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[PMID]: 29367490 [Au] Autor: Asakawa T; Takano Y; Ohta A; Asakawa H [Ad] Endereço: School of Chemistry, College of Science and Engineering, Kanazawa University. [Ti] Título: Aggregation and pH Responsive Behavior of Thioester Surfactants and Formation of Disulfide Linkages in Aqueous Solutions. [So] Source: J Oleo Sci;67(2):199-206, 2018 Feb 01. [Is] ISSN: 1347-3352 [Cp] País de publicação: Japan [La] Idioma: eng [Ab] Resumo: pH responsive surfactants, [C H N(CH ) (CH ) SCOCH ]Br (C nSAc, n = 4, 11, 12), were prepared, and their properties in aqueous solution were examined. The critical micelle concentration (cmc) and critical vesicle concentration (cvc) were determined based on changes in conductivity, as well as by fluorescence measurements, and light scattering methods. A significant increase in the light scattering intensities of the C nSAc (n=11, 12) systems suggested that the growth of aggregates was accompanied by considerable counterion binding with increasing surfactant concentration. The diameter of C 11SAc, recorded by the dynamic light scattering measurements, was about 9.6 ±1.0 nm, which was slightly smaller than that for didodecyldimethylammonium bromide (DDAB) vesicles. The thioester group was easily hydrolyzed upon the addition of NaOH, while it was hardly hydrolyzed with the addition of HCl. The time course of alkaline hydrolysis was examined by the conductivity measurements and high-performance liquid chromatography analysis. [C H N(CH ) (CH ) SS(CH ) N(CH ) C H ]2Br (2C 11SS) was generated in the C 11SAc alkaline solution because of air oxidation. The C 11SAc alkaline solution gradually became an opaque blue color with increasing light scattering at 346 nm, indicating the remarkable growth of vesicles. The chemical structure of 2C 11SS was consistent with that of a disulfide linked double tailed surfactant, similar to DDAB. The disulfide linkage between the double tailed surfactants will contribute to the stabilization and growth of vesicles. [Mh] Termos MeSH primário: Ésteres/química Tensoativos/química Água/química [Mh] Termos MeSH secundário: Dissulfetos/química Difusão Dinâmica da Luz Concentração de Íons de Hidrogênio Hidrólise Micelas Oxirredução Compostos de Amônio Quaternário/química Soluções Tensão Superficial [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Disulfides); 0 (Esters); 0 (Micelles); 0 (Quaternary Ammonium Compounds); 0 (Solutions); 0 (Surface-Active Agents); 059QF0KO0R (Water); 13146-86-6 (didodecyldimethylammonium) [Em] Mês de entrada: 1803 [Cu] Atualização por classe: 180309 [Lr] Data última revisão: 180309 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 180126 [St] Status: MEDLINE [do] DOI: 10.5650/jos.ess17192

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[PMID]: 29367489 [Au] Autor: Ogura T; Sato T; Abe M; Okano T [Ad] Endereço: Research & Development Headquarters, LION Corporation. [Ti] Título: Small Angle X-ray Scattering and Electron Spin Resonance Spectroscopy Study on Fragrance Infused Cationic Vesicles Modeling Scent-Releasing Fabric Softeners. [So] Source: J Oleo Sci;67(2):177-186, 2018 Feb 01. [Is] ISSN: 1347-3352 [Cp] País de publicação: Japan [La] Idioma: eng [Ab] Resumo: Industrially relevant systems for household and personal-care products often involve a large number of components. Such multiple component formulations are indispensable and effective for functionalization of the products, but may simultaneously provide more complex structural features compared to those in ideal systems comprising a smaller number of highly pure substances. Using cryogenic transmission electron microscopy (cryo-TEM), small angle X-ray scattering (SAXS), and electron spin resonance (ESR) spectroscopy, we have investigated effects of fragrance-incorporation into cationic vesicles on their bilayer structures and membrane-membrane interactions. Cationic vesicles were prepared from TEQ surfactant, whose major component was di(alkyl fatty ester) quaternary ammonium methosulfate, and fragrance components, l-menthol, linalool, and d-limonene, were infused into the vesicle membranes to model scent-releasing fabric softeners. The cryo-TEM images confirm formation of multilamellar vesicles (MLVs). Generalized indirect Fourier transformation (GIFT) analysis of the SAXS intensities based on the modified Caillé structure factor model reveals that incorporation of a more hydrophobic fragrance component leads to a more pronounced increase of the surface separation (water layer thickness). Furthermore, the fragrance-infused systems show longer-range order of the bilayer correlations and enhanced undulation fluctuation of the membranes than those in the TEQ alone system. The spin-label ESR results indicate different restricted molecular motions in the TEQ bilayers depending on the labeled position and their marked changes upon addition of the fragrance components, suggesting different mixing schemes and solubilization positions of the fragrance molecules in the TEQ bilayers. The present data have demonstrated how the infused fragrance molecules having different hydrophobicity and molecular architectures into the cationic vesicles affect the membrane structures and the intermembrane interactions, which may provide useful information for precisely controlling a fragrance-releasing property. [Mh] Termos MeSH primário: Cicloexenos/química Espectroscopia de Ressonância de Spin Eletrônica Mentol/química Monoterpenos/química Odorantes Espalhamento a Baixo Ângulo Terpenos/química Difração de Raios X [Mh] Termos MeSH secundário: Cátions Interações Hidrofóbicas e Hidrofílicas Bicamadas Lipídicas Membranas Artificiais Microscopia Eletrônica de Transmissão Compostos Orgânicos/química Compostos de Amônio Quaternário/química [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Cations); 0 (Cyclohexenes); 0 (Lipid Bilayers); 0 (Membranes, Artificial); 0 (Monoterpenes); 0 (Organic Chemicals); 0 (Quaternary Ammonium Compounds); 0 (Terpenes); 0 (fabric softeners); 1490-04-6 (Menthol); 9MC3I34447 (limonene); D81QY6I88E (linalool) [Em] Mês de entrada: 1803 [Cu] Atualização por classe: 180309 [Lr] Data última revisão: 180309 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 180126 [St] Status: MEDLINE [do] DOI: 10.5650/jos.ess17186

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[PMID]: 29238190 [Au] Autor: Salade L; Wauthoz N; Deleu M; Vermeersch M; De Vriese C; Amighi K; Goole J [Ad] Endereço: Laboratoire de Pharmacie Galénique et de Biopharmacie, Université libre de Bruxelles (ULB), Brussels. [Ti] Título: Development of coated liposomes loaded with ghrelin for nose-to-brain delivery for the treatment of cachexia. [So] Source: Int J Nanomedicine;12:8531-8543, 2017. [Is] ISSN: 1178-2013 [Cp] País de publicação: New Zealand [La] Idioma: eng [Ab] Resumo: The aim of the present study was to develop a ghrelin-containing formulation based on liposomes coated with chitosan intended for nose-brain delivery for the treatment of cachexia. Among the three types of liposomes developed, anionic liposomes provided the best results in terms of encapsulation efficiency (56%) and enzymatic protection against trypsin (20.6% vs 0% for ghrelin alone) and carboxylesterase (81.6% vs 17.2% for ghrelin alone). Ghrelin presented both electrostatic and hydrophobic interactions with the anionic lipid bilayer, as demonstrated by isothermal titration calorimetry. Then, anionic liposomes were coated with -(2-hydroxy) propyl-3-trimethyl ammonium chitosan chloride. The coating involved a size increment from 146.9±2.7 to 194±6.1 nm, for uncoated and coated liposomes, respectively. The ζ-potential was similarly increased from -0.3±1.2 mV to 6±0.4 mV before and after coating, respectively. Chitosan provided mucoadhesion, with an increase in mucin adsorption of 22.9%. Enhancement of permeation through the Calu3 epithelial monolayer was also observed with 10.8% of ghrelin recovered in the basal compartment in comparison to 0% for ghrelin alone. Finally, aerosols generated from two nasal devices (VP3 and SP270) intended for aqueous dispersion were characterized with either coated or uncoated liposomes. Contrarily to the SP270 device, VP3 device showed minor changes between coated and uncoated liposome aerosols, as shown by their median volume diameters of 38.4±5.76 and 37.6±5.74 µm, respectively. Overall, the results obtained in this study show that the developed formulation delivered by the VP3 device can be considered as a potential candidate for nose-brain delivery of ghrelin. [Mh] Termos MeSH primário: Caquexia/tratamento farmacológico Sistemas de Liberação de Medicamentos/métodos Grelina/administração & dosagem Lipossomos/administração & dosagem Lipossomos/química [Mh] Termos MeSH secundário: Administração Intranasal/instrumentação Adsorção Aerossóis/química Encéfalo/efeitos dos fármacos Quitosana/análogos & derivados Quitosana/química Estabilidade de Medicamentos Grelina/química Seres Humanos Interações Hidrofóbicas e Hidrofílicas Mucinas/metabolismo Compostos de Amônio Quaternário/química Eletricidade Estática [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Aerosols); 0 (Ghrelin); 0 (Liposomes); 0 (Mucins); 0 (N-(2-hydroxypropyl)-3-trimethylammonium chitosan); 0 (Quaternary Ammonium Compounds); 9012-76-4 (Chitosan) [Em] Mês de entrada: 1803 [Cu] Atualização por classe: 180309 [Lr] Data última revisão: 180309 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 171215 [St] Status: MEDLINE [do] DOI: 10.2147/IJN.S147650

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[PMID]: 28271736 [Au] Autor: Lv L; Zhang X; Qiao J [Ad] Endereço: a College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse , Tongji University , Shanghai , People's Republic of China. [Ti] Título: Flocculation of low algae concentration water using polydiallyldimethylammonium chloride coupled with polysilicate aluminum ferrite. [So] Source: Environ Technol;39(1):83-90, 2018 Jan. [Is] ISSN: 0959-3330 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: The combined application of polydiallyldimethylammonium chloride (PDADMAC) and polysilicate aluminum ferrite (PSFA) was investigated to treat low algae density water samples, in which Microcystis aeruginosa is one of the dominant species. coagulation performance of M. aeruginosa was studied with regard to algal removal, Algal density was evaluated by determining the change in the optical density of the algal culture suspension at 680 nm and chlorophyll a. The dissolved organic matter, cellular morphology, viability, and recovery of M. aeruginosa cells after flocculation and sedimentation were also included. In addition, the effects of pH and addition order of PSFA and PDADMAC on algal removal were investigated. The removal efficiency of algae coagulated using combined PDADMAC and PSFA was improved by 34.5% and 19.3%, respectively. The organic matter removal was also enhanced. The optimum pH range for algal removal is 7.0-10.0, and the preferable addition sequence is the simultaneous addition of PDADMAC and PSFA. Scanning electron microscopy observation indicated that the combined usage of PDADMAC and PSFA caused no damage to the algal cell. Moreover, the experiment on algal recovery demonstrated that PDADMAC has bacteriostatic ability. [Mh] Termos MeSH primário: Polietilenos/química Compostos de Amônio Quaternário/química Eliminação de Resíduos Líquidos/métodos [Mh] Termos MeSH secundário: Alumínio/química Compostos Férricos/química Floculação Microalgas Silicatos/química [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Ferric Compounds); 0 (Polyethylenes); 0 (Quaternary Ammonium Compounds); 0 (Silicates); 1317-54-0 (ferrite); 26062-79-3 (poly-N,N-dimethyl-N,N-diallylammonium chloride); CPD4NFA903 (Aluminum) [Em] Mês de entrada: 1803 [Cu] Atualização por classe: 180308 [Lr] Data última revisão: 180308 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170309 [St] Status: MEDLINE [do] DOI: 10.1080/09593330.2017.1296028

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[PMID]: 28746793 [Au] Autor: de Morais DR; Barbosa IL; Cunha KF; Tripodi GL; Angolini CFF; Franco MF; de Aquino EM; Eberlin MN; Costa JL [Ad] Endereço: ThoMSon Mass Spectrometry Laboratory, University of Campinas, Institute of Chemistry, Campinas, São Paulo, 13083-970, Brazil. [Ti] Título: EASI-IMS an expedite and secure technique to screen for 25I-NBOH in blotter papers. [So] Source: J Mass Spectrom;52(10):701-706, 2017 Oct. [Is] ISSN: 1096-9888 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: The increasing number of new psychoactive substances (NPS) and their quick worldwide spreading, often only slightly modified in the form of new derivatives and analogues, have brought the need for fast, wide-ranging, and unequivocal identification methods in clinical and forensic investigations. Because it usually provides secure results, gas chromatography coupled to mass spectrometry (GC-MS) has been routinely employed as the standard technique for the detection of NPS in blotter papers. For 25I-NBOH (N-(2-hydroxybenzyl)-2-(4-iodo-2,5-dimethoxyphenyl)ethan-1-aminium), however, GC-MS analysis of an blotter paper extract leads to incorrect results. In this work, we investigated whether easy ambient sonic-spray mass spectrometry imaging (EASI-IMS), and ambient ionization MS method can be applied directly to the surface of the sample requiring therefore no extraction or sample preparations, would serve as an efficient, sensitive, and secure alternative for 25I-NBOH screening. [Mh] Termos MeSH primário: Cromatografia Gasosa-Espectrometria de Massas/métodos Psicotrópicos/análise Compostos de Amônio Quaternário/análise Compostos de Amônio Quaternário/química [Mh] Termos MeSH secundário: Cromatografia Líquida de Alta Pressão/métodos Seres Humanos Papel Psicotrópicos/química Sensibilidade e Especificidade Espectrometria de Massas por Ionização por Electrospray/métodos [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (N-(2-hydroxybenzyl)-2-(4-iodo-2,5-dimethoxyphenyl)ethan-1-aminium); 0 (Psychotropic Drugs); 0 (Quaternary Ammonium Compounds) [Em] Mês de entrada: 1802 [Cu] Atualização por classe: 180227 [Lr] Data última revisão: 180227 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170727 [St] Status: MEDLINE [do] DOI: 10.1002/jms.3977

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[PMID]: 28457785 [Au] Autor: Glushakova LG; Alto BW; Kim MS; Bradley A; Yaren O; Benner SA [Ad] Endereço: Firebird Biomolecular Sciences LLC,13709 Progress Blvd, Box 17, Alachua, FL 32615, United States. [Ti] Título: Detection of chikungunya viral RNA in mosquito bodies on cationic (Q) paper based on innovations in synthetic biology. [So] Source: J Virol Methods;246:104-111, 2017 Aug. [Is] ISSN: 1879-0984 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: Chikungunya virus (CHIKV) represents a growing and global concern for public health that needs inexpensive and convenient methods to collect mosquitoes as potential carriers so that they can be preserved, stored and transported for later and/or remote analysis. Reported here is a cellulose-based paper, derivatized with quaternary ammonium groups ("Q-paper") that meets these needs. In a series of tests, infected mosquito bodies were squashed directly on Q-paper. Aqueous ammonia was then added on the mosquito bodies to release viral RNA that adsorbed on the cationic surface via electrostatic interactions. The samples were then stored (frozen) or transported. For analysis, the CHIKV nucleic acids were eluted from the Q-paper and PCR amplified in a workflow, previously developed, that also exploited two nucleic acid innovations, ("artificially expanded genetic information systems", AEGIS, and "self-avoiding molecular recognition systems", SAMRS). The amplicons were then analyzed by a Luminex hybridization assay. This procedure detected CHIKV RNA, if present, in each infected mosquito sample, but not in non-infected counterparts or ddH O samples washes, with testing one week or ten months after sample collection. [Mh] Termos MeSH primário: Aedes/virologia Vírus Chikungunya/genética Vírus Chikungunya/isolamento & purificação Papel RNA Viral/isolamento & purificação Biologia Sintética/métodos [Mh] Termos MeSH secundário: Animais Hibridização de Ácido Nucleico/métodos Preservação Biológica Compostos de Amônio Quaternário/química RNA Viral/genética Manejo de Espécimes/instrumentação Manejo de Espécimes/métodos Biologia Sintética/instrumentação [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Quaternary Ammonium Compounds); 0 (RNA, Viral) [Em] Mês de entrada: 1802 [Cu] Atualização por classe: 180226 [Lr] Data última revisão: 180226 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170502 [St] Status: MEDLINE

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[PMID]: 28448961 [Au] Autor: Divya KP; Dharuman V [Ad] Endereço: Molecular Electronics Laboratory, Department of Bioelectronics and Biosensors, Science Campus, Alagappa University, Karaikudi 630003, India. [Ti] Título: Supported binary liposome vesicle-gold nanoparticle for enhanced label free DNA and protein sensing. [So] Source: Biosens Bioelectron;95:168-173, 2017 Sep 15. [Is] ISSN: 1873-4235 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: Supported binary liposome mixture of cationic liposome N-[1-(2,3-Dioleoyloxy)propyl]-N,N,N-trimethylammonium propane (DOTAP) and the zwitterionic liposome 1,2-Dioleoyl-sn-Glycero-3-Phosphoethanolamine (DOPE) were tethered on thiol monolayers in the absence and presence of gold nanoparticle to enhance sensor stability and sensitivity for label free DNA and protein sensing for the first time. Cysteamine hydrochloride (Cyst), 3-Mercaptopropionic acid (MPA), 11-Mercaptoundecanoic acid (MUDA) and 11-amino-1-undecane thiol (AUT) monolayers were used as tethers on gold surfaces. Electrochemical studies in the presence of [Fe(CN) ] indicate that the presence of both DOPE and AuNP decreases the electrostatic interaction between DOTAP and MPA layer during the formation of DOPE-DOTAP-AuNP (DDA) whereas they enhance the repulsive force on the Cyst and AUT monolayers. In the thiol monolayer supported DDA, the gelation of neutral lipid DOPE by the AuNP is disfavored which inturn promotes stability of vesicle structure. The membrane protein melittin's interaction with the DDA indicates the presence of intact vesicle by showing decreased charge transfer for the MUDA and AUT in the presence of [Fe(CN) ] . On the contrary, the presence of the bilayer and semi circled DDA on the MPA and cysteamine layers were confirmed by the increased redox reaction. Atomic Force Microscopic (AFM) and Transmission Electron Microscopic (TEM) images support the presence of an array like semi circled DDA on the MPA and well separated DDA vesicles on the MUDA with variable sizes. Dynamic Light Scattering (DLS) and Fourier Transform Infrared spectroscopy (FTIR) suggest effective coordination between DOPE, DOTAP and AuNP. Label free DNA hybridization sensing in presence of the negatively charged [Fe(CN) ] indicates the lowest DNA detection limit of 1×10 M with linearity range 1×10 to 1×10 M. Similarly, streptavidin sensing shows the lowest detection of 1ngml with a linear range 100ng to 1µg due to the increased reactive sites and distance. [Mh] Termos MeSH primário: Técnicas Biossensoriais Ácidos Nucleicos Livres/isolamento & purificação Lipossomos/química Proteínas/isolamento & purificação [Mh] Termos MeSH secundário: Ácido 3-Mercaptopropiônico Ácidos Nucleicos Livres/química Cisteamina/química Ácidos Graxos Monoinsaturados/química Ouro/química Limite de Detecção Lipídeos/química Nanopartículas Metálicas/química Microscopia de Força Atômica Microscopia Eletrônica de Transmissão Hibridização de Ácido Nucleico Fosfatidiletanolaminas/química Compostos de Amônio Quaternário/química [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Cell-Free Nucleic Acids); 0 (Fatty Acids, Monounsaturated); 0 (Lipids); 0 (Liposomes); 0 (Phosphatidylethanolamines); 0 (Proteins); 0 (Quaternary Ammonium Compounds); 2462-63-7 (dioleoyl phosphatidylethanolamine); 5UX2SD1KE2 (Cysteamine); 7440-57-5 (Gold); B03TJ3QU9M (3-Mercaptopropionic Acid); MR86K0XRQP (1,2-dioleoyloxy-3-(trimethylammonium)propane) [Em] Mês de entrada: 1802 [Cu] Atualização por classe: 180214 [Lr] Data última revisão: 180214 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170428 [St] Status: MEDLINE

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[PMID]: 29323846 [Au] Autor: Nosik NN; Nosik DN; Chizhov AI [Ti] Título: A comparative analysis of virucidal efficiency of biocide agents. [So] Source: Vopr Virusol;62(1):41-5, 2017. [Is] ISSN: 0507-4088 [Cp] País de publicação: Russia (Federation) [La] Idioma: eng [Ab] Resumo: The main groups of biocide agents used for inactivation of bacteria and viruses were studied for their virucidal activity against enveloped (HIV, viral hepatitis C, influenza virus A) and non-enveloped viruses (poliovirus, adenovirus). Their efficiency was analyzed. Quarterly ammonium compounds (QAC) themselves are not able to properly inactivate non-enveloped viruses. However, they can be successfully applied in combination with other biocides (guanidines, aldehydes). Effective composition of QAC with amines and guanidines provided inactivation of viruses (4.0 lgTCID50) in concentrations of 0.166-0.280% for non-enveloped viruses and 0.080-00.185% for enveloped viruses. The combination of QAC with aldehydes is especially effective (0.04-0.64% for non-enveloped viruses). The virucidal efficiency does not directly depend on the QAC concentration in the chemical disinfectants. [Mh] Termos MeSH primário: Aldeídos/farmacologia Desinfetantes/farmacologia Guanidinas/farmacologia Compostos de Amônio Quaternário/farmacologia Inativação de Vírus [Mh] Termos MeSH secundário: Adenoviridae/efeitos dos fármacos Adenoviridae/fisiologia Aldeídos/química Desinfetantes/química Guanidinas/química HIV/efeitos dos fármacos HIV/fisiologia Hepacivirus/efeitos dos fármacos Hepacivirus/fisiologia Vírus da Influenza A/efeitos dos fármacos Vírus da Influenza A/fisiologia Poliovirus/efeitos dos fármacos Poliovirus/fisiologia Compostos de Amônio Quaternário/química Relação Estrutura-Atividade [Pt] Tipo de publicação: COMPARATIVE STUDY; JOURNAL ARTICLE [Nm] Nome de substância: 0 (Aldehydes); 0 (Disinfectants); 0 (Guanidines); 0 (Quaternary Ammonium Compounds) [Em] Mês de entrada: 1802 [Cu] Atualização por classe: 180208 [Lr] Data última revisão: 180208 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 180112 [St] Status: MEDLINE

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[PMID]: 29281881 [Au] Autor: Wang H; Chen M; Jin C; Niu B; Jiang S; Li X; Jiang S [Ad] Endereço: Anhui Institute of Agro-Products Intensive Processing Technology , 230009, Hefei, Anhui P. R. China. [Ti] Título: Antibacterial [2-(Methacryloyloxy) ethyl] Trimethylammonium Chloride Functionalized Reduced Graphene Oxide/Poly(ethylene-co-vinyl alcohol) Multilayer Barrier Film for Food Packaging. [So] Source: J Agric Food Chem;66(3):732-739, 2018 Jan 24. [Is] ISSN: 1520-5118 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: The objective of present work was to construct antibacterial [2-(methacryloyloxy) ethyl] trimethylammonium chloride functionalized reduced graphene oxide/poly(ethylene-co-vinyl alcohol) (MTAC-rGO/EVOH) multilayer barrier films by using layer-by-layer assembly under a parallel electric field. Besides barrier and mechanical properties, the antibacterial activities of the film and cytotoxicity of MTAC-rGO nanosheets were extensively investigated. The functionalization of rGO was achieved by grafting MTAC onto a graphene framework through C (sp )-C bonds. The assembly of MTAC-rGO on the EVOH matrix not only significantly improved film mechanical strength, but also endowed the targeting film with outstanding moisture barrier even under a relative humidity of 99% (e.g., 0.019 g m s atm for (MTAC-rGO/EVOH) ) besides good oxygen barrier (e.g., 0.07 cm m d atm for (MTAC-rGO/EVOH) ). Among the testing films, MTAC-rGO/EVOH film had the best antibacterial activity, and the activity against S. aureus was better than E. coli. Meanwhile, the cytotoxicity of MTAC-rGO nanosheets was very low. Results suggest that MTAC-rGO/EVOH film may have great potential in food active packaging. [Mh] Termos MeSH primário: Antibacterianos/farmacologia Embalagem de Alimentos/instrumentação Ácidos Polimetacrílicos/farmacologia Polivinil/farmacologia Compostos de Amônio Quaternário/farmacologia [Mh] Termos MeSH secundário: Antibacterianos/química Bactérias/efeitos dos fármacos Fenômenos Biomecânicos Grafite/química Óxidos/química Ácidos Polimetacrílicos/química Polivinil/química Compostos de Amônio Quaternário/química [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Anti-Bacterial Agents); 0 (Oxides); 0 (Polymethacrylic Acids); 0 (Polyvinyls); 0 (Quaternary Ammonium Compounds); 0 (poly(2-(methacryoyloxy)ethyl)trimethylammonium chloride); 25067-34-9 (ethylene-vinyl alcohol copolymer); 7782-42-5 (Graphite) [Em] Mês de entrada: 1802 [Cu] Atualização por classe: 180207 [Lr] Data última revisão: 180207 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 171229 [St] Status: MEDLINE [do] DOI: 10.1021/acs.jafc.7b04784

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[PMID]: 27770416 [Au] Autor: Besic S; Minteer SD [Ad] Endereço: Department of Chemistry, Saint Louis University, Saint Louis, MO, 63103, USA. [Ti] Título: Micellar Polymer Encapsulation of Enzymes. [So] Source: Methods Mol Biol;1504:93-108, 2017. [Is] ISSN: 1940-6029 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Although enzymes are highly efficient and selective catalysts, there have been problems incorporating them into fuel cells. Early enzyme-based fuel cells contained enzymes in solution rather than immobilized on the electrode surface. One problem utilizing an enzyme in solution is an issue of transport associated with long diffusion lengths between the site of bioelectrocatalysis and the electrode. This issue drastically decreases the theoretical overall power output due to the poor electron conductivity. On the other hand, enzymes immobilized at the electrode surface have eliminated the issue of poor electron conduction due to close proximity of electron transfer between electrode and the biocatalyst. Another problem is inefficient and short term stability of catalytic activity within the enzyme that is suspended in free flowing solution. Enzymes in solutions are only stable for hours to days, whereas immobilized enzymes can be stable for weeks to months and now even years. Over the last decade, there has been substantial research on immobilizing enzymes at electrode surfaces for biofuel cell and sensor applications. The most commonly used techniques are sandwich or wired. Sandwich techniques are powerful and successful for enzyme immobilization; however, the enzymes optimal activity is not retained due to the physical distress applied by the polymer limiting its applications as well as the non-uniform distribution of the enzyme and the diffusion of analyte through the polymer is slowed significantly. Wired techniques have shown to extend the lifetime of an enzyme at the electrode surface; however, this technique is very hard to master due to specific covalent bonding of enzyme and polymer which changes the three-dimensional configuration of enzyme and with that decreases the optimal catalytic activity. This chapter details encapsulation techniques where an enzyme will be immobilized within the pores/pockets of the hydrophobically modified micellar polymers such as Nafion and chitosan. This strategy has been shown to safely immobilize enzymes at electrode surfaces with storage and continuous operation lifetime of more than 2 years. [Mh] Termos MeSH primário: Quitosana/análogos & derivados Enzimas Imobilizadas/química Polímeros de Fluorcarboneto/química Micelas [Mh] Termos MeSH secundário: Aminação Fontes de Energia Bioelétrica Técnicas Biossensoriais Eletrodos Interações Hidrofóbicas e Hidrofílicas Oxirredução Porosidade Compostos de Amônio Quaternário/química [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Enzymes, Immobilized); 0 (Fluorocarbon Polymers); 0 (Micelles); 0 (Quaternary Ammonium Compounds); 39464-59-0 (perfluorosulfonic acid); 9012-76-4 (Chitosan) [Em] Mês de entrada: 1801 [Cu] Atualização por classe: 180115 [Lr] Data última revisão: 180115 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161023 [St] Status: MEDLINE

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