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1.
Braz Oral Res ; 33: e086, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31483052

RESUMO

Treatment of patients with bisphosphonate usage is a significant concern for oral surgeons because it interferes with jaw bone turnover and regeneration. In case of adverse effects manifesting related to bisphosphonate use, oral surgeons are usually treating and keep the patient's symptoms under control. In this study, we aimed to investigate a new treatment protocol for medication-related osteonecrosis of the jaw (MRONJ). This treatment protocol consisted of administering human parathyroid hormone (hPTH) loaded chitosan microspheres which were prepared by ionotropic gelation method or/and the prepared microspheres were suspended in a poloxamer gel. After in-vitro optimization studies, the efficacy of the chosen formulations was evaluated in-vivo studies. Zoledronic acid was administered daily to forty-eight adult female Sprague-Dawley rats, divided into four experimental groups, at a daily concentration of 0.11 mg/kg over three weeks to induce the MRONJ model. At the end of this period, maxillary left molar teeth were extracted. In the first group, the subjects received no treatment. In the negative control group, poloxamer hydrogel containing empty microspheres were immediately applied to the soft tissues surrounding the extraction socket. The treatment group-1 was treated with local injections of poloxamer hydrogel containing hPTH. The treatment group-2 was treated with a single local injection of poloxamer hydrogel containing hPTH-loaded chitosan microspheres. Both treatment groups received a total of 7 µg of hPTH at the end of the treatment protocol. Our study demonstrates successful attenuation of MRONJ through a local drug delivery system combined with hPTH, as opposed to previously attempted treatment strategies.


Assuntos
Conservadores da Densidade Óssea/farmacologia , Quitosana/farmacologia , Maxila/efeitos dos fármacos , Hormônio Paratireóideo/farmacologia , Animais , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/tratamento farmacológico , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/etiologia , Conservadores da Densidade Óssea/efeitos adversos , Conservadores da Densidade Óssea/uso terapêutico , Quitosana/uso terapêutico , Preparações de Ação Retardada , Feminino , Humanos , Maxila/patologia , Microesferas , Modelos Animais , Hormônio Paratireóideo/uso terapêutico , Poloxâmero/administração & dosagem , Poloxâmero/química , Ratos Sprague-Dawley , Ácido Zoledrônico/efeitos adversos
2.
Braz Oral Res ; 33: e075, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31432926

RESUMO

Resinous infiltrants are indicated in the treatment of incipient carious lesions, and further development of these materials may contribute to greater control of these lesions. The aim of this study was to analyze the physical and antibacterial properties of experimental infiltrants containing iodonium salt and chitosan. Nine experimental infiltrants were formulated by varying the concentration of the diphenyliodonium salt (DPI) at 0, 0.5 and 1 mol%; and chitosan at 0, 0.12 and 0.25 g%. The infiltrants contained the monomeric base of triethylene glycol dimethacrylate and bisphenol-A dimethacrylate ethoxylate in a 75 and 25% proportion by weight, respectively; 0.5 mol% camphorquinone and 1 mol% ethyl 4-dimethylaminobenzoate. The degree of conversion was evaluated using Fourier transformer infrared spectroscopy, and the flexural strength and elastic modulus using the three-point bending test. Sorption and solubility in water, and antibacterial analysis (minimum inhibitory concentration and minimum bactericidal concentration) were also analyzed. Data was analyzed statistically by two-way ANOVA and Tukey's test (p<0.05), with the exception of the antibacterial test, which was evaluated by visual inspection. In general, the infiltrant group containing 0.5% DPI and 0.12% chitosan showed high values of degree of conversion, higher values of elastic modulus and flexural strength, and lower sorption values in relation to the other groups. Antibacterial activity was observed in all the groups with DPI, regardless of the concentration of chitosan. The addition of DPI and chitosan to experimental infiltrants represents a valid option for producing infiltrants with desirable physical and antibacterial characteristics.


Assuntos
Antibacterianos/química , Quitosana/química , Resinas Compostas/química , Metacrilatos/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Sais/química , Análise de Variância , Antibacterianos/farmacologia , Quitosana/farmacologia , Resinas Compostas/farmacologia , Módulo de Elasticidade , Resistência à Flexão , Lactobacillus acidophilus/efeitos dos fármacos , Cura Luminosa de Adesivos Dentários , Teste de Materiais , Metacrilatos/farmacologia , Testes de Sensibilidade Microbiana , Polietilenoglicóis/farmacologia , Ácidos Polimetacrílicos/farmacologia , Valores de Referência , Reprodutibilidade dos Testes , Sais/farmacologia , Solubilidade , Estatísticas não Paramétricas , Streptococcus mutans/efeitos dos fármacos
3.
Parasitol Res ; 118(7): 2053-2063, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31187224

RESUMO

Cryptosporidium is a ubiquitous harsh protozoan parasite that resists many disinfectants. It remains viable and infective for a long time in water and food causing global outbreaks. Chitosan (the deacetylated chitin molecule) was used in its nanosuspension form to evaluate its effect against Cryptosporidium parvum. The experiments were performed in vitro in serial concentrations and confirmed in mice in vivo infectivity assay. Chitosan nanoparticles (Cs NPs) were toxic to Cryptosporidium oocysts. The effect appeared to decrease the number of Cryptosporidium oocysts and altered their content. The destruction rate of oocysts was dependent on the dose of chitosan and the time of exposure (P < 0.05). Higher doses of Cs NPs over a prolonged period exhibited a significantly higher destruction rate. Using staining and light microscopy, remarkable destructive changes were observed in the oocysts' morphology. The minimal lethal dose for > 90% of oocysts was 3000 µg/ml, no mice infections in vivo were observed. The results in this study elucidate Cs NPs as an effective anti-cryptosporidial agent.


Assuntos
Antiprotozoários/farmacologia , Quitosana/farmacologia , Criptosporidiose/tratamento farmacológico , Cryptosporidium parvum/efeitos dos fármacos , Animais , Antiprotozoários/administração & dosagem , Quitosana/administração & dosagem , Criptosporidiose/parasitologia , Feminino , Camundongos , Nanopartículas/química , Oocistos/efeitos dos fármacos
4.
Carbohydr Polym ; 219: 240-250, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151522

RESUMO

In this study, Schiff bases of chitosan (CS) were synthesized using citronellal, citral, and their derivatives containing selenium and sulfur. Organoselenium and organosulfur compounds show attractive biological and pharmaceutical activities, which can be beneficial to CS-based materials. From the characterization analyses, it was found that the CS-derivatives containing organoselenium and organosulfur compounds exhibited the highest conversion degrees (23 and 28%). Biological assays were conducted using films prepared by the blending of CS-derivatives and poly(vinyl alcohol). The antimicrobial evaluation indicated that the film prepared with the sulfur-containing CS was the most active against the tested pathogens (Escherichia coli, Staphylococcus aureus, and Candida albicans) since it reduced considerably their counts (42.5%, 17.4%, and 18.7%). Finally, in vivo assays revealed that this film attenuates atopic dermatitis-like symptoms in mice by suppressing the increase of myeloperoxidase (MPO) activity and reactive species (RS) levels induced by 2,4-dinitrochlorobenzene (DNCB). In summary, CS-derivatives containing chalcogens, mainly organosulfur, are potential candidates for biomedical applications such as for the treatment of chronic skin diseases.


Assuntos
Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Quitosana , Dermatite Atópica/tratamento farmacológico , Compostos Organosselênicos/farmacologia , Bases de Schiff/farmacologia , Animais , Candida albicans/efeitos dos fármacos , Calcogênios/farmacologia , Quitosana/análogos & derivados , Quitosana/farmacologia , Dermatite Atópica/induzido quimicamente , Dinitroclorobenzeno/química , Modelos Animais de Doenças , Escherichia coli/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Peroxidase/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos
5.
Carbohydr Polym ; 219: 261-268, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151524

RESUMO

Chitosan-based films with incorporated supercritical CO2 hop extract (HE) were developed and evaluated regarding structural, physicochemical, and antibacterial properties. The morphological and spectroscopic analyses have confirmed successful incorporation of HE into the polymer matrix, which affected films' structure and visual appearance. The presence of HE has caused a reduction in the hydrophilic character of films, but also provided a complete UV light blockage at wavelengths below 350 nm. Furthermore, a declining trend of tensile strength (from 14.4 MPa to 6.4 MPa) and Young's modulus (from 218.8 MPa to 26.9 MPa), as well as an ascending trend of elongation at break (from 10.7% to 35.1%), have been observed after the extract incorporation. The total phenolic content in the films was up to ∼13 mgGAE gfilm-1. Besides, the HE-loaded films exhibited antibacterial activity against foodborne pathogen Bacillus subtilis.


Assuntos
Antibacterianos , Bacillus subtilis/efeitos dos fármacos , Materiais Biocompatíveis , Quitosana , Extratos Vegetais , Antibacterianos/química , Antibacterianos/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Dióxido de Carbono/química , Quitosana/química , Quitosana/farmacologia , Módulo de Elasticidade , Interações Hidrofóbicas e Hidrofílicas , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Resistência à Tração
6.
Carbohydr Polym ; 219: 269-279, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151525

RESUMO

The protective mechanism of chitosan oligosaccharide (COS) against lipopolysaccharides (LPS) -induced inflammatory responses in IPEC-J2 and in mice with DSS dextran sulfate sodium (DSS) -induced colitis is reported. Upon exposure to LPS, the proliferation rate of IPEC-J2 cells markedly decreased, and epithelial cell integrity was compromised. However, COS pretreatment significantly reduced these changes. Low-concentration (200 µg/mL) COS up-regulated Toll-like receptor 4 (TLR4) and nuclear p65 expression, but inhibited LPS-induced expression of nuclear p65, IL-6, and IL-8. Addition of the TLR4 inhibitor reduced nuclear p65, IL-6, and IL-8 expression in IPEC-J2 cells exposed to COS or LPS alone, and a slight up-regulation in nuclear p65 was observed in COS and LPS co-treated cells. Medium-dose COS (600 mg/kg/d) protected against DSS-induced colitis, in which TLR4 and nuclear p65 expression levels were decreased. We postulate that the prevention of both LPS- and DSS -induced inflammatory responses in IPEC-J2 cells and mice by COS are related to the inhibition of the TLR4/NF-κB signaling pathway.


Assuntos
Quitosana/farmacologia , Colite/tratamento farmacológico , Inflamação/tratamento farmacológico , Oligossacarídeos/farmacologia , Receptor 4 Toll-Like/metabolismo , Fator de Transcrição RelA/metabolismo , Animais , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Colite/induzido quimicamente , Sulfato de Dextrana/química , Modelos Animais de Doenças , Inflamação/induzido quimicamente , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Lipopolissacarídeos/química , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais/efeitos dos fármacos
7.
Carbohydr Polym ; 219: 290-297, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151528

RESUMO

Microbial contamination has evolved as a life-threatening problem afflicting people due to various diseases caused by pathogenic bacteria in drinking water. Thus developing novel antibacterial materials is an urgent need. Herein, a chitosan (CTS)/ biochar-nanosilver (C-Ag) antibacterial composite was prepared by a method of CTS-coated on C-Ag obtained through a facile high-temperature carbonization process using corn straw as the carbon substrate. The results from FT-IR, XRD, SEM and TG-DSC revealed that the biochar loading spherical silver nanoparticles was coated with CTS in the composite. The antibacterial activity of the CTS/C-Ag composite was investigated using the plate counting method with Escherichia coli (E. coli), and the results suggest that the composite exhibited excellent antibacterial activity against E. coli. In this application study, it was proven that the CTS/C-Ag composite exhibits sustainable antibacterial activity and good reusability for drinking water. Therefore, the CTS/C-Ag composite has potential application in drinking water treatment.


Assuntos
Antibacterianos , Quitosana/farmacologia , Água Potável , Escherichia coli/efeitos dos fármacos , Nanocompostos/química , Purificação da Água/métodos , Antibacterianos/química , Antibacterianos/farmacologia , Carvão Vegetal/química , Quitosana/química , Água Potável/análise , Água Potável/microbiologia , Nanopartículas Metálicas/química , Extratos Vegetais/química , Prata/química , Zea mays/química
8.
Carbohydr Polym ; 219: 334-343, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151533

RESUMO

The objective of this work was to investigate the effect of the addition of carboxymethyl chitosan on the structural properties and antilisterial activity of nisin-incorporated chitosan films. Chitosan and carboxymethyl chitosan solutions were prepared with different mass ratios and bacteriocin nisin was added (0, 1000 and 6000 IU/ml). Filmogenic solutions were cast, dried and their physico-chemical and antimicrobial properties were investigated. For the same chitosan/carboxymethyl chitosan mass ratio, the addition of NIS at 6000 IU/ml led to changes in the macro- and microstructure, as well as in physico-chemical properties of films. On the other hand, carboxymethyl chitosan had a plasticizing effect and enhanced the distribution of the bacteriocin within the biopolymer matrix. Moreover, nisin-incorporated blend films of chitosan and carboxymethyl chitosan were more effective against Listeria monocytogenes than their pure chitosan counterparts. This study showed that different formulations of nisin-incorporated composite films of chitosan and carboxymethyl chitosan may provide options for developing bioactive packaging to improve food safety.


Assuntos
Antibacterianos , Quitosana/análogos & derivados , Conservantes de Alimentos , Listeria monocytogenes/efeitos dos fármacos , Nisina , Antibacterianos/química , Antibacterianos/farmacologia , Quitosana/química , Quitosana/farmacologia , Microbiologia de Alimentos , Embalagem de Alimentos , Conservação de Alimentos , Conservantes de Alimentos/química , Conservantes de Alimentos/farmacologia , Nisina/química , Nisina/farmacologia
9.
J Sci Food Agric ; 99(13): 6032-6041, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31226218

RESUMO

BACKGROUND: In order to inhibit microorganisms and improve storage quality of fresh-cut cucumber, fresh-cut cucumber was treated by carbon dots (CDs) from kelp/chitosan (CH) coating solution with CD concentrations of 0%, 1.5%, 3% and 4.5% and then packaged as well as stored at 4 °C for 15 days. The effect of CDs/CH coating on microorganisms and the quality of modified-atmosphere-packaged fresh-cut cucumber during storage were investigated. RESULTS: The CDs was monodispersed spherical morphology with size distribution of 0.54-0.83 nm. Interaction of CDs and CH had the generation of strong hydrogen bond. Inhibition zone diameters of CDs/CH coating against Staphylococcus aureus and Escherichia coli were enhanced with the increase of CD concentrations. Moreover, CDs/CH coating inhibited the growth of total number of colonies, mold, and yeast in modified-atmosphere-packaged fresh-cut cucumber during storage. A coating of 4.5% CDs/CH effectively reduced the losses of weight, firmness, and total soluble solids, the degradation of ascorbic acid content and flavor, and inhibited peroxidases activity, as well as decreased water mobility in fresh-cut cucumber during storage. CONCLUSION: The results indicated that a CDs/CH coating was helpful for inhibiting microorganisms and improving storage quality, and could be an effective method to prolong shelf life of fresh-cut cucumber. © 2019 Society of Chemical Industry.


Assuntos
Carbono/farmacologia , Quitosana/farmacologia , Cucumis sativus/efeitos dos fármacos , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Carbono/química , Quitosana/química , Cucumis sativus/microbiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Embalagem de Alimentos , Conservação de Alimentos/instrumentação , Conservantes de Alimentos/química , Armazenamento de Alimentos , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Humanos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Paladar
10.
J Agric Food Chem ; 67(25): 6911-6920, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31194542

RESUMO

Improving the root system architecture (RSA) under adverse environmental conditions by using biostimulants is emerging as a new way to boost crop productivity. Recently, we have reported the characterization of novel chitosan-based microparticles (CS-MPs) with promising biological properties as rooting agents in lettuce. In this work, we demonstrated that in contrast to bulk chitosan (CS), which exerts root growth inhibition, CS-MPs promoted root growth and development from 1 to 10 µg mL-1 without cytotoxicity effects at higher doses in Arabidopsis and lettuce seedlings. In addition, we studied the mechanistic mode of action of CS-MPs in the development of early RSA in the Arabidopsis model. CS-MPs unchained accurate and sustained spatio-temporal activation of the nuclear auxin signaling pathway. Our findings validated a promising scenario for the application of CS-MPs in the modulation of RSA to respond to changing soil environments and improve crop performance.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Quitosana/química , Quitosana/farmacologia , Ácidos Indolacéticos/farmacologia , Alface/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Arabidopsis/efeitos dos fármacos , Alface/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
11.
Fish Shellfish Immunol ; 90: 431-439, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31082516

RESUMO

The effectiveness of ionotropic gelation method (by combining alginate and chitosan) vaccine against Lactococcus garvieae and Streptococcus iniae was examined in rainbow trout. Fish were separated into four groups and fed the distinctive examined feeds. Our groups were included: A) fish immunized by chitosan-alginate coated vaccine, B) fish immunized by non-coated vaccine, C) fish feed by chitosan-alginate coated pellets without vaccine and D) fish feed by basic diet (non-coated and without vaccine). In groups A and B, the vaccination was carried out for 14 days. Fish of group C, like groups A and B were fed 14 days with pellets covered with chitosan-alginate without vaccine and a short time later they were fed with control diet. On day 0, 20, 40 and 60 of the trial, serum samples were extracted. Fish were challenged with L. garvieae and S. iniae after 60 days of research. Innate immunity components containing complement activity, total protein and IgM appeared no significant changes nearly in all groups during the 60 days that the examination finished. Although, bactericidal activity and lysozyme activity demonstrated a significant increase on days 20, 40 and 60 in group A compared to control groups (C and D) (P < 0.05) and similar results about the blood respiratory burst activity just on days 20 and 40 were obtained. Also, the relative expression of IL-6 of group A, was significantly higher compared to all of other groups (B, C and D) on days 20 and 60 of experiment (P < 0.05). The same results were obtained about the relative expression of IgM. The serum ELISA antibody titer against L. garvieae, increased significantly on days 20 and 40 of experiment in fish immunized by chitosan-alginate coated vaccine (Group A) compared to control groups (C and D)(P < 0.05) while the result of ELISA test against S. iniae was significantly higher on days 40 and 60 of experiment in group A compared to groups B, C and D (P < 0.05). After challenge with these two live bacteria (S. iniae and L. garvieae), a survival rates of 76.67 ±â€¯5.77% (challenged with S. iniae) and 66.67 ±â€¯5.77% (challenged with L. garvieae) were seen in group immunized with chitosan-alginate coated vaccine (Group A), which were higher than survival rates gotten in other trial groups (P < 0.05). The consequences of the present experiment show that the oral vaccination of rainbow trout with improved chitosan-alginate (via ionotropic procedure) (group A) properly secures this important fish against Lactococcus garvieae and Streptococcus iniae.


Assuntos
Vacinas Bacterianas/imunologia , Doenças dos Peixes/prevenção & controle , Infecções por Bactérias Gram-Positivas/veterinária , Lactococcus/imunologia , Oncorhynchus mykiss/imunologia , Streptococcus iniae/imunologia , Administração Oral , Alginatos/farmacologia , Animais , Quitosana/farmacologia , Infecções por Bactérias Gram-Positivas/prevenção & controle , Infecções Estreptocócicas/prevenção & controle , Infecções Estreptocócicas/veterinária , Vacinas Estreptocócicas/imunologia
12.
Carbohydr Polym ; 217: 116-125, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31079667

RESUMO

Chitosan-gum arabic-based polyelectrolyte complexed films with cinnamon essential oil (CEO) and clove essential oil (CLO) were developed. The effect of EO concentrations, types and their combinations on the physical, thermal and antimicrobial properties of films were investigated. The results showed that the incorporation of EOs decreased the ζ-potential and viscosity, but increased the particle size of film-forming dispersions. Films incorporated with CEO and combined EOs exhibited better water barrier properties compared to those with CLO and single EO. Films containing CEO showed lower EO loss and higher thermal stability compared to those containing CLO, and the reason was attributed to the stronger interactions between chitosan, gum arabic and CEO. The combination of EOs resulted in higher retention and delayed release rate in food stimulant, resulting in stronger antimicrobial activities. The performance of films with the CEO and the combined EOs brought new formulation ideas in antimicrobial films.


Assuntos
Antibacterianos/farmacologia , Quitosana/farmacologia , Goma Arábica/farmacologia , Óleos Voláteis/farmacologia , Antibacterianos/química , Quitosana/química , Cinnamomum zeylanicum/química , Escherichia coli/efeitos dos fármacos , Goma Arábica/química , Membranas Artificiais , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Tamanho da Partícula , Staphylococcus/efeitos dos fármacos , Syzygium/química , Temperatura Ambiente , Resistência à Tração , Viscosidade
13.
Carbohydr Polym ; 217: 126-134, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31079668

RESUMO

Longan pulp is an excellent source of polysaccharides and other nutrients that have many health benefits. However, longans is susceptible to pulp breakdown after harvest and loses its nutrition values. To solve this problem, this study aimed to study the effects of a novel chitosan, Kadozan, on pulp breakdown index, contents of pectin, cellulose and hemicelluloses, and activities of enzymes in longan pulp relating to disassembly of polysaccharides (XET, PE, PG, ß-Gal, and cellulase). The data illustrated that, compared to the control longans, chitosan-treated longans contained higher amounts of CWM, CSP, ISP, cellulose and hemicelluloses, but exhibited lower pulp breakdown index, lower activities of cell wall-disassembling enzymes, and contained lower WSP amount. These results suggested that Kadozan with a dilution of 1:500 (VKadozan: VKadozan + Water) could significantly decrease activities of disassembling-enzymes and depolymerization of polysaccharides in cell wall, and subsequently alleviate pulp breakdown and prolong storage-life of postharvest longans.


Assuntos
Parede Celular/efeitos dos fármacos , Quitosana/farmacologia , Inibidores Enzimáticos/farmacologia , Frutas/metabolismo , Polissacarídeos/metabolismo , Sapindaceae/metabolismo , Parede Celular/metabolismo , Celulose/metabolismo , Conservação de Alimentos/métodos , Qualidade dos Alimentos , Glicosídeo Hidrolases/antagonistas & inibidores , Hidrólise/efeitos dos fármacos , Pectinas/metabolismo
14.
Carbohydr Polym ; 217: 98-109, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31079690

RESUMO

Chitin is an abundant natural polymer and its deacetylated derivative chitosan has been a focus for the development of biobased, biocompatible and antimicrobial materials. In this work, a green and scalable route to grafting polycaprolactone (PCL) to chitosan using an enzyme catalysed reactive extrusion process is described. FTIR, 1H and 13C NMR spectroscopy and HSQC analysis confirm grafting of PCL to chitosan and show differences in the grafting pattern obtained using two commercially produced lipase enzymes from Candida antarctica (CALB® and NovoCor®). The thermostable NovoCor enzyme gave a much higher grafting yield (96.3%) than the less thermostable CALB enzyme (5.90%). In the esterification reaction, CALB preferentially catalyses reaction on primary OH groups at the C-6 position of chitosan, whereas NovoCor catalyses on the secondary OH groups of chitosan at the C-3 position. This is related to the differences in the selectivity of the two lipase enzymes. The control synthesized without enzyme did not show any grafting reaction. The degree of crystallinity and thermal stability of the lipase catalysed copolymer was reduced compared to unmodified chitosan. Moreover, the PCL grafted chitosan produced by a solvent free reactive extrusion route retained antimicrobial property against E.coli. Such grafted co-polymers may have applications in the controlled release coatings and tissue culture surfaces.


Assuntos
Antibacterianos/síntese química , Quitosana/síntese química , Lipase/química , Poliésteres/síntese química , Antibacterianos/farmacologia , Quitosana/farmacologia , Escherichia coli/efeitos dos fármacos , Química Verde/métodos , Poliésteres/farmacologia , Estudo de Prova de Conceito , Staphylococcus aureus/efeitos dos fármacos , Temperatura Ambiente
15.
Molecules ; 24(9)2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31083306

RESUMO

(1) Background: The effectiveness of chitosan to improve the action of antimicrobial compounds against planktonic bacteria and young biofilms has been widely investigated in Dentistry, where the biofilm lifecycle is a determining factor for the success of antibacterial treatment. In the present study, mature Streptococcus mutans biofilms were treated with chitosan dispersion (CD) or chitosan microparticles (CM). (2) Methods: CD at 0.25% and 1% were characterized by texture analysis, while CD at 2% was spray-dried to form CM, which were characterized with respect to particle size distribution, zeta potential, and morphology. After determining the minimum inhibitory and bactericidal concentrations, S. mutans biofilms were grown on glass slides exposed 8×/day to 10% sucrose and 2×/day to CD or CM at 0.25% and 1%. Biofilm viability and acidogenicity were determined, using appropriate control groups for each experiment. (3) Results: CD had high viscosity and CM were spherical, with narrow size distribution and positive zeta potential. CM affected bacterial viability and acidogenicity in mature S. mutans biofilms more strongly than CD, especially at 1%. (4) Conclusions: Both chitosan forms exerted antimicrobial effect against mature S. mutans biofilms. CM at 1% can reduce bacterial viability and acidogenicity more effectively than CD at 1%, and thereby be more effective to control the growth of mature biofilms in vitro.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Quitosana/química , Quitosana/farmacologia , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Polissacarídeos/química , Polissacarídeos/farmacologia , Streptococcus mutans
16.
Bull Exp Biol Med ; 166(6): 779-784, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31028582

RESUMO

The cytotoxicity and antioxidant effects of chitosan-(poly)nitoxides of different molecular weights containing a nitroxide radical of the piperidine structure were studied on tumor (HeLa, A172, and HepG2) and normal (Vero) cell lines. The chitosan-(poly)nitroxides exhibited low cytotoxicity. Under conditions of oxidative stress induced with tert-butyl hydroperoxide, the most pronounced decrease in ROS levels in the presence of chitosan-(poly)nitroxides was observed in normal cells. In cell homogenates, the decrease in malondialdehyde levels was observed only in the presence of low-molecular-weight chitosan-(poly)nitroxide irrespective of the cell line. Our data demonstrate that the cell-specific antioxidant properties of chitosan-(poly)nitroxides are related to their penetration into cells and interaction with intracellular membranes.


Assuntos
Antioxidantes/farmacologia , Quitosana/farmacologia , Óxidos de Nitrogênio/química , Estresse Oxidativo/efeitos dos fármacos , Piperidinas/farmacologia , Animais , Antioxidantes/síntese química , Linhagem Celular Tumoral , Cercopithecus aethiops , Quitosana/análogos & derivados , Quitosana/síntese química , Células HeLa , Células Hep G2 , Humanos , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Neuroglia/patologia , Especificidade de Órgãos , Piperidinas/síntese química , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade , Células Vero , terc-Butil Hidroperóxido/antagonistas & inibidores , terc-Butil Hidroperóxido/farmacologia
17.
IET Nanobiotechnol ; 13(1): 30-35, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30964034

RESUMO

This study was designed to evaluate and compare the stability, antioxidant and anticancer activities of selenium nanoparticles (SeNPs) decorated with different molecular weight (MW) of chitosan (CS) (1500 Da, 48 kDa, 510 kDa). The size range of well-dispersed SeNPs was effectively controlled by I- first and then coated with CS. The morphology, size and surface charge of generated SeNPs were characterised by several technologies. Fourier transform infrared spectroscopy was used to investigate the relationship between SeNPs and CS. SeNPs decorated with CS (510 kDa) can keep stable for more than 45 days. As observed from the results of a simple photometric system, the antioxidant activities of decorated SeNPs were enhanced compared to undecorated SeNPs. SeNPs coated with higher MW of CS (510 kDa) showed the strongest antioxidant activities. Moreover, the treatments of SeNPs decorated with CS inhibited the growth of HepG2 cells in a time- and dose-dependent manner. The proposed results demonstrated the critical roles of the MW of CS on the stability, antioxidant and anticancer properties of CS-coated SeNPs, which provided an important design cue for future applications of functional foods and additives.


Assuntos
Antineoplásicos , Antioxidantes , Quitosana , Nanopartículas/química , Selênio , Antineoplásicos/química , Antineoplásicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Quitosana/farmacologia , Células Hep G2 , Humanos , Peso Molecular , Selênio/química , Selênio/farmacologia
18.
Mar Drugs ; 17(4)2019 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-31013628

RESUMO

Chitin was extracted from Polybius henslowii, a swimming crab, captured in large quantities throughout the Portuguese coast by purse seine vessels as bycatch. After standard chitin extraction procedures, water-soluble chitosan products were obtained via two different methods: (1) N-acetylation with the addition of acetic anhydride and (2) a reaction with hydrogen peroxide. The chemical structure and molecular weight of chitosan derivatives, water-soluble chitosan (WSC) and chitooligosaccharides (COS), were confirmed by Fourier Transform Infrared Spectroscopy (FT-IR) and gel permeation chromatography (GPC). Antioxidant and metal chelation activities were evaluated, and the growth inhibition capacity was tested on four phytopatogens. The chitooligosaccharides from pereopods (pCOS) and shell body parts (sCOS) inhibited all fungal species tested, particularly Cryphonectria parasitica with 84.7% and 85.5%, respectively. Both radical scavenging and antifungal activities proved to be dose-dependent. Chitooligosaccharides with a low molecular weight (2.7, 7.4, and 10.4 Kg·mol-1) showed the highest activity among all properties tested. These results suggested that chitosan derivatives from P. henslowii raw material could potentially be used against phytopathogens or as ingredient in cosmetics and other products related to oxidative stress.


Assuntos
Antifúngicos/farmacologia , Antioxidantes/farmacologia , Braquiúros/química , Quitosana/farmacologia , Animais , Antifúngicos/química , Antioxidantes/química , Quitina/análogos & derivados , Quitina/química , Quitina/farmacologia , Quitosana/química , Fungos/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Peso Molecular , Polímeros/química , Polímeros/farmacologia , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Água
19.
Molecules ; 24(7)2019 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-30970577

RESUMO

Psoriasis is a chronic inflammatory skin disease characterized by hyperproliferation of the epidermal cells and is clinically presented as thick, bright red to pink plaques with a silvery scale. Photodynamic therapy (PDT) using visible light has become of increasing interest in the treatment of inflammatory skin diseases. In this study, we demonstrate that a combination of curcumin-loaded chitosan/alginate nanoparticles (Cur-CS/Alg NPs) and blue light emitting diodes (LED) light irradiation effectively suppressed the hyperproliferation of tumor necrosis factor-alpha (TNF-α)-induced cultured human kerlatinocyte (HaCaT) cells. The Cur-CS/Alg NPs were fabricated by emulsification of curcumin in aqueous sodium alginate solution and ionotropic gelation with calcium chloride and chitosan using an optimized formulation derived from a Box-Behnken design. The fabricated Cur-CS/Alg NPs were characterized for their particle size, zeta potential, encapsulation efficiency, and loading capacity. The surrogate 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, to measure the relative number of viable cells, showed that the CS/Alg NPs were nontoxic to normal HaCaT cells, while 0.05 µg/mL and 0.1 µg/mL of free curcumin and Cur-CS/Alg NPs inhibited the hyperproliferation of HaCaT cells induced by TNF-α. However, the Cur-CS/Alg NPs demonstrated a stronger effect than the free curcumin, especially when combined with blue light irradiation (10 J/cm²) from an LED-based illumination device. Therefore, the Cur-CS/Alg NPs with blue LED light could be potentially developed into an effective PDT system for the treatment of psoriasis.


Assuntos
Proliferação de Células , Sistemas de Liberação de Medicamentos , Queratinócitos/metabolismo , Luz , Nanopartículas/química , Psoríase/terapia , Fator de Necrose Tumoral alfa/farmacologia , Alginatos/química , Alginatos/farmacologia , Linhagem Celular Transformada , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Quitosana/química , Quitosana/farmacologia , Curcumina/química , Curcumina/farmacologia , Humanos , Queratinócitos/fisiologia , Psoríase/metabolismo , Psoríase/patologia , Fator de Necrose Tumoral alfa/metabolismo
20.
Mater Sci Eng C Mater Biol Appl ; 101: 243-253, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31029317

RESUMO

Developing a simple produces for efficient derivation of motor neurons (MNs) is essential for neural tissue engineering studies. Stem cells with high capacity for neural differentiation and scaffolds with the potential to promote motor neurons differentiation are promising candidates for neural tissue engineering. Recently, human olfactory ecto-mesenchymal stem cells (OE-MSCs), which are isolated easily from the olfactory mucosa, are considered a new hope for neuronal replacement due to their neural crest origin. Herein, we synthesized conducting hydrogels using different concentration of chitosan-g-aniline pentamer, gelatin, and agarose. The chemical structures, swelling and deswelling ratio, ionic conductivity and thermal properties of the hydrogel were characterized. Scaffolds with 10% chitosan-g-aniline pentamer/gelatin (S10) were chosen for further investigation and the potential of OE-MSCs as a new source for programming to motor neuron-like cells investigated on tissue culture plate (TCP) and conductive hydrogels. Cell differentiation was evaluated at the level of mRNA and protein synthesis and indicated that conductive hydrogels significantly increased the markers related to motor neurons including Hb-9, Islet-1 and ChAT compared to TCP. Taken together, the results suggest that OE-MSCs would be successfully differentiated into motor neuron-like cells on conductive hydrogels and would have a promising potential for treating motor neuron-related diseases.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Quitosana/farmacologia , Condutividade Elétrica , Gelatina/farmacologia , Hidrogéis/farmacologia , Células-Tronco Mesenquimais/citologia , Neurônios Motores/citologia , Sefarose/farmacologia , Compostos de Anilina/síntese química , Compostos de Anilina/farmacologia , Fosfatos de Cálcio/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Quitosana/síntese química , Quitosana/química , Força Compressiva , Gelatina/química , Humanos , Hidrogéis/química , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/ultraestrutura , Neurônios Motores/efeitos dos fármacos , Bulbo Olfatório/citologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura Ambiente , Termogravimetria , Tecidos Suporte/química
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