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1.
Food Chem ; 338: 127825, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32810814

RESUMO

Four soluble dietary fibers (SDFs) were fortified with corn starch (CS) at different concentrations to match the same viscosity equivalents. The mixtures were subjected to a simulated digestion procedure to study the effects of SDFs on viscosity properties and digestion kinetics of CS. Results showed that SDFs increased the hydration property and decreased the water mobility of digesta. During digestion process, SDFs increased the apparent viscosity of digesta to some extent, and showed significant difference to delay the decay of digesta viscosity (kv). The amylolysis inhibitory ability was similar when each SDF was present at the same viscosity equivalent, however, significant differences were found on the digestion rate constant of k2. Linear correlations between kv and k2 were established for 1 and 2 equivalent groups. These results demonstrated that SDFs could delay the digestion process as chemistry differences, which related to their ability on delaying the change of digesta viscosity.


Assuntos
Fibras na Dieta/farmacologia , Amido/química , Amido/farmacocinética , Animais , Digestão , Suco Gástrico/efeitos dos fármacos , Suco Gástrico/metabolismo , Cinética , Mananas/química , Polissacarídeos/química , Polissacarídeos Bacterianos/química , Solubilidade , Viscosidade
2.
Food Chem ; 336: 127634, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32777654

RESUMO

Bilayer colorimetric films were developed for monitoring fish spoilage by using gelatin (GN) incorporated with ZnO nanoparticles as the upper layer (GN-ZnO), and gellan gum (GG) incorporated with mulberry anthocyanins (MBA) as the lower layer (GG-MBA). The color stability of the bilayer colorimetric films under visible and ultraviolet light was improved with the increase of ZnO nanoparticles content. Meanwhile, the bilayer films had good NH3 sensitivity. The limit of detection of the GG-MBA/GN-2.0% ZnO film to NH3 was 0.01 mM. The electrochemical writing ability of the bilayer films was also identified, indicating the feasibility of inks-free printing on biopolymer films. Finally, the GG-MBA/GN-2.0% ZnO film with an electrochemical writing pattern was used to monitor crucian spoilage. The GG-MBA/GN-2.0% ZnO film with electrochemical writing pattern showed visible color changes with the crucian spoilage. In conclusion, the bilayer colorimetric film was expected to be a good fish spoilage indicator in smart packaging.


Assuntos
Embalagem de Alimentos/métodos , Inocuidade dos Alimentos , Luz , Animais , Antocianinas/química , Cor , Produtos Pesqueiros/análise , Embalagem de Alimentos/instrumentação , Gelatina/química , Concentração de Íons de Hidrogênio , Nanopartículas Metálicas/química , Morus/química , Morus/metabolismo , Polissacarídeos Bacterianos/química , Resistência à Tração , Óxido de Zinco/química
3.
Cell Prolif ; 53(10): e12907, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32951298

RESUMO

OBJECTIVE: Tissue engineering is a promising strategy for repair of large bone defect. However, the immune system reactions to biological scaffold are increasingly being recognized as a crucial factor influencing regeneration efficacy. In this study, a bone-bioactive hydrogel bead loaded with interleukin-4 (IL-4) was used to regulate macrophages polarization and accelerate bone regeneration. METHODS: IL-4-loaded calcium-enriched gellan gum (Ca-GG + IL-4) hydrogel beads were synthesised. And the effect on cell behaviour was detected. Furthermore, the effect of the Ca-GG + IL-4 hydrogel bead on macrophage polarization and the effect of macrophage polarization on bone mesenchymal stem cells (BMSCs) apoptosis and osteogenic differentiation were evaluated in vitro and in vivo. RESULTS: BMSCs were able to survive in the hydrogel regardless of whether IL-4 was incorporated. Immunofluorescence staining and qPCR results revealed that Ca-GG + IL-4 hydrogel bead could promote M2 macrophage polarization and increase transforming growth factor (TGF)-ß1 expression level, which activates the TGF-ß1/Smad signalling pathway in BMSCs and promotes osteogenic differentiation. Moreover, immunohistochemical analysis demonstrated Ca-GG + IL-4 hydrogel bead could promote M2 macrophage polarization and reduce cell apoptosis in vivo. In addition, micro-CT and immunohistochemical analysis at 12 weeks post-surgery showed that Ca-GG + IL-4 hydrogel bead could achieve superior bone defect repair efficacy in vivo. CONCLUSIONS: The Ca-GG + IL-4 hydrogel bead effectively promoted bone defect regeneration via regulating macrophage polarization, reducing cell apoptosis and promoting BMSCs osteogenesis through TGF-ß1/Smad pathway. Therefore, it is a promising strategy for repair of bone defect.


Assuntos
Regeneração Óssea , Diferenciação Celular/efeitos dos fármacos , Hidrogéis/química , Interleucina-4/farmacologia , Osteogênese/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Tecidos Suporte/química , Animais , Apoptose/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Interleucina-4/química , Interleucina-4/metabolismo , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/citologia , Macrófagos/metabolismo , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Polissacarídeos Bacterianos/química , Células RAW 264.7 , Ratos , Ratos Sprague-Dawley , Proteínas Smad/metabolismo , Engenharia Tecidual , Fator de Crescimento Transformador beta1/metabolismo
4.
Nat Commun ; 11(1): 4723, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948778

RESUMO

O-Acetylation of the capsular polysaccharide (CPS) of Neisseria meningitidis serogroup A (NmA) is critical for the induction of functional immune responses, making this modification mandatory for CPS-based anti-NmA vaccines. Using comprehensive NMR studies, we demonstrate that O-acetylation stabilizes the labile anomeric phosphodiester-linkages of the NmA-CPS and occurs in position C3 and C4 of the N-acetylmannosamine units due to enzymatic transfer and non-enzymatic ester migration, respectively. To shed light on the enzymatic transfer mechanism, we solved the crystal structure of the capsule O-acetyltransferase CsaC in its apo and acceptor-bound form and of the CsaC-H228A mutant as trapped acetyl-enzyme adduct in complex with CoA. Together with the results of a comprehensive mutagenesis study, the reported structures explain the strict regioselectivity of CsaC and provide insight into the catalytic mechanism, which relies on an unexpected Gln-extension of a classical Ser-His-Asp triad, embedded in an α/ß-hydrolase fold.


Assuntos
Cápsulas Bacterianas/química , Cápsulas Bacterianas/metabolismo , Neisseria meningitidis Sorogrupo A/metabolismo , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/metabolismo , Acetilação , Acetiltransferases , Anticorpos Antibacterianos , Cápsulas Bacterianas/genética , Cápsulas Bacterianas/imunologia , Vacinas Bacterianas/imunologia , Hexosaminas , Modelos Moleculares , Neisseria meningitidis Sorogrupo A/genética , Polissacarídeos Bacterianos/genética , Polissacarídeos Bacterianos/imunologia , Conformação Proteica
5.
Nat Commun ; 11(1): 4434, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32895393

RESUMO

Neisseria meningitidis serogroup A capsular polysaccharide (MenA CPS) consists of (1 → 6)-2-acetamido-2-deoxy-α-D-mannopyranosyl phosphate repeating units, O-acetylated at position C3 or C4. Glycomimetics appear attractive to overcome the CPS intrinsic lability in physiological media, due to cleavage of the phosphodiester bridge, and to develop a stable vaccine with longer shelf life in liquid formulation. Here, we generate a series of non-acetylated carbaMenA oligomers which are proven more stable than the CPS. An octamer (DP8) inhibits the binding of a MenA specific bactericidal mAb and polyclonal serum to the CPS, and is selected for further in vivo testing. However, its CRM197 conjugate raises murine antibodies towards the non-acetylated CPS backbone, but not the natural acetylated form. Accordingly, random O-acetylation of the DP8 is performed, resulting in a structure (Ac-carbaMenA) showing improved inhibition of anti-MenA CPS antibody binding and, after conjugation to CRM197, eliciting anti-MenA protective murine antibodies, comparably to the vaccine benchmark.


Assuntos
Glicoconjugados/síntese química , Neisseria meningitidis Sorogrupo A/imunologia , Polissacarídeos Bacterianos/síntese química , Vacinas Conjugadas , Animais , Anticorpos Antibacterianos/análise , Anticorpos Neutralizantes/química , Cápsulas Bacterianas/imunologia , Biomimética/métodos , Glicoconjugados/imunologia , Camundongos , Neisseria meningitidis Sorogrupo A/química , Neisseria meningitidis Sorogrupo A/efeitos dos fármacos , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/imunologia , Vacinas Conjugadas/química , Vacinas Conjugadas/microbiologia
6.
Int J Nanomedicine ; 15: 5253-5264, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801690

RESUMO

Background and Aim: Flibanserin (FLB) is a multifunctional serotonergic agent used for treating hypoactive sexual desire disorder in premenopausal women via oral administration. FLB has a reported limited oral bioavailability of 33% that could be attributed to the drug's first-pass metabolism. In addition, FLB has a pH-dependent solubility that could be a challenging factor for drug dissolution in the body neutral fluid, and consequently, absorption via mucosal barriers. Thus, this work aims at investigating the potential of utilizing nanostructured lipid carriers (NLCs) to overcome the aforementioned drawbacks and to enhance nose-to-brain drug delivery. Methods: Box-Behnken design was applied to explore the impact of solid lipid % (SL%, X 1), liquid lipid % (LL%, X 2), and sonication time (ST, X 3) on particle size. The optimized NLC formulation was characterized and incorporated into gellan gum in situ gel. The prepared gel was subjected to in vitro drug release, in vivo pharmacokinetic performance, and histopathological assessment in rats. Results: Statistical analysis revealed a significant negative effect for both SL% and ST on NLCs size. In contrast, a significant positive effect was observed for the LL%. The optimized formulation showed spherical shape with vesicular size of 114.63 nm. The optimized FLB-NLC in situ gel exhibited adequate stability and enhanced in vitro release compared to raw FLB control gel. The plasma and brain concentrations of the drug after nasal administration in rats increased by more than 3-6-fold, respectively, compared to raw FLB in situ gel. In addition, the histopathological studies revealed the absence of any pathological signs. Conclusion: The aforementioned results highlight the safety of FLB-NLC in situ nasal gel and its potential to improve the drug bioavailability and brain delivery.


Assuntos
Benzimidazóis/administração & dosagem , Encéfalo/efeitos dos fármacos , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/química , Nanoestruturas/administração & dosagem , Administração Intranasal , Animais , Benzimidazóis/farmacocinética , Disponibilidade Biológica , Portadores de Fármacos/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Géis , Lipídeos/administração & dosagem , Lipídeos/química , Masculino , Nanoestruturas/química , Tamanho da Partícula , Polissacarídeos Bacterianos/química , Ratos Wistar , Solubilidade
7.
Am J Trop Med Hyg ; 103(3): 1032-1038, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32720632

RESUMO

Transcutaneous vaccination can induce both mucosal and systemic immune responses. However, there are few data on anti-polysaccharide responses following transcutaneous vaccination of polysaccharides, despite the role that anti-polysaccharide responses play in protecting against intestinal mucosal and respiratory pathogens. Whether transcutaneous vaccination with a conjugate polysaccharide vaccine would be able to induce memory responses is also unknown. To address this, we transcutaneously vaccinated mice with virulence antigen (Vi) polysaccharide of Salmonella enterica serovar Typhi (the cause of typhoid fever), either in unconjugated or conjugated form (the latter as a Vi-DT conjugate). We also assessed the ability of the immunoadjuvant cholera toxin to impact responses following vaccination. We found that presenting Vi in a conjugate versus nonconjugate form transcutaneously resulted in comparable serum IgG responses but higher serum and lamina propria lymphocyte IgA anti-Vi responses, as well as increased IgG memory responses. The addition of immunoadjuvant did not further increase these responses; however, it boosted fecal IgA and serum IgG anti-Vi responses. Our results suggest that transcutaneous vaccination of a conjugate vaccine can induce systemic as well as enhanced mucosal and memory B-cell anti-polysaccharide responses.


Assuntos
Anticorpos Antibacterianos/sangue , Imunidade Humoral/efeitos dos fármacos , Imunidade nas Mucosas/efeitos dos fármacos , Salmonella typhi/imunologia , Febre Tifoide/prevenção & controle , Vacinas Tíficas-Paratíficas/administração & dosagem , Vacinação/métodos , Administração Cutânea , Animais , Modelos Animais de Doenças , Feminino , Humanos , Esquemas de Imunização , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Memória Imunológica/efeitos dos fármacos , Camundongos , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/imunologia , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/patogenicidade , Febre Tifoide/imunologia , Febre Tifoide/microbiologia , Vacinas Tíficas-Paratíficas/biossíntese , Vacinas Conjugadas
8.
Adv Exp Med Biol ; 1250: 79-93, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32601939

RESUMO

Treatment for the osteochondral defects (ODs) is more challenging nowadays that needs to be addressed by developing alternative bone tissue engineering materials. Gellan gum (GG) is a widely used natural polysaccharide in the field of tissue engineering (TE) and regenerative medicine due to its versatile properties. There are many reports about the successful application of GG in cartilage tissue engineering and guiding bone formation. Functional coatings and porous composite materials have been introduced in next-generation materials for treating OD, whereas osteoconductive materials, such as demineralized bone particle (DBP) or bone derivatives, are used. However, modification of porosity, biocompatibility, cell proliferation, and mechanical properties is needed. DBP can activate human mesenchymal stem cells to differentiate into osteoblast cells. In this chapter, the potential application of GG with DBP in different combinations was reviewed, and the best suitable combinations were selected and further studied in small animal models for the soft and hard tissue engineering applications; also its application in the osteochondral integration fields were briefly discussed.


Assuntos
Regeneração Óssea , Polissacarídeos Bacterianos , Engenharia Tecidual , Animais , Galinhas , Humanos , Hidrogéis , Polissacarídeos Bacterianos/química , Engenharia Tecidual/métodos
9.
Food Chem ; 333: 127418, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32653680

RESUMO

Fermented camel milk possesses a weak (liquid-like) gel structure. We aimed to 1) investigate the characteristics, bioactivities and rheological properties of the exopolysaccharide (EPS) produced by Lactococcus garvieae-C47 (exopolysaccharide-C47 product), a potential probiotic bacterium, on milk extracted from camels and 2) examine the rheological properties of the fermented camel milk produced by L. garvieae-C47. Exopolysaccharide-C47 product (molecular weight: 7.3 × 106 Da) was composed of the following monosaccharides: glucose (82.51%), arabinose (5.32%) and xylose (12.17%). The antioxidant, antitumor and α-amylase inhibitory activities of exopolysaccharide-C47 product reached up to 67.52, 59.35 and 91.0%, respectively. The apparent viscosity of exopolysaccharide-C47 product decreased with the increase in shear rate and declined by increasing the temperature up to 50 °C. The rheological properties of exopolysaccharide-C47 product are influenced by the salt type and pH value. The exopolysaccharide product produced by L. garvieae C47 possesses valuable health benefits and has the ability to improve the weak structure of fermented camel milk.


Assuntos
Fermentação , Lactococcus/metabolismo , Leite/microbiologia , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/farmacologia , Probióticos/metabolismo , Reologia , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Antioxidantes/química , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Camelus , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Peso Molecular , Polissacarídeos Bacterianos/biossíntese , Viscosidade , alfa-Amilases/antagonistas & inibidores
10.
J Dairy Sci ; 103(8): 6830-6842, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32475665

RESUMO

In this study, we purified and characterized exopolysaccharide (EPS) produced by a high-EPS-producing dairy starter bacterium, Streptococcus thermophilus ASCC 1275. Crude EPS was extracted from S. thermophilus ASCC 1275 and partially purified using dialysis. Further purification and fractionation of exopolysaccharide was conducted using HPLC on a Superose 6 column (Cytiva/Global Life Sciences Solutions, Marlborough, MA). Glycosyl composition analysis, linkage analysis along with 1-dimensional and 2-dimensional nuclear magnetic resonance spectroscopy were performed to deduce the structure of EPS. Three fractions (F) obtained from gel permeation chromatography were termed F1 (2.6%), F2 (45.8%), and F3 (51.6%) with average molecular weights of approximately 511, 40, and 5 kDa, respectively. Monosaccharide composition analysis revealed the dominance of glucose, galactose, and mannose in all 3 fractions. Major linkages observed in F3 were terminal galactopyranosyl (t-Gal), 3-linked glucopyranosyl (3-Glc), 3-linked galactofuranosyl (3-Galf), and 3,6-linked glucopyranosyl (3,6-Glc) and major linkages present in F2 were 4-Glc (48 mol%), followed by terminal mannopyranosyl (t-Man), 2- + 3-linked mannopyranosyl (2-Man+3-Man), and 2,6-linked mannopyranosyl (2,6-Man; total ∼28 mol%). The 1-dimensional and 2-dimensional nuclear magnetic resonance spectroscopy revealed that F2 comprised mannans linked by (1→2) linkages and F3 consisted of linear chains of α-d-glucopyranosyl (α-d-Glcp), ß-d-glucopyranosyl (ß-d-Glcp), and ß-d-galactofuranosyl (ß-d-Galf) connected by (1→3) linkages; branching was through (1→6) linkage in F3. A possible structure of EPS in F2 and F3 was proposed.


Assuntos
Polissacarídeos Bacterianos/química , Streptococcus thermophilus/química , Galactose/química , Glucose/química , Espectroscopia de Ressonância Magnética , Mananas/química , Peso Molecular , Polissacarídeos Bacterianos/isolamento & purificação , Conformação Proteica
11.
PLoS Biol ; 18(6): e3000728, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32516311

RESUMO

The development of multicellularity is a key evolutionary transition allowing for differentiation of physiological functions across a cell population that confers survival benefits; among unicellular bacteria, this can lead to complex developmental behaviors and the formation of higher-order community structures. Herein, we demonstrate that in the social δ-proteobacterium Myxococcus xanthus, the secretion of a novel biosurfactant polysaccharide (BPS) is spatially modulated within communities, mediating swarm migration as well as the formation of multicellular swarm biofilms and fruiting bodies. BPS is a type IV pilus (T4P)-inhibited acidic polymer built of randomly acetylated ß-linked tetrasaccharide repeats. Both BPS and exopolysaccharide (EPS) are produced by dedicated Wzx/Wzy-dependent polysaccharide-assembly pathways distinct from that responsible for spore-coat assembly. While EPS is preferentially produced at the lower-density swarm periphery, BPS production is favored in the higher-density swarm interior; this is consistent with the former being known to stimulate T4P retraction needed for community expansion and a function for the latter in promoting initial cell dispersal. Together, these data reveal the central role of secreted polysaccharides in the intricate behaviors coordinating bacterial multicellularity.


Assuntos
Myxococcus xanthus/citologia , Myxococcus xanthus/metabolismo , Polissacarídeos Bacterianos/metabolismo , Acetilação , Vias Biossintéticas/genética , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Membrana Celular/metabolismo , Família Multigênica , Myxococcus xanthus/genética , Polissacarídeos Bacterianos/química , Espectroscopia de Prótons por Ressonância Magnética , Tensoativos/metabolismo
12.
PLoS One ; 15(6): e0235168, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32579611

RESUMO

OBJECTIVE: There is an increasing need for small diameter vascular grafts with superior host hemo- and cytocompatibilities, such as low activation of platelets and leukocytes. Therefore, we aimed to investigate whether the preparation of bacterial nanocellulose grafts with different inner surfaces has an impact on in vitro host cytocompatibility. METHODS: We have synthesized five different grafts in a bioreactor, namely open interface surface (OIS), inverted (INV), partially air dried (PAD), surface formed in air contact (SAC) and standard (STD) that were characterized by a different surface roughness. The grafts (length 55 mm, inner diameter 5 mm) were attached to heparinized polyvinyl chloride tubes, loaded with human blood and rotated at 37°C for 4 hours. Then, blood was analyzed for frequencies of cellular fractions, oxidative products, soluble complement and thrombin factors. The results were compared to clinically approved grafts made of polyethylene terephthalate and expanded polytetrafluoroethylene. Additionally, blood platelets were labelled with 111Indium-oxine to visualize the distribution of adherent platelets in the loop by scintigraphy. RESULTS: SAC nanocellulose grafts with the lowest surface roughness exhibited superior performance with <10% leukocyte and <50% thrombocyte loss in contrast to other grafts that exhibited >65% leukocyte and >90% thrombocyte loss. Of note, SAC nanocellulose grafts showed lowest radioactivity with scintigraphy analyses, indicating reduced platelet adhesion. Although the levels of reactive oxygen species and cell free DNA did not differ significantly, the levels of thrombin-antithrombin complexes were lowest in SAC grafts. However, all nanocellulose grafts exhibited enhanced complement activation. CONCLUSION: The systematic variation of the inner surfaces of BNC vascular grafts significantly improves biocompatibility. Especially, SAC grafts exhibited the lowest loss of platelets as well as leukocytes and additionally significantly diminished activation of the coagulation system. Further animal studies are needed to study in vivo biocompatibilities.


Assuntos
Materiais Biocompatíveis/química , Prótese Vascular , Celulose/química , Polissacarídeos Bacterianos/química , Grau de Desobstrução Vascular/fisiologia , Animais , Coagulação Sanguínea/efeitos dos fármacos , Implante de Prótese Vascular/métodos , Celulose/ultraestrutura , Oclusão de Enxerto Vascular/fisiopatologia , Oclusão de Enxerto Vascular/prevenção & controle , Heparina/farmacologia , Humanos , Teste de Materiais/métodos , Microscopia Eletrônica de Varredura , Adesividade Plaquetária/fisiologia , Polietilenotereftalatos/química , Politetrafluoretileno/química , Propriedades de Superfície , Grau de Desobstrução Vascular/efeitos dos fármacos
13.
J Biosci Bioeng ; 130(3): 283-289, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32507385

RESUMO

A novel exopolysaccharide (EPS) from Paenibacillus polymyxa PYQ1 was extracted, well purified and characterized. This EPS was homogeneous glucomannan-type polysaccharide with the average molecular weight of 4.38 × 106 Da. Structural characterization indicated that the monosaccharides of EPS were pyranoses connected by ß-glycosidic linkages. Furthermore, our results showed the protective benefits of EPS against UVC induced cytotoxicity in HaCaT cells through scavenging excessive reactive oxygen species, mitigating the decrease of mitochondrial membrane potential, improving catalase activity and maintaining membrane integrity. Taken together, this study qualified EPS from P. polymyxa PYQ1 was a promising natural polymer which worth further investigation as a skin-care agent.


Assuntos
Citoproteção/efeitos dos fármacos , Paenibacillus polymyxa/metabolismo , Polissacarídeos Bacterianos/isolamento & purificação , Polissacarídeos Bacterianos/farmacologia , Raios Ultravioleta/efeitos adversos , Catalase/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos da radiação , Peso Molecular , Monossacarídeos/análise , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/química , Espécies Reativas de Oxigênio/metabolismo
14.
PLoS One ; 15(6): e0233952, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32498075

RESUMO

This study aimed to produce cellulose-based conductive fabrics with electrical conductivity and flexibility. Bacterial cellulose (BC) and three chemical cellulose (CC), namely methyl cellulose (MC), hydroxypropyl cellulose (HPMC) and carboxymethyl cellulose (CMC) were in situ polymerized with aniline and the four conductive cellulose fabrics were compared and evaluated. Matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy analysis confirmed that three CC-PANI composites displayed longer and more stable polymerization pattern than BC-PANI because of the different polymerization method: bulk polymerization for BC-PANI and emulsion polymerization for CC-PANI, respectively. The electrical conductivity of BC-PANI and CC-PANI were ranging from 0.962 × 10-2 S/cm to 2.840 × 10-2 S/cm. MC-PANI showed the highest electrical conductivity among the four conductive cellulose fabrics. The flexibility and crease recovery results showed that MC-PANI had the highest flexibility compared to BC-PANI, HPMC-PANI, and CMC-PANI. These results have confirmed that the electrical conductivity and flexibility were influenced by the type of cellulose, and MC-PANI was found to have the best performance in the electrical conductivity and flexibility.


Assuntos
Carboximetilcelulose Sódica/química , Celulose/análogos & derivados , Metilcelulose/química , Polissacarídeos Bacterianos/química , Têxteis , Compostos de Anilina/química , Celulose/química , Elasticidade , Condutividade Elétrica , Nanocompostos/química , Polimerização , Têxteis/análise , Dispositivos Eletrônicos Vestíveis
15.
Appl Environ Microbiol ; 86(15)2020 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-32444475

RESUMO

In developing countries, Shigella flexneri is the most common enteric pathogen causing bacillary dysentery. Biofilm formation by S. flexneri can cause the emergence of antibiotic-resistant strains, which poses serious threats to food safety and human health. In this study, the effects of Lactobacillus plantarum 12 exopolysaccharides (L-EPSs) and S. flexneri exopolysaccharides (S-EPSs) on S. flexneri CMCC51574 biofilm formation were investigated. The results showed that L-EPS could decrease polysaccharide production in the extracellular polymeric matrix of S. flexneri and inhibit biofilm formation by S. flexneri L-EPS could decrease the minimum biofilm elimination concentration (MBEC) of antibiotics against S. flexneri biofilm and inhibit S. flexneri adhesion to and invasion into HT-29 cell monolayers, which might be ascribed to S. flexneri biofilm disturbance by L-EPS. In contrast, S-EPS exhibited the opposite effects compared to L-EPS. The monosaccharide composition analysis showed that L-EPS was composed of mannose, glucuronic acid, galactosamine, glucose, galactose, and xylose, with the molar ratio of 32.26:0.99:1.79:5.63:0.05:4.07, while S-EPS was composed of mannose, glucuronic acid, galactosamine, glucose, and galactose, with the molar ratio of 25.43:2.28:7.13:5.35. L-EPS was separated into the neutral polysaccharide L-EPS 1-1 and the acidic polysaccharide L-EPS 2-1 by ion-exchange chromatography and gel chromatography. L-EPS 2-1 exerted higher antibiofilm activity than L-EPS 1-1. The antibiofilm activity of L-EPS might be associated with its structure.IMPORTANCE S. flexneri is a widespread foodborne pathogen causing food contamination and responsible for food poisoning outbreaks related to various foods in developing countries. Not only has biofilm formation by S. flexneri been difficult to eliminate, but it has also increased the drug resistance of the strain. In the present study, it was demonstrated that L-EPSs secreted by Lactobacillus plantrum 12 could inhibit S. flexneri biofilm formation on, adhesion to, and invasion into HT-29 cells. Also, L-EPSs could decrease the minimum biofilm elimination concentration (MBEC) of the antibiotics used against S. flexneri biofilm. Therefore, L-EPSs were shown to be bioactive macromolecules with the potential ability to act against S. flexneri infections.


Assuntos
Biofilmes/efeitos dos fármacos , Lactobacillus plantarum/química , Polissacarídeos Bacterianos/química , Shigella flexneri/efeitos dos fármacos , Disenteria Bacilar/tratamento farmacológico , Probióticos/química , Shigella flexneri/fisiologia
16.
J Food Sci ; 85(6): 1799-1804, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32458576

RESUMO

Demand for antimicrobial packaging films is growing due to public attention to food safety. The structures and properties of gellan gum-guar gum blend films incorporated with nisin were investigated in this paper. Fourier transform infrared spectroscopy, rheological analyses showed intermolecular interactions among gellan gum, guar gum, and nisin. Furthermore, scanning electron microscopy and thermogravimetric analysis also indicated higher compatibility of the blend film components and better thermal stability than the gellan gum film. Tensile strength (TS), elongation at break (EAB) and water vapor permeability (WVP) of the blend films were enhanced with the addition of guar gum. The TS of the blend film reached 2.89 × 103  MPa, the EAB increased to 67.99%, and the WVP increased to 1.80 × 10-5  g/mm·s·Pa. Additionally, the film with nisin had antibacterial activity for Bacillus subtilis. The results demonstrated that a homogenous and smooth antimicrobial film with gellan gum, guar gum, and nisin could be a good option of antimicrobial packaging film for food preservation. PRACTICAL APPLICATION: This work investigated blend package films of gellan gum and guar gum incorporated with nisin. The results showed compatibility and thermal stability of the film were improved with adding a certain amount of guar gum, and also antibacterial activity for Bacillus subtilis of the blend film with nisin. Therefore, it can be used to the development of antimicrobial packaging films.


Assuntos
Embalagem de Alimentos/instrumentação , Galactanos/química , Mananas/química , Nisina/química , Gomas Vegetais/química , Polissacarídeos Bacterianos/química , Antibacterianos/química , Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Plásticos Biodegradáveis/química , Plásticos Biodegradáveis/farmacologia , Microscopia Eletrônica de Varredura , Nisina/farmacologia , Permeabilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Vapor/análise , Resistência à Tração
17.
Food Chem ; 328: 127082, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32464554

RESUMO

Acorn flour was used as a gluten-free ingredient to produce acorn muffins. Interaction effects between xanthan (X), carboxymethyl cellulose (CMC) and κ-carrageenan (κ-C) (0-0.3%) on the height and textural parameters of the formulated acorn flour muffins were investigated using a mixture design approach. Each studied parameter was optimized individually. Then, an optimal formulation giving a product with characteristics as close as possible to those of a wheat flour muffin sample was determined. Results revealed that addition of each hydrocolloid separately, or their ternary combination improved the muffin height. Optimal height value was predicted to reach 3.96 cm when using 26.8% X, 50.5% CMC and 22.7% κ-C. As regard to textural parameters (firmness, cohesiveness, springiness and adhesiveness), presence of the three hydrocolloids had an antagonistic effect. The best hydrocolloids mixture giving optimal height (3.92 cm), firmness (3.19 N) and adhesiveness (0.66 N) was that containing 20.5% X and 79.5% CMC.


Assuntos
Farinha/análise , Quercus/química , Carragenina/química , Coloides , Dieta Livre de Glúten , Humanos , Polissacarídeos Bacterianos/química
18.
Carbohydr Polym ; 237: 116172, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32241441

RESUMO

Albeit gelatin hard capsules were predominantly applied, their disadvantages call for endeavours on non-gelatin capsules in healthcare aspects. Herein, high molecular weight (Mw = 1 × 106) pullulan was purified from yeast fermentation broth. This high Mw pullulan and commercial low Mw pullulan were respectively co-blended with gellan to prepare the optimal solutions for capsule production. Further investigations, including loss-on-drying, brittleness and tightness, showed that the obtained pullulan-gellan capsules were of low water content, brittleness, leakage, and of high tightness. These capsules exhibited an extended release of amoxicillin over 60 min in simulated gastric fluid. Although the use of high and low Mw pullulan produced composite capsules with similar properties, the required concentration of high Mw pullulan was nearly half of that for low Mw pullulan, suggesting a cost-saving characteristic of using high Mw pullulan. This work proposes a potential substitution of gelatin with pullulan-gellan composites for preparing hard capsules.


Assuntos
Glucanos/química , Polissacarídeos Bacterianos/química , Amoxicilina/química , Antibacterianos/química , Cápsulas , Preparações de Ação Retardada/química , Liberação Controlada de Fármacos , Suco Gástrico/química , Peso Molecular , Reologia
19.
Carbohydr Polym ; 237: 116160, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32241445

RESUMO

Polysaccharides derived from microorganisms have received considerable attention in designing hydrogel materials. However, most microbial polysaccharide-constructed hydrogels evaluated in preclinical trials are not favorable candidates for biomedical applications owing to concerns regarding poor mechanical strength and complicated fabrication process. Herein, we describe a new polysaccharide hydrogel scaffold containing salecan together with gellan gum network as the polymeric matrix. Properly controlling the physical and chemical properties including swelling, water release, thermal stability, viscoelasticity and morphology of the resulting gel are easily achieved by simply changing the salecan/gellan gum ratios. Notably, these salecan/gellan gum scaffolds friendly support cell survival and proliferation. More significantly, we have systematically evaluated these developed hydrogels for the biocompatible experiments in vitro and in vivo and results indicated the products are non-toxic. Taken together, such hydrogels derived from microbial polysaccharides and readily synthesized through a one-step mixing protocol have translational potentials in the clinic serving as cell devices for tissue engineering.


Assuntos
Materiais Biocompatíveis , Hidrogéis , Polissacarídeos Bacterianos , Tecidos Suporte , beta-Glucanas , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Elasticidade , Fibroblastos/efeitos dos fármacos , Humanos , Hidrogéis/química , Hidrogéis/farmacologia , Masculino , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/farmacologia , Ratos Sprague-Dawley , Engenharia Tecidual , Viscosidade , beta-Glucanas/química , beta-Glucanas/farmacologia
20.
Int J Nanomedicine ; 15: 2027-2044, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32273700

RESUMO

Purpose: As one of the classic anti-Canidia albicans (CA) and vulvovaginal candidiasis (VVC) drugs, nystatin (NYS) is limited by poor water solubility and easy aggregation. Traditional NYS vaginal delivery formulations do not fully adapt to the specific environment of the vaginal cavity. The use of exopolysaccharides (EPS) has great application potential in emulsifiers, but its use has not been reported in nanoemulsions. In this work, an EPS/NYS nanoemulsion (ENNE) was developed to improve the activities of NYS against CA and VVC. Methods: The ENNE was prepared by ultrasonic method using EPS as an emulsifier, liquid paraffin oil as an oil phase, PEG400 as a co-emulsifier, and NYS as the loaded drug. ENNE preparation was optimized by response surface method. After optimization, in vitro and in vivo analysis of the anti-CA activity; animal experiments; staining with propidium iodide (PI), periodic acid-schiff (PAS), and hematoxylin-eosin (H&E); and cytokine experiments were performed to investigate the therapeutic ability against VVC. Results: The optimal formulation and preparation parameters of ENNE were determined as follows: EPS content of 1.5%, PEG400 content of 3.2%, NYS content of 700 µg/mL, paraffin oil content of 5.0%, ultrasonic time of 15 min, and ultrasonic amplitude of 35%. The ENNE showed an encapsulated structure with an average particle size of 131.1 ± 4.32 nm. ENNE exhibited high storage and pH stability, as well as slow release. The minimum inhibitory concentration (MIC) of ENNE against CA was only 0.125 µg/mL and the inhibition zone was 19.0 ± 0.5 mm, for greatly improved anti-CA effect. The prepared ENNE destroyed the membrane of CA cells, and exhibited good anti-CA effect in vivo and therapeutic ability against VVC. Conclusion: The results of this study will promote the application of EPS in nanotechnology, which should lead to new and effective local drug formulations for treating VVC.


Assuntos
Antifúngicos/administração & dosagem , Candidíase Vulvovaginal/tratamento farmacológico , Emulsões/química , Nanoestruturas/administração & dosagem , Nistatina/administração & dosagem , Administração Intravaginal , Animais , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Citocinas , Emulsificantes/química , Emulsões/administração & dosagem , Feminino , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Nanoestruturas/química , Nistatina/farmacologia , Tamanho da Partícula , Polietilenoglicóis/química , Polissacarídeos Bacterianos/química , Ultrassom/métodos
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