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1.
Int J Mol Sci ; 22(4)2021 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-33672995

RESUMEN

Multidrug-resistant (MDR) bacteria constitute a global health issue. Over the past ten years, interest in nanoparticles, particularly metallic ones, has grown as potential antibacterial candidates. However, as there is no consensus about the procedure to characterize the metallic nanoparticles (MNPs; i.e., metallic aggregates) and evaluate their antibacterial activity, it is impossible to conclude about their real effectiveness as a new antibacterial agent. To give part of the answer to this question, 12 nm gold and silver nanoparticles have been prepared by a chemical approach. After their characterization by transmission electronic microscopy (TEM), Dynamic Light Scattering (DLS), and UltraViolet-visible (UV-vis) spectroscopy, their surface accessibility was tested through the catalytic reduction of the 4-nitrophenol, and their stability in bacterial culture medium was studied. Finally, the antibacterial activities of 12 nm gold and silver nanoparticles facing Staphylococcus aureus and Escherichia coli have been evaluated using the broth microdilution method. The results show that gold nanoparticles have a weak antibacterial activity (i.e., slight inhibition of bacterial growth) against the two bacteria tested. In contrast, silver nanoparticles have no activity on S. aureus but demonstrate a high antibacterial activity against Escherichia coli, with a minimum inhibitory concentration of 128 µmol/L. This high antibacterial activity is also maintained against two MDR-E. coli strains.


Asunto(s)
Antibacterianos/toxicidad , Escherichia coli/efectos de los fármacos , Oro/química , Nanopartículas del Metal/toxicidad , Plata/química , Staphylococcus aureus/efectos de los fármacos , Antibacterianos/química , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Dispersión Dinámica de Luz , Escherichia coli/crecimiento & desarrollo , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Pruebas de Sensibilidad Microbiana/métodos , Microscopía Electrónica de Transmisión , Espectrofotometría , Staphylococcus aureus/crecimiento & desarrollo
2.
Life Sci ; 273: 119306, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33662434

RESUMEN

AIMS: The present study aims to target the quorum sensing (QS) accessory gene regulator A (AgrA) of Staphylococcus aureus to curtail bacterial virulence through drug repurposing approach. MAIN METHODS: In silico screening of chemical ligands that bind specifically to the S. aureus C-LytTR domain of AgrA (AgrAC) was carried out. AgrA inhibition and downregulation of virulence genes linked to QS system of S. aureus were determined. Efficacy, dermal toxicity and drug tolerance induction were tested in Balb/C mice dermonecrosis model. KEY FINDINGS: Bumetanide bound to the conserved amino acid Tyr-229 of AgrA and showed 70% AgrA inhibition at 0.1 µM. Highly significant reduction in the expression of representative virulence genes such as alpha-hemolysin (~5 log2-fold), phenol-soluble modulins (~4 log2-fold) and panton-valentine leukocidin (~3 log2-fold) was noted in vitro. In vivo studies signified bumetanide to be highly effective in controlling the ulcer development and promoted wound healing. Also, the tested substance did not have dermal toxicity and no tolerance induction as well. SIGNIFICANCE: Targeting the QS regulators could be a possible alternative approach to curtail virulence in S. aureus. In addition, if the QS inhibitors are repurposed it could accelerate the drug development process and reduce the cost. The identified drug bumetanide inhibited AgrA and the results were in comparable to that of a known virulence inhibitor, diflunisal. The newly reported results of bumetanide in this study are expected to mark the drug's visibility for antibiotic adjunctive therapy and topical drug formulations for skin infections research.


Asunto(s)
Proteínas Bacterianas/antagonistas & inhibidores , Bumetanida/farmacología , Reposicionamiento de Medicamentos , Inhibidores del Simportador de Cloruro Sódico y Cloruro Potásico/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Transactivadores/antagonistas & inhibidores , Virulencia/efectos de los fármacos , Animales , Femenino , Ratones , Ratones Endogámicos BALB C , Percepción de Quorum , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/crecimiento & desarrollo
3.
Medicine (Baltimore) ; 100(13): e25285, 2021 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-33787613

RESUMEN

ABSTRACT: Surface treatment of medical devices may be a way of avoiding the need for replacement of these devices and the comorbidities associated with infection. The aim of this study was to evaluate whether pre- and postcontamination washing of 2 prostheses with different textures can decrease bacterial contamination.The following microorganisms were evaluated: Staphylococcus aureus, Staphylococcus epidermidis, Proteus mirabilis and Enterococcus faecalis. Silicone and expanded polytetrafluoroethylene vascular prostheses were used and divided into 3 groups: prostheses contaminated; prostheses contaminated and treated before contamination; and prostheses contaminated and treated after contamination. Treatments were performed with antibiotic solution, chlorhexidine and lidocaine. After one week of incubation, the prostheses were sown in culture medium, which was incubated for 48 hours. The area of colony formation was evaluated by fractal dimension, an image analysis tool.The antibiotic solution inhibited the growth of S epidermidis and chlorhexidine decrease in 53% the colonization density for S aureus in for both prostheses in the pre-washing. In postcontamination washing, the antibiotic solution inhibited the growth of all bacteria evaluated; there was a 60% decrease in the colonization density of S aureus and absence of colonization for E faecalis with chlorhexidine; and lidocaine inhibited the growth of S aureus in both prostheses.Antibiotic solution showed the highest efficiency in inhibiting bacterial growth, especially for S epidermidis, in both washings. Lidocaine was able to reduce colonization by S aureus in post-contamination washing, showing that it can be used as an alternative adjuvant treatment in these cases.


Asunto(s)
Prótesis Vascular/microbiología , Descontaminación/métodos , Desinfectantes/administración & dosificación , Infecciones Relacionadas con Prótesis/prevención & control , Antibacterianos/administración & dosificación , Recuento de Colonia Microbiana , Enterococcus faecalis/crecimiento & desarrollo , Humanos , Lidocaína/administración & dosificación , Politetrafluoroetileno , Diseño de Prótesis , Infecciones Relacionadas con Prótesis/microbiología , Proteus mirabilis/crecimiento & desarrollo , Siliconas , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus epidermidis/crecimiento & desarrollo
4.
Int J Food Microbiol ; 344: 109116, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33676332

RESUMEN

Staphylococcus aureus is among the most common zoonotic pathogens originating from animals consumed as food, especially raw chicken meat (RCM). As far as we know, this might be the first report that explores the efficacy of metal oxide nanoparticles (MONPs), such as zinc peroxide nanoparticles (ZnO2-NPs), zinc oxide nanoparticles (ZnO-NPs), and titanium dioxide nanoparticles (TiO2-NPs) against multidrug resistant (MDR) and/or pandrug resistant (PDR) S. aureus strains with a strong biofilm-producing ability isolated from RCM and giblets. The overall prevalence of coagulase-positive staphylococci was 21%, with a contamination level range between 102 and 104 CFU/g. The incidence of virulence genes See (21/36), pvl (16/36), clfA (15/36), sec (12/36), tst (12/36), and sea (11/36) among S. aureus strains were relatively higher those of seb, sed, fnbA, and fnbB. For antimicrobial resistance gene distribution, most strains harbored the blaZ gene (25/36), aacA-aphD gene (24/36), mecA gene (22/36), vanA gene (20/36), and apmA gene (20/36) confirmed the prevalence of MDR among S. aureus of RCM products. However, cfr (11/36), spc (9/36), and aadE (7/36) showed a relatively lower existence. The data of antibiogram resistance profiles was noticeably heterogeneous (25 patterns) with 32 MDR and four PDR S. aureus strains. All tested strains had a very high MAR index value (>0.2) except the P11 pattern (GEN, MXF, PMB), which showed a MAR index of 0.19. Among the strong biofilm-producing ability (BPA), 14 (70%) strains were isolated from wet markets, while only six strong BPA strains were isolated from supermarkets. The mean values of BPA ranged from 2.613 ± 0.04 to 11.013 ± 0.05. Clearly, ZnO2-NPs show significant inhibitory activity against S. aureus strains compared with those produced by the action of ZnO-NPs and TiO2-NPs. The results of anti-inflammatory activity suggest ZnO2-NPs as a lead compound for designing an alternative antimicrobial agent against drug-resistant and strong biofilm-producing S. aureus isolates from retail RCM and giblets.


Asunto(s)
Antibacterianos/farmacología , Contaminación de Alimentos/prevención & control , Staphylococcus aureus/crecimiento & desarrollo , Titanio/farmacología , Óxido de Zinc/farmacología , Animales , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Pollos/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Carne/microbiología , Nanopartículas del Metal , Pruebas de Sensibilidad Microbiana , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/prevención & control , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/aislamiento & purificación , Virulencia/genética
5.
Nat Commun ; 12(1): 1887, 2021 03 25.
Artículo en Inglés | MEDLINE | ID: mdl-33767207

RESUMEN

Coagulase-negative staphylococci and Staphylococcus aureus colonize similar niches in mammals and conceivably compete for space and nutrients. Here, we report that a coagulase-negative staphylococcus, Staphylococcus chromogenes ATCC43764, synthesizes and secretes 6-thioguanine (6-TG), a purine analog that suppresses S. aureus growth by inhibiting de novo purine biosynthesis. We identify a 6-TG biosynthetic gene cluster in S. chromogenes and other coagulase-negative staphylococci including S. epidermidis, S. pseudintermedius and S. capitis. Recombinant S. aureus strains harbouring this operon produce 6-TG and, when used in subcutaneous co-infections in mice with virulent S. aureus USA300, protect the host from necrotic lesion formation. Used prophylactically, 6-TG reduces necrotic skin lesions in mice infected with USA300, and this effect is mediated by abrogation of toxin production. RNAseq analyses reveal that 6-TG downregulates expression of genes coding for purine biosynthesis, the accessory gene regulator (agr) and ribosomal proteins in S. aureus, providing an explanation for its effect on toxin production.


Asunto(s)
Infecciones Cutáneas Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus/genética , Staphylococcus/metabolismo , Tioguanina/metabolismo , Animales , Proteínas Bacterianas/biosíntesis , Coagulasa/deficiencia , Femenino , Ratones , Ratones Endogámicos BALB C , Purinas/biosíntesis , Proteínas Ribosómicas/biosíntesis , Staphylococcus aureus/patogenicidad , Staphylococcus capitis/metabolismo , Staphylococcus epidermidis/metabolismo , Tioguanina/farmacología , Transactivadores/biosíntesis
6.
Carbohydr Polym ; 255: 117337, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33436180

RESUMEN

Pathogens in the food and environment pose a great threat to human health. To solve this problem, we described a novel route to synthesize antibacterial epsilon-poly-L-lysine (EPL) anchored dicarboxyl cellulose beads. Cellulose beads were prepared via a sol-gel transition method and oxidized by sodium periodate and sodium chlorite to form carboxyl groups. EPL was anchored on the beads using carbodiimide mediated amidation. The structure and morphology of beads were characterized by FTIR, XPS, XRD, SEM, and TGA. After dissolution and regeneration, the crystalline form of cellulose is transformed from cellulose I to cellulose II. The thermal degradation temperature of the beads is 200∼300 °C.The samples displayed excellent antimicrobial activity against Staphylococcus aureus, Alicyclobacillus acidoterrestris and Escherichia coli within 12 h. The beads could be biodegraded in soil after 20 days. The biodegradable beads exhibited great potential in food and environmental applications.


Asunto(s)
Alicyclobacillus/efectos de los fármacos , Antibacterianos/farmacología , Celulosa/farmacología , Escherichia coli/efectos de los fármacos , Polilisina/química , Staphylococcus aureus/efectos de los fármacos , Alicyclobacillus/crecimiento & desarrollo , Antibacterianos/síntesis química , Biodegradación Ambiental , Carbodiimidas/química , Celulosa/análogos & derivados , Cloruros/química , Escherichia coli/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Oxidación-Reducción , Ácido Peryódico/química , Transición de Fase , Staphylococcus aureus/crecimiento & desarrollo
7.
Carbohydr Polym ; 255: 117484, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33436244

RESUMEN

Wound dressing composed of chitosan, based crosslinked gelatin/ polyvinyl pyrrolidone, embedded silver nanoparticles were fabricated using solution casting method. The membrane was characterized by FTIR, SEM and TGA. Glutaraldehyde (0.5 %) was used for the crosslinking of membrane components and associated with 7-folds boosted mechanical performance, 28 % more hydrolytic stability, 3-folds thickness reduction and morphological roughness. Silver nanoparticles were characterized by UV-vis, XRD and TEM for an average size of 9.9 nm. The membrane with higher concentration of silver nanoparticles showed maximum antibacterial activity against human pathogenic bacteria; and the measured inhibition zones ranged from 1.5 to 3 cm. The activity of the particles ranged from severe to complete reduction in Penicillin, Erythromycin and Macrolide family's resistance genes expression such as ß-Lactamase, mecA and erm. This developed membrane can serve as promising and cost-effective system against severe diabetic and burn wound infections.


Asunto(s)
Antibacterianos/farmacología , Vendajes , Quitosano/química , Citrullus colocynthis/química , Gelatina/química , Povidona/química , Plata/farmacología , Bacillus subtilis/efectos de los fármacos , Bacillus subtilis/crecimiento & desarrollo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple/genética , Eritromicina/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Humanos , Macrólidos/farmacología , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Metiltransferasas/genética , Metiltransferasas/metabolismo , Pruebas de Sensibilidad Microbiana , Proteínas de Unión a las Penicilinas/genética , Proteínas de Unión a las Penicilinas/metabolismo , Penicilinas/farmacología , Cultivo Primario de Células , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/crecimiento & desarrollo , Salmonella typhi/efectos de los fármacos , Salmonella typhi/crecimiento & desarrollo , Plata/química , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , beta-Lactamasas/genética , beta-Lactamasas/metabolismo
8.
Carbohydr Polym ; 255: 117488, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33436248

RESUMEN

A novel pH-sensitive colorimetric film was prepared based on immobilizing red barberry anthocyanins (RBAs) within composite chitin nanofiber (CNF) and methylcellulose (MC) matrices. The incorporation of CNFs and RBAs improved their mechanical properties, moisture resistance, and UV-vis screening properties. Moreover, the RBAs could be used as colorimetric indicators to detect food spoilage because they are sensitive to changes in pH and ammonia gas production. The RBA-halochromic indicator changed from reddish/crimson → pink → yellow with increasing pH, and from pink → yellow with increasing ammonia vapor concentration. Furthermore, the smart films possessed good antioxidant and antimicrobial activity owing to the presence of the RBAs and CNFs. Finally, the validity of the indicator to monitor the freshness/spoilage of a model food (fish) was demonstrated. Overall, this study shows that active/smart films can be assembled from food grade ingredients that can protect and monitor the freshness of products, like meat and fish.


Asunto(s)
Antocianinas/química , Antiinfecciosos/química , Antioxidantes/química , Berberis/química , Quitina/química , Embalaje de Alimentos/métodos , Materiales inteligentes/química , Amoníaco/análisis , Amoníaco/química , Antiinfecciosos/farmacología , Antioxidantes/farmacología , Biodegradación Ambiental , Compuestos de Bifenilo/antagonistas & inhibidores , Color , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Productos Pesqueros/análisis , Frutas/química , Humanos , Concentración de Iones de Hidrógeno , Membranas Artificiales , Metilcelulosa/química , Nanofibras/química , Nanofibras/ultraestructura , Picratos/antagonistas & inhibidores , Extractos Vegetales/química , Materiales inteligentes/farmacología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Resistencia a la Tracción
9.
J Agric Food Chem ; 69(3): 1068-1078, 2021 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-33448221

RESUMEN

Nowadays, films with antibacterial activity and applied for freshness monitoring by colorimetric response have been drawing growing attention in food packaging. However, the development of versatile antibacterial and colorimetric agents is still highly desirable. Herein, WO3 nanorods are incorporated in a polyvinyl alcohol (PVA) matrix to develop a novel composite film with photothermal antibacterial activity and freshness monitoring faculty. The interaction between WO3 nanorods and PVA is due to hydrogen bonds. Compared with the PVA film, the presence of WO3 nanorods can significantly enhance the mechanical and barrier properties; typically, the target film (WO3/PVA)4 shows an increase in tensile strength by 52.7% and Young's modulus by 400.0% and a decrease in oxygen permeability by 72.4% and water vapor permeability by 66.9%. The films demonstrate a WO3 content-dependent antibacterial activity. Under irradiation of near-infrared light (NIR808), the synergistic effect of physical damage, oxidative stress, and temperature increase markedly improves the antibacterial activity of (WO3/PVA)4, showing an antibacterial efficiency of ∼90% against Escherichia coli or beyond 90% against Staphylococcus aureus. The incorporated WO3 nanorods demonstrate lower cytotoxicity toward the model cells of human colon cancer cell line HT-29. The (WO3/PVA)4 film exhibits colorimetric response to H2S and can also be used for pork freshness monitoring as an indicator.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Embalaje de Alimentos/instrumentación , Óxidos/química , Alcohol Polivinílico/química , Tungsteno/química , Antibacterianos/síntesis química , Antibacterianos/efectos de la radiación , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Enlace de Hidrógeno , Rayos Infrarrojos , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Resistencia a la Tracción
10.
Int J Biol Macromol ; 172: 350-359, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33453258

RESUMEN

The improper management of wound exudates can expose the wound to bacterial invasion, skin maceration etc. thereby resulting in prolonged wound healing. Biopolymers are characterized by hydrophilic functional groups which when employed for the development of wound dressings promote the wound dressings capability to absorb a high amount of wound exudates. Alginate-gum acacia sponges were prepared from a combination of biopolymers such as sodium alginate and gum acacia in varying amounts with carbopol via crosslinking with 1 and 2% CaCl2. The prepared sponges were loaded with a combination of ampicillin and norfloxacin. In vitro antibacterial analysis revealed that the antibacterial activity of the loaded antibiotics was retained and the sponges were effective against gram-positive and gram-negative bacteria. The sponges displayed rapid and high absorption capability in the range of 1022-2419% at pH 5.5 simulating wound exudates, and 2268-5042% at pH 7.4 simulating blood within a period of 1-3 h. Furthermore, the whole blood clotting studies further revealed low absorbance values when compared to the control revealing the good clotting capability of the sponges. The unique features of the sponges revealed their potential application for the management of infected, high exuding and bleeding wounds.


Asunto(s)
Resinas Acrílicas/química , Alginatos/química , Antibacterianos/farmacología , Vendajes , Cloruro de Calcio/química , Goma Arábiga/química , Ampicilina/química , Ampicilina/farmacología , Antibacterianos/química , Coagulación Sanguínea/efectos de los fármacos , Liofilización/métodos , Humanos , Pruebas de Sensibilidad Microbiana , Norfloxacino/química , Norfloxacino/farmacología , Porosidad , Proteus vulgaris/efectos de los fármacos , Proteus vulgaris/crecimiento & desarrollo , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/crecimiento & desarrollo
11.
Int J Biol Macromol ; 172: 515-523, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33476614

RESUMEN

A pH-sensitive food packaging film was prepared based on konjac glucomannan (KGM) and hydroxypropyl methyl cellulose (HPMC) incorporated with mulberry extracts2 (MBE). FT-IR and XRD analysis revealed that there are good molecular interactions among the three components. The incorporation of MBE into KGM and HPMC (KH) films can significantly improve the mechanical properties and UV resistance. Notably, the KH-MBE-20% film almost completely blocked UV light in the range of 200-600 nm. The best antioxidant and antibacterial properties were obtained when the addition of MBE in the composite film was 20%. In addition, KH-MBE film has good responsiveness to buffers with pH range from 2 to 12. In visual monitoring experiments using the film on fresh fish, the color of the KH-MBE film changed from purple to gray to yellow as the freshness of the fish decreased, and the KH-MBE-20% film had the best color stability. Therefore, intelligent packaging of KH-MBE film has potential applications in real-time monitoring of fish freshness.


Asunto(s)
Antibacterianos/química , Antioxidantes/química , Derivados de la Hipromelosa/química , Mananos/química , Morus/química , Protectores Solares/química , Antibacterianos/farmacología , Antioxidantes/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Productos Pesqueros/análisis , Embalaje de Alimentos/métodos , Frutas/química , Humanos , Concentración de Iones de Hidrógeno , Derivados de la Hipromelosa/farmacología , Mananos/farmacología , Membranas Artificiales , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/química , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Protectores Solares/farmacología , Rayos Ultravioleta
12.
Int J Biol Macromol ; 173: 99-108, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33460660

RESUMEN

The present investigation reports an in-vitro study using combination of laccase and an enhancer capable of inhibiting the growth of pathogenic microorganisms, preventing biofilm formation, and whitening teeth. Laccase-cinnamic acid system remarkably inhibited the growth of Aggregatibacter actinomycetemcomitans, Candida albicans, S. aureus, and Streptococcus mutans whilst showed no significant effects on Gram-negative bacteria. Data presented that cinnamic acid (10 mM) with laccase (0.125 U ml-1) led to a maximum decrease of about 90%, in S. mutans biofilm formation. The confocal laser scanning microscopy showed considerable detachment of S. mutans cells from glass substratum. The combined laccase-cinnamic acid system could remove teeth discoloration caused by coffee. SEM of the teeth surface exhibited no damages such as surface cracking or fracture. Liquid chromatography-tandem mass spectrometry (LC-MS) and cyclic voltammetry (CV) studies showed that laccase can catalyze the one-electron oxidation of cinnamic acid to the respective radical. This radical can then undergo several fates, including recombination with another radical to form a dimeric species, dismutation of the radical back to cinnamic acid or decarboxylation to give various reduced oxygen species. Therefore, the redox potential values of phenolic monomers/oligomers are related with their biological activities.


Asunto(s)
Aggregatibacter actinomycetemcomitans/efectos de los fármacos , Antibacterianos/farmacología , Cinamatos/farmacología , Proteínas Fúngicas/farmacología , Lacasa/farmacología , Aggregatibacter actinomycetemcomitans/crecimiento & desarrollo , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Ácidos Cafeicos/farmacología , Candida albicans/efectos de los fármacos , Candida albicans/crecimiento & desarrollo , Catecoles/farmacología , Sinergismo Farmacológico , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Proteínas Fúngicas/aislamiento & purificación , Ácido Gálico/farmacología , Hidroquinonas/farmacología , Lacasa/aislamiento & purificación , Lactobacillus/efectos de los fármacos , Lactobacillus/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Oxidación-Reducción , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/crecimiento & desarrollo , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Streptococcus mutans/efectos de los fármacos , Streptococcus mutans/crecimiento & desarrollo , Blanqueadores Dentales/farmacología
13.
Int J Biol Macromol ; 173: 203-210, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33484799

RESUMEN

Nonwoven fabrics containing silver nanoparticles (AgNPs) are widely utilized to assist management of infected wounds and those at risk of infection. However, such materials have varied responses due to their chemical nature. Herein we investigated the correlation between the concentration of AgNPs taken up by nonwoven viscose material and antibacterial activity in a simulated wound fluid model against two bacterial models (i.e., Escherichia coli and Staphylococcus aureus). Thereafter, the developed nonwoven viscose containing AgNPs were independently coated with two polyacid carbohydrate polymers (i.e., carboxymethyl chitosan (CMCs), alginate (ALG)), and gelatin (GEL) protein in order to study their influence on the physical and biological attributes in vitro and in vivo. Intensive characterizations were utilized to monitor the physicochemical features of the developed nonwoven viscose. The results demonstrated that higher concentrations of AgNPs were taken up by viscose fabric whilewhile increasing AgNPs in the colloidal solution during padding process. Overall, the treated nonwoven fabric with and without polymers' coatings showed remarkable antibacterial activity against two bacterial models in vitro. As well as they achieved high and speed wound recovery in rats which was almost similar to commercial dermazin treatment. Therefore, it validates excellent nonwoven dressing clinically relevant to the wound type and condition.


Asunto(s)
Quemaduras Químicas/tratamiento farmacológico , Infecciones por Escherichia coli/tratamiento farmacológico , Nanopartículas del Metal/química , Plata/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , Cicatrización de Heridas/efectos de los fármacos , Alginatos/química , Animales , Antibacterianos/química , Antibacterianos/farmacología , Vendajes , Quemaduras Químicas/microbiología , Carboximetilcelulosa de Sodio/química , Quitosano/análogos & derivados , Quitosano/química , Preparaciones de Acción Retardada/química , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Infecciones por Escherichia coli/microbiología , Gelatina/química , Nanopartículas del Metal/ultraestructura , Ratas , Plata/química , Piel/efectos de los fármacos , Piel/microbiología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Cicatrización de Heridas/fisiología
14.
Int J Biol Macromol ; 171: 158-165, 2021 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-33418040

RESUMEN

Superhydrophobic cotton fabrics were fabricated using chitosan/titanium dioxide (TiO2) nanocomposites. Morphology results revealed that the fabric's surface was utterly coated by the nanoparticles leading to the formation of a highly packed nano-scale structure in the case of superhydrophobic coating. X-ray photoelectron spectroscopy results also proved that TiO2 nanoparticles were highly adsorbed onto the fabric's top layer. Durability of the superhydrophobic coating was investigated by immersing the fabric into harsh solutions and also by subjecting the fabric to sonication. The results showed the high resistance of the superhydrophobic fabric against harsh conditions. The nanocomposite-coated fabrics were found to exhibit promising UV-protecting properties especially for the superhydrophobic fabric which showed around 80% enhancement in the UV protecting properties as compared with the uncoated fabric. The bacterial adhesion results revealed that the combination of chitosan and TiO2 results in high antibacterial properties against E. coli and S. aureus bacteria. The bacterial reduction percentages were further increased to 99.8 and 97.3% against E. coli and S. aureus, respectively, once the superhydrophobic character was also induced to the fabrics. The developed nanocomposite coated fabrics exhibited promising potential to be used as antibacterial and self-cleaning garments in hospital-related applications.


Asunto(s)
Antibacterianos/farmacología , Quitosano/farmacología , Nanocompuestos/química , Nanopartículas/química , Protectores Solares/farmacología , Titanio/farmacología , Antibacterianos/química , Quitosano/química , Fibra de Algodón/análisis , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Pruebas de Sensibilidad Microbiana , Nanocompuestos/ultraestructura , Nanopartículas/ultraestructura , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Protectores Solares/química , Textiles/análisis , Titanio/química
15.
Carbohydr Polym ; 256: 117524, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33483045

RESUMEN

Curdlan hydrogel obtained after thermal gelling exhibits elasticity and high water-absorbing capacity. However, its modifications leading to the increase of biofunctionality usually alter its solubility and reduce mechanical parameters. Therefore, curdlan hydrogel was modified by deposition of polydopamine to improve its capacity to bind biologically active molecules with free amino groups. It exhibited the unchanged structure, mechanical properties and increased soaking capacity. Aminoglycoside antibiotic (gentamicin) as a model molecule was effectively immobilized to such modified curdlan via quinone moiety (but not amino groups) of polydopamine. Approximately 50 % of the immobilized drug was released following Fickian diffusion and inhibited the bacterial growth in matrix-surrounding medium in prolonged manner. The remaining drug amount was stably attached and prevented the hydrogel against bacterial adhesion even when all the mobile drug has been released. Therefore, polydopamine-modified curdlan hydrogel shows the potential for fabrication of functional materials for different purposes, including drug-loaded biomaterials.


Asunto(s)
Antibacterianos/metabolismo , Materiales Biocompatibles Revestidos/síntesis química , Gentamicinas/metabolismo , Hidrogeles/síntesis química , Indoles/química , Polímeros/química , beta-Glucanos/química , Antibacterianos/farmacología , Adhesión Bacteriana/efectos de los fármacos , Materiales Biocompatibles Revestidos/farmacología , Portadores de Fármacos , Composición de Medicamentos/métodos , Liberación de Fármacos , Elasticidad , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Gentamicinas/farmacología , Humanos , Hidrogeles/farmacología , Cinética , Pruebas de Sensibilidad Microbiana , Solubilidad , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/crecimiento & desarrollo , Humectabilidad
16.
Carbohydr Polym ; 251: 117131, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33142662

RESUMEN

Bacterial cellulose (BC) is used in various fields for its unique physical properties, but does not have the antimicrobial properties needed for the food and biomedical industries. Co-culture fermentation is a method commonly used in biotechnology to address high costs. A nisin-containing BC film (BC-N) was obtained by co-cultivating the BC-producing strain Enterobacter sp. FY-07 with the nisin-producing strain Lactococcus lactis N8. The physical properties of BC-N were similar those of BC, but the BC-N film had a specific strong inhibitory effect on Gram-positive bacteria. The antibacterial mechanism of BC-N was pore formation, but the obtained BC-N film had no significant impact on mammalian cell viability. This study provides a low-cost, facile and efficient technique to confer BC with antimicrobial properties. This strategy can be applied to introduce other functions into BC, and develop applications for BC polymers.


Asunto(s)
Antibacterianos/farmacología , Celulosa/química , Técnicas de Cocultivo/métodos , Enterobacter/metabolismo , Lactococcus lactis/metabolismo , Nanoestructuras/química , Nisina/farmacología , Antibacterianos/química , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Nanoestructuras/administración & dosificación , Nisina/química , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo
17.
Carbohydr Polym ; 254: 117433, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33357906

RESUMEN

Driven by the need to find alternatives to control Staphylococcus aureus infections, this work describes the development of chitosan-based particulate systems as carriers for antimicrobial glycolipids. By using a simple ionic gelation method stable nanoparticles were obtained showing an encapsulation efficiency of 41.1 ± 8.8 % and 74.2 ± 1.3 % and an average size of 210.0 ± 15.7 nm and 329.6 ± 8.0 nm for sophorolipids and rhamnolipids chitosan-nanoparticles, respectively. Glycolipids incorporation and particle size was correspondingly corroborated by FTIR-ATR and TEM analysis. Rhamnolipids chitosan nanoparticles (RLs-CSp) presented the highest antimicrobial effect towards S. aureus (ATCC 25923) exhibiting a minimal inhibitory concentration of 130 µg/mL and a biofilm inhibition ability of 99 %. Additionally, RLs-CSp did not interfere with human dermal fibroblasts (AG22719) viability and proliferation under the tested conditions. The results revealed that the RLs-CSp were able to inhibit bacterial growth showing adequate cytocompatibility and might become, after additional studies, a valuable approach to prevent S. aureus related infections.


Asunto(s)
Antibacterianos/química , Quitosano/química , Portadores de Fármacos , Glucolípidos/química , Ácidos Oléicos/química , Staphylococcus aureus/efectos de los fármacos , Tensoactivos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Ciclo Celular/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Glucolípidos/aislamiento & purificación , Glucolípidos/farmacología , Humanos , Pruebas de Sensibilidad Microbiana , Nanopartículas/química , Nanopartículas/ultraestructura , Ácidos Oléicos/aislamiento & purificación , Ácidos Oléicos/farmacología , Tamaño de la Partícula , Staphylococcus aureus/crecimiento & desarrollo , Tensoactivos/aislamiento & purificación , Tensoactivos/farmacología
18.
Carbohydr Polym ; 254: 117464, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33357923

RESUMEN

The fabrication of polymeric composite hydrogel with hierarchical structure in a simple, controllable, and straightforward process poses great importance for manufacturing nanomaterials and subsequent applications. Herein, we report a one-step and template-free counterion exchange method to construct free-standing carboxylated cellulose nanofiber composite hydrogels. Metal ions were electrochemically and locally released from the electrode and chelated with carboxylated cellulose nanofibers, leading to the in-situ formation of composite hydrogels. The properties of composite hydrogels can be easily programmed by the type of electrode, current density, and electrodeposited suspension. Significantly, the composited hydrogels exhibited interconnected nanoporous structure, enhanced thermal degradation, improved mechanical strength and antibacterial activity. The results suggest great potential of anodic electrodeposition to fabricate nanofiber/metal composite hydrogels.


Asunto(s)
Antibacterianos/química , Celulosa/análogos & derivados , Técnicas Electroquímicas , Nanofibras/química , Phaeophyta/química , Antibacterianos/farmacología , Cationes Bivalentes , Cationes Monovalentes , Celulosa/ultraestructura , Cobre/química , Cobre/farmacología , Electrodos , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Hidrogeles , Hierro/química , Hierro/farmacología , Pruebas de Sensibilidad Microbiana , Nanofibras/ultraestructura , Plata/química , Plata/farmacología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Resistencia a la Tracción , Residuos
19.
Carbohydr Polym ; 254: 117465, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33357924

RESUMEN

Designing multifunctional surfaces is key to develop advanced materials for orthopedic applications. In this study, we design a double-layer coating, assembled onto the completely regular titania nanotubes (cRTNT) array. Benefiting from the biological and topological characteristics of chitosan nanofibers (CH) and reduced graphene oxide (RGO) through a unique assembly, the designed material features promoted osteoblast cell viability, prolonged antibiotic release profile, as well as inhibited bacterial biofilm formation. The synergistic effect of RGO and CH on the biological performance of the surface is investigatSed. The unique morphology of the nanofibers leads to the partial coverage of RGO-modified nanotubes, providing an opportunity to access the sublayer properties. Another merit of this coating lies in its morphological similarity to the extracellular matrix (ECM) to boost cellular performance. According to the results of this study, this platform holds promising advantages over the bare and bulk biopolymer-modified TNTs.


Asunto(s)
Quitosano/síntesis química , Materiales Biocompatibles Revestidos/química , Grafito/química , Nanocompuestos/química , Osteoblastos/efectos de los fármacos , Titanio/química , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Adhesión Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Materiales Biocompatibles Revestidos/farmacología , Portadores de Fármacos , Liberación de Fármacos , Humanos , Cinética , Nanocompuestos/ultraestructura , Nanotubos/química , Nanotubos/ultraestructura , Osteoblastos/citología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Vancomicina/farmacología
20.
Carbohydr Polym ; 251: 117058, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33142610

RESUMEN

Silk fibroin (SF) is increasingly needed in tissue engineering for its superior biocompatibility. However, the practical applications of pure SF biomaterials confront bacterial infection problems. In this study, chitosan (CS) and polydopamine (PDA) were introduced into electrospun nanofibrous SF mats through layer-by-layer self-assembly (LBL) to obtain enhanced antibacterial ability and cytocompatibility. The surface morphology and composition analysis confirmed the successful deposition. After depositing 15 bilayers, the tensile modulus of the mats in wet condition increased from 2.16 MPa (pristine SF mats) to 4.89 MPa. A trend towards better hydrophilicity performance was also recorded with more bilayers coating on the mats. Besides, LBL structured mats showed improved antibacterial ability of more than 98 % against E. coli and S. aureus. In addition, advancement in biocompatibility was observed during the proliferation experiment of L929 cells. Overall, the deposition of CS and PDA may further expand the use of SF in biomedical field.


Asunto(s)
Quitosano/química , Fibroínas/química , Indoles/química , Nanofibras/química , Polímeros/química , Animales , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Supervivencia Celular/efectos de los fármacos , Quitosano/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroínas/farmacología , Interacciones Hidrofóbicas e Hidrofílicas , Indoles/farmacología , Ratones , Polímeros/farmacología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Ingeniería de Tejidos/métodos
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