicidas/metabolismo , Reprodutibilidade dos Testes , Verduras/química
14.
J Chromatogr A ; 1294: 145-51, 2013 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-23643186

RESUMO

A novel, simple, and economical method for the preparation of chiral stationary phases for chip-based enantioselective open tubular capillary electrochromatography (OT-CEC) using polydopamine (PDA) coating as an adhesive layer was reported for the first time. After the poly(dimethylsiloxane) (PDMS) microfluidic chip was filled with dopamine (DA) solution, PDA film was gradually formed and deposited on the inner wall of microchannel as permanent coating via the oxidation of DA by the oxygen dissolved in the solution. Due to possessing plentiful catechol and amine functional groups, PDA coating can serve as a versatile multifunctional platform for further secondary reactions, leading to tailoring of the coatings for protein bioconjugation by the thiols and amines via Michael addition or Schiff base reactions. Bovine serum albumin (BSA), acting as a target protein, was then stably and homogeneously immobilized in the PDA-coated PDMS microchannel to fabricate a novel protein stationary phase. Compared with the native PDMS microchannels, the modified surfaces exhibited much better wettability, more stable and enhanced electroosmotic mobility, and less nonspecific adsorption. The water contact angle and electroosmotic flow of PDA/BSA-coated PDMS substrate were measured to be 44° and 2.83×10(-4)cm(2)V(-1)s(-1), compared to those of 112° and 2.10×10(-4)cm(2)V(-1)s(-1) from the untreated one, respectively. Under a mild condition, d- and l-tryptophan were efficiently separated with a resolution of 1.68 within 130s utilizing a separation length of 37mm coupled with in-column amperometric detection on the PDA/BSA-coated PDMS microchips. This present versatile platform, facile conjugation of biomolecules onto microchip surfaces via mussel adhesive protein inspired coatings, may offer new processing strategies to prepare a biomimetic surface design on microfluidic chips, which is promising in high-throughput and complex biological analysis.


Assuntos
Eletrocromatografia Capilar/métodos , Indóis/química , Polímeros/química , Soroalbumina Bovina/isolamento & purificação , Adsorção , Animais , Eletrocromatografia Capilar/instrumentação , Bovinos , Soroalbumina Bovina/química , Estereoisomerismo
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