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1.
J Med Microbiol ; 70(10)2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34612810

RESUMO

Introduction. The emergence of multidrug-resistant Salmonella Typhimurium strains has increased the need for safe, alternative therapies from natural sources with antibacterial properties.Hypothesis/Gap Statement. There are no published data regarding the use of chitosan propolis nanocomposite (CPNP) either alone or in combination with antibiotics as antimicrobials against S. Typhimurium, especially in Egypt.Aim. This study evaluated the antibacterial activities of five antimicrobials [apramycin, propolis, chitosan nanoparticles (CNPs), chitosan propolis nanocomposite (CPNP) and CPNP +apramycin] against ten virulent and multidrug-resistant (MDR) S. Typhimurium field strains recovered from diarrheic rabbits through in vitro and in vivo study.Methodology. The expression levels of three virulence genes of S. Typhimurium strains were determined by quantitative reverse-transcription PCR (RT-qPCR) after exposure to sub-inhibitory concentrations of apramycin, propolis, CNPs, CPNP alone, and CPNP +apramycin. Additionally, 90 New Zealand rabbits were divided into control and experimentally S. Typhimurium-infected groups. The infected rabbits were orally administered saline solution (infected-untreated); 10 mg apramycin/kg (infected-apramycin-treated); 50 mg propolis/kg (infected-propolis-treated); 15 mg CPNP/kg (infected-CPNP-treated) and 15 mg CPNP +10 mg apramycin/kg (infected-CPNP +apramycin-treated) for 5 days.Results. The RT-qPCR analysis revealed different degrees of downregulation of all screened genes. Furthermore, the treatment of infected rabbits with CPNP or CPNP +apramycin significantly improved performance parameters, and total bacterial and Salmonella species counts, while also modulating both oxidative stress and altered liver and kidney parameters.Conclusion. This work demonstrates the use of CPNP alone or in combination with apramycin in the treatment of S. Typhimurium in rabbits.


Assuntos
Antibacterianos/uso terapêutico , Quitosana/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Nanocompostos/uso terapêutico , Própole/química , Infecções por Salmonella/tratamento farmacológico , Salmonella typhimurium/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/metabolismo , Carga Bacteriana/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quitosana/farmacologia , Quitosana/uso terapêutico , Chlorocebus aethiops , Farmacorresistência Bacteriana Múltipla/genética , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanocompostos/química , Nebramicina/análogos & derivados , Nebramicina/farmacologia , Nebramicina/uso terapêutico , Própole/farmacologia , Própole/uso terapêutico , Coelhos , Infecções por Salmonella/microbiologia , Salmonella typhimurium/patogenicidade , Células Vero , Virulência/genética
2.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 29(5): 1685-1689, 2021 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-34627463

RESUMO

Whether in war or peace, timely, effective and accurate hemostasis is an important measure to improve the survival rate and cure rate of the wounded. All the countries in the world are actively developing different types of hemostatic materials so as to reduce the amount of bleeding in an emergency and create favorable conditions for subsequent transport and treatment. At present, the commercialized hemostatic materials are mainly divided into natural biological, synthetic biological, mineral and coagulation components, but all these materials have their own limitations. In this article, the characteristics of chitosan and its derivatives are reviewed as the representatives of the natural organic macromolecular polysaccharide hemostasis materials. Their molecular structures, biomedical properties, domestic and foreign research and application progress as well as comparison with applications of other hemostatic materials are involved. The further research is prospected for optimization and innovation to develop composite chitosan hemostatic materials with the function of hemostasis, antibiosis, pain relief and promoting wound healing.


Assuntos
Quitosana , Hemostáticos , Coagulação Sanguínea , Quitosana/farmacologia , Hemorragia , Hemostasia , Humanos
3.
Biomolecules ; 11(8)2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34439803

RESUMO

Developing multifunctional systems for the biomimetic remineralization of human enamel is a challenging task, since hydroxyapatite (HAP) rod structures of tooth enamel are difficult to replicate artificially. The paper presents the first report on the simultaneous use of chitosan (CS) and agarose (A) in a biopolymer-based hydrogel for the biomimetic remineralization of an acid-etched native enamel surface during 4-10-day immersion in artificial saliva with or without (control group) fluoride. Scanning electron microscopy coupled with energy-dispersive X-ray spectrometry, Fourier transform infrared and Raman spectroscopies, X-ray diffraction, and microhardness tests were applied to investigate the properties of the acid-etched and remineralized dental enamel layers under A and CS-A hydrogels. The results show that all biomimetic epitaxial reconstructed layers consist mostly of a similar hierarchical HAP structure to the native enamel from nano- to microscale. An analogous Ca/P ratio (1.64) to natural tooth enamel and microhardness recovery of 77.4% of the enamel-like layer are obtained by a 7-day remineralization process in artificial saliva under CS-A hydrogels. The CS component reduced carbonation and moderated the formation of HAP nanorods in addition to providing an extracellular matrix to support growing enamel-like structures. Such activity lacked in samples exposed to A-hydrogel only. These data suggest the potential of the CS-A hydrogel in guiding the formation of hard tissues as dental enamel.


Assuntos
Materiais Biomiméticos/farmacologia , Quitosana/farmacologia , Esmalte Dentário/efeitos dos fármacos , Durapatita/química , Sefarose/farmacologia , Remineralização Dentária/métodos , Condicionamento Ácido do Dente/métodos , Materiais Biomiméticos/química , Tampões (Química) , Quitosana/química , Esmalte Dentário/fisiologia , Esmalte Dentário/ultraestrutura , Durapatita/metabolismo , Humanos , Hidrogéis/química , Hidrogéis/farmacologia , Teste de Materiais/métodos , Dente Molar/cirurgia , Saliva/química , Sefarose/química , Extração Dentária
4.
Food Res Int ; 147: 110491, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399487

RESUMO

The present study aimed to investigate the effect of chitosan edible coating containing 0.15% oregano essential oil (OEO) or 0.60% cinnamon essential oil (CEO) on the quality characteristics and dynamic changes in the bacterial community of roast duck slices under modified atmosphere packaging (MAP, 30% CO2/70% N2) during 21 days of storage at 2 ± 2 °C. The results showed that the application of chitosan coating (CH) alone inhibited the growth of microorganisms and prevented lipid oxidation throughout storage. Moreover, the storage stability was further improved by including OEO or CEO, which lowered (P < 0.05) values for total viable count (TVC), Enterobacteriaceae, 2-thiobarbituric acid reactive substance (TBARS) and total volatile basic nitrogen (TVB-N). Based on the microbiological results, the shelf-life of CH-OEO and CH-CEO treated roast duck slices was prolonged by at least 7 days compared to that of the control. In addition, packaging types applied in this study played a major role in the bacterial community development. Notably, Vibrio spp. were the most predominant bacteria in all samples, when TVC values approached the shelf-life threshold, suggesting that this bacterium may be the main contributor to the spoilage of roast duck. The growth inhibition of Vibrio spp. in the CH-OEO and CH-CEO treatments during the early period of chilled storage might be the reason for the extension of the shelf life. Taken together, CH incorporated with OEO or CEO could be developed as prospective edible packaging materials to preserve roast duck meat.


Assuntos
Quitosana , Óleos Voláteis , Origanum , Animais , Atmosfera , Bactérias , Quitosana/farmacologia , Cinnamomum zeylanicum , Patos , Microbiologia de Alimentos , Embalagem de Alimentos , Conservação de Alimentos , Carne , Óleos Voláteis/farmacologia , Estudos Prospectivos
5.
Molecules ; 26(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34443619

RESUMO

This study was designed to investigate the influence of dietary chitosan feeding-duration on glucose and lipid metabolism in diabetic rats induced by streptozotocin and nicotinamide [a non-insulin-dependent diabetes mellitus (NIDDM) model]. Male Sprague-Dawley rats were used as experimental animals and divided into short-term (6 weeks) and long-term (11 weeks) feeding durations, and each duration contained five groups: (1) control, (2) control + 5% chitosan, (3) diabetes, (4) diabetes + 0.8 mg/kg rosiglitazone (a positive control), and (5) diabetes + 5% chitosan. Whether the chitosan feeding was for 6 or 11 weeks, the chitosan supplementation decreased blood glucose and lipids levels and liver lipid accumulation. However, chitosan supplementation decreased plasma tumor necrosis factor (TNF)-α, insulin levels, alanine aminotransferase (ALT) activity, insulin resistance (HOMA-IR), and adipose tissue lipoprotein lipase activity. Meanwhile, it increased plasma high-density lipoproteins (HDL)-cholesterol level, plasma angiopoietin-like-4 protein expression, and plasma triglyceride levels (at 11-week feeding duration only). Taken together, 11-week (long-term) chitosan feeding may help to ameliorate the glucose and lipid metabolism in a NIDDM diabetic rat model.


Assuntos
Quitosana/farmacologia , Diabetes Mellitus Experimental/metabolismo , Carboidratos da Dieta/farmacologia , Glucose/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
6.
Int J Mol Sci ; 22(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34360752

RESUMO

Polymeric-based nano drug delivery systems have been widely exploited to overcome protein instability during formulation. Presently, a diverse range of polymeric agents can be used, among which polysaccharides, such as chitosan (CS), hyaluronic acid (HA) and cyclodextrins (CDs), are included. Due to its unique biological and physicochemical properties, CS is one of the most used polysaccharides for development of protein delivery systems. However, CS has been described as potentially immunogenic. By envisaging a biosafe cytocompatible and haemocompatible profile, this paper reports the systematic development of a delivery system based on CS and derived with HA and CDs to nanoencapsulate the model human phenylalanine hydroxylase (hPAH) through ionotropic gelation with tripolyphosphate (TPP), while maintaining protein stability and enzyme activity. By merging the combined set of biopolymers, we were able to effectively entrap hPAH within CS nanoparticles with improvements in hPAH stability and the maintenance of functional activity, while simultaneously achieving strict control of the formulation process. Detailed characterization of the developed nanoparticulate systems showed that the lead formulations were internalized by hepatocytes (HepG2 cell line), did not reveal cell toxicity and presented a safe haemocompatible profile.


Assuntos
Quitosana , Enzimas Imobilizadas , Teste de Materiais , Nanopartículas/química , Fenilalanina Hidroxilase , Quitosana/química , Quitosana/farmacologia , Avaliação Pré-Clínica de Medicamentos , Estabilidade Enzimática , Enzimas Imobilizadas/química , Enzimas Imobilizadas/farmacologia , Células HEK293 , Células Hep G2 , Humanos , Fenilalanina Hidroxilase/química , Fenilalanina Hidroxilase/farmacologia
7.
Molecules ; 26(15)2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34361651

RESUMO

Here we introduce a new method aiming the immobilization of bioactive principles onto polymeric substrates, combining a surface activation and emulsion entrapment approach. Natural products with antimicrobial/antioxidant properties (essential oil from Syzygium aromaticum-clove and vegetal oil from Argania spinosa L-argan) were stabilized in emulsions with chitosan, a natural biodegradable polymer that has antimicrobial activity. The emulsions were laid on poly(lactic acid) (PLA), a synthetic biodegradable plastic from renewable resources, which was previously activated by plasma treatment. Bioactive materials were obtained, with low permeability for oxygen, high radical scavenging activity and strong inhibition of growth for Listeria monocytogenes, Salmonella Typhimurium and Escherichia coli bacteria. Clove oil was better dispersed in a more stable emulsion (no separation after six months) compared with argan oil. This leads to a compact and finely structured coating, with better overall properties. While both clove and argan oils are highly hydrophobic, the coatings showed increased hydrophilicity, especially for argan, due to preferential interactions with different functional groups in chitosan. The PLA films coated with oil-loaded chitosan showed promising results in retarding the food spoilage of meat, and especially cheese. Argan, and in particular, clove oil offered good UV protection, suitable for sterilization purposes. Therefore, using the emulsion stabilization of bioactive principles and immobilization onto plasma activated polymeric surfaces we obtained a bioactive material that combines the physical properties and the biodegradability of PLA with the antibacterial activity of chitosan and the antioxidant function of vegetal oils. This prevents microbial growth and food oxidation and could open new perspectives in the field of food packaging materials.


Assuntos
Quitosana , Óleo de Cravo , Emulsões , Microbiologia de Alimentos/métodos , Embalagem de Alimentos/métodos , Inocuidade dos Alimentos/métodos , Óleos Vegetais , Antibacterianos/química , Antibacterianos/farmacologia , Quitosana/química , Quitosana/farmacologia , Óleo de Cravo/química , Óleo de Cravo/farmacologia , Emulsões/química , Emulsões/farmacologia , Óleos Vegetais/química , Óleos Vegetais/farmacologia
8.
Int J Mol Sci ; 22(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34445554

RESUMO

The aim of this study was to evaluate the effect of different concentrations of chitosan polymer on dentinal enzymatic activity by means of gelatin and in situ zymography. Human dentin was frozen and ground in a miller. Dentin powder aliquots were demineralized with phosphoric acid and treated with three different concentrations of lyophilized chitosan polymer (1, 0.5 and 0.1 wt%) dissolved in distilled water. Dentin proteins were extracted from each experimental group and electrophoresed under non-reducing conditions in 10% SDS-PAGE containing fluorescein-labeled gelatin. After 48 h in the incubation buffer at 37 °C, proteolytic activity was registered under long-wave UV light scanner and quantified by using Image J software. Furthermore, additional teeth (n = 4) were prepared for the in situ zymographic analysis in unrestored as well as restored dentin pretreated with the same chitosan primers. The registered enzymatic activity was directly proportional to the chitosan concentration and higher in the restored dentin groups (p < 0.05), except for the 0.1% chitosan primer. Chitosan 0.1% only showed faint expression of enzymatic activity compared to 1% and 0.5% concentrations. Chitosan 0.1% dissolved in water can produce significant reduction in MMPs activity and could possibly contribute to bond strength preservation over time.


Assuntos
Quelantes/farmacologia , Quitosana/farmacologia , Dentina/enzimologia , Metaloproteinases da Matriz/metabolismo , Dentina/efeitos dos fármacos , Humanos , Teste de Materiais
9.
Molecules ; 26(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34361552

RESUMO

Postharvest pathogens such as C. gloeosporioides (MA), C.oxysporum (ME) and P. steckii (MF) are the causal agents of disease in mangoes. This paper presents an in vitro investigation into the antifungal effect of a chitosan (CTS)/nano-titanium dioxide (TiO2) composite coating against MA, ME and MF. The results indicated that, the rates of MA, ME and MF mortality following the single chitosan treatment were 63.3%, 84.8% and 43.5%, respectively, while the rates of mycelial inhibition were 84.0%, 100% and 25.8%, respectively. However, following the addition of 0.5% nano-TiO2 into the CTS, both the mortality and mycelial inhibition rates for MA and ME reached 100%, and the mortality and mycelial inhibition rate for MF also increased significantly, reaching 75.4% and 57.3%, respectively. In the MA, the dry weight of mycelia after the CTS/0.5% nano-TiO2 treatment decreased by 36.3% in comparison with the untreated group, while the conductivity value was about 1.7 times that of the untreated group, and the protein dissolution rate and extravasation degree of nucleic acids also increased significantly. Thus, this research revealed the potential of CTS/nano-TiO2 composite coatings in the development of new antimicrobial materials.


Assuntos
Antifúngicos , Quitosana , Colletotrichum/crescimento & desenvolvimento , Nanocompostos , Titânio , Antifúngicos/química , Antifúngicos/farmacologia , Quitosana/química , Quitosana/farmacologia , Mangifera/microbiologia , Nanocompostos/química , Nanocompostos/uso terapêutico , Doenças das Plantas/microbiologia , Titânio/química , Titânio/farmacologia
10.
Int J Biol Macromol ; 187: 492-512, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34324908

RESUMO

With increasing global cases and mortality rates due to COVID-19 infection, finding effective therapeutic interventions has become a top priority. Marine resources are not explored much and to be taken into consideration for exploring antiviral potential. Chitosan (carbohydrate polymer) is one such bioactive glycan found ubiquitously in marine organisms. The presence of reactive amine/hydroxyl groups, with low toxicity/allergenicity, compels us to explore it against SARS-CoV-2. We have screened a library of chitosan derivatives by site-specific docking at not only spike protein Receptor Binding Domain (RBD) of wild type SARS-CoV-2 but also on RBD of B.1.1.7 (UK) and P.1 (Brazil) SARS-CoV-2 variants. The obtained result was very interesting and ranks N-benzyl-O-acetyl-chitosan, Imino-chitosan, Sulfated-chitosan oligosaccharides derivatives as a potent antiviral candidate due to its high binding affinity of the ligands (-6.0 to -6.6 kcal/mol) with SARS-CoV-2 spike protein RBD and they critically interacting with amino acid residues Tyr 449, Asn 501, Tyr 501, Gln 493, Gln 498 and some other site-specific residues associated with higher transmissibility and severe infection. Further ADMET analysis was done and found significant for exploration of the future therapeutic potential of these three ligands. The obtained results are highly encouraging in support for consideration and exploration in further clinical studies of these chitosan derivatives as anti-SARS-CoV-2 therapeutics.


Assuntos
Antivirais/farmacologia , Quitosana/farmacologia , Variação Genética , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Antivirais/química , Sítios de Ligação , Brasil , Quitosana/química , Modelos Moleculares , Simulação de Acoplamento Molecular , Ligação Proteica , Conformação Proteica/efeitos dos fármacos , SARS-CoV-2/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Reino Unido , Internalização do Vírus/efeitos dos fármacos
11.
Int J Mol Sci ; 22(14)2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34299229

RESUMO

At present, silk fibroin (SF) hydrogel can be prepared by means of electrodeposition at 25 V in direct current (DC) mode. Reducing the applied voltage would provide benefits, including lower fabrication costs, less risk of high voltage shocks, and better stability of devices. Here, a simple but uncommon strategy for SF-based hydrogel preparation using 4 V in DC mode is discussed. SF was mixed and cross-linked with carboxymethyl chitosan (CMCS) through hydrogen bonding, then co-deposited on the graphite electrode. The thickness, mass, and shape of the SF/CMCS hydrogel were easily controlled by adjusting the electrodeposition parameters. Morphological characterization of the prepared hydrogel via SEM revealed a porous network within the fabricated hydrogel. This structure was due to intermolecular hydrogen bonding between SF and CMCS, according to the results of thermogravimetric analysis and rheological measurements. As a potential wound dressing, SF/CMCS hydrogel maintained a suitable moisture environment for wound healing and demonstrated distinct properties in terms of promoting the proliferation of HEK-293 cells and antibacterial activity against Escherichia coli and Staphylococcus aureus. Furthermore, histological studies were conducted on a full-thickness skin wound in rats covered with the SF/CMCS hydrogel, with results indicating that this hydrogel can promote wound re-epithelization and enhance granulation tissue formation. These results illustrate the feasibility of using the developed strategy for SF-based hydrogel fabrication in practice for wound dressing.


Assuntos
Quitosana/análogos & derivados , Fibroínas/farmacologia , Hidrogéis/síntese química , Animais , Antibacterianos/química , Bandagens , Materiais Biocompatíveis/química , Quitosana/química , Quitosana/farmacologia , Escherichia coli , Feminino , Fibroínas/química , Células HEK293 , Humanos , Hidrogéis/química , Camundongos , Staphylococcus aureus , Cicatrização/fisiologia
12.
J Endod ; 47(9): 1435-1444, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34214497

RESUMO

INTRODUCTION: Crosstalk between immune cells and tissue-resident cells regulates the pathophysiology and posttreatment healing of apical periodontitis. This investigation aimed to understand the influence of residual root canal biofilm on macrophage (MQ)-periodontal ligament fibroblast (PdLF) interaction and evaluate the effect of engineered chitosan-based nanoparticles (CSnp) on MQ-PdLF interactions in residual biofilm-mediated inflammation. METHODS: Six-week-old Enterococcus faecalis biofilms in root canal models were disinfected conventionally using sodium hypochlorite alone or followed by calcium hydroxide medication or CSnp dispersed in carboxymethylated chitosan (CMCS). The effect of the treated biofilms (n = 25/group) on the inflammatory response of THP-1-differentiated MQ monoculture versus coculture with PdLF was evaluated for cell viability, MQ morphometric characterization, inflammatory mediators (nitric oxide, tumor necrosis factor alpha, interleukin [IL]-1 beta, IL-1RA, IL-6, transforming growth factor beta 1 [TGF-ß1], and IL-10), and the expression of transcription factors (pSTAT1/pSTAT6)/cluster of differentiation markers (CD80/206) after 24, 48, and 72 hours of interaction. PdLF transwell migration was evaluated after 8 and 24 hours. Unstimulated cells served as the negative control, whereas untreated biofilm was the positive control. RESULTS: Biofilm increased nitric oxide and IL-1ß but suppressed IL-10, IL-1RA, and PdLF migration with significant cytotoxic effects. CSnp/CMCS reduced nitric oxide and IL-1ß (P < .01) while maintaining ≥90% cell survival up to 72 hours with evident M2-like MQ phenotypic changes in coculture. CSnp/CMCS also increased the IL-1RA/IL-1ß ratio and enhanced TGF-ß1 production over time (P < .05, 72 hours). In coculture, CSnp/CMCS showed the highest IL-10 level at 72 hours (P < .01), reduced the pSTAT1/pSTAT6 ratio, and enhanced PdLF migration (P < .01, 24 hours). CONCLUSIONS: CSnp/CMCS medication facilitated MQ switch toward M2 (regulatory/anti-inflammatory) phenotype and PdLF migration via paracrine signaling.


Assuntos
Quitosana , Nanopartículas , Biofilmes , Quitosana/farmacologia , Fibroblastos , Humanos , Inflamação , Macrófagos , Ligamento Periodontal
13.
Molecules ; 26(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202905

RESUMO

Cereals are subject to contamination by pathogenic fungi, which damage grains and threaten public health with their mycotoxins. Fusarium graminearum and its mycotoxins, trichothecenes B (TCTBs), are especially targeted in this study. Recently, the increased public and political awareness concerning environmental issues tends to limit the use of traditional fungicides against these pathogens in favor of eco-friendlier alternatives. This study focuses on the development of biofungicides based on the encapsulation of a curcumin derivative, tetrahydrocurcumin (THC), in polysaccharide matrices. Starch octenylsuccinate (OSA-starch) and chitosan have been chosen since they are generally recognized as safe. THC has been successfully trapped into particles obtained through a spray-drying or freeze-drying processes. The particles present different properties, as revealed by visual observations and scanning electron microscopy. They are also different in terms of the amount and the release of encapsulated THC. Although freeze-dried OSA-starch has better trapped THC, it seems less able to protect the phenolic compound than spray-dried particles. Chitosan particles, both spray-dried and lyophilized, have shown promising antifungal properties. The IC50 of THC-loaded spray-dried chitosan particles is as low as 0.6 ± 0.3 g/L. These particles have also significantly decreased the accumulation of TCTBs by 39%.


Assuntos
Antifúngicos , Agentes de Controle Biológico , Quitosana , Fusarium/crescimento & desenvolvimento , Amido/análogos & derivados , Antifúngicos/química , Antifúngicos/farmacologia , Agentes de Controle Biológico/química , Agentes de Controle Biológico/farmacologia , Quitosana/química , Quitosana/farmacologia , Curcumina/análogos & derivados , Curcumina/química , Curcumina/farmacologia , Amido/química , Amido/farmacologia
14.
Molecules ; 26(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204251

RESUMO

Despite the advantages presented by synthetic polymers such as strength and durability, the lack of biodegradability associated with the persistence in the environment for a long time turned the attention of researchers to natural polymers. Being biodegradable, biopolymers proved to be extremely beneficial to the environment. At present, they represent an important class of materials with applications in all economic sectors, but also in medicine. They find applications as absorbers, cosmetics, controlled drug delivery, tissue engineering, etc. Chitosan is one of the natural polymers which raised a strong interest for researchers due to some exceptional properties such as biodegradability, biocompatibility, nontoxicity, non-antigenicity, low-cost and numerous pharmacological properties as antimicrobial, antitumor, antioxidant, antidiabetic, immunoenhancing. In addition to this, the free amino and hydroxyl groups make it susceptible to a series of structural modulations, obtaining some derivatives with different biomedical applications. This review approaches the physico-chemical and pharmacological properties of chitosan and its derivatives, focusing on the antimicrobial potential including mechanism of action, factors that influence the antimicrobial activity and the activity against resistant strains, topics of great interest in the context of the concern raised by the available therapeutic options for infections, especially with resistant strains.


Assuntos
Quitosana/química , Quitosana/isolamento & purificação , Quitosana/farmacologia , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Materiais Biocompatíveis/química , Biopolímeros/química , Sistemas de Liberação de Medicamentos , Humanos , Nanopartículas/química , Polímeros/química
15.
Int J Biol Macromol ; 185: 832-848, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34237361

RESUMO

Over the last few years, several attempts have been made to replace petrochemical products with renewable and biodegradable components. The most challenging part of this approach is to obtain bio-based materials with properties and functions equivalent to those of synthetic products. Various naturally occurring polymers such as starch, collagen, alginate, cellulose, and chitin represent attractive candidates as they could reduce dependence on synthetic products and consequently positively impact the environment. Chitosan is also a unique bio-based polymer with excellent intrinsic properties. It is known for its anti-bacterial and film-forming properties, has high mechanical strength and good thermal stability. Nanotechnology has also applied chitosan-based materials in its most recent achievements. Therefore, numerous chitosan-based bionanocomposites with improved physical and chemical characteristics have been developed in an eco-friendly and cost-effective approach. This review discusses various sources of chitosan, its properties and methods of modification. Also, this work focuses on diverse preparation techniques of chitosan-based bionanocomposites and their emerging application in various sectors. Additionally, this review sheds light on future research scope with some drawbacks and challenges to motivate the researchers for future outstanding research works.


Assuntos
Antibacterianos/química , Quitosana/química , Antibacterianos/farmacologia , Quitosana/farmacologia , Estrutura Molecular , Nanocompostos , Resistência ao Cisalhamento , Termodinâmica
16.
Int J Biol Macromol ; 185: 572-581, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34216659

RESUMO

Chitosan microspheres (CMS) by the emulsion-chemical cross-linking method with and without lysozyme immobilization were synthesized and characterized. The technique conditions were adjusted, and spherical particles with approximate diameters of 3.74 ± 1.08 µm and 0. 29 ± 0.029 µm to CMS and chitosan-lysozyme microspheres (C-LMS), respectively, were obtained. The microspheres were characterized by scanning electron microscopy (FESEM), Spectroscopy Fourier Transform Spectroscopy (ATR-FTIR), X-ray diffraction (XRD), and zeta potential. Particle size was identified by laser light scattering (DLS) and the thermal properties by Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA) were determined. By the lysis of Micrococcus lysodeikticus, the activity of the microspheres was determined, and the results correlated with the amount of lysozyme used in the immobilization process and the enzyme loading efficiency was 67%. Finally, release tests pointed out the amount of enzyme immobilized on the microsphere surface. These results showed that chitosan microspheres could be used as material for lysozyme immobilization by cross-linking technique. The antimicrobial activity was tested by inhibition percent determination, and it evidenced both chitosan microspheres (CMS) and chitosan-lysozyme microspheres (C-LMS) positive antimicrobial activity to Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa.


Assuntos
Antibacterianos/farmacologia , Quitosana/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Muramidase/química , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Varredura Diferencial de Calorimetria , Quitosana/química , Emulsões , Enzimas Imobilizadas/química , Microscopia Eletrônica de Varredura , Microesferas , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície , Termogravimetria , Difração de Raios X
17.
Life Sci ; 282: 119806, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34252419

RESUMO

PURPOSE: Tuberculosis, a cost and life threatening disease, was being subjected for improving vaccine strategies beyond BCG. Thus, a novel particulate delivery system using alginate-coated chitosan nanoparticles including PPE17 protein and CpG were administered through intranasal (IN) and subcutaneous (SC) routes. METHODS: The encapsulated nanoparticles were first characterized for size, surface charge, encapsulation efficiency and in vitro release of PPE17 antigen. The nanoparticles were then administered intranasal and subcutaneously to evaluate the induction of systemic and/or mucosal immune responses in mice. RESULTS: According to our result, the mean size of nanoparticles was measured about 427 nm, and exhibited a negative zeta potential of -37 mV. Following subcutaneous and intranasal administration, the results from cytokines assay showed that an increasing in the level of IFN-γ, and adversely a decrease in the level of IL-4 (presumptive Th1 biased immune response) was happened and also a notable elicitation in IL-17 cytokine was observed. CONCLUSION: In conclusion, our study demonstrated that alginate-coated chitosan nanoparticles showed to be an effective way to improve BCG efficiency as booster strategy for subcutaneous vaccine, and also can induce strong immune responses as prime strategy through intranasal vaccination.


Assuntos
Antígenos de Bactérias , Portadores de Fármacos , Nanopartículas , Células Th1/imunologia , Vacinas contra a Tuberculose , Tuberculose/imunologia , Administração Intranasal , Alginatos/química , Alginatos/farmacologia , Animais , Antígenos de Bactérias/química , Antígenos de Bactérias/farmacologia , Quitosana/química , Quitosana/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Injeções Subcutâneas , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/química , Nanopartículas/uso terapêutico , Células Th1/patologia , Tuberculose/prevenção & controle , Vacinas contra a Tuberculose/química , Vacinas contra a Tuberculose/farmacologia
18.
Molecules ; 26(14)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34299652

RESUMO

Implantable medical devices (IMDs) are susceptible to microbial adhesion and biofilm formation, which lead to several clinical complications, including the occurrence of implant-associated infections. Polylactic acid (PLA) and its composites are currently used for the construction of IMDs. In addition, chitosan (CS) is a natural polymer that has been widely used in the medical field due to its antimicrobial and antibiofilm properties, which can be dependent on molecular weight (Mw). The present study aims to evaluate the performance of CS-based surfaces of different Mw to inhibit bacterial biofilm formation. For this purpose, CS-based surfaces were produced by dip-coating and the presence of CS and its derivatives onto PLA films, as well surface homogeneity were confirmed by contact angle measurements, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The antimicrobial activity of the functionalized surfaces was evaluated against single- and dual-species biofilms of Staphylococcus aureus and Pseudomonas aeruginosa. Chitosan-based surfaces were able to inhibit the development of single- and dual-species biofilms by reducing the number of total, viable, culturable, and viable but nonculturable cells up to 79%, 90%, 81%, and 96%, respectively, being their activity dependent on chitosan Mw. The effect of CS-based surfaces on the inhibition of biofilm formation was corroborated by biofilm structure analysis using confocal laser scanning microscopy (CLSM), which revealed a decrease in the biovolume and thickness of the biofilm formed on CS-based surfaces compared to PLA. Overall, these results support the potential of low Mw CS for coating polymeric devices such as IMDs where the two bacteria tested are common colonizers and reduce their biofilm formation.


Assuntos
Biofilmes/efeitos dos fármacos , Quitosana , Implantes Experimentais/microbiologia , Pseudomonas aeruginosa/fisiologia , Staphylococcus aureus/fisiologia , Biofilmes/crescimento & desenvolvimento , Quitosana/química , Quitosana/farmacologia , Propriedades de Superfície
19.
Int J Mol Sci ; 22(14)2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34299068

RESUMO

The biomedical and therapeutic importance of chitosan and chitosan derivatives is the subject of interdisciplinary research. In this analysis, we intended to consolidate some of the recent discoveries regarding the potential of chitosan and its derivatives to be used for biomedical and other purposes. Why chitosan? Because chitosan is a natural biopolymer that can be obtained from one of the most abundant polysaccharides in nature, which is chitin. Compared to other biopolymers, chitosan presents some advantages, such as accessibility, biocompatibility, biodegradability, and no toxicity, expressing significant antibacterial potential. In addition, through chemical processes, a high number of chitosan derivatives can be obtained with many possibilities for use. The presence of several types of functional groups in the structure of the polymer and the fact that it has cationic properties are determinant for the increased reactive properties of chitosan. We analyzed the intrinsic properties of chitosan in relation to its source: the molecular mass, the degree of deacetylation, and polymerization. We also studied the most important extrinsic factors responsible for different properties of chitosan, such as the type of bacteria on which chitosan is active. In addition, some chitosan derivatives obtained by functionalization and some complexes formed by chitosan with various metallic ions were studied. The present research can be extended in order to analyze many other factors than those mentioned. Further in this paper were discussed the most important factors that influence the antibacterial effect of chitosan and its derivatives. The aim was to demonstrate that the bactericidal effect of chitosan depends on a number of very complex factors, their knowledge being essential to explain the role of each of them for the bactericidal activity of this biopolymer.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Biopolímeros/química , Quitosana/química , Quitosana/farmacologia
20.
Carbohydr Polym ; 268: 118246, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34127225

RESUMO

The inferior tendon healing after surgery is inextricably linked to the surgical suture. Poor load transfer along the suture often results in a high tendon re-tear rate. Besides, the severe inflammation and infection induced by sutures even cause a second surgery. Herein, to alleviate the above-mentioned issues, a multifunctional suture was fabricated by decorating chitosan/gelatin-tannic acid (CS/GE-TA) on the porous tape suture. The porous tape suture ensured the required mechanical properties and sufficient space for tissue integration. Compared to the pristine suture, the CS/GE-TA decorated suture (TA100) presented a 332% increase in pull-out force from the tendon, indicating potentially decreased re-tear rates. Meanwhile, TA100 showed superior anti-inflammatory and antibacterial performances. In vivo experiments further proved that TA100 could not only reduce inflammatory action but also facilitate collagen deposition and blood vessel formation. These results indicate that the multifunctional sutures are promising candidates for accelerating tendon healing.


Assuntos
Antibacterianos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Inflamação/tratamento farmacológico , Suturas , Tendões/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Quitosana/química , Quitosana/farmacologia , Quitosana/uso terapêutico , Escherichia coli/efeitos dos fármacos , Gelatina/química , Gelatina/farmacologia , Gelatina/uso terapêutico , Indóis/química , Indóis/farmacologia , Indóis/uso terapêutico , Inflamação/patologia , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Polímeros/química , Polímeros/farmacologia , Polímeros/uso terapêutico , Porosidade , Células RAW 264.7 , Staphylococcus aureus/efeitos dos fármacos , Suínos , Taninos/química , Taninos/farmacologia , Taninos/uso terapêutico , Tendões/patologia , Resistência à Tração
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