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1.
Fish Shellfish Immunol ; 113: 35-41, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33785470

RESUMO

The present study was performed to evaluate the toxic effects of feed-born zearalenone (ZEN) on antioxidative status, immunity, transcriptomic responses of European seabass, and the modulating roles of dietary garlic and/or chitosan powders. Fish (30.7 ± 0.6 g) were randomly arranged in five experimental groups (in triplicates), whereas the first group was fed on the control diet only without any supplements (control), and the second group was fed on the basal diet contaminated with ZEN (0.725 mg/kg diet). Three other groups were fed on ZEN-contaminated diets and simultaneously supplemented with garlic powder (GP) (30 g/kg diet) (ZEN + GP), chitosan powder (CH) (10 g/kg diet) (ZEN + CH), and a mixture of GP and CH (ZEN + GP + CH). Fish were fed on the experimental diets thrice a day for 4 weeks. Two-way ANOVA revealed a gradual decline in serum superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities in the ZEN group reaching their lowest levels at the 4th week. Contrariwise, malondialdehyde levels were markedly higher in the ZEN group reaching their highest values at the end of the experiment. A significant decline of total immunoglobulins (P < 0.05) was observed in the serum of the ZEN group, especially after the 4th week. Moreover, significant down-regulation of interleukin-4 (IL-4) and interleukin 1 beta (IL-1ß) genes (P < 0.05) alongside significant up-regulation of tumor necrosis factor-alpha (TNF-α) and heat shock protein 70 (HSP70) genes (P < 0.05) in the liver and anterior kidney of ZEN-intoxicated group. Interestingly, dietary supplementation with GP and CH significantly attenuated ZEN-induced oxidative stress, immunosuppression, and modulated transcriptomic responses of ZEN-exposed fish. Moreover, combined dietary supplementation of both feed additives resulted in better effects than each one alone.


Assuntos
Antioxidantes/metabolismo , Bass/imunologia , Quitosana/metabolismo , Citocinas/genética , Alho/química , Proteínas de Choque Térmico HSP70/genética , Imunidade Inata , Zearalenona/toxicidade , Ração Animal/análise , Animais , Quitosana/administração & dosagem , Citocinas/metabolismo , Dieta/veterinária , Suplementos Nutricionais/análise , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Imunidade Inata/efeitos dos fármacos , Distribuição Aleatória , Transcrição Genética
2.
J Agric Food Chem ; 69(11): 3371-3379, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33688734

RESUMO

Partially acetylated chito-oligosaccharides (paCOSs) are bioactive compounds with potential medical applications. Their biological activities are largely dependent on their structural properties, in particular their degree of polymerization (DP) and the position of the acetyl groups along the glycan chain. The production of structurally defined paCOSs in a purified form is highly desirable to better understand the structure/bioactivity relationship of these oligosaccharides. Here, we describe a newly discovered chitinase from Paenibacillus pabuli (PpChi) and demonstrate by mass spectrometry that it essentially produces paCOSs with a DP of three and four that carry a single N-acetylation at their reducing end. We propose that this specific composition of glucosamine (GlcN) and N-acetylglucosamine (GlcNAc) residues, as in GlcN(n)GlcNAc1, is due to a subsite specificity toward GlcN residues at the -2, -3, and -4 positions of the partially acetylated chitosan substrates. In addition, the enzyme is stable, as evidenced by its long shelf life, and active over a large temperature range, which is of high interest for potential use in industrial processes. It exhibits a kcat of 67.2 s-1 on partially acetylated chitosan substrates. When PpChi was used in combination with a recently discovered fungal auxilary activity (AA11) oxidase, a sixfold increase in the release of oligosaccharides from the lobster shell was measured. PpChi represents an attractive biocatalyst for the green production of highly valuable paCOSs with a well-defined structure and the expansion of the relatively small library of chito-oligosaccharides currently available.


Assuntos
Quitinases , Quitosana , Acetilação , Animais , Quitina/metabolismo , Quitinases/metabolismo , Quitosana/metabolismo , Oligossacarídeos , Paenibacillus
3.
Molecules ; 26(4)2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33672446

RESUMO

Over the past decade, reckless usage of synthetic pesticides and fertilizers in agriculture has made the environment and human health progressively vulnerable. This setting leads to the pursuit of other environmentally friendly interventions. Amongst the suggested solutions, the use of chitin and chitosan came about, whether alone or in combination with endophytic bacterial strains. In the framework of this research, we reported an assortment of studies on the physico-chemical properties and potential applications in the agricultural field of two biopolymers extracted from shrimp shells (chitin and chitosan), in addition to their uses as biofertilizers and biostimulators in combination with bacterial strains of the genus Bacillus sp. (having biochemical and enzymatic properties).


Assuntos
Bacillus/metabolismo , Quitina/metabolismo , Quitosana/metabolismo , Produtos Agrícolas/metabolismo , Exoesqueleto/química , Animais , Configuração de Carboidratos , Quitina/química , Quitina/isolamento & purificação , Quitosana/química , Quitosana/isolamento & purificação , Crustáceos
4.
Molecules ; 26(4)2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33546424

RESUMO

Silybum marianum (L.) Gaertn is a rich source of antioxidants and anti-inflammatory flavonolignans with great potential for use in pharmaceutical and cosmetic products. Its biotechnological production using in vitro culture system has been proposed. Chitosan is a well-known elicitor that strongly affects both secondary metabolites and biomass production by plants. The effect of chitosan on S. marianum cell suspension is not known yet. In the present study, suspension cultures of S. marianum were exploited for their in vitro potential to produce bioactive flavonolignans in the presence of chitosan. Established cell suspension cultures were maintained on the same hormonal media supplemented with 0.5 mg/L BAP (6-benzylaminopurine) and 1.0 mg/L NAA (α-naphthalene acetic acid) under photoperiod 16/8 h (light/dark) and exposed to various treatments of chitosan (ranging from 0.5 to 50.0 mg/L). The highest biomass production was observed for cell suspension treated with 5.0 mg/L chitosan, resulting in 123.3 ± 1.7 g/L fresh weight (FW) and 17.7 ± 0.5 g/L dry weight (DW) productions. All chitosan treatments resulted in an overall increase in the accumulation of total flavonoids (5.0 ± 0.1 mg/g DW for 5.0 mg/L chitosan), total phenolic compounds (11.0 ± 0.2 mg/g DW for 0.5 mg/L chitosan) and silymarin (9.9 ± 0.5 mg/g DW for 0.5 mg/L chitosan). In particular, higher accumulation levels of silybin B (6.3 ± 0.2 mg/g DW), silybin A (1.2 ± 0.1 mg/g DW) and silydianin (1.0 ± 0.0 mg/g DW) were recorded for 0.5 mg/L chitosan. The corresponding extracts displayed enhanced antioxidant and anti-inflammatory capacities: in particular, high ABTS antioxidant activity (741.5 ± 4.4 µM Trolox C equivalent antioxidant capacity) was recorded in extracts obtained in presence of 0.5 mg/L of chitosan, whereas highest inhibitions of cyclooxygenase 2 (COX-2, 30.5 ± 1.3 %), secretory phospholipase A2 (sPLA2, 33.9 ± 1.3 %) and 15-lipoxygenase (15-LOX-2, 31.6 ± 1.2 %) enzymes involved in inflammation process were measured in extracts obtained in the presence of 5.0 mg/L of chitosan. Taken together, these results highlight the high potential of the chitosan elicitation in the S. marianum cell suspension for enhanced production of antioxidant and anti-inflammatory silymarin-rich extracts.


Assuntos
Anti-Inflamatórios , Antioxidantes , Quitosana , Lignanas , Cardo-Mariano/metabolismo , Células Vegetais/metabolismo , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/metabolismo , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Quitosana/química , Quitosana/metabolismo , Quitosana/farmacologia , Humanos , Lignanas/biossíntese , Lignanas/química , Lignanas/farmacologia , Cardo-Mariano/citologia , Saccharomyces cerevisiae/crescimento & desenvolvimento , Ovinos
5.
Biochem Biophys Res Commun ; 546: 162-168, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33582560

RESUMO

In the field of implantable medical devices, the antibacterial extracellular matrix (ECM) biologic scaffold, which is constructed by modifying biomaterials with antibacterial peptides, has excellent potential. An antibacterial peptide-modified ECM scaffold was formed with chitosan (CS), antimicrobial peptide (AMP), and ECM scaffold. Chitosan has a firm positive-charge surface and can combine with the ECM scaffold material to form a positive-charge layer on the surface. The surface potential was characterized using a surface potential map. Infrared spectroscopy and scanning electron microscopy (SEM) were used to observe the scaffold surface characteristics and cell morphology. Fluorescence staining and MTS assay kit were used to assess cytotoxicity and biocompatibility. To evaluate the antibacterial and repairing effects on the infected wounds in vivo, a subcutaneous antibacterial test of rabbit back was conducted. The antibacterial peptide-modified ECM scaffold was successfully formed and presented an excellent three-dimensional micro-surface porous structure. The antibacterial peptide-modified ECM scaffold could be effectively-prepared by surface modification and activation. Fluorescence staining tests showed good cell adhesion, proliferation ability, and cell affinity. The in vivo experiment indicated that the antibacterial ECM scaffold had antibacterial and healing-promotion abilities.


Assuntos
Antibacterianos/química , Antibacterianos/metabolismo , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Peptídeos/química , Tecidos Suporte/química , Animais , Adesão Celular , Proliferação de Células , Quitosana/química , Quitosana/metabolismo , Resistência Microbiana a Medicamentos , Feminino , Testes de Sensibilidade Microbiana , Peptídeos/metabolismo , Coelhos , Propriedades de Superfície , Cicatrização
6.
Cell Prolif ; 54(3): e13004, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33543561

RESUMO

OBJECTIVES: Endoscopic submucosal dissection (ESD), a preferential approach for early oesophageal neoplasms, inevitably results in oesophageal strictures in patients. Clinical use of glucocorticoids through submucosal injection is beneficial for inhibiting oesophageal stricture following injury; however, it also has limitations, such as dose loss and perforation. Hence, alternatives to glucocorticoid therapy should be developed. METHODS: A novel porous composite scaffold, ChCo-TAMS, composed of chitosan, collagen-I and triamcinolone acetonide (TA) loaded into poly (lactic-co-glycolic) acid (PLGA) microspheres (TAMS), was successfully constructed and subjected to biological testing to ameliorate oesophageal ESD-related stenosis. RESULTS: The synthesized biomaterials displayed unique properties in inhibiting the activation of macrophages, chemokine-mediated cell recruitment and fibrogenesis of fibroblasts. Further application of the scaffolds in the rat dermal defect and porcine oesophageal ESD model showed that these novel scaffolds played a robust role in inhibiting wound contracture and oesophageal ESD strictures. CONCLUSIONS: The developed composite scaffolds provide a promising clinical medical device for the prevention of post-operative oesophageal stricture.


Assuntos
Quitosana/farmacologia , Colágeno/efeitos dos fármacos , Constrição Patológica/patologia , Neoplasias Esofágicas/tratamento farmacológico , Estenose Esofágica/tratamento farmacológico , Animais , Materiais Biocompatíveis/metabolismo , Quitosana/metabolismo , Colágeno/metabolismo , Constrição Patológica/etiologia , Neoplasias Esofágicas/patologia , Estenose Esofágica/prevenção & controle , Camundongos , Microesferas , Triancinolona/metabolismo , Triancinolona Acetonida/administração & dosagem , Triancinolona Acetonida/farmacologia
7.
Fish Shellfish Immunol ; 111: 160-169, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33556553

RESUMO

The present study was carried out to investigate the effects of dietary bovine lactoferrin (BLF) or chitosan nanoparticles (CHN) alone or in combinations on serum biochemical indices, antioxidative capacity, transcriptomic responses, non-specific immunity, and resistance of Nile tilapia (Oreochromis niloticus) against challenge with Aeromonas hydrophila. Fish were fed on the basal diet with no supplements and served as control (CTR), and six other experimental diets containing different levels of BLF (800 and 1200 mg per kg diet), CHN (500 and 1000 mg per kg diet), and their combinations (400 mg BLF plus 250 mg CHN per kg diet, and 600 mg BLF plus 500 mg CHN per kg diet) for 45 days. At the end of the experiment, serum, and tissue specimens (liver and kidney) were collected, fish in all groups were challenged with A. hydrophila and then observed for another ten days to calculate the RPS. Compared to the CTR group, no significant differences were recorded in TP, ALB, GLO, BUN, and CREAT values among all treatments. Serum LYZ, ALT, AST, and ALP enzyme activities were significantly increased in all experimental groups over the CTR (P < 0.05), and their highest values were recorded in the combined treatments. Moreover, dietary supplementation with CHN (1000 mg/kg) and combined treatments significantly increased the SOD, CAT, and GSH-Px enzyme activities compared to other groups (P < 0.05). The highest mRNA expression levels of IGF-1 gene in liver, and IL-1ß, and IFN-γ genes in kidneys were found in CHN (1000 mg/kg) group and combined treatments more than other groups. Interestingly, no, or mild histopathological alterations were noticed in the hepatopancreas and posterior kidney of the treated groups. A significantly higher RPS was identified in the combined treatments challenged with A. hydrophila compared with the CTR group. This study exemplifies the positive impacts of dietary supplementation with BLF or CHN alone or combinations on the antioxidative status, immunity, and disease resistance of Nile tilapia.


Assuntos
Antibacterianos/metabolismo , Antioxidantes/metabolismo , Quitosana/metabolismo , Ciclídeos/imunologia , Resistência à Doença/imunologia , Doenças dos Peixes/imunologia , Lactoferrina/metabolismo , Transcriptoma/imunologia , Aeromonas hydrophila/fisiologia , Ração Animal/análise , Animais , Antibacterianos/administração & dosagem , Análise Química do Sangue/veterinária , Quitosana/administração & dosagem , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Enzimas/metabolismo , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Lactoferrina/administração & dosagem , Nanopartículas/administração & dosagem , Nanopartículas/metabolismo , Distribuição Aleatória
8.
Drug Dev Ind Pharm ; 47(3): 477-483, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33621153

RESUMO

Background: Organ transplantation is an important and critical procedure, which requires the suppression of immunity, and to suppress the immunity, a constant plasma concentration of immunosuppressant is required.Objectives: The said objective can be achieved by formulating a controlled release drug delivery system of the drug. Chitosan (CHT) nanoparticles (NPs) have been revolutionizing the conventional drug delivery system, for the past two decades. The aim of the current research work was to develop and evaluate CHT-based mycophenolate mofetil (MMF) loaded nanoparticles (CHT/MMF-NPs) using different drug to polymer ratios.Methods: The challenge was to entrap a lipophilic drug within NPs by the ionic gelation method of the positively charged CHT, using tripolyphosphate (TPP) as the crosslinking agent. The prepared CHT/MMF-NPs were evaluated for physical and chemical characterizations, including particle size, surface charge, entrapment efficiency (EE), surface morphology by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) for chemical compatibilities, X-ray diffractometry (XRD) and in-vitro dissolution studies.Results: Outcomes of the studies revealed that particles were 260 ± 17 nm in diameter, with the smooth and regular surface. Satisfactory values of EE (99%) have indicated the suitability of selected ingredients and employed methodology. Moreover, FTIR has confirmed the chemical compatibilities of the formulations. In-vitro dissolution studies have indicated diffusion type of controlled and sustained drug release during 24 h, with zero-order, as best fit kinetic model.Conclusion: Conclusively, the successful achievement of objectives has indicated the suitability of excipients and methodology to prepare CHT/MMF-NPs for better therapeutic outcomes.


Assuntos
Quitosana , Nanopartículas , Quitosana/metabolismo , Preparações de Ação Retardada , Portadores de Fármacos , Liberação Controlada de Fármacos , Ácido Micofenólico , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier
9.
J Agric Food Chem ; 69(1): 78-87, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33393308

RESUMO

Chitooligosaccharides (COS) generated from either chitin (chitin oligosaccharides) or chitosan (chitosan oligosaccharides) have a wide range of applications in agriculture, medicine, and other fields. Here, we report the characterization of a chitosanase from Bacillus amyloliquefaciens (BamCsn) and the importance of a tryptophan (Trp), W204, for BamCsn activity. BamCsn hydrolyzed the chitosan polymer by an endo mode. It also hydrolyzed chitin oligosaccharides and interestingly exhibited transglycosylation activity on chitotetraose and chitopentaose. Mutation of W204, a nonconserved amino acid in chitosanases, to W204A abolished the hydrolytic activity of BamCsn, with a change in the structure that resulted in a decreased affinity for the substrate and impaired the catalytic ability. Phylogenetic analysis revealed that BamCsn could belong to a new class of chitosanases that showed unique properties like transglycosylation, cleavage of chitin oligosaccharides, and the presence of W204 residues, which is important for activity. Chitosanases belonging to the BamCsn class showed a high potential to generate COS from chitinous substrates.


Assuntos
Bacillus amyloliquefaciens/enzimologia , Proteínas de Bactérias/metabolismo , Glicosídeo Hidrolases/metabolismo , Oligossacarídeos/biossíntese , Bacillus amyloliquefaciens/química , Bacillus amyloliquefaciens/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Biocatálise , Quitina/metabolismo , Quitosana/metabolismo , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/genética , Concentração de Íons de Hidrogênio , Hidrólise , Especificidade por Substrato
10.
J Agric Food Chem ; 69(3): 1049-1056, 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33428421

RESUMO

In situ H2O2 generation systems are efficient for H2O2-dependent biocatalytic oxidation reactions. Here, we report that lytic polysaccharide monooxygenases (LPMOs), copper-dependent polysaccharide monooxygenases, can efficiently supply H2O2 in situ to dye-decolorizing peroxidases (DyPs) using substrate gallic acid (GA) for chitosan functionalization. The maximum grafting ratio induced by the cascade reaction was significantly higher than that achieved by a reaction with initial exogenous H2O2. The maximum grafting ratio was obtained with 12 g/L GA, 5.6 mg/L DyP, 20-30 mg/L LPMO, and pH 4.5-5.0. UV-vis, Fourier transform infrared (FT-IR), and nuclear magnetic resonance (1H NMR) spectroscopy confirmed GA grafting onto chitosan. X-ray diffraction (XRD) analysis and thermogravimetric analysis (TGA) indicated that GA-chitosan conjugates had lower thermal stability and crystallinity than chitosan. The GA-chitosan conjugates had significantly higher antioxidant activity than chitosan. This study supplies a green and high-efficiency approach to achieve an enzymatic cascade reaction for chitosan functionalization and has potential applications in H2O2-dependent biocatalytic oxidation reactions.


Assuntos
Quitosana/química , Proteínas Fúngicas/química , Oxigenases de Função Mista/química , Peroxidase/química , Antioxidantes/química , Antioxidantes/metabolismo , Quitosana/metabolismo , Temperatura Alta , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Oxirredução , Peroxidase/genética , Peroxidase/metabolismo , Pleurotus/enzimologia , Pleurotus/genética , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
11.
Fish Shellfish Immunol ; 110: 91-99, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33453383

RESUMO

Nowadays there is a great attention for nanotechnology in aquaculture production. It has an efficient role in nutrients and drugs delivery, ponds sterilization, water treatment and aquatic diseases reduction. Till now, there is no available data on impact of selenite-loaded chitosan nanoparticles (SeChNPs) on Nile tilapia. Hence, the current study investigated the effects of selenite-loaded chitosan nanoparticles supplementation on the growth, immune, antioxidant and apoptotic related genes as well as resistance to Aeromonas hydrophila of Nile tilapia, Oreochromis niloticus. A total of 400 fish were randomly divided into four groups, and each group retained five replicates. The control group was fed a basal diet (with inorganic se), other groups fed diets supplemented with SeChNPs 0.5, 1 and 2 g/kg diet. The loading concentration of Se to ChNPs was 0.3, 0.6 and 1.2 mg/0.5, 1 and 2 gm respectively. Fish groups fed SeChNPs (0.5 and 1 g/kg) exhibited the highest final body gain, better feed utilization. Additionally, the expression of myostatin gene was down-regulated by 0.2 and 0.3 fold in group fed 0.5 and 1 g/kg SeChNPs when compared with control group. Dietary inclusion of SeChNPs increased serum lysozyme, alternative complement and myeloperoxidase activities and immunoglobulin type M level. Supplementation of SeChNPs at the level of 2 g/kg up-regulated glutathione peroxidase, superoxide dismutase and catalase expression by 1.12, 4.9 and 2.31 folds respectively, in comparison with control group. In contrast, the levels of C- reactive protein and malondialdehyde were reduced. The expression of IL-10, IL-8, TNF-α and IL-1ß genes was up-regulated after dietary inclusion of different levels of SeChNPs in a dose dependent manner. Post-challenge, the highest survival rate was detected in group fed 2 g/kg SeChNPs (93%) in contrast, the control group was displayed the lowest survival rate (45%). After challenge with A. hydrophila, the expression of caspase 1 was up-regulated in groups fed 1 and 2 g/kg of SeChNPs. Moreover, the maximum down-regulation of cytochromes P450 and heat shock protein were found in 2 g/kg SeChNPs supplemented group (reduced by 0.4 and 0.6-fold, respectively, when compared with control group). In conclusion, the ameliorative effects of SeChNPs on Nile tilapia growth resulted from immune stimulatory and free radicals scavenging effects of selenium loaded chitosan nano composite.


Assuntos
Antioxidantes/metabolismo , Ciclídeos/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/imunologia , Imunidade Inata/genética , Nanopartículas/metabolismo , Selênio/metabolismo , Aeromonas hydrophila/efeitos dos fármacos , Ração Animal/análise , Animais , Caspase 1/imunologia , Quitosana/administração & dosagem , Quitosana/metabolismo , Ciclídeos/genética , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/metabolismo , Sistema Enzimático do Citocromo P-450/imunologia , Dieta/veterinária , Suplementos Nutricionais/análise , Resistência à Doença/genética , Relação Dose-Resposta a Droga , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Proteínas de Choque Térmico/imunologia , Nanopartículas/administração & dosagem , Distribuição Aleatória , Selênio/administração & dosagem , Transcriptoma/imunologia
12.
Carbohydr Polym ; 253: 117246, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33279001

RESUMO

A carrier and an oral absorbent for the treatment of chronic diseases in the form of a tablet was prepared from granulated chitosan (G-CS) particles. The resulting tablet was highly dispersible and disintegrated rapidly (< 30 s) in aqueous media. The non-granulated chitosan (N-CS) powder partially crystallized (2θ = 12-15° and 20°) during wet granulation to give G-CS crystalline particles. The rate of penetration of water into G-CS aggregates was markedly faster than that for N-CS aggregates, as evidenced by the ease of disintegration of the tablets. The rapid disintegration and dispersion of the tablets in vivo was confirmed by MRI measurements after the oral administration of the both tablets to rats. Some ureic toxins were adsorbed more strongly to G-CS tablets than on N-CS tablets. The results suggest that G-CS tablets have great potential for use as a fast disintegrating carrier and as an oral adsorbent in lifestyle-related diseases.


Assuntos
Quitosana/administração & dosagem , Quitosana/química , Estilo de Vida , Desintoxicação por Sorção/métodos , Comprimidos/administração & dosagem , Comprimidos/química , Administração Oral , Adsorção , Animais , Quitosana/metabolismo , Doença Crônica/tratamento farmacológico , Cristalização , Portadores de Fármacos/química , Trato Gastrointestinal/diagnóstico por imagem , Trato Gastrointestinal/metabolismo , Imageamento por Ressonância Magnética , Masculino , Pós/química , Ratos , Ratos Wistar , Comprimidos/metabolismo , Temperatura , Água/química
13.
Int J Biol Macromol ; 169: 321-329, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33310094

RESUMO

Osteosarcoma has a high prevalence among children and adolescents. Common treatments of this disease are not promising enough. Molecular processes involved in the pathogenesis of osteosarcoma are not fully understood. Besides, the remnants of tumor cells after surgery can cause bone destruction and recurrence of the disease. Thus, there is a need to develop novel drugs or enhancing the currently-used drugs as well as identifying bone-repairing methods. Chitosan is a natural compound produced by the deacetylation of chitin. Research has shown that chitosan can be used in various fields due to its beneficial effects, such as biodegradability and biocompatibility. Regarding cancer, chitosan exerts several anti-tumor activities. Moreover, it can be used in diagnostic techniques, drug delivery systems, and cell culture methods. Herein, we aim to discuss the potential roles of chitosan in studying and treating osteosarcoma. We review the literature on chitosan's applications as a drug delivery system and how it can be combined with other substances to improve its ability of local drug delivery. We take a look into the studies concerning the possible benefits of chitosan in the field of bone tissue engineering and 3D culturing. Furthermore, anti-cancer activities of different compounds of chitosan are reviewed.


Assuntos
Quitosana/uso terapêutico , Osteossarcoma/tratamento farmacológico , Materiais Biocompatíveis/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Quitina/química , Quitina/farmacologia , Quitosana/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Humanos , Engenharia Tecidual/métodos
14.
Proc Natl Acad Sci U S A ; 117(34): 20932-20942, 2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32778594

RESUMO

Many pathogenic fungi exploit stomata as invasion routes, causing destructive diseases of major cereal crops. Intensive interaction is expected to occur between guard cells and fungi. In the present study, we took advantage of well-conserved molecules derived from the fungal cell wall, chitin oligosaccharide (CTOS), and chitosan oligosaccharide (CSOS) to study how guard cells respond to fungal invasion. In Arabidopsis, CTOS induced stomatal closure through a signaling mediated by its receptor CERK1, Ca2+, and a major S-type anion channel, SLAC1. CSOS, which is converted from CTOS by chitin deacetylases from invading fungi, did not induce stomatal closure, suggesting that this conversion is a fungal strategy to evade stomatal closure. At higher concentrations, CSOS but not CTOS induced guard cell death in a manner dependent on Ca2+ but not CERK1. These results suggest that stomatal immunity against fungal invasion comprises not only CTOS-induced stomatal closure but also CSOS-induced guard cell death.


Assuntos
Quitina/metabolismo , Estômatos de Plantas/imunologia , Estômatos de Plantas/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/fisiologia , Cálcio/metabolismo , Morte Celular/efeitos dos fármacos , Quitina/fisiologia , Quitosana/metabolismo , Fungos/metabolismo , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/fisiologia , Transdução de Sinais/efeitos dos fármacos
15.
An Acad Bras Cienc ; 92 Suppl 1: e20180885, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32491134

RESUMO

To investigate the simultaneous influence of different non-nutritional factors in production and physical-chemical characteristics of chitosan obtained by Syncephalastrum racemosum we used individually agroindustrial wastes as the only nutritional sources for fungus growth. The growth conditions were evaluated according to Factorial Design, 24 with three central points in order to determine the mainly factors for maximum production of microbiological chitosan in submerged culture. Syncephalastrum racemosum grown in corn steep liquor and yield up to 7.8 g chitosan/kg of substrate in the best condition by factorial design. The microbiological chitosan obtained has deacetilation degree 88.14%, crystallinity rate of 55.96%, mass decomposition process at 304.43 ºC, and low molecular weight. To fast production we performed a kinetic study and confirmed that at 36 h the chitosan production is higher and the physical-chemical characteristics were maintained. This research describes, for the first time, the factorial study of chitosan production by Syncephalastrum racemosum in agroindustrial wastes and its economic potential for commercialization.


Assuntos
Biodegradação Ambiental , Quitosana/metabolismo , Fungos/crescimento & desenvolvimento , Resíduos Industriais/economia , Fatores de Tempo
16.
AAPS PharmSciTech ; 21(4): 131, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32405869

RESUMO

5-Fluorouracil is a member of cytotoxic drugs with poor selectivity to cancer cells. Currently, systemic administration of this anti-cancer drug (oral or injection) exposes normal tissues to the drug-induced toxicity. Nowadays, attention has been greatly directed towards in situ gel-forming systems that can be injected into the affected tissues in its sol form with a minimally invasive technique. More specifically, chitosan hydrogel systems were in focus due to their antibacterial effect as well as their biodegradable, biocompatible, and mucoadhesive properties. In the present work, 5-fluorouracil was loaded on various thermosensitive chitosan hydrogel systems cross linked with different linking agents like ß-glycerophosphate, pluronic F127, and hydroxyapatite. Also, methotrexate was added to 5-fluorouracil in order to gain its previously reported synergistic effects. Firstly, a compatibility study was performed using UV-spectrophotometric, infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) techniques to exclude the possibility of any physical or chemical interactions between the selected drugs and excipients. The prepared hydrogel systems were characterized for their physicochemical properties including organoleptic, pH, syringeability and injectability, viscosity, and gelation temperature (Tgel) by various analysis techniques. Moreover, the in vitro release behavior of 5-fluorouracil and methotrexate was determined with a modified analytical method. The results indicated that chitosan hydrogel system cross-linked with a combination of ß- glycerophosphate, and 10 % pluronicF127 (F4) showed the most suitable physicochemical properties and release profile. Accordingly, this formula can be considered as a missionary system for localized sustained delivery of cytotoxic drugs.


Assuntos
Quitosana/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Fluoruracila/metabolismo , Hidrogéis/metabolismo , Metotrexato/metabolismo , Antimetabólitos Antineoplásicos/química , Antimetabólitos Antineoplásicos/metabolismo , Varredura Diferencial de Calorimetria/métodos , Quitosana/química , Hidrogéis/química , Temperatura
17.
Life Sci ; 254: 117768, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32407840

RESUMO

AIMS: In this study, we used a cross-junction microfluidic device for preparation of alendronate-loaded chitosan nanoparticles with desired characteristics to introduce a suitable element for bone tissue engineering scaffolds. MAIN METHODS: By controlling the reaction condition in microfluidic device, six types of alendronate-loaded chitosan nanoparticles were fabricated which had different physical properties. Hydrodynamic diameter of synthetized particles was evaluated by dynamic light scattering (102 to 215 nm). Nanoparticle morphology was determined by SEM and AFM images. The osteogenic effects of prepared selected nanoparticles on human adipose stem cells (hA-MSCs) were evaluated by assessment of alkaline phosphatase (ALP) activity, calcium deposition, ALP and osteopontin gene expression. KEY FINDINGS: The highest loading efficiency percentage (%LE) was %32.42 ± 2.02. Based on MTT assessment, two samples which had no significant cytotoxicity were chosen for further studies (particle sizes and %LE were 142 ± 6.1 nm, 198 ± 16.56 nm, %16.76 ± 3.91 and %32.42 ± 2.02, respectively). In vitro release behavior of nanoparticles displayed pH responsive characteristics. Significant faster release was seen in acidic pH = 5.8 than neutral pH = 7.4. The selected nanoparticles demonstrated higher ALP activity at 14 days in comparison to selected blank sample and osteogenic differentiation media (ODM) and a downregulation at 21 days in comparison to 14 days. Calcium content assay at 21 days displayed significant differences between alendronate-loaded nanoparticles and ODM. ALP and osteopontin mRNA expression was significantly higher than the cells cultured in ODM at 14 and 21 days. SIGNIFICANCE: We concluded that our prepared nanoparticles significantly enhanced osteogenic differentiation of hA-MSCs and can be a suitable compartment of bone tissue engineering scaffolds.


Assuntos
Alendronato/metabolismo , Osteogênese/efeitos dos fármacos , Engenharia Tecidual/instrumentação , Adipócitos , Animais , Regeneração Óssea/efeitos dos fármacos , Osso e Ossos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Quitosana/metabolismo , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Microfluídica/métodos , Nanopartículas , Células-Tronco/efeitos dos fármacos , Engenharia Tecidual/métodos , Tecidos Suporte
18.
Poult Sci ; 99(4): 2061-2067, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32241491

RESUMO

This experiment was conducted to investigate the effect of dietary chitosan oligosaccharide (COS) on growth performance, nutrient digestibility, jejunal morphology, gene expression, and plasma antioxidant enzymes in male broiler chickens under experimentally induced stress via in-feed dexamethasone (DEX). On day 3 after hatching, male broiler chicks were assigned to 2 diets supplemented with COS at 0 or 1 g/kg in a randomized complete block design and fed to day 27 after hatching. Birds were pooled within each diet (0 or 1 g/kg COS) to equalize the average BW and fed 2 diets supplemented with 0 or 1 g/kg DEX, within each dietary COS, from day 20 to 27 after hatching. This resulted in a 2 × 2 factorial arrangement of treatments with 2 levels each of COS and DEX, 8 replicate cages of 7 birds per cage. On day 27 after hatching, birds were weighed and euthanized, and samples were collected. Dietary COS decreased (P < 0.05) DEX-induced effects (interaction; P < 0.05) on BW, BW gain, and gain:feed. Dietary COS supplementation attenuated the DEX effects (interaction; P < 0.05) on villus height, crypt depth, villus height to crypt depth ratio, and ileal digestibility of dry matter and energy. The DEX-induced effect of relative mRNA expression of jejunal mucosa IL-6, IL-10, and claudin-1 was reduced by dietary COS supplementation (interaction; P < 0.05). Responses (interaction; P < 0.05) in the activity of plasma superoxide dismutase, catalase, and glutathione peroxidase to COS and DEX were similar to those observed with the relative mRNA expression. Chitosan oligosaccharide supplementation increased (P < 0.05) the mRNA expression of IL-8 and occludin. In conclusion, dietary COS decreased the DEX-induced effect by improving growth performance, nutrient digestibility, jejunal morphology, gene expression, and plasma antioxidant enzymes in broiler chickens. This implies that dietary COS may be useful for ameliorating the negative effect of stress on gut health in broiler chickens.


Assuntos
Antioxidantes , Galinhas/fisiologia , Quitosana/metabolismo , Imunidade/efeitos dos fármacos , Oligossacarídeos/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Ração Animal/análise , Animais , Quitosana/administração & dosagem , Dexametasona/farmacologia , Dieta/veterinária , Suplementos Nutricionais/análise , Imunossupressores/farmacologia , Masculino , Oligossacarídeos/administração & dosagem , Distribuição Aleatória , Estresse Fisiológico/fisiologia
19.
J Nanobiotechnology ; 18(1): 45, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32169073

RESUMO

BACKGROUND: To effectively applied nanomaterials (NMs) in medicine, one of the top priorities is to address a better understanding of the possible sub-organ transfer, clearance routes, and potential toxicity of the NMs in the liver and kidney. RESULTS: Here we explored how the surface chemistry of polyethylene glycol (PEG), chitosan (CS), and polyethylenimine (PEI) capped gold nanoparticles (GNPs) governs their sub-organ biodistribution, transfer, and clearance profiles in the liver and kidney after intravenous injection in mice. The PEG-GNPs maintained dispersion properties in vivo, facilitating passage through the liver sinusoidal endothelium and Disse space, and were captured by hepatocytes and eliminated via the hepatobiliary route. While, the agglomeration/aggregation of CS-GNPs and PEI-GNPs in hepatic Kupffer and endothelial cells led to their long-term accumulation, impeding their elimination. The gene microarray analysis shows that the accumulation of CS-GNPs and PEI-GNPs in the liver induced obvious down-regulation of Cyp4a or Cyp2b related genes, suggesting CS-GNP and PEI-GNP treatment impacted metabolic processes, while the PEI-GNP treatment is related with immune responses. CONCLUSIONS: This study demonstrates that manipulation of nanoparticle surface chemistry can help NPs selectively access distinct cell types and elimination pathways, which help to clinical potential of non-biodegradable NPs.


Assuntos
Ouro/metabolismo , Ouro/toxicidade , Rim/metabolismo , Fígado/metabolismo , Nanopartículas Metálicas/toxicidade , Animais , Quitosana/metabolismo , Citosol , Modelos Animais de Doenças , Expressão Gênica/efeitos dos fármacos , Ouro/sangue , Rim/patologia , Cinética , Fígado/patologia , Masculino , Nanopartículas Metálicas/química , Camundongos , Camundongos Endogâmicos ICR , Tamanho da Partícula , Polietilenoglicóis/metabolismo , Polietilenoimina/metabolismo , Ratos , Ratos Wistar , Distribuição Tecidual , Transcriptoma
20.
Sci Rep ; 10(1): 4329, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32152368

RESUMO

Chitin deacetylase (CDA) can hydrolyse the acetamido group of chitin polymers to produce chitosans, which are used in various fields including the biomedical and pharmaceutical industries, food production, agriculture, and water treatment. CDA represents a more environmentally-friendly and easier to control alternative to the chemical methods currently utilised to produce chitosans from chitin; however, the majority of identified CDAs display activity toward low-molecular-weight oligomers and are essentially inactive toward polymeric chitin or chitosans. Therefore, it is important to identify novel CDAs with activity toward polymeric chitin and chitosans. In this study, we isolated the bacterium Rhodococcus equi F6 from a soil sample and showed that it expresses a novel CDA (ReCDA), whose activity toward 4-nitroacetanilide reached 19.20 U/mL/h during fermentation and was able to deacetylate polymeric chitin, colloidal chitin, glycol-chitin, and chitosan. Whole genome sequencing revealed that ReCDA is unique to the R. equi F6 genome, while phylogenetic analysis indicated that ReCDA is evolutionarily distant from other CDAs. In conclusion, ReCDA isolated from the R. equi F6 strain expands the known repertoire of CDAs and could be used to deacetylate polymeric chitosans and chitin in industrial applications.


Assuntos
Genoma Bacteriano , Genômica , Rhodococcus equi/classificação , Rhodococcus equi/genética , Acetilação , Amidoidrolases/biossíntese , Amidoidrolases/genética , Amidoidrolases/metabolismo , Biopolímeros , Quitosana/metabolismo , Genômica/métodos , Fenótipo , Filogenia , Rhodococcus equi/enzimologia , Rhodococcus equi/isolamento & purificação , Sequenciamento Completo do Genoma
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