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1.
Chem Commun (Camb) ; 55(98): 14717-14720, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31702759

RESUMO

The final step in the biosynthesis of l-carnitine in humans is catalysed by the 2-oxoglutarate and ferrous iron dependent oxygenase, γ-butyrobetaine hydroxylase (BBOX). 1H and 19F NMR studies inform on the BBOX mechanism including by providing evidence for cooperativity between monomers in substrate/some inhibitor binding. The value of the 19F NMR methods is demonstrated by their use in the design of new BBOX inhibitors.


Assuntos
Inibidores Enzimáticos/química , Espectroscopia de Ressonância Magnética , gama-Butirobetaína Dioxigenase/metabolismo , Betaína/análogos & derivados , Betaína/síntese química , Betaína/química , Betaína/metabolismo , Carnitina/biossíntese , Carnitina/síntese química , Carnitina/química , Carnitina/metabolismo , Desenho de Drogas , Inibidores Enzimáticos/síntese química , Flúor/química , gama-Butirobetaína Dioxigenase/antagonistas & inibidores
2.
J Chromatogr A ; 1608: 460419, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31439439

RESUMO

To increase metabolome coverage in global LC-MS metabolomics, often both reversed-phase liquid chromatography (RPLC) and hydrophilic-interaction liquid chromatography (HILIC) are implemented in parallel. However, there is a lack of consensus in the literature on the best HILIC stationary phase to employ for global metabolomics of human biological fluids. The objective of this study was to compare in detail the performance of two commonly employed HILIC phases: zwitterionic sulfobetaine ZIC-HILIC stationary phase and an underivatized silica HILIC stationary phase. During method development, the effect of salt concentration in the mobile phase was also investigated, and 5 mM ammonium acetate was selected. The stationary phases were evaluated using a mixture of 37 polar standards covering a range of logP values (-10 to 3.73), molecular weights (59-776 Da), charges (15 anions, 11 cations, and 11 neutral) as well as 17 lipid standards to understand phospholipid behaviour on the two stationary phases. The criteria used for the comparison included the quality of the chromatographic peak shape, adequate analyte retention, peak separation capability, and metabolite coverage. The zwitterionic ZIC-HILIC column provided better chromatographic performance over the silica stationary phase with 14 standards achieving good quality peaks compared to the 7 with the silica column. Only 2 standards were undetected with the ZIC-HILIC column compared to the 14 undetected with the silica column. In human plasma, 1966 and 1650 metabolites were observed on the ZIC-HILIC column in positive and negative electrospray ionization (ESI) respectively. On the silica HILIC column, 1773 and 2028 metabolites were observed in positive and negative ESI respectively, showing comparable performance of the two phases. Next, the effect of adding 10 mM ammonium phosphate to the samples to improve the analyte peak shape and metabolite coverage was investigated for both ZIC-HILIC and silica HILIC. In contrast with recently reported results for pZIC-HILIC, there was no clear evidence that ammonium phosphate addition was beneficial for human plasma samples. In conclusion, ZIC-HILIC provided better chromatographic performance for polar plasma metabolomics than underivatized silica in terms of chromatographic peak shape and chromatographic resolution, while maintaining comparable metabolite coverage. The addition of ammonium phosphate to human plasma was not beneficial for either of the two stationary phases.


Assuntos
Cromatografia Líquida/instrumentação , Plasma/química , Betaína/análogos & derivados , Betaína/química , Cromatografia Líquida/métodos , Cromatografia de Fase Reversa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Espectrometria de Massas/métodos , Metaboloma , Metabolômica/instrumentação , Metabolômica/métodos , Fosfatos/química , Dióxido de Silício/química
3.
J Agric Food Chem ; 67(32): 8958-8966, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31334644

RESUMO

The functional role of human milk oligosaccharides (HMOs) is closely associated with their type, composition, and structure. However, a detailed analysis of HMOs is difficult because neutral oligosaccharides (NHMOs) are mixed with sialylated oligosaccharides (SHMOs) in milk. Here, NHMOs were separated from SHMOs by DEAE-52 anion chromatography, and lactose was removed by graphite carbon solid-phase extraction. Lactose-free NHMOs were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) based on Girard's reagent P on-target derivatization (GPOD), and SHMOs were analyzed by MALDI-TOF-MS following selective sialic acid derivatization and GPOD. Sixty-four oligosaccharides were detected: 36 NHMOs, of which 28 were fucosylated, and 28 SHMOs, of which 8 with α-2,3-linked monosialic acid, 2 with α-2,3-linked disialic acid, 10 with α-2,6-linked monosialic acid, 2 with α-2,6-linked disialic acid, and 5 with both α-2,3- and α-2,6-linked disialic acid. These findings provide the groundwork for further characterization of the structure and activity of HMOs.


Assuntos
Betaína/análogos & derivados , Leite Humano/química , Oligossacarídeos/química , Betaína/química , Feminino , Humanos , Ácido N-Acetilneuramínico/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
4.
Bioprocess Biosyst Eng ; 42(11): 1721-1730, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31312897

RESUMO

Collecting microalgae from water with less energy and cost is significant to gain economic profit from microalgae harvesting and processing. Foam separation has certain advantages including low energy consumption, simple operation and easy maintenance of the equipment. Natural surfactants, compared to traditional surfactants, were used to harvest and separate the freshwater microalgae Desmodesmus brasiliensis by foam separation. Results showed a recovery percentage of 93.6% and an enrichment ratio of 23.1 with the natural surfactant cocamidopropyl betaine (CAPB), suggesting that this low-cost surfactant can be applied to microalgae biomass recovery on a commercial scale using foam separation with no negative effect on the content of microalgae chlorophyll, carotenoid or protein.


Assuntos
Betaína/análogos & derivados , Clorofíceas/citologia , Água Doce/microbiologia , Microalgas/citologia , Microalgas/isolamento & purificação , Tensoativos/química , Betaína/química , Floculação
5.
J Toxicol Sci ; 44(6): 393-403, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31167989

RESUMO

To predict the results of a 24-hr closed human patch test, we previously recommended the use of in vitro test with a reconstructed human epidermis (RhE) model adopted in OECD TG 439, and proposed the margin method, which includes evaluation of twice the concentration to avoid a false positive for surfactants. Therefore, in this study, we used LabCyte EPI-MODEL as a RhE model, and confirmed the reproducibility of this method using five surfactants, including benzalkonium chloride (BC), sodium lauryl sulfate (SLS), and lauryl betaine (LB), for which false negative results have previously been reported, and three different surfactants. For all surfactants, prediction of patch test results using a margin of two revealed that human tests could be performed safely, confirming the utility of the margin method. In addition, we examined the relationship with critical micellar concentration (CMC). The IC50 for cell viability in the RhE model for three types of surfactants (BC, SLS, and LB) was 2.7- to 49.7-times the CMC. Therefore, the range of concentrations in which tests were performed with the present method was within the range of concentrations with high cleansing. Furthermore, we examined the relationship between cell viability and release of the inflammatory mediator interleukin-1α (IL-1α). IL-1α release was associated with cell viability, supporting the results of the human patch test.


Assuntos
Epiderme/efeitos dos fármacos , Testes de Irritação da Pele , Tensoativos/toxicidade , Alternativas aos Testes com Animais , Compostos de Benzalcônio/toxicidade , Betaína/análogos & derivados , Betaína/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Epiderme/metabolismo , Humanos , Interleucina-1alfa/metabolismo , Testes do Emplastro , Reprodutibilidade dos Testes , Dodecilsulfato de Sódio/toxicidade
6.
Nanoscale ; 11(21): 10167-10171, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31112182

RESUMO

We have introduced a non-hormonal hyperglycemia treatment strategy by using an injectable glucose-responsive boronic acid- zwitterionic nanogel. The synthesized system, similar to an artificial liver, is capable of storing/releasing glucose at high/low blood glucose concentrations. In vivo performance revealed that the injection of the nanogels can effectively regulate blood glucose in type 1 diabetic rats for at least 6 hours.


Assuntos
Betaína/análogos & derivados , Glicemia/metabolismo , Ácidos Borônicos , Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Hiperglicemia , Nanoestruturas , Animais , Betaína/síntese química , Betaína/química , Betaína/farmacologia , Ácidos Borônicos/síntese química , Ácidos Borônicos/química , Ácidos Borônicos/farmacologia , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Géis , Hiperglicemia/sangue , Hiperglicemia/tratamento farmacológico , Masculino , Nanoestruturas/química , Nanoestruturas/uso terapêutico , Ratos , Ratos Sprague-Dawley
7.
Mater Sci Eng C Mater Biol Appl ; 100: 94-103, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30948130

RESUMO

Various glucose-sensitive drug delivery platforms have been developed recently to treat diabetes. However, there is much less work has been reported on treatment of diabetes and vascular diabetes complications simultaneously. In this work, a novel polysaccharide-based micelle-hydrogel synergistic therapy system was fabricated to address this limitation. Zwitterionic dialdehyde starch-based micelles (SB-DAS-VPBA) were synthesized via single electron transfer-living radical polymerization (SET-LRP). Hydrophilic segment sulfobetaine (SB) and hydrophobic segment 4­vinylphenylboronic acid (VPBA) were grafted to the dialdehyde starch (DAS) backbones. Then, chitosan/dialdehyde starch derivatives (CS/SB-DAS-VPBA) micelle-hydrogel was synthesized by Schiff-base bonds. Insulin and nattokinase were loaded to obtain the micelle-hydrogel synergistic therapy system. In vitro drug delivery and blood clots dissolution behaviors were determined. Results suggest that the micelle-hydrogel synergistic therapy system not only possesses glucose-responsive insulin delivery property, but also provides good thrombolytic capacity. Thus, this micelle-hydrogel synergistic therapy system can be used as a platform for diabetes and vascular diabetes complications treatment.


Assuntos
Hidrogéis/química , Micelas , Amido/análogos & derivados , Betaína/análogos & derivados , Betaína/química , Ácidos Borônicos/química , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Hemólise/efeitos dos fármacos , Humanos , Hidrogéis/farmacologia , Amido/química , Compostos de Vinila/química
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 216: 190-201, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-30901704

RESUMO

Spectral-fluorescent properties of polymethine dye probes anionic 3,3'-di(sulfopropyl)-4,5,4',5'-dibenzo-9-ethylthiacarbocyanine-betaine (DEC) and cationic 3,3',9-trimethylthiacarbocyanine iodide (Cyan 2) in the presence of biological surfactants, bile salts sodium cholate (NaC), sodium deoxycholate (NaDC) and sodium taurocholate (NaTC), as well as sodium dodecyl sulfate (SDS), have been studied in a wide range of surfactant concentrations. When a surfactant is introduced into a solution of DEC, changes of the spectral-fluorescent properties are observed due to decomposition of dye dimers into cis-monomers and cis-trans conversion of the resulting monomers. In the presence of SDS, both processes occur in parallel, caused by noncovalent interaction of dye monomers with micelles, and mainly occur near the critical micelle concentration (CMC). In contrast, upon the introduction of increasing concentrations of bile salts, decomposition of dye dimers into the monomers begins at lower concentrations than cis-trans conversion. The former process is almost completed at concentrations close to CMC of secondary micelles (CMC2), while the latter process occurs even at concentrations of bile salts much higher than CMC2. Hence, DEC can serve as a probe that permits estimating the value of CMC2 and is indicative of reorganization of secondary micelles upon an increase in bile salt concentration. Aggregation of DEC and Cyan 2 on bile salts is also observed. Since it is observed at relatively low concentrations of bile salts (

Assuntos
Carbocianinas/metabolismo , Ácido Desoxicólico/metabolismo , Indóis/metabolismo , Colato de Sódio/metabolismo , Tensoativos/metabolismo , Ácido Taurocólico/metabolismo , Betaína/análogos & derivados , Betaína/metabolismo , Carbocianinas/química , Ácido Desoxicólico/química , Dimerização , Indóis/química , Micelas , Colato de Sódio/química , Dodecilsulfato de Sódio/química , Dodecilsulfato de Sódio/metabolismo , Espectrometria de Fluorescência , Tensoativos/química , Ácido Taurocólico/química
9.
Molecules ; 24(3)2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30736477

RESUMO

Enzyme-assisted derivatization for sterol analysis (EADSA) is a technology designed to enhance sensitivity and specificity for sterol analysis using electrospray ionization⁻mass spectrometry. To date it has only been exploited on sterols with a 3ß-hydroxy-5-ene or 3ß-hydroxy-5α-hydrogen structure, using bacterial cholesterol oxidase enzyme to convert the 3ß-hydroxy group to a 3-oxo group for subsequent derivatization with the positively charged Girard hydrazine reagents, or on substrates with a native oxo group. Here we describe an extension of the technology by substituting 3α-hydroxysteroid dehydrogenase (3α-HSD) for cholesterol oxidase, making the method applicable to sterols with a 3α-hydroxy-5ß-hydrogen structure. The 3α-HSD enzyme works efficiently on bile alcohols and bile acids with this stereochemistry. However, as found by others, derivatization of the resultant 3-oxo group with a hydrazine reagent does not go to completion in the absence of a conjugating double bond in the sterol structure. Nevertheless, Girard P derivatives of bile alcohols and C27 acids give an intense molecular ion ([M]⁺) upon electrospray ionization and informative fragmentation spectra. The method shows promise for analysis of bile alcohols and 3α-hydroxy-5ß-C27-acids, enhancing the range of sterols that can be analyzed at high sensitivity in sterolomic studies.


Assuntos
Ácidos e Sais Biliares/análise , Colestanóis/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Betaína/análogos & derivados , Ácidos e Sais Biliares/química , Colestanóis/química , Cromatografia Líquida , Hidroxiesteroide Desidrogenases/química , Espectrometria de Massas , Oxirredução , Esteróis/análise , Esteróis/química , Especificidade por Substrato
10.
J Bacteriol ; 201(7)2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30670548

RESUMO

l-Carnitine is a trimethylammonium compound mostly known for its contribution to fatty acid transport into mitochondria. In bacteria, it is synthesized from γ-butyrobetaine (GBB) and can be used as a carbon source. l-Carnitine can be formed directly by GBB hydroxylation or synthesized via a biosynthetic route analogous to fatty acid degradation. However, this multistep pathway has not been experimentally characterized. In this work, we identified by gene context analysis a cluster of l-carnitine anabolic genes next to those involved in its catabolism and proceeded to the complete in vitro characterization of l-carnitine biosynthesis and degradation in Sinorhizobium meliloti The five enzymes catalyzing the seven steps that convert GBB to glycine betaine are described. Metabolomic analysis confirmed the multistage synthesis of l-carnitine in GBB-grown cells but also revealed that GBB is synthesized by S. meliloti To our knowledge, this is the first report of aerobic GBB synthesis in bacteria. The conservation of l-carnitine metabolism genes in different bacterial taxonomic classes underscores the role of l-carnitine as a ubiquitous nutrient.IMPORTANCE The experimental characterization of novel metabolic pathways is essential for realizing the value of genome sequences and improving our knowledge of the enzymatic capabilities of the bacterial world. However, 30% to 40% of genes of a typical genome remain unannotated or associated with a putative function. We used enzyme kinetics, liquid chromatography-mass spectroscopy (LC-MS)-based metabolomics, and mutant phenotyping for the characterization of the metabolism of l-carnitine in Sinorhizobium meliloti to provide an accurate annotation of the corresponding genes. The occurrence of conserved gene clusters for carnitine metabolism in soil, plant-associated, and marine bacteria underlines the environmental abundance of carnitine and suggests this molecule might make a significant contribution to ecosystem nitrogen and carbon cycling.


Assuntos
Carnitina/metabolismo , Redes e Vias Metabólicas/genética , Sinorhizobium meliloti/genética , Sinorhizobium meliloti/metabolismo , Aerobiose , Betaína/análogos & derivados , Betaína/metabolismo , Biotransformação , Metabolômica , Família Multigênica
11.
Anal Chim Acta ; 1048: 105-114, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30598139

RESUMO

Sensitive glycomics analysis by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is of great importance but significantly hampered by their low ionization efficiency and labile sialic acid moieties. Chemical derivatization offers a viable way to improve both the ionization efficiency and analytical sensitivity of the glycans in MS analysis by altering their hydrophobicity or charge property. Here we employed Girard's reagent T (GT) for on-target derivatization (GTOD) of reducing glycan under mild acid condition to form stable hydrazones at room temperature, allowing rapid and sensitive identification of neutral and sialylated glycans in positive-ion mode as only permanently positive charged molecular ions without multiple ion adducts by MALDI-TOF-MS. The MS signal intensities of lactose, sialylated N-glycans derived from bovine fetuin and neutral N-glycans derived from RNaseB and ovalbumin were boosted by 7.44, 9.13, 12.96 and 13.47 folds on average (n = 3), respectively. More importantly, after GTOD strategy, unwanted desialylation of sialylated glycans during MS was suppressed. The detection limit of the assay is desirable since the nanogram of N-glycans derived from 0.16 µg ovalbumin could be detected. The assay demonstrated good stability (RSD≤2.95%, within 10 days), reliable reproducibility (RSD = 2.96%, n = 7) and a desirable linear dynamic range from 78 nmol/mL to 10 µmol/mL. The strategy has been successfully applied to MS analysis of reducing glycans from human milks, neutral and sialylated O-, N-glycans from glycoproteins, and reducing glycans derived from glycosphingolipids, presenting neater [M]+ signals which allow detection of more low-abundance glycans and assignation of Neu5Ac vs. Neu5Gc or fucose vs. hexose in glycans due to the absence of the ambiguous interpretation from multiple peaks (ion adducts [M+Na]+ and [M+K]+). Moreover, the GTOD assay prevents desialylation during MALDI-TOF-MS profiling and enables distinct linkage-specific characterization of terminal sialic acids of N-glycans derived from human serum protein when combines with an esterification.


Assuntos
Betaína/análogos & derivados , Glicômica/métodos , Oligossacarídeos/química , Polissacarídeos/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Betaína/química , Proteínas Sanguíneas/química , Feminino , Glicoproteínas/química , Glicoesfingolipídeos/química , Humanos , Proteínas do Leite/química , Leite Humano/química , Reprodutibilidade dos Testes , Ácidos Siálicos/química
12.
Langmuir ; 35(5): 1727-1739, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29925240

RESUMO

Poly(ethylene terephtalate) (PET)-based materials face general biofouling issues that we addressed by grafting a copolymer of glycidyl methacrylate and sulfobetaine methacrylate, poly(GMA- r-SBMA). The grafting procedure involved a dip-coating step followed by UV-exposure and led to successful grafting of the copolymer as evidenced by X-ray photoelectron spectroscopy and zeta potential measurements. It did not modify the pore size nor the porosity of the PET membranes. In addition, their surface hydrophilicity was considerably improved, with a water contact angle falling to 30° in less than 20 s and 0° in less than 1 min. The effect of copolymer concentration in the coating bath (dip-coating procedure) and UV exposure time (UV step) were scrutinized during biofouling studies involving several bacteria such as Escherichia coli and Stenotrophomonas maltophilia, but also whole blood and HT1080 fibroblasts cells. The results indicate that if all conditions led to improved biofouling mitigation, due to the efficiency of the zwitterionic copolymer and grafting procedure, a higher concentration (15 mg/mL) and longer UV exposure time (at least 10 min) enhanced the grafting density which reflected on the biofouling results and permitted a better general biofouling control regardless of the nature of the biofoulant (bacteria, blood cells, fibroblasts).


Assuntos
Polietilenotereftalatos/química , Aderência Bacteriana/efeitos dos fármacos , Betaína/análogos & derivados , Betaína/síntese química , Betaína/química , Incrustação Biológica/prevenção & controle , Células Sanguíneas/efeitos dos fármacos , Linhagem Celular Tumoral , Compostos de Epóxi/síntese química , Compostos de Epóxi/química , Escherichia coli/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/síntese química , Metacrilatos/química , Polietilenotereftalatos/síntese química , Stenotrophomonas maltophilia/efeitos dos fármacos
13.
Langmuir ; 35(5): 1391-1403, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30134095

RESUMO

A procedure for the preparation of copolymers bearing sulfobetaine and carboxybetaine methacrylic-based monomers by free-radical polymerization is described and discussed. A combination of monomers affects the upper critical solution temperature (UCST) in water and in the presence of a simple NaCl electrolyte while retaining the zwitterionic character. In addition, hydrogel samples were prepared and showed tunable water structure and mechanical properties. The total nonfreezable water content decreases with the amount of carboxybetaine segment in the hydrogel feed and the compression moduli were in a range of 0.7-1.6 MPa. Responses to external conditions such as temperature and ion strength were investigated and a potential application such as modulated thermal detection is proposed. The presence of the carboxylate group in the carboxybetaine segment enables a small fluorescence probe and peptide bearing RDG motif to be attached to polymer and hydrogel samples, respectively. The hydrogel samples functionalized with the RGD motif exhibit controlled cell adhesion. Such synthetic strategy based on combination of different zwitterionic segments offers a simple pathway for the development of zwitterionic materials with programmable properties.


Assuntos
Adesão Celular/efeitos dos fármacos , Ácidos Polimetacrílicos/farmacologia , Água/química , Células 3T3 , Animais , Betaína/análogos & derivados , Betaína/química , Hidrogéis/síntese química , Hidrogéis/química , Hidrogéis/farmacologia , Concentração de Íons de Hidrogênio , Camundongos , Concentração Osmolar , Polimerização , Ácidos Polimetacrílicos/síntese química , Ácidos Polimetacrílicos/química , Temperatura de Transição , Substâncias Viscoelásticas/síntese química , Substâncias Viscoelásticas/química , Substâncias Viscoelásticas/farmacologia
14.
Langmuir ; 35(5): 1642-1651, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30114915

RESUMO

Biomaterials-associated infections (BAIs) are related to bacterial colonization on medical devices, which lead to a serious medical burden, such as increased healthcare cost, prolonged hospital stays, and high mortality and morbidity. To reduce the risk of infections, in this work, a new approach which makes use of a bioinspired coating with dual antimicrobial and antifouling functions was developed through rapid deposition of functional polydopamine (pDA) and antimicrobial copper ions, and subsequent conjugation of zwitterionic antifouling sulfobetaine (SB) moieties by the aza-Michael addition reaction. pDA permits surface-independent versatile functionalization on a variety of substrates, such as TiO2, SiO2, gold, plastics, and Nitinol alloy. The characterizations for chemical elemental compositions and hydrophilicity by X-ray photoelectron spectroscopy and contact angle goniometer, respectively, indicating the successful grafting of SB moieties and the presence of copper ions in the pDA adlayers. Ellipsometric thicknesses of the thin films were followed to monitor the formation of pDA films and the changes after the post conjugation. UV-vis spectroscopy and inductively coupled plasma-mass spectrometry revealed the coordination structure of catechol-Cu, and release profile of Cu2+ from the constructed functional coatings. The superhydrophilic and charge-balanced SB interface allowed effective resistance of bacterial adsorption. Intriguingly, we scrutinized that the release of bactericidal copper ions enables killing the residual amount of adsorbed bacteria. Moreover, viability tests for fibroblast cells indicate the excellent biocompatibility of the developed medical coatings. For real-world implementation, the antifouling and antimicrobial coatings were applied on commercially available silicone-based urinary catheters, and the existence of bacteria was evaluated by using the plate-counting assay. The results showed an undetectable level of living bacteria. Consequently, the dual functional medical coating offers a promising approach to eliminate BAIs for practical applications.


Assuntos
Antibacterianos/farmacologia , Incrustação Biológica/prevenção & controle , Materiais Revestidos Biocompatíveis/farmacologia , Animais , Antibacterianos/química , Aderência Bacteriana/efeitos dos fármacos , Betaína/análogos & derivados , Betaína/química , Betaína/farmacologia , Materiais Revestidos Biocompatíveis/química , Cobre/química , Cobre/farmacologia , Escherichia coli/efeitos dos fármacos , Indóis/química , Indóis/farmacologia , Camundongos , Células NIH 3T3 , Polímeros/química , Polímeros/farmacologia , Staphylococcus epidermidis/efeitos dos fármacos , Cateteres Urinários/microbiologia
15.
J Clin Invest ; 129(1): 373-387, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30530985

RESUMO

BACKGROUND: l-Carnitine, an abundant nutrient in red meat, accelerates atherosclerosis in mice via gut microbiota-dependent formation of trimethylamine (TMA) and trimethylamine N-oxide (TMAO) via a multistep pathway involving an atherogenic intermediate, γ-butyrobetaine (γBB). The contribution of γBB in gut microbiota-dependent l-carnitine metabolism in humans is unknown. METHODS: Omnivores and vegans/vegetarians ingested deuterium-labeled l-carnitine (d3-l-carnitine) or γBB (d9-γBB), and both plasma metabolites and fecal polymicrobial transformations were examined at baseline, following oral antibiotics, or following chronic (≥2 months) l-carnitine supplementation. Human fecal commensals capable of performing each step of the l-carnitine→γBB→TMA transformation were identified. RESULTS: Studies with oral d3-l-carnitine or d9-γBB before versus after antibiotic exposure revealed gut microbiota contribution to the initial 2 steps in a metaorganismal l-carnitine→γBB→TMA→TMAO pathway in subjects. Moreover, a striking increase in d3-TMAO generation was observed in omnivores over vegans/vegetarians (>20-fold; P = 0.001) following oral d3-l-carnitine ingestion, whereas fasting endogenous plasma l-carnitine and γBB levels were similar in vegans/vegetarians (n = 32) versus omnivores (n = 40). Fecal metabolic transformation studies, and oral isotope tracer studies before versus after chronic l-carnitine supplementation, revealed that omnivores and vegans/vegetarians alike rapidly converted carnitine to γBB, whereas the second gut microbial transformation, γBB→TMA, was diet inducible (l-carnitine, omnivorous). Extensive anaerobic subculturing of human feces identified no single commensal capable of l-carnitine→TMA transformation, multiple community members that converted l-carnitine to γBB, and only 1 Clostridiales bacterium, Emergencia timonensis, that converted γBB to TMA. In coculture, E. timonensis promoted the complete l-carnitine→TMA transformation. CONCLUSION: In humans, dietary l-carnitine is converted into the atherosclerosis- and thrombosis-promoting metabolite TMAO via 2 sequential gut microbiota-dependent transformations: (a) initial rapid generation of the atherogenic intermediate γBB, followed by (b) transformation into TMA via low-abundance microbiota in omnivores, and to a markedly lower extent, in vegans/vegetarians. Gut microbiota γBB→TMA/TMAO transformation is induced by omnivorous dietary patterns and chronic l-carnitine exposure. TRIAL REGISTRATION: ClinicalTrials.gov NCT01731236. FUNDING: NIH and Office of Dietary Supplements grants HL103866, HL126827, and DK106000, and the Leducq Foundation.


Assuntos
Aterosclerose , Betaína/análogos & derivados , Carnitina/sangue , Clostridiales/metabolismo , Microbioma Gastrointestinal , Metilaminas/metabolismo , Animais , Aterosclerose/metabolismo , Aterosclerose/microbiologia , Aterosclerose/patologia , Betaína/sangue , Feminino , Humanos , Masculino , Camundongos , Projetos Piloto , Veganos
16.
Caries Res ; 53(1): 1-9, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29874648

RESUMO

This study investigated the effect of surfactants associated with sodium fluoride (NaF) on enamel erosion prevention, using an erosion-remineralization in vitro model. Sodium lauryl sulfate (SLS), polysorbate 20 (P20), and cocoamidopropyl betaine (CAPB) were tested, at concentrations of 1.0 and 1.5%, and associated or not with NaF (275 ppm). The control groups were distilled water and the NaF solution. Bovine enamel samples (n = 12) were prepared and submitted to a 5-day cycling model: acid challenge (0.3% citric acid, pH 2.6, 4×/day), human saliva (2 h, 4×/day), and the treatment solutions (2 min, 2×/day). The protective potential of the agents against initial erosion was assessed by microhardness and the surface loss by profilometry. Enamel surface wettability was determined by goniometry, protein adsorption was measured by spectroscopy (FTIR), and the KOH-soluble fluoride was quantified. Goniometry showed that SLS and CAPB increased enamel wettability. No differences were found among the surfactants regarding protein adsorption. Microhardness showed that SLS reduced NaF protection. P20 (1 and 1.5%) and CAPB 1.5% presented a protective effect, but lower than the NaF solution. Profilometry showed that CAPB protected enamel, but no agent associated with NaF promoted a higher protection than the NaF solution alone. KOH-soluble fluoride analysis showed that all surfactants reduced the fluoride adsorption on the enamel surface. Therefore, the surfactants tested (except for P20) changed the enamel surface energy. The SLS decreased the protective potential of NaF on initial erosion, but no tested agent interfered with the protective effect of NaF on enamel erosive wear.


Assuntos
Betaína/análogos & derivados , Cariostáticos/farmacologia , Esmalte Dentário/patologia , Polissorbatos/farmacologia , Dodecilsulfato de Sódio/farmacologia , Fluoreto de Sódio/farmacologia , Tensoativos/farmacologia , Erosão Dentária/prevenção & controle , Adsorção/efeitos dos fármacos , Análise de Variância , Animais , Betaína/química , Betaína/farmacologia , Bovinos , Ácido Cítrico/efeitos adversos , Esmalte Dentário/efeitos dos fármacos , Dureza , Polissorbatos/química , Saliva/fisiologia , Dodecilsulfato de Sódio/química , Tensoativos/química , Erosão Dentária/induzido quimicamente , Molhabilidade/efeitos dos fármacos , Espectroscopia por Absorção de Raios X
17.
Langmuir ; 35(5): 1631-1641, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30558419

RESUMO

Poly(carboxybetaine) (pCB) hydrogels do not elicit a foreign body response due to their low-fouling properties, making them ideal implantable materials for in vivo drug and cell delivery. Current reported pCB hydrogels are cross-linked using cytotoxic UV-initiated radical polymerization limiting clinical and in vivo translation. For clinical translation, we require in situ and biorthogonal cross-linking of pCB hydrogels that are both low-fouling and low-swelling to limit nonspecific interactions and minimize tissue damage, respectively. To this end, we synthesized carboxybetaine (CB) random copolymers (molecular weight (MW): ∼7-33 kDa; D: 1.1-1.36) containing azide (pCB-azide) or strained alkyne (Dibenzocyclooctyne (DBCO); pCB-DBCO) that rapidly cross-link upon mixing. Unlike CB homopolymers and other CB copolymers studied, high DBCO content pCB-DBCO30 (30% DBCO mole fraction) is thermoresponsive with a upper critical solution temperature (UCST; cloud point of ∼20 °C at 50 g/L) in water due to electrostatic associations. Due to the antipolyelectrolyte effect, pCB-DBCO30 is salt-responsive and is soluble even at low temperatures in 5 M NaCl, which prevents zwitterion electrostatic associations. pCB-azide and pCB-DBCO with 0.05 to 0.16 cross-linker mole fractions rapidly formed 10 wt % hydrogels upon mixing that were low-swelling (increase of ∼10% in wet weight) while remaining low-fouling to proteins (∼10-20 µg cm-2) and cells, making them suitable for in vivo applications. pCB-X31 hydrogels composed of pCB-azide32 and pCB-DBCO30 formed opaque gels in water and physiological conditions that shrunk to ∼70% of their original wet weight due to pCB-DBCO30's greater hydrophobicity and interchain electrostatic interactions, which promotes nonspecific protein adsorption (∼35 µg cm-2) and cell binding. Once formed, the electrostatic interactions in pCB-X31 hydrogels are not fully reversible with heat or salt. Although, pCB-X31 hydrogels are transparent when initially prepared in 5 M NaCl. This is the first demonstration of a thermo- and salt-responsive CB copolymer that can tune hydrogel protein and cell fouling properties.


Assuntos
Betaína/análogos & derivados , Hidrogéis/química , Polímeros/química , Animais , Betaína/metabolismo , Betaína/farmacologia , Incrustação Biológica/prevenção & controle , Bovinos , Adesão Celular/efeitos dos fármacos , Módulo de Elasticidade , Hidrogéis/metabolismo , Hidrogéis/farmacologia , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Células NIH 3T3 , Polímeros/metabolismo , Polímeros/farmacologia , Ligação Proteica , Soroalbumina Bovina/metabolismo , Eletricidade Estática
18.
Bioorg Med Chem Lett ; 28(23-24): 3665-3669, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30528978

RESUMO

Two novel zwitterionic N-chlorohydantoin biocides, containing an N-chlorohydantoin unit and a sulfobetaine unit or a carboxybetaine unit, were chemically synthesized and characterized. Using the quaternary ammonium N-chlorohydantoin as control, the antibacterial activity of synthetic zwitterionic N-chlorohydantoins was challenged and the antibacterial data showed that carboxybetaine N-chlorohydantoin exhibited distinctively higher biocidal efficacy than QA counterpart, while sulfobetaine N-chlorohydantoin displayed slightly inferior antimicrobial efficacy. Our results may inspire further exploration of more zwitterionic N-chlorohydantoin analogs for antibacterial application.


Assuntos
Antibacterianos/síntese química , Betaína/análogos & derivados , Antibacterianos/química , Antibacterianos/farmacologia , Betaína/química , Parede Celular/metabolismo , Escherichia coli/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Compostos de Amônio Quaternário/química , Staphylococcus aureus/efeitos dos fármacos
19.
Molecules ; 23(12)2018 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-30558219

RESUMO

Given that the peculiar redox behavior of ergothioneine involves a rapid regeneration process, the measurement of its precursor and redox metabolite hercynine could be particularly useful in assessing its role in oxidative stress or other biological processes. Thus, a LC-MS/MS method for the determination of hercynine concentrations in whole blood was developed. After lysis of red blood cells by cold water, samples were filtered on micro concentrators at a controlled temperature of 4 °C. The clear filtered fluid was then treated with diethylpyrocarbonate to derivatize hercynine for the analysis by LC-MS/MS. The derivatized analyte was isocratically separated as a carbethoxy derivative on a C18 column with a mobile phase of an aqueous 0.1% v/v formic acid and acetonitrile (95:5). Effluents were monitored by MRM transitions at m/z 270.28→95 and 273.21→95 for hercynine and its deuterated counterpart, respectively. No cross-talk between MRM transitions was observed and a good linearity was found within a range of 35⁻1120 nmol/L. The LOD and LOQ were, respectively, 10.30 and 31.21 nmol/L with an intraday and intermediate precision below 7%. The average hercynine concentration in whole blood from 30 healthy male volunteers (aged 77 ± 12 years) was 178.5 ± 118.1 nmol/L. Overall, the method is easy to perform, allowing a rapid and accurate assessment of whole blood concentrations of hercynine.


Assuntos
Antioxidantes/análise , Betaína/análogos & derivados , Histidina/análogos & derivados , Espectrometria de Massas em Tandem/métodos , Acetonitrilos/análise , Betaína/sangue , Cromatografia Líquida , Formiatos/análise , Histidina/sangue , Humanos , Estresse Oxidativo/fisiologia
20.
Biomolecules ; 8(4)2018 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-30380655

RESUMO

We have investigated myoglobin protein denaturation using the zwitterionic detergent Empigen BB (EBB, N,N-Dimethyl-N-dodecylglycine betaine). A combination of absorbance, fluorescence, and circular dichroism spectroscopic measurements elucidated the protein denaturation and heme dissociation from myoglobin. The results indicated that Empigen BB was not able to fully denature the myoglobin structure, but apparently can induce the dissociation of the heme group from the protein. This provides a way to estimate the heme binding free energy, ΔGdissociation. As ionic liquids (ILs) have been shown to perturb the myoglobin protein, we have investigated the effects of the ILs 1-butyl-3-methylimidazolium chloride (BMICl), 1-ethyl-3-methylimidazolium acetate (EMIAc), and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIBF4) in aqueous solution on the ΔGdissociation values. Absorbance experiments show the ILs had minimal effect on ΔGdissociation values when compared to controls. Fluorescence and circular dichroism data confirm the ILs have no effect on heme dissociation, demonstrating that low concentrations ILs do not impact the heme dissociation from the protein and do not significantly denature myoglobin on their own or in combination with EBB. These results provide important data for future studies of the mechanism of IL-mediated protein stabilization/destabilization and biocompatibility studies.


Assuntos
Betaína/análogos & derivados , Betaína/farmacologia , Detergentes/farmacologia , Glicina/análogos & derivados , Glicina/farmacologia , Heme/metabolismo , Líquidos Iônicos/farmacologia , Mioglobina/metabolismo , Animais , Dicroísmo Circular , Cavalos , Micelas , Mioglobina/química , Compostos Orgânicos/farmacologia , Desnaturação Proteica/efeitos dos fármacos , Desdobramento de Proteína/efeitos dos fármacos , Espectrometria de Fluorescência , Termodinâmica
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