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1.
PLoS One ; 15(8): e0237218, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32760143

RESUMO

Influenza is an infectious respiratory illness caused by influenza viruses. Despite yearly updates, the efficacy of influenza vaccines is significantly curtailed by the virus antigenic drift and antigenic shift. These constant changes to the influenza virus make-up also challenge the development of a universal flu vaccine, which requires conserved antigenic regions shared by influenza viruses of different subtypes. We propose that it is possible to bypass these challenges by the development of an influenza vaccine based on conserved proteins delivered in an adjuvanted nanoparticle system. In this study, we generated influenza nanoparticle constructs using trimethyl chitosan nanoparticles (TMC nPs) as the carrier of recombinant influenza hemagglutinin subunit 2 (HA2) and nucleoprotein (NP). The purified HA2 and NP recombinant proteins were encapsulated into TMC nPs to form HA2-TMC nPs and NP-TMC nPs, respectively. Primary human intranasal epithelium cells (HNEpCs) were used as an in vitro model to measure immunity responses. HA2-TMC nPs, NP-TMC nPs, and HA2-NP-TMC nPs (influenza nanoparticle constructs) showed no toxicity in HNEpCs. The loading efficiency of HA2 and NP into the TMC nPs was 97.9% and 98.5%, respectively. HA2-TMC nPs and NP-TMC nPs more efficiently delivered HA2 and NP proteins to HNEpCs than soluble HA2 and NP proteins alone. The induction of various cytokines and chemokines was more evident in influenza nanoparticle construct-treated HNEpCs than in soluble protein-treated HNEpCs. In addition, soluble factors secreted by influenza nanoparticle construct-treated HNEpCs significantly induced MoDCs maturation markers (CD80, CD83, CD86 and HLA-DR), as compared to soluble factors secreted by protein-treated HNEpCs. HNEpCs treated with the influenza nanoparticle constructs significantly reduced influenza virus replication in an in vitro challenge assay. The results indicate that TMC nPs can be used as influenza vaccine adjuvants and carriers capable of delivering HA2 and NP proteins to HNEpCs.


Assuntos
Adjuvantes Imunológicos/farmacologia , Quitosana/farmacologia , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/farmacologia , Influenza Humana/prevenção & controle , Adjuvantes Imunológicos/administração & dosagem , Animais , Linhagem Celular , Células Cultivadas , Quitosana/administração & dosagem , Cães , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/farmacologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/administração & dosagem , Glicoproteínas de Hemaglutininação de Vírus da Influenza/farmacologia , Humanos , Vacinas contra Influenza/administração & dosagem , Influenza Humana/imunologia , Células Madin Darby de Rim Canino , Nanopartículas/administração & dosagem , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Proteínas de Ligação a RNA/administração & dosagem , Proteínas de Ligação a RNA/farmacologia , Proteínas do Core Viral/administração & dosagem , Proteínas do Core Viral/farmacologia
2.
Int J Food Microbiol ; 331: 108786, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-32659617

RESUMO

Sweet orange essential oil is obtained from the peels of Citrus sinensis (CSEO) by cold pressing, and used as a valuable product by the food industry. Nanoencapsulation is known as a valid strategy to improve chemical stability, organoleptic properties, and delivery of EO-based products. In the present study we encapsulated CSEO using chitosan nanoemulsions (cn) as nanocarrier, and evaluated its antimicrobial activity in combination with mild heat, as well as its sensorial acceptability in orange and apple juices. CSEO composition was analyzed by GC-MS, and 19 components were identified, with limonene as the predominant constituent (95.1%). cn-CSEO was prepared under low shear conditions and characterized according to droplet size (<60 nm) and polydispersity index (<0.260 nm). Nanoemulsions were stable for at least 3 months at 4 ± 2 °C. cn-CSEO were compared with suspensions of CSEO (s-CSEO) (0.2 µL of CSEO/mL) in terms of antibacterial activity in combination with mild heat (52 °C) against Escherichia coli O157:H7 Sakai. cn-CSEO displayed a greater bactericidal activity than s-CSEO at pH 7.0 and pH 4.0. The validation in fruit juices showed an improved bactericidal effect of cn-CSEO in comparison with s-CSEO when combined with mild heat in apple juice, but not in orange juice. In both juices, the combination of CSEO and mild heat exerted synergistic lethal effects, reducing the treatment time to cause the inactivation of up to 5 Log10 cycles of E. coli O157:H7 Sakai cells. Finally, the sensory characteristics of both juices were acceptable either when using s-CSEO or CSEO nanoemulsified with chitosan. Therefore, as a promising carrier for lipophilic substances, the encapsulation of EOs with chitosan nanoemulsions might represent an advantageous alternative when combined with mild heat to preserve fruit juices.


Assuntos
Quitosana/química , Emulsões/farmacologia , Conservação de Alimentos/métodos , Sucos de Frutas e Vegetais/microbiologia , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Bebidas/microbiologia , Quitosana/farmacologia , Citrus sinensis/química , Contagem de Colônia Microbiana , Emulsões/química , Escherichia coli O157/efeitos dos fármacos , Frutas/química , Temperatura Alta , Malus/microbiologia
3.
Int J Food Microbiol ; 330: 108766, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32659522

RESUMO

The aim of the study was to explore the antifungal and aflatoxin B1 inhibitory efficacy of nanoencapsulated antifungal formulation. Mixture design response surface methodology (RSM) was utilized to design the antifungal formulation (SBC 4:1:1) based on the combination of chemically characterized Ocimum sanctum (S), O. basilicum (B), and O. canum (C) against Aspergillus flavus. The SBC was incorporated inside the chitosan nanomatrix (Ne-SBC) using an ultrasonic probe (40 kHz) and interactions were confirmed by SEM, FTIR and XRD analysis. The results showed that the Ne-SBC possessed enhanced antifungal and aflatoxin B1 inhibitory effect over the free form of SBC. The biochemical and in silico results indicate that the antifungal and aflatoxin B1 inhibitory effect was related to perturbance in the plasma membrane function (ergosterol biosynthesis and membrane cation) mitochondrial membrane potential, C-sources utilization, antioxidant defense system, and the targeted gene products Erg 28, cytochrome c oxidase subunit Va, and Nor-1. In-situ observation revealed that Ne-SBC effectively protects the Avena sativa seeds from A. flavus and AFB1 contamination and preserves its sensory profile. The findings suggest that the fabrication of SBC inside the chitosan nano-matrix has promising use in the food industries as an antifungal agent.


Assuntos
Aflatoxina B1/antagonistas & inibidores , Antifúngicos/farmacologia , Microbiologia de Alimentos , Ocimum/química , Óleos Voláteis/farmacologia , Aflatoxina B1/metabolismo , Antifúngicos/química , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/metabolismo , Quitosana/química , Quitosana/farmacologia , Composição de Medicamentos , Ocimum/classificação , Óleos Voláteis/química , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Sementes/microbiologia
4.
Gene ; 755: 144845, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32522696

RESUMO

Plant immune regulation is a defensive strategy of plants for protection against pathogen invasion, and Chitosan-N (CTS-N) can induce plant autoimmunity regulation mechanisms. CTS-N was found to induce an immunomodulatory response in papaya against Papaya leaf-distortion mosaic virus (PLDMV). To date, the gene expression profile of CTS-N-induced papaya immunomodulatory response has not been reported. Here, the transcriptional map of papaya leaf genes were subjected to three treatments, viz., non-viral inoculation without CTS-N treatment (CK), virus inoculation without CTS-N treatment (CG), and virus inoculation of 1 g/L treatment (B). These were studied by pot culture experiment. Comparison of the B group with the CG group revealed 732 upregulated and 510 downregulated genes. Comparison of the CG group with the CK group revealed 909 upregulated and 1024 downregulated genes. To determine gene function, gene ontology (GO) analysis was performed, where 480 biological process genes, 256 molecular function genes, and 343 cell composition genes were differentially expressed. Kyoto Encyclopedia of Genes and Genomes (KEGG) results revealed that the top three pathways were phenylpropane biosynthesis, starch and sucrose metabolism, and plant hormone signal transduction. Real-time Quantitative PCR (qPCR) results were consistent with the transcriptome results, with a correlation coefficient of 0.87. The results of the transcriptional group showed that genes associated with plant resistance were induced by CTS-N-treatment in papaya. The chitinase gene was related to the plant disease process. Related genes in plant hormone signal transduction pathways are associated with plant resistance, and six differentially expressed genes were correlated with enhanced immune resistance in papaya.


Assuntos
Carica/genética , Carica/imunologia , Imunidade Vegetal/imunologia , Quitosana/farmacologia , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Análise em Microsséries/métodos , Doenças das Plantas/genética , Potyvirus/imunologia , Potyvirus/patogenicidade , Transcriptoma/genética
5.
Int J Food Microbiol ; 331: 108694, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-32521373

RESUMO

This study evaluated if coatings with chitosan (Chi) and phenolic-rich extract from acerola (Malpighia emarginata D.C., PEA) or jabuticaba (Plinia jaboticaba (Vell.) Berg, PEJ) processing by-products are effective to control the development of rot caused by Lasiodiplodia pseudotheobromae, L. viticola, L. euphorbicola, L. theobromae and L. hormozganensis in papaya (Carica papaya L.) fruit. Effects of formulated coatings on some physicochemical parameters indicative of postharvest quality of papaya were investigated. Twenty-six different phenolics were found in PEA and PEJ, including flavonoids, stilbenes, tannins and phenolic acids. Chi (1-5 mg/mL), PEA and PEJ (25-100 mg/mL) separately caused mycelial growth inhibition on all isolates. Combinations of Chi (3 and 4 mg/mL) and PEA (50 and 75 mg/mL) or PEJ (75 and 100 mg/mL) had additive interactions. Coatings with Chi (4 mg/mL) and PEA (50 or 75 mg/mL) or PEA (75 or 100 mg/mL) inhibited rot development in papaya fruit infected with Lasiodiplodia isolates during 8 days of room temperature storage. Coatings with 4 mg/mL Chi and 75 mg/mL PEA or 100 mg/mL PEJ were the most effective to control rot development. These coatings did not affect negatively physicochemical parameters indicative of postharvest quality of papaya fruit during storage. Coatings with combined Chi and PEA or PEJ could be novel strategies to control postharvest rot caused by Lasiodiplodia in papaya fruit.


Assuntos
Carica/microbiologia , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Frutas/microbiologia , Malpighiaceae/química , Myrtaceae/química , Extratos Vegetais/farmacologia , Ascomicetos/efeitos dos fármacos , Quitosana/farmacologia , Fenóis/farmacologia
6.
Int J Food Microbiol ; 326: 108650, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32402916

RESUMO

Use of carbon dots (CDs) in combination with aqueous chitosan solution to extend shelf life and improve stability of soy milk was investigated. Soy milk samples with chitosan solution (0.00%, 0.08%, 0.12%, 0.16% and 0.20%) and banana-based CDs (4%, 6% and 8%) were prepared and stored at room temperature (25-30 °C) for shelf life evaluation. Soy milk with 0.16% chitosan solution exhibited improved stability as evident by increased viscosity, stability coefficient, zeta potential and decreased centrifugation rate compared with soy milk without chitosan. The suitable amount of carbon dots could effectively inhibit the growth of Escherichia coli, Staphylococcus aureus and Bacillus subtilis. Soy milk with 0.16% chitosan and 8% CDs exhibited longer shelf life and significantly lower total bacterial count after storage at room temperature for up to 4 days. Electronic nose-based flavor characteristics of all treated soy milk samples were not far from that of the control sample.


Assuntos
Bacillus subtilis/crescimento & desenvolvimento , Quitosana/farmacologia , Escherichia coli/crescimento & desenvolvimento , Armazenamento de Alimentos/estatística & dados numéricos , Leite de Soja/metabolismo , Staphylococcus aureus/crescimento & desenvolvimento , Bacillus subtilis/efeitos dos fármacos , Carbono/farmacologia , Escherichia coli/efeitos dos fármacos , Contaminação de Alimentos/análise , Pontos Quânticos , Staphylococcus aureus/efeitos dos fármacos , Paladar , Água/farmacologia
7.
Int J Food Microbiol ; 326: 108649, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32402917

RESUMO

In this study we assessed the efficacy of chitosan (CHI) (2%) emulsion added with Ruta graveolens L. essential oil (REO) at different concentrations (0.5%, 1.0% and 1.5%) to control C. gloesporioides grows both "in situ" and "in vitro" in papaya Maradol (Carica papaya L.). In vitro studies showed a decrease on fungal growth (mycelia diameter) with the increase of REO concentration, while 0.5% of REO induce a reduction of 56.42%, REO at 1.0% and 1.5% induced a reduction of 97%. Microscopic analysis showed irreversible deleterious morphological and ultrastructural alterations as well as changes in conidia morphology, and conidia germination inhibition up to 90%. Among the most abundant REO constituents, 2-Nonanol showed strong antifungal activity followed by 2-Undecanone, Benzyl acetate, 2-Nonanone, 2-Tridecanone and 2-Dodecanone. Studies "in situ" on papaya fruit during 12 days at 20 °C, showed a reduction of the C. gloesporioides lesion expansion by 50% using CHI-REO 0.5% emulsions and by 100% with treatments of CHI-REO 1.0 and 1.5%, in addition the emulsions were efficacious to reduce the fruit surface microbiota. On the other hand, physicochemical analysis of the papaya fruits demonstrated that CHI-REO emulsions treatment delayed papaya ripening without affecting the organoleptic characteristics. All these results demonstrated for the first time the application of coatings CHI-REO as a postharvest treatment for the control of anthracnose on papaya fruit.


Assuntos
Antifúngicos/farmacologia , Carica/microbiologia , Quitosana/farmacologia , Colletotrichum/efeitos dos fármacos , Óleos Voláteis/farmacologia , Ruta/metabolismo , Emulsões , Frutas/microbiologia , Micélio/crescimento & desenvolvimento , Esporos Fúngicos/crescimento & desenvolvimento
8.
Biofouling ; 36(2): 222-233, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32316774

RESUMO

The antimicrobial activity of gold and silver nanoparticles (AuNPs, AgNPs), chitosan (CS) and their combinations was established by determining the minimum inhibitory concentration for planktonic (MICPC80) and biofilm growth (MICBC80), for biofilm formation (MICBF80), metabolic activity (MICBM80) and reduction (MICBR80), and for the metabolic activity of preformed biofilm (MICMPB80). Biofilms were quantified in microtitre plates by crystal violet staining and metabolic activity was evaluated by the MTT assay. Chitosan effectively suppressed biofilm formation (0.31-5 mg ml-1) in all the tested strains, except Salmonella enterica Infantis (0.16-2.5 mg ml-1) where CS and its combination with AgNPs induced biofilm formation. Nanoparticles inhibited biofilm growth only when the highest concentrations were used. Even though AuNPs, AgNPs and CS were not able to remove biofilm mass, they reduced its metabolic activity by at least 80%. The combinations of nanoparticles with CS did not show any significant positive synergistic effect on the tested target properties.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Quitosana/farmacologia , Ouro/farmacologia , Nanopartículas Metálicas/química , Prata/farmacologia , Antibacterianos/química , Biofilmes/crescimento & desenvolvimento , Quitosana/química , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Microbiologia de Alimentos , Ouro/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Prata/química
9.
PLoS One ; 15(4): e0231998, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32330169

RESUMO

Two experiments were conducted to evaluate the immune response of broilers vaccinated with Salmonella chitosan-nanoparticle (CNP) vaccine and challenged with Salmonella. The Salmonella CNP vaccine was synthesized with Salmonella enterica outer membrane proteins (OMPs) and flagellin proteins. In Experiment I, birds were orally gavaged with PBS or 500, 1000, or 2000µg of CNP vaccine 1 and 7d-of-age. At 14d-of-age, birds were orally challenged with 1 X 105 CFU/bird of live S. Enteritidis (SE). Macrophage-nitrite production 11d-post-challenge was higher (P<0.05) in the 500µg group when compared to the control. At d14 (8h-post-challenge), broilers vaccinated with 1000µg CNP had higher (P<0.05) serum anti-OMPs IgG and IgA and cloacal anti-OMP IgA amounts. At 11d-post-challenge, birds vaccinated with 1000µg CNP vaccine had greater (P<0.05) bile anti-OMP and anti-flagellin IgA amounts. At 11d-post-challenge, birds administered 1000µg CNP vaccine has increased (P<0.05) IL-1ß and IL-10 mRNA in cecal tonsils. In Experiment II, birds were orally gavaged with PBS or 1000µg CNP or a live commercial vaccine at 1 and 7d-of-age. At 14d-of-age, birds were orally challenged with 1 X 105 CFU/bird of live SE or S. Heidelberg (SH). Birds vaccinated with CNP showed higher (P<0.05) serum anti-OMPs IgG amounts at 8h-post-challenge. At 4d-post-SH challenge, birds vaccinated with CNP had higher (P<0.05) bile anti-flagellin IgA amounts. CNP decreased (P<0.05) anti-OMPs IgG levels in serum at 2d-post-SE challenge and 4d-post-SH or SE challenge. Salmonella Enteritidis loads in cecal content at 2d-post-challenge was decreased (P<0.05) by 65.9% in birds vaccinated with CNP, when compared to the control. Chitosan-nanovaccine had no adverse effects on bird's production performance. In conclusion, 1000µg CNP vaccine can induce a specific immune response against Salmonella and has the potential to mitigate SE cecal colonization in broiler birds.


Assuntos
Galinhas/imunologia , Quitosana/farmacologia , Vacinas contra Salmonella/imunologia , Animais , Proteínas da Membrana Bacteriana Externa/imunologia , Ceco/metabolismo , Galinhas/microbiologia , Quitosana/imunologia , Flagelina/imunologia , Antígenos de Histocompatibilidade Classe II , Nanopartículas/uso terapêutico , Doenças das Aves Domésticas/imunologia , Salmonella/imunologia , Salmonella/patogenicidade , Salmonelose Animal/imunologia , Salmonella enterica/metabolismo , Salmonella enteritidis/imunologia , Vacinas/imunologia , Vacinas Atenuadas/imunologia
10.
J Food Sci ; 85(4): 947-955, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32237089

RESUMO

Edible packaging films have been widely studied because of its safety, green, and effective characteristics. In this paper, chitosan (CH) edible films containing hexahydro-ß-acids (HBA) were prepared, and its physical and mechanical properties, bioactivity, and their impact on the shelf life of pork were investigated. The infrared spectra indicated that the molecular interaction between CH and HBA was observed. Scanning electron microscopy was used to analyze the surface morphology of the film, and light transmittance analysis displayed that the addition of HBA enhanced the film's UV blocking performance. Compared to the CH film, the tensile strength of CH-HBA film increased to 29.19 ± 0.45 MPa, and the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) reached 1.40 ± 0.01 mg rutin/cm2 of the film. The antibacterial activity of the CH-HBA film on Escherichia coli (44825) and Staphylococcus aureus (26001) showed that the CH-HBA film is a feasible antibacterial package. Furthermore, compared to pork packaged in CH and polyethylene films, fresh pork packaged with CH-HBA films displayed prolongation of shelf life due to reduction in microbial proliferation, thiobarbituric values, pH, and total volatile base nitrogen contents during storage at 4 °C for 16 days. The freshness of pork was prolonged by 7-8 days when the dosage of HBA was increased to 0.3% from 0.1% (w/v). These results revealed that the CH-HBA film can effectively extend the shelf life of pork. PRACTICAL APPLICATION: This study effectively prolonged the shelf life of pork. A chitosan-edible film combined with hexahydro-ß-acids has a potential application value in replacing traditional packaged fresh meat.


Assuntos
Antibacterianos/farmacologia , Quitosana/farmacologia , Embalagem de Alimentos/instrumentação , Carne Vermelha/análise , Ácidos/análise , Ácidos/farmacologia , Animais , Antibacterianos/análise , Quitosana/análise , Filmes Comestíveis , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Embalagem de Alimentos/métodos , Armazenamento de Alimentos , Carne Vermelha/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Suínos , Resistência à Tração
11.
Artigo em Inglês | MEDLINE | ID: mdl-32120172

RESUMO

Chitosan oligosaccharides (COS) worked effectively in multiple plant-pathogen interactions as plant immunity regulator, however, due to the complexity of the COS-induced immune signaling network, the topic requires further investigation. In the present study, quantitative analysis of proteins was performed to investigate the underlying mechanism of COS induced resistance to Pseudomonas syringae pv. tomato DC3000 (Pst DC3000) in Arabidopsis thaliana. 4303 proteins were successfully quantified, 186, 217 and 207 proteins were differently regulated in mock + Pst, COS, and COS + Pst treated plants, respectively, compared with mock plants. From detailed functional and hierarchical clustering analysis, a priming effect of COS on plant immune system by pre-regulated the key proteins related to signaling transduction, defense response, cell wall biosynthesis and modification, plant growth and development, gene transcription and translation, which confers enhanced resistance when Pst DC3000 infection in Arabidopsis. Moreover, RACK1B which has the potential to be the key kinase receptor for COS signals was found out by protein-protein interaction network analysis of COS responsive proteins. In conclusion, COS treatment enable plant to fine-tuning its defense mechanisms for a more rapid and stronger response to future pathogen attacks, which obviously enhances plants defensive capacity that makes COS worked effectively in multiple plant-pathogen interactions.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Quitosana , Resistência à Doença , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Quitosana/farmacologia , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteômica , Pseudomonas syringae/fisiologia
12.
J Food Sci ; 85(4): 1240-1247, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32198774

RESUMO

Mold growth on sausage casing during processing is an important problem in fermented sausages. In this work, sausages were dipped into 1% chitosan (C), 1% thyme essential oil in 1% chitosan (CT), 1% rosemary essential oil in 1% chitosan (CR), 20% potassium sorbate (PS) as chemical antifungal, and 1% acetic acid solution (AA) as chitosan solver, or distilled water (DW) as control after fermentation (at day 4). The changes in microbiological (total viable count, lactic acid bacteria [LAB], Micrococcaceae, Enterobacteriaceae, and mold and yeast counts) and physicochemical attributes of the sausages during 12 days of processing were monitored. As expected, LAB were the most dominant microbiota in fermented sausages and the dipping process did not have any negative effect. Additionally, the treatment with C, CT, and CR suppressed the growth of spoilage microorganisms, which resulted in a significant reduction (P < 0.01) of about 1.4 to 1.6 log CFU/g in Enterobacteriaceae counts at day 12. The C, CT, and CR similarly suppressed the growth of fungi in the interior of the sausages, and the antifungal treatment significantly reduced (P < 0.01) the load of fungi on the casing. Throughout the study, approximately log counts of 3 and 4 in lower molds and yeasts in the casings treated with PS and CR were found, respectively, as compared to DW. Finally, the microbial quality of the end product was notably improved. PRACTICAL APPLICATION: Processing conditions such as high humidity and O2 in the ripening chamber result in undesirable fungal growth on the casings of the sausages. Fermented sausages are usually treated with weak acids such as sorbic or benzoic acids or their salts to inhibit mold growth during the drying process. However, increasing consumer demand to reduce the use of chemicals encourages the applications of natural antifungals.


Assuntos
Quitosana/farmacologia , Microbiologia de Alimentos , Conservação de Alimentos/métodos , Fungos/efeitos dos fármacos , Produtos da Carne/microbiologia , Animais , Antifúngicos/farmacologia , Contagem de Colônia Microbiana , Fermentação , Fungos/crescimento & desenvolvimento , Produtos da Carne/análise , Óleos Voláteis
13.
Carbohydr Polym ; 235: 115949, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32122485

RESUMO

Photodynamic antifungal therapy is a promising treatment for increasing drug-resistant fungi. However, low physiological solubility and low fungi-affinity of most potential photosensitizers limits their therapeutic efficacy. To improve the water-solubility and photodynamic antifungal activity of zinc(II) phthalocyanine, two molecular-weight carboxymethyl chitosans (CMC1,50 kDa; CMC2,170 kDa) were herein respectively conjugated with 1-[4-(2-aminoethyl)phenoxy] zinc(II) phthalocyanine (ZnPcN) and further quaternized, and eight novel conjugates were obtained and characterized. Their photophysical and photochemical properties, cellular uptakes and in vitro photodynamic antifungal activities against Candida albicans have also been investigated. All the conjugates are less aggregated in water than ZnPcN. The low-molecular-weight CMC1-conjugated ZnPcN is more readily ingested and highly photoactive. Mainly due to its highest uptake by Candida cells, a conjugate of CMC1 and ZnPcN shows the highest photocytotoxicity with an IC90 value down to 0.72 µM. Further quaternization decreases the photocytotoxicity. Additionally, the conjugates show special affinity to the mitochondria of C. albicans.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Quitosana/análogos & derivados , Indóis/farmacologia , Compostos Organometálicos/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Candida albicans/citologia , Quitosana/química , Quitosana/farmacologia , Indóis/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Compostos Organometálicos/química , Tamanho da Partícula , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Propriedades de Superfície
14.
Carbohydr Polym ; 235: 115968, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32122502

RESUMO

This study aimed at decontamination of seeds destined for edible sprout production from Listeria using chitosan (CS) coatings incorporated with synergetic lysozyme-nisin (LYS-NIS) mixtures. Low molecular weight (LMW) CS coating showed the highest potency against Listeria innocua, followed by medium molecular weight (MMW) and high molecular weight (HMW) CSs. The LMW CS film with LYS-NIS also caused almost 1.5-fold greater log reduction (∼5 log) in initial L. innocua load of broth culture than MMW and HMW CS films with LYS-NIS within 6 days. Moreover, LMW CS coating with LYS-NIS reduced the initial Listeria loads of inoculated mung beans, lentils, and wheats by 3.3, 3.4 and 4.1 log, respectively. Antimicrobial coating did not affect seed germination rates considerably. The LYS-NIS addition increased yellowness and opacity of films, and caused limited changes in their mechanical and morphological properties. LMW CS coating with LYS-NIS reduces risk of listeriosis from sprouted seeds.


Assuntos
Antibacterianos/farmacologia , Quitosana/farmacologia , Listeria/química , Muramidase/metabolismo , Nisina/farmacologia , Sementes/efeitos dos fármacos , Antibacterianos/química , Quitosana/química , Microbiologia de Alimentos , Conservação de Alimentos , Listeria/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Muramidase/química , Nisina/química , Tamanho da Partícula , Sementes/crescimento & desenvolvimento , Sementes/microbiologia , Propriedades de Superfície
15.
Carbohydr Polym ; 235: 115973, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32122505

RESUMO

This work was designed to develop the chitosan-based melatonin layer-by-layer assembly (CMLLA) via the inclusion method. The structural characterizations and interaction present in CMLLA were investigated by the scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier Transform-Infrared spectroscopy (FTIR). The ratio of chitosan (CH) to carboxymethylcellulose (CMC) greatly influenced the mechanical properties, including the tensile strength, moisture content and color performance. Results showed that both antioxidant and antimicrobial properties of CMLLA were enhanced with the addition of melatonin (MLT). Furthermore, it was demonstrated that the CMLLA with 1.2 % (w/v) CH, 0.8 % (w/v) CMC and 50 mg/L MLT better contributed to the delay of chlorophyll degradation and the maintenance of shelf-life quality. Results from this study might open up new insights into the approaches of quality improvement of postharvest fresh products by incorporating the natural antioxidant compounds into natural polymers.


Assuntos
Antibacterianos/química , Antioxidantes/química , Quitosana/química , Materiais Revestidos Biocompatíveis/química , Bicamadas Lipídicas/química , Melatonina/química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Antioxidantes/síntese química , Antioxidantes/farmacologia , Compostos de Bifenilo/antagonistas & inibidores , Configuração de Carboidratos , Quitosana/farmacologia , Materiais Revestidos Biocompatíveis/síntese química , Materiais Revestidos Biocompatíveis/farmacologia , Escherichia coli/efeitos dos fármacos , Bicamadas Lipídicas/síntese química , Bicamadas Lipídicas/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Melatonina/farmacologia , Tamanho da Partícula , Picratos/antagonistas & inibidores , Salmonella enteritidis/efeitos dos fármacos , Propriedades de Superfície , Resistência à Tração
16.
Ulus Travma Acil Cerrahi Derg ; 26(2): 163-170, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32185761

RESUMO

BACKGROUND: Different pharmacological agents are developed to control bleeding. However, it is critical for these agents to induce thrombin formation and have an effect on vasoconstriction, coagulation, and scaffold. In this study, we aimed to demonstrate the agents' ability to stop bleeding properties on minor and major open bleedings after skin clefts, extracorporal injuries, traumatic cuts, spontaneous or surgical intervention besides scaffold properties. For this purpose, a new and authentic hemostatic agent, processed diatomite (PD) and the most preferred chitosan in the medical area were used to test blood stopping and scaffold effects in a rat femoral bleeding model. The samples were examined by scanning electron microscopy (SEM), and the results on blood stopping were shared. METHODS: The current experimental study was conducted on rats. The effects of hemostatic agents on our femoral bleeding model were determined. In this study, 22 male Wistar albino rats weighing 158-215 g, were used. The rats were assigned randomly to three groups: control group (n=6), chitosan group (n=8), and PD group (n=8). Bleeding time, scaffold formation, weight differences, histopathological effect and scanning electron microscope (SEM) analyses were performed. RESULTS: In our experimental model, weight loss was 5.0±1.3 g for the control group, 2.9±1.1 g for the chitosan group, and 2.7±1.0 g for the PD group, respectively. When weighed before and after the experiment, there was a significant change in weights of rats in chitosan, and PD groups regarding scaffold formation: it was complete for six rats (75%) and weak for two (25%) rats in chitosan group; however, it was complete for seven rats (87.5%) and weak for one (12.5%) rat in the PD group. Scaffold formation was significant for the chitosan and PD groups versus the control group (p=0.002). CONCLUSION: In our study, the scaffold formed by PD exerts appropriate porousness and contributes to fibrin formation and prevent re-bleeding. PD had a strong and significant scaffold effect. The effectiveness of PD to stop bleeding was equal to chitosan. Besides being natural, hemostatic agents should not induce cellular damage. We histopathologically demonstrated that PD was harmless for the natural structure of cells and vessels in the femoral site.


Assuntos
Hemorragia/fisiopatologia , Hemostasia/efeitos dos fármacos , Hemostáticos/farmacologia , Animais , Quitosana/farmacologia , Terra de Diatomáceas/farmacologia , Modelos Animais de Doenças , Masculino , Ratos , Ratos Wistar
17.
BMC Complement Med Ther ; 20(1): 23, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-32020892

RESUMO

BACKGROUND: Chondrocyte apoptosis activated by the mitochondrial dependent pathway serves a crucial role in cartilage degeneration of osteoarthritis (OA). In the present study, the protective effects of CMCS against sodium nitroprusside (SNP)-induced chondrocyte apoptosis were evaluated and the underlying molecular mechanisms were elucidated. METHODS: Chondrocytes were isolated from articular cartilage of SD rats and identified by type II collagen immunohistochemistry. The chondrocytes stimulated with or without SNP to induce apoptosis, were treated by CMCS for various concentrations. The cell viability were determined by MTT and LDH assays. Cell apoptotic ratio was determined by Annexin V-FITC/PI staining. Mitochondrial membrane potential (ΔΨm) was detected by using Rhodamine123 (Rho123) staining. To understand the mechanism, the mRNA expression levels of Bcl-2, Bax, cytochrome c (Cyt c) and cleaved caspase-3 were detected by real-time PCR and western blot analysis, respectively. RESULTS: It was shown using the MTT and LDH assays that CMCS protected the viability of chondrocyte against SNP damage. Annexin V-FITC/PI and Rho123 staining showed that CMCS not only inhibited the cell apoptosis but also restored the reduction of the ΔΨm in chondrocytes. In SNP-induced chondrocytes, CMCS down-regulated the expression of Bax, Cyt c and cleaved caspase-3 but upregulated the expression of Bcl-2, as shown by real-time PCR and western blot. CONCLUSIONS: Taken together, these results indicated that CMCS has the protective effect on chondrocytes against SNP-induced apoptosis, at least partly, via inhibiting the mitochondrial dependent apoptotic pathway. Thus, CMCS may be potentially used as a biological agent for prevention and treatment of OA.


Assuntos
Apoptose/efeitos dos fármacos , Quitosana/farmacologia , Condrócitos/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Animais , Células Cultivadas , Quitosana/química , Condrócitos/citologia , Óxido Nítrico , Nitroprussiato , Ratos , Ratos Sprague-Dawley
18.
J Biotechnol ; 310: 89-96, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32017955

RESUMO

Brucellosis is a worldwide bacterial zoonosis disease. Live attenuated Brucella vaccines have several drawbacks. Thus development of a safe and effective vaccine for brucellosis is a concern of many scientists. FliC protein contributes in virulence of Brucella; hence, it is a promising target for brucellosis vaccine. In this study, Mannosylated Chitosan Nanoparticles (MCN) loaded with FliC protein were synthesized as a targeted vaccine delivery system. The immunogenicity and protective efficacy of FliC and FliC-MCN against Brucella infection were evaluated in BALB/c mice. After cloning, expression and purification, FliC protein was loaded on MCN. The particle size, loading efficiency and in vitro release of the NPs were determined. Our investigation revealed that FliC and FliC-MCN could significantly increase specific IgG response (higher IgG2a titers). Besides, spleen cells from immunized mice produced high level of IFN-γ and IL-2 and low level IL-10 cytokines. Immunization with FliC and FliC-MCN conferred significant degree of protection against B. melitensis 16 M and B. abortus 544 infections. Overall these results indicate that FliC protein would be a novel potential antigen candidate for the development of a subunit vaccine against B. melitensis and B. abortus. Moreover, MCN could be used as an adjuvant and targeted vaccine delivery system.


Assuntos
Antígenos de Bactérias , Vacina contra Brucelose , Brucella abortus/imunologia , Brucella melitensis/imunologia , Brucelose/prevenção & controle , Quitosana , Manose , Nanopartículas/química , Animais , Antígenos de Bactérias/química , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica , Vacina contra Brucelose/química , Vacina contra Brucelose/imunologia , Vacina contra Brucelose/farmacologia , Brucelose/imunologia , Brucelose/patologia , Quitosana/química , Quitosana/imunologia , Quitosana/farmacologia , Cisplatino , Feminino , Ifosfamida , Manose/química , Manose/imunologia , Manose/farmacologia , Camundongos Endogâmicos BALB C , Mitomicina
19.
J Biotechnol ; 310: 103-113, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32023480

RESUMO

The inflammation of chronic wounds generally causes delaying their healing process. The present work aims to formulate a wound dressing polyelectrolyte membrane based on chitosan (Ch) and sodium hyaluronate (HA) loaded with glutathione (GSH). The membrane types (Ch/HA and Ch/HA/GSH) were examined by Fourier transform infrared spectroscopy (FT-IR). The material properties were further investigated using thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM). Physical characteristics of the prepared membranes, such as wettability, surface roughness, and mechanical properties were determined by standard experimental methods. In vitro assays were used to evaluate the haemocompatibility, thrombogenicity, and cytotoxicity of the membranes. The wound healing examined using a standard rat model exhibited a progress at exploiting the Ch/HA/GSH-type membranes compared to a bicomponent Ch/HA membrane or a "dry" healing wound. Histological examination of the recovered skin confirmed the visual observations. In conclusion, in vivo study results assert that Ch/HA/GSH is a proper wound-dressing for healing the chronic skin wounds.


Assuntos
Quitosana , Glutationa , Ácido Hialurônico , Membranas Artificiais , Polieletrólitos , Cicatrização/efeitos dos fármacos , Animais , Quitosana/química , Quitosana/farmacologia , Feminino , Glutationa/química , Glutationa/farmacologia , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Polieletrólitos/química , Polieletrólitos/farmacologia , Ratos , Ratos Wistar
20.
Carbohydr Polym ; 234: 115903, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32070523

RESUMO

In this study, 2-urea-chitosan oligosaccharide derivatives (2-urea-COS derivatives) and 2,6-diurea-chitosan oligosaccharide derivatives (2,6-diurea-COS derivatives) were successfully designed and synthesized via intermediate 2-methoxyformylated chitosan oligosaccharide. All samples were characterized and compared based on FT-IR, 1H NMR spectroscopy, and elemental analysis. The antifungal effects of COS derivatives were tested against Fusarium oxysporum f. sp. niveum, Phomopsis asparagus, and Botrytis cinereal. Their antioxidant properties, including superoxide radicals' scavenging activity, hydroxyl radicals' scavenging activity, and DPPH radicals' scavenging activity were also explored within different concentrations. COS derivatives bearing urea groups showed improved bioactivity compared with pristine COS and 2,6-diurea-COS derivatives had a higher biological activity than 2-urea-COS derivatives in tested concentrations. Additionally, L929 cells were used to carry out cytotoxicity test of COS and COS derivatives by CCK-8 assay. The results indicated that some of samples showed low cytotoxicity. These findings offered a suggestion that COS derivatives bearing urea groups are promising biological materials.


Assuntos
Antifúngicos/farmacologia , Antioxidantes/farmacologia , Quitosana/farmacologia , Oligossacarídeos/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Antioxidantes/síntese química , Antioxidantes/química , Ascomicetos/efeitos dos fármacos , Compostos de Bifenilo/antagonistas & inibidores , Botrytis/efeitos dos fármacos , Quitosana/química , Fusarium/efeitos dos fármacos , Radical Hidroxila/antagonistas & inibidores , Testes de Sensibilidade Microbiana , Estrutura Molecular , Oligossacarídeos/síntese química , Oligossacarídeos/química , Picratos/antagonistas & inibidores , Superóxidos/antagonistas & inibidores
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