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1.
Nat Commun ; 12(1): 1673, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33723263

RESUMO

There are increasing efforts to engineer functional compartments that mimic cellular behaviours from the bottom-up. One behaviour that is receiving particular attention is motility, due to its biotechnological potential and ubiquity in living systems. Many existing platforms make use of the Marangoni effect to achieve motion in water/oil (w/o) droplet systems. However, most of these systems are unsuitable for biological applications due to biocompatibility issues caused by the presence of oil phases. Here we report a biocompatible all aqueous (w/w) PEG/dextran Pickering-like emulsion system consisting of liposome-stabilised cell-sized droplets, where the stability can be easily tuned by adjusting liposome composition and concentration. We demonstrate that the compartments are capable of negative chemotaxis: these droplets can respond to a PEG/dextran polymer gradient through directional motion down to the gradient. The biocompatibility, motility and partitioning abilities of this droplet system offers new directions to pursue research in motion-related biological processes.


Assuntos
Lipossomos/química , Quimiotaxia , Dextranos/química , Emulsões , Movimento (Física) , Tamanho da Partícula , Polietilenoglicóis/química , Água
2.
Food Chem ; 352: 129332, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33690075

RESUMO

In order to construct a novel and efficient calcium delivery system, a dextran- casein phosphopeptide (CPP) conjugates as calcium carrier was prepared by Maillard reaction of CPP and dextran. The preparation of the conjugates, construction of calcium delivery system and digestion in vitro were studied. The grafting rate of conjugates, which was confirmed by migration and intensity changes in the characteristic peaks using ultraviolet-visible and Fourier transform infrared spectroscopy, reached 48.88%. The microscopy showed CPP was coated with dextran, the conjugates with a kind of "shell-core" structure had excellent stability. Compared with CPP, the chelating rate of conjugates increased from 6.0% to 13.87%, and the calcium retention rate improved from 1.09% to 7.90% in vitro digestion. The calcium binding capacity and effect of controlled release of the conjugates were superior to those of CPP. Therefore, the conjugates could be used as an effective carrier for new calcium supplements.


Assuntos
Cálcio/química , Caseínas/química , Dextranos/química , Digestão , Portadores de Fármacos/química , Fosfopeptídeos/química , Cálcio/metabolismo , Reação de Maillard
3.
Food Chem ; 352: 129376, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33662917

RESUMO

In the present study, three types of polyphenols, namely, (-)-epigallocatechin-3-gallate (EGCG), catechin (C), and gallic acid (GA), were grafted to myofibrillar protein (MP)-dextran (DX) conjugate through a free radical-mediated adduction method. The analysis of secondary structure showed that conjugation of polyphenols induced a decrease in contents of α-helix structures. The surface hydrophobicity of MP-DX conjugate was increased after polyphenols were covalently adducted, while that of the free amino, thiol groups, and tyrosine residues were decreased, especially with the addition of EGCG (p < 0.05). Analysis of rheological properties showed that covalently linking of polyphenols decreased the thermal gelling capacity by inhibiting myosin-head aggregation and myosin tails interaction. Moreover, polyphenol adduction was able to remarkably improve the thermal stability and antioxidant activity of MP-DX conjugate. The findings regarding enhanced functionalities evidence potential of applying the ternary adduct as a novel antioxidant.


Assuntos
Antioxidantes/química , Dextranos/química , Temperatura Alta , Proteínas Musculares/química , Polifenóis/química , Estabilidade Proteica , Estrutura Secundária de Proteína
4.
ACS Appl Mater Interfaces ; 13(6): 7060-7069, 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33543622

RESUMO

Hydrogels as wound dressings have received great attention in recent years. It is highly important yet challenging to develop hydrogel dressings that are biocompatible and that can promote wound healing by lowering the risk of inflammatory responses. In this work, we designed and prepared zwitterionic dextran-based hydrogels using carboxybetaine dextran (CB-Dex) and sulfobetaine dextran (SB-Dex) as raw materials, respectively. The efficacy of CB-Dex and SB-Dex hydrogels in promoting wound recovery was evaluated using a mouse skin wound model. Results suggested that the zwitterionic dextran wound dressings showed a faster healing rate than natural dextran hydrogel and a commercial wound dressing (Duoderm film) due to their excellent protein resistance and capacity to scavenge free hydroxyl radicals. In addition, both CB-Dex and SB-Dex hydrogel wound dressings showed excellent cytocompatibility with NIH3T3 and L929 cells, as well as antibacterial adhesion against Staphylococcus aureus and Escherichia coli. Furthermore, both zwitterionic hydrogels demonstrated self-healing properties and can be stretched to adapt to irregular full-thickness wound beds. More importantly, they can be removed from the wound site painlessly by washing with normal saline. Overall, this work provided a new pathway to fabricate multifunctional polysaccharide hydrogels for wound treatment and pain relief when changing wound dressings.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Incrustação Biológica/prevenção & controle , Dextranos/farmacologia , Hidrogéis/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/síntese química , Antibacterianos/química , Antioxidantes/síntese química , Antioxidantes/química , Bandagens , Linhagem Celular , Dextranos/síntese química , Dextranos/química , Escherichia coli/efeitos dos fármacos , Feminino , Hidrogéis/síntese química , Hidrogéis/química , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Estrutura Molecular , Células NIH 3T3 , Tamanho da Partícula , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície
5.
Carbohydr Polym ; 256: 117504, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33483027

RESUMO

Oral administration of insulin (INS) would represent a revolution in the treatment of diabetes, considering that this route mimics the physiological dynamics of endogenous INS. Nano- and microencapsulation exploiting the advantageous polysaccharides properties has been considered an important technological strategy to protect INS against harsh conditions of gastrointestinal tract, in the same time that improve the permeability via transcellular and/or paracellular pathways, safety and in some cases even selectivity for targeting delivery of INS. In fact, some polysaccharides also give to the systems functional properties such as pH-responsiveness, mucoadhesiveness under specific physiological conditions and increased intestinal permeability. In general, all polysaccharides can be functionalized with specific molecules becoming more selective to the cells to which INS is delivered. The present review highlights the advances in the past 10 years on micro- and nanoencapsulation of INS exploiting the unique natural properties of polysaccharides, including chitosan, starch, alginate, pectin, and dextran, among others.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Hipoglicemiantes/farmacocinética , Insulina/farmacocinética , Nanopartículas/química , Administração Oral , Alginatos/química , Animais , Quitosana/química , Dextranos/química , Diabetes Mellitus/metabolismo , Diabetes Mellitus/patologia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Humanos , Hipoglicemiantes/metabolismo , Insulina/metabolismo , Mucosa Intestinal/metabolismo , Nanopartículas/administração & dosagem , Pectinas/química , Permeabilidade , Amido/química
6.
Carbohydr Polym ; 256: 117523, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33483044

RESUMO

EPS-BMS, is to our knowledge, the first high molecular weight exopolysaccharide from potential probiotic Leuconostoc citreum-BMS strain that consists on a mixture of α-(1,6)-dextran branched at the third position and ß-(2,6)-levan. This sample exhibited interesting rheological and emulsifying properties under different conditions. Steady shear experiments proved that EPS-BMS had a pseudoplastic behavior without thixotropic properties. Interestingly, pseudoplasticity was maintained even under stress conditions of temperature, pH and salts, which could provide some sensory properties for food products such as mouth feel. Dynamic oscillatory measurements reflected a liquid-like behavior of the sample regardless of the studied EPS concentration, pH, temperature and ionic force. Results related to the emulsifying as well as interfacial properties showed that EPS-BMS had great potential to be applied as emulsifier and/or emulsion stabilizer in both neutral and acidic conditions. Based on the properties reported in this work, EPS-BMS could be potentially applied in the food industry.


Assuntos
Dextranos/química , Emulsificantes/química , Frutanos/química , Leuconostoc/química , Polissacarídeos Bacterianos/química , Probióticos/química , Culinária/métodos , Dextranos/isolamento & purificação , Emulsificantes/isolamento & purificação , Frutanos/isolamento & purificação , Humanos , Concentração de Íons de Hidrogênio , Leuconostoc/metabolismo , Polissacarídeos Bacterianos/isolamento & purificação , Probióticos/metabolismo , Reologia , Sais/química , Percepção Gustatória/fisiologia , Temperatura
7.
J Chromatogr A ; 1638: 461879, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33465583

RESUMO

Two commercially available agarose ion exchange media, DEAE-Capto and DEAE-Sepharose FF (DEAE-FF), and two gigaporous media DEAE -AP-120 nm and DEAE-AP-280 nm were evaluated for their applicability in adsorption of five proteins with large span of radius ranges from 2.9 nm to 14.1 nm, which include ovalbumin, bovine serum albumin (BSA), haptoglobin, thyroglobulin and hepatitis B surface antigen (HBsAg) virus like particle. The average pore radius of the four media was determined to be 6.9 nm, 18.5 nm, 59.4 nm and 139.3 nm, respectively, which was obtained by log normal distribution for DEAE-Capto and DEAE-FF and by bimodal Gaussian distribution for the two DEAE-AP media. The performance of these four media including phase ratio, static and dynamic binding capacity, and transport properties for the adsorption of these five model proteins as function of pore-to-adsorbate size ratio were investigated and compared. The best ratio of pore-to-adsorbate size was found dependent on the protein size. For protein with radius from 2.9 nm (ovalbumin) to 5.4 nm (BSA), the agarose media was superior to gigaporous media. Both the static and dynamic adsorption capacities reduced with the increase of pore size, and the highest values were obtained at the smallest pore-to-adsorbate size of about 2 times in this study, although the highest accessible surface area was obtained at pore-to-adsorbate size ratio about 16 to 20. For proteins with radius of 5.4 nm or larger than that, their adsorption capacities decreased firstly and then increased with the increase of ratio of pore-to-adsorbate size, and the highest values were obtained on the gigaporous media DEAE-AP-280 nm, which could provide faster diffusivity and larger accessible surface area. However, protein with radius of 14.1 nm (HBsAg) had much lower capacities compared to other proteins at the same pore-to-adsorbate size ratio, implying large protein needs greater pore-to-adsorbate size ratio to achieve a satisfactory capacity. For all the five tested proteins, the DEAE-Capto media having the smallest pore radius and branched dextran chains, was found superior to DEAE-FF in terms of both higher adsorption capacities and uptake kinetics, which suggested that the "chain delivery effect" took place on proteins over large size span from ovalbumin to HBsAg, though the effect on the larger proteins was much less significant than that on the smaller ones. Results from the present work provided more information on how do the relationships of pore size of chromatography media and adsorbate size interactively affect the chromatography behaviors, thus will provide general guidance for selection of suitable adsorbent for biologics of a given size.


Assuntos
Cromatografia por Troca Iônica/métodos , Ovalbumina/química , Sefarose/química , Vírion/química , Adsorção , Animais , Bovinos , Cromatografia em Gel , Simulação por Computador , Meios de Cultura , Dextranos/química , Antígenos de Superfície da Hepatite B/química , Cinética , Ligantes , Tamanho da Partícula , Porosidade , Soroalbumina Bovina/química , Temperatura
8.
Carbohydr Polym ; 254: 117280, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33357856

RESUMO

Polysaccharides have been used widely in many industries, from food technology and mining to cosmetics and biomedical applications. Over recent years there has been growing interest in the development of responsive polysaccharides with unique and switchable properties, particularly systems that display lower-critical solution temperatures (LCSTs). Therefore, in this study we aimed to investigate a novel strategy that would allow the conversion of non-responsive polysaccharides into thermoresponsive polysaccharides with tuneable LCSTs. Through the functionalisation of dextran with alkylamide groups (isopropyl amide, diethyl amide, piperidinyl and diisobutyl amide) using a carbodiimide coupling approach in conjunction with amic acid derivatives, we prepared a library of novel dextrans with various degrees of substitution (DS), which were characterised via nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). The alkylamide-functionalised dextrans were found to have good solubility in aqueous solutions, with the exception of those having a high DS of large hydrophobic substituents. Determination of the thermoresponsive characteristics of the polymer solutions via UV-vis spectroscopy revealed that the LCST of the alkylamide-functionalised dextrans was highly dependent on the type of alkylamide group and the DS and could be tuned over a large range (5-35 °C). Above the LCST, all of the thermoresponsive alkylamide-functionalised dextrans formed colloidal dispersions with particles sizes ranging from 400 -600 nm, as determined by dynamic light scattering (DLS). In addition, the polymers were found to exhibit a fast and reversible phase transition in solution with narrow hysteresis (∼ 1-5 °C). Finally, the injectability and biocompatibility of the novel thermoresponsive dextrans was confirmed in vivo via subcutaneous and intracranial ventricle injections, with no local or systemic toxicity noted over a 14 d period. Overall, the alkylamide-functionalised dextrans display interesting thermoresponsive properties and trends that may make them useful in biomedical applications, such as drug-delivery.


Assuntos
Polissacarídeos/química , Alquilação , Amidas/química , Animais , Materiais Biocompatíveis/administração & dosagem , Materiais Biocompatíveis/química , Materiais Biocompatíveis/toxicidade , Cromatografia em Gel , Dextranos/administração & dosagem , Dextranos/química , Dextranos/toxicidade , Difusão Dinâmica da Luz , Teste de Materiais , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , Peso Molecular , Ressonância Magnética Nuclear Biomolecular , Tamanho da Partícula , Transição de Fase , Polissacarídeos/administração & dosagem , Polissacarídeos/toxicidade , Espectrofotometria , Temperatura
9.
Carbohydr Polym ; 251: 116980, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142555

RESUMO

Phytoglycogen nanoparticles are highly branched polymers of anhydroglucose units (AGUs) produced as soft, compact nanoparticles by sweet corn. By combining results of dialysis, ellipsometry and gravimetric analysis experiments, we constructed a master plot of the osmotic pressure Π -concentration C data for phytoglycogen nanoparticles that spans the complete range ∼ 0% w/w

Assuntos
Glicogênio/química , Nanopartículas/química , Dextranos/química , Diálise , Módulo de Elasticidade , Fenômenos Mecânicos , Pressão Osmótica , Água/química , Zea mays/química
10.
Biomed Pharmacother ; 134: 111171, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33383312

RESUMO

Periodontitis is a multifactorial chronic infectious disease leading to a host immune response involving inflammatory cytokines, especially IL-1ß, which is the main reason for further developing this disease. IL-1 receptor antagonist (IL-1ra) binds IL-1 receptor, inhibiting IL-1ß signaling and reducing the levels of other cytokines closely related to periodontitis, such as IL-6 and TNF-α. Therefore, the use of IL-1ra to inhibit periodontitis development in a system, ensuring its sustained release, might be an effective way to combat this disease. Hence, in this study, a novel IL-1ra-loaded dextran/PLGA microsphere was developed to allow the sustained release of IL-1ra and enhance the anti-inflammatory properties. Therefore, this study's purposes were to develop a novel periodontal treatment for inhibition and treatment of periodontitis and evaluate the sustained-release effect and anti-inflammatory properties of IL-1ra-loaded dextran/PLGA microspheres in vitro by cell experiments and in vivo by animal experiments. The results showed that IL-1ra-loaded dextran/PLGA microspheres were non-toxic both in vitro and in vivo and could be used as a safe and effective treatment. In addition, these microspheres could significantly prolong the half-life of IL-1ra drug, exerting a useful anti-inflammatory effect in macrophages stimulated with P. gingivalis lipopolysaccharide and in rats with periodontitis. In conclusion, IL-1ra-loaded dextran/PLGA microsphere might be a useful tool to combat periodontal disease.


Assuntos
Anti-Inflamatórios/farmacologia , Dextranos/química , Portadores de Fármacos , Proteína Antagonista do Receptor de Interleucina 1/farmacologia , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Periodontite/prevenção & controle , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Animais , Anti-Inflamatórios/química , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Composição de Medicamentos , Proteína Antagonista do Receptor de Interleucina 1/química , Lipopolissacarídeos/isolamento & purificação , Lipopolissacarídeos/toxicidade , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Microesferas , Periodontite/imunologia , Periodontite/metabolismo , Porphyromonas gingivalis/química , Células RAW 264.7 , Ratos Sprague-Dawley
11.
Carbohydr Polym ; 251: 117040, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142598

RESUMO

Bacterial infection is one of the most formidable problems in wound healing, which inflicts severe pain on patients while causing wound ulceration. Here, we prepared an injectable self-healing carbon dot hydrogel with outstanding antibacterial activity only using ε-poly(L-lysine) carbon dot (PL-CD) and oxidized dextran (ODA). The particle size of PL-CD prepared by pyrolysis of poly-l-lysine was about 3 nm. Moreover, PL-CD with abundant -NH2 on its surface could not only act as nodes to connect ODA through Schiff base to construct PL-CD@ODA hydrogel network, but also offer excellent antibacterial properties. As the contacting and releasing antibacterial action of the PL-CD@ODA hydrogel, nearly 100 % of the 107 CFU/mL of S. aureus was killed after 10 min of contacting. In addition, PL-CD@ODA hydrogel showed flexible injectability and extremely strong self-healing properties after being severely damaged. When 1000 % shear stress applied to the hydrogel, complete healing could be achieved within a few seconds.


Assuntos
Antibacterianos/química , Carbono , Dextranos , Hidrogéis , Nanopartículas/química , Polilisina/análogos & derivados , Cicatrização/efeitos dos fármacos , Antibacterianos/farmacologia , Infecções Bacterianas/terapia , Carbono/química , Carbono/farmacologia , Dextranos/química , Dextranos/farmacologia , Humanos , Hidrogéis/química , Hidrogéis/farmacologia , Polilisina/química , Polilisina/farmacologia , Staphylococcus aureus/efeitos dos fármacos
12.
J Chromatogr A ; 1632: 461610, 2020 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-33080533

RESUMO

Due to the heterogeneous and isomeric nature of glycans, the development of an advanced separation of distinct glycan isomers is essential for glycan research and application. In this study, we utilized porous graphite carbon (PGC) chromatography for the separation of isomeric oligosaccharides without reduction or chemical derivatization at 190 °C in a custom-built heating oven. Furthermore, the fine structures of glycan isomers could be identified by using ultrahigh temperature PGC liquid chromatography mass spectrometry (UHT-PGC-LCMS). A nonreduced hydrolyzed dextran was applied to verify the performance of UHT-PGC. When the temperature of the PGC column was increased from 25 to 190 °C, the liquid chromatography separation power of the nonreduced dextran ladder significantly increased. The advantage of the UHT-PGC column was its high peak capacity with gradient elution in 10 min at 190 °C, 6700 psi, and a 250 µL/min flow rate for native glycan analysis. Four synthetic Lewis antigen isomers were used to elucidate the separation effectiveness in UHT-PGC. Moreover, mass spectrometry-based sequencing to generate specific diagnostic ions from the four synthetic Lewis antigens was used to predict isomeric glycans based on the relative intensity ratio (RIR) of diagnostic ions. The intensities of the diagnostic ions of synthetic isomers were used to identify each isomer of the fucosylated glycan. The results clearly showed that terminal Lewis A and X residues were in the 3- and 6-arms of N-glycan, respectively.


Assuntos
Cromatografia Líquida/métodos , Fucose/química , Fucose/isolamento & purificação , Grafite/química , Espectrometria de Massas em Tandem/métodos , Temperatura , Dextranos/química , Glicosilação , Hidrólise , Íons , Isomerismo , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Porosidade , Fatores de Tempo
13.
J Chromatogr A ; 1628: 461431, 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32822972

RESUMO

The separation of the proteins Bovine Serum Albumin (BSA) and Myoglobin (Mb) was achieved by Size-Exclusion Simulated Moving Bed (SE-SMB) and performed experimentally in the FlexSMB® unit, an SMB unit designed and built in the Laboratory of Separation and Reaction Engineering. Before accomplishing the separation experiments in the mentioned unit, separation regions were computed by simulation based on a phenomenological mathematical model to determine appropriate operating conditions. The developed model was validated in advance, against fixed-bed dynamic adsorption experimental results, for pure component and binary mixtures. Then the SMB experiments were carried out, and purities of the Mb on the extract and BSA on the raffinate streams were 98% and 96%, respectively. The achieved recoveries were 80% of Mb on the extract and 94% of BSA on the raffinate. Lastly, productivities of 6.4 gprotein⋅lads-1⋅day-1 for the extract and 28.8 gprotein⋅lads-1⋅day-1 for the raffinate were obtained.


Assuntos
Cromatografia em Gel/métodos , Mioglobina/isolamento & purificação , Soroalbumina Bovina/isolamento & purificação , Adsorção , Animais , Calibragem , Bovinos , Dextranos/química , Cavalos , Modelos Teóricos
14.
Int J Nanomedicine ; 15: 4959-4967, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764929

RESUMO

Background: Particle-based drug delivery systems (DDSs) have a demonstrated value for drug discovery and development. However, some problems remain to be solved, such as limited stimuli, visual-monitoring. Aim: To develop an intelligent multicolor DDSs with both near-infrared (NIR) controlled release and macroscopic color changes. Materials and Methods: Microparticles comprising GO/pNIPAM/PEGDA composite hydrogel inverse opal scaffolds, with dextran and calcium alginate hydrogel were synthesized using SCCBs as the template. The morphology of microparticle was observed under scanning electron microscopy, and FITC-dextran-derived green fluorescence images were determined using a confocal laser scanning microscope. During the drug release, FITC-dextran-derived green fluorescence images were captured using fluorescent inverted microscope. The relationship between the power of NIR and the drug release rate was obtained using the change in optical density (OD) values. Finally, the amount of drug released could be estimated quantitatively used the structural color or the reflection peak position. Results: A fixed concentration 8% (v/v) of PEGDA and 4mg/mL of GO was chosen as the optimal concentration based on the balance between appropriate volume shrinkage and structure color. The FITC-dextran was uniformly encapsulated in the particles by using 0.2 wt% sodium alginate. The microcarriers shrank because of the photothermal response and the intrinsic fluorescence intensity of FITC-dextran in the microparticles gradually decreased at the same time, indicating drug release. With an increasing duration of NIR irradiation, the microparticles gradually shrank, the reflection peak shifted toward blue and the structural color changed from red to orange, yellow, green, cyan, and blue successively. The drug release quantity can be predicted by the structural color of microparticles. Conclusion: The multicolor microparticles have great potential in drug delivery systems because of its vivid reporting color, excellent photothermal effect, and the good stimuli responsivity.


Assuntos
Portadores de Fármacos/química , Microesferas , Resinas Acrílicas/química , Alginatos/química , Cor , Dextranos/química , Liberação Controlada de Fármacos , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/química , Hidrogéis/química , Fenômenos Ópticos , Polietilenoglicóis/química
15.
J Chromatogr A ; 1625: 461343, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709308

RESUMO

A simple magnetic dispersive solid-phase extraction (MDSPE) methodology based on mesoporous Fe3O4@ succinic acid nanospheres and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has been developed to determine kanamycin (KNM) and neomycin (NEO) contents in Measles, Mumps, and Rubella (MMR) vaccine products. The monodispersed mesoporous Fe3O4 nanospheres with self-assembled carboxyl terminated shell have been prepared via a simple solvothermal method. These as-synthesized mesoporous Fe3O4 nanospheres showed a high magnetic saturation value (Ms = 46 emu g-1) and large specific surface area (111.12 m2 g-1) which made them potential candidates as sorbents in magnetic solid-phase extraction. The adsorption experimental data fitted well with the Freundlich-Langmuir isotherm and followed a pseudo-second-order kinetic model. Moreover influential parameters on extraction efficiency were investigated and optimized. Under optimal conditions, the limits of detection for KNM and NEO were 1.0 and 0.1 ng mL-1, respectively. Recovery assessments using real samples exhibited recoveries in the range of 96.0 ± 4.3 to 101.5 ± 7.1 %, with relative standard deviations of <10.7% (for intra- day) and <14.6% (for inter- day). The proposed method was successfully applied for different spiked and un-spiked MMR vaccine samples. The presented extraction method provides a fast, selective, robust and practical platform for the detection of KNM and NEO in MMR vaccine samples.


Assuntos
Dextranos/química , Canamicina/análise , Nanopartículas de Magnetita/química , Vacina contra Sarampo/análise , Caxumba/imunologia , Nanosferas/química , Neomicina/análise , Vacina contra Rubéola/análise , Espectrometria de Massas em Tandem/métodos , Adsorção , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Cinética , Limite de Detecção , Magnetismo , Nanosferas/ultraestrutura , Reprodutibilidade dos Testes , Extração em Fase Sólida , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier , Ácido Succínico/química , Fatores de Tempo , Água/química
16.
Food Chem ; 330: 127154, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32531630

RESUMO

Dextran-containing sourdough has been exploited in breadmaking, obtaining additive-free bread of high quality. Effect of dextran, weak acidification and their association on gluten dough structure, thermal properties and rheology was investigated. Electrophoresis (SDS-PAGE) showed that dextran and acids both lowered the band intensity in the high molecular weight area (Mw > 175 kDa) and size exclusion (SE-HPLC) revealed that weak acidification induced a decrease of 4.73% of the glutenin macropolymer (GMP) content. The higher free thiol (SH) was observed after dextran addition, further suggesting the hindered glutenin polymerization. Fourier transform infrared spectroscopy (FTIR) found that dextran and weak acidity caused increased ß-turn and decreased ß-sheet structures, suggesting a gluten of lower coherence and resistance to extension. Weakened thermal stability and viscoelasticity were subsequently detected by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic rheology. However, structural, thermal and rheological properties of the weakly acidified group were improved by the associated dextran.


Assuntos
Dextranos/química , Glutens/química , Varredura Diferencial de Calorimetria , Concentração de Íons de Hidrogênio , Polimerização , Reologia , Triticum/química , Viscosidade
17.
J Chromatogr A ; 1626: 461268, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32507331

RESUMO

A recent article in Journal of Chromatography A 1561 (2018) 67-75 authored by J.-L. Wang, E. Alasonati, P. Fisicaro, M. F. Benedetti, and M. Martin and having the title Theoretical and experimental investigation of the focusing position in asymmetrical flow field-flow fractionation (AF4) is discussed. It is found that some statements and conclusions are to some degree questionable or confusing. In addition the experiments to measure the focusing position were not well defined. Authors' assumption of the constancy of the cross-flow velocity along the channel is pointed out to actually be valid as evidenced by a theoretical analysis as well as experimental findings in the literature. Claims that a "fingering" phenomenon of a focused blue dextran stripe would contribute to overall band broadening are contradicted.


Assuntos
Fracionamento por Campo e Fluxo/métodos , Dextranos/química , Humanos
18.
Pharm Res ; 37(6): 100, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32436083

RESUMO

PURPOSE: We investigated the potential correlations between skin barrier integrity and hydrophilic drugs distribution in skin in the presence of different types of penetration enhancers (PEs) and their combinations. METHODS: We measured skin conductivity to evaluate skin barrier integrity before and after the topical application of different chemical PEs, physical PE, peptide PE and their combinations in vitro. We also investigated their effect on the skin distribution profiles of two hydrophilic model drugs, Fluorescein sodium (376 Da) and Fluorescein isothiocyanate-dextrans 10 (10 KDa). RESULTS: The physical PE significantly increased the skin conductivity compared to all other PEs, while the peptide PE had no effect on it. The drug deposition in different skin layers was not only dependent on PE applied but also its own molecular weight. We further found two excellent correlations: one (R2 = 0.9388) between skin barrier integrity and total skin absorption of FNa and another one(R2 = 0.9212) between skin barrier integrity and the deposition of FNa in dermis and receptor in presence of chemical or physical PEs and their combinations. CONCLUSIONS: The total skin absorption or the deposition in dermis and receptor of small hydrophilic drug in the presence of chemical and physical PEs and their combinations show a good correlation with skin barrier integrity. However, such correlations hold true neither for large hydrophilic drug nor for peptide PE. All good relationships found in this work will allow screening suitable PEs or combinations by measuring the skin conductivity induced by corresponding PEs. Graphical Abstract The total skin absorption of small hydrophilic drug shows a good correlation with skin barrier integrity in the presence of chemical and physical penetration enhancers and their combinations. However, such a correlation hold true neither for large hydrophilic drug nor for peptide penetration enhancer.


Assuntos
Melhoramento Biomédico/métodos , Portadores de Fármacos/química , Peptídeos/química , Preparações Farmacêuticas/química , Absorção Cutânea/efeitos dos fármacos , Pele/metabolismo , Administração Cutânea , Animais , Dextranos/administração & dosagem , Dextranos/química , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Excipientes/química , Fluoresceína/administração & dosagem , Fluoresceína/química , Fluoresceína-5-Isotiocianato/administração & dosagem , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/química , Cobaias , Humanos , Interações Hidrofóbicas e Hidrofílicas , Técnicas In Vitro , Conformação Molecular , Estrutura Molecular , Peso Molecular , Permeabilidade , Preparações Farmacêuticas/administração & dosagem , Solubilidade , Relação Estrutura-Atividade , Distribuição Tecidual
19.
J Food Sci ; 85(6): 1707-1716, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32449946

RESUMO

In this paper, we studied the effect of glycosylation reaction on the molecular structure and functional properties of whey protein isolate (WPI), and studied the effect of reaction temperature (50 to 90 °C) on the molecular structure and functional properties of WPI-dextran conjugates (WPI-D). The results of the extent of glycation (EG) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis confirmed the formation of WPI-D. Circular dichroism (CD), Fourier transform infrared spectrum, and fluorescence spectroscopy indicated that the molecular structure of WPI was changed after glycosylation-the ß-sheet content was decreased and the tryptophan content was increased. The emulsifying properties and the ability to encapsulate ß-carotene of WPI-D were improved compared with WPI (P < 0.05). When the reaction temperature was 70 and 80 °C, the EG and the ability to encapsulate ß-carotene of WPI-D were better (P < 0.05), which was related to protein unfolding. However, due to the polymerization between the WPI molecules, the emulsion activity index of WPI-D and the ability to encapsulate ß-carotene were lowered at 90 °C (P < 0.05). Therefore, the glycosylation reaction can change the molecular structure and functional properties of WPI; the emulsifying properties and the ability to encapsulate ß-carotene of WPI-D can be changed by controlling the reaction temperature of glycosylation. PRACTICAL APPLICATION: The glycosylation reaction can change the molecular structure and functional properties of Whey protein isolate; the emulsifying properties and the ability to encapsulate ß-carotene of WPI-dextran conjugates can be changed by controlling the reaction temperature of glycosylation.


Assuntos
Dextranos/química , Proteínas do Soro do Leite/química , beta Caroteno/química , Animais , Bovinos , Eletroforese em Gel de Poliacrilamida , Emulsões/química , Glicosilação , Conformação Proteica , Temperatura
20.
Sci Rep ; 10(1): 6595, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32313146

RESUMO

We report a flexible single-cell isolation method by imaging-assisted hydrogel formation. Our approach consists of imaging-aided selective capture of cells of interest by encasing them into a polymeric hydrogel, followed by removal of unwanted cells and subsequent release of isolated cells by enzymatic hydrogel degradation, thus offering an opportunity for further analysis or cultivation of selected cells. We achieved high sorting efficiency and observed excellent viability rates (>98%) for NIH/3T3 fibroblasts and A549 carcinoma cells isolated using this procedure. The method presented here offers a mask-free, cost-efficient and easy-to-use alternative to many currently existing surface-based cell-sorting techniques, and has the potential to impact the field of cell culturing and isolation, e.g. single cell genomics and proteomics, investigation of cellular heterogeneity and isolation of best performing mutants for developing new cell lines.


Assuntos
Separação Celular/métodos , Hidrogéis/química , Imageamento Tridimensional , Análise de Célula Única , Células A549 , Animais , Sobrevivência Celular , Dextranos/química , Humanos , Metacrilatos/química , Camundongos , Microscopia Confocal , Células NIH 3T3
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