RESUMO
Owing to its antimicrobial activity, electrochemically activated water (ECAW) is a potential alternative to chemical disinfectants for eliminating foodborne pathogens, including Salmonella Heidelberg, from food processing facilities. However, their antibiofilm activity remains unclear. This study aimed to evaluate the antibiofilm activity of ECAW against S. Heidelberg biofilms formed on stainless steel and polyethylene and to determine its corrosive capacity. ECAW (200 ppm) and a broad-spectrum disinfectant (0.2%) were tested for their antibiofilm activity against S. Heidelberg at 25 °C and 37 °C after 10 and 20 min of contact with stainless steel and polyethylene. Potentiostatic polarization tests were performed to compare the corrosive capacity of both compounds. Both compounds were effective in removing S. Heidelberg biofilms. Bacterial counts were significantly lower with ECAW than with disinfectant in polyethylene, regardless the time of contact. The time of contact and the surface significantly influenced the bacterial counts of S. Heidelberg. Temperature was not an important factor affecting the antibiofilm activities of the compounds. ECAW was less corrosive than the disinfectant. ECAW demonstrated a similar or even superior effect in the control of S. Heidelberg biofilms, when compared to disinfectants, reducing bacterial counts by up to 5 log10 CFU cm-2. The corrosion of stainless steel with ECAW was similar to that of commercial disinfectants. This technology is a possible alternative for controlling S. Heidelberg in the food production chain.
Assuntos
Cáusticos , Desinfetantes , Aço Inoxidável , Cáusticos/farmacologia , Biofilmes , Salmonella , Desinfetantes/farmacologia , Polietilenos/farmacologia , Microbiologia de AlimentosRESUMO
AIM: Natural substances such as omega-3 have been used in the medical field due to their numerous properties and, in particular, modulating effect on the systemic and local inflammatory processes. Thus, this study evaluated the influence of omega-3 supplementation on the subcutaneous tissue response of endodontic sealers in Wistar Rats. METHODOLOGY: Polyethylene tubes were implanted in the subcutaneous tissue of 48 animals (one empty for control and three filled with Sealapex, AH Plus or Endofill). The animals were treated with omega-3 (TO) or water (TW). Treatments started 15 days before implantation until euthanasia. After 5, 15 and 30 days (n = 8), animals were euthanized and polyethylene tubes and surrounding tissue were removed and processed for histological analysis. The inflammatory reaction was analysed by Haematoxylin and Eosin stain and immunolabelling for IL-6 and TNF-α. The collagen maturity was analysed by picrosirius red stain and calcium deposition by von Kossa stain and polarized light. Results were statistically analysed (p < .05). RESULTS: Amongst TW sealer groups, Endofill evoked a more intense inflammatory infiltrate compared with AH Plus and control in the 30-day period (p = .009). However, in TO sealer groups, there was no difference amongst the sealers and control in all periods (p > .05). Comparing each sealer as a function of the supplementation with water or omega-3, there are differences for Endofill (p = .001) and Sealapex (p = .005) in the 30-day period, presenting lower inflammatory infiltrate in the animals treated with omega-3. A higher percentage of immature fibres was observed at 15 and 30 days in the TO group, compared with the TW group (p < .05). The deposition of calcium particles was observed only by Sealapex in all periods, despite the supplementation procedure. CONCLUSIONS: Omega-3 supplementation influence the tissue reactions of endodontic sealers, modulating inflammation, the immunolabelling of IL-6 and TNF-α, the repair process and it does not interfere with calcium deposition.
Assuntos
Materiais Restauradores do Canal Radicular , Tela Subcutânea , Animais , Cálcio , Suplementos Nutricionais , Resinas Epóxi , Inflamação , Interleucina-6/farmacologia , Teste de Materiais , Polietilenos/farmacologia , Ratos , Ratos Wistar , Materiais Restauradores do Canal Radicular/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , ÁguaRESUMO
INTRODUCTION: Acrylic resins are used in the preparation of facial prostheses and may be colonized by fungi. Here, we verified the antifungal efficacy of this material after surface treatment using poly (diallyldimethylammonium chloride). METHODS: Acrylic resin specimens with and without surface treatment were subjected to tests for fungistatic and fungicidal activities. Standard strains of Candida albicans and Aspergillus niger were used. RESULTS: After surface treatment, the fungistatic and fungicidal efficacies of the resins against C. albicans and fungistatic action against A. niger were verified. CONCLUSIONS: The surface treatment was a determinant of the antifungal activity of the material.
Assuntos
Resinas Acrílicas/química , Antifúngicos/farmacologia , Aspergillus niger/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Polietilenos/farmacologia , Compostos de Amônio Quaternário/farmacologia , Temperatura , Materiais Dentários , Teste de Materiais , Testes de Sensibilidade MicrobianaRESUMO
Abstract INTRODUCTION: Acrylic resins are used in the preparation of facial prostheses and may be colonized by fungi. Here, we verified the antifungal efficacy of this material after surface treatment using poly (diallyldimethylammonium chloride). METHODS: Acrylic resin specimens with and without surface treatment were subjected to tests for fungistatic and fungicidal activities. Standard strains of Candida albicans and Aspergillus niger were used. RESULTS: After surface treatment, the fungistatic and fungicidal efficacies of the resins against C. albicans and fungistatic action against A. niger were verified. CONCLUSIONS: The surface treatment was a determinant of the antifungal activity of the material.
Assuntos
Polietilenos/farmacologia , Aspergillus niger/efeitos dos fármacos , Temperatura , Resinas Acrílicas/química , Candida albicans/efeitos dos fármacos , Compostos de Amônio Quaternário/farmacologia , Antifúngicos/farmacologia , Teste de Materiais , Testes de Sensibilidade Microbiana , Materiais DentáriosRESUMO
Hybrid nanoparticles of poly(methylmethacrylate) synthesized in the presence of poly (diallyldimethyl ammonium) chloride by emulsion polymerization exhibited good colloidal stability, physical properties, and antimicrobial activity but their synthesis yielded poor conversion. Here we create antimicrobial coatings from casting and drying of the nanoparticles dispersions onto model surfaces such as those of silicon wafers, glass coverslips, or polystyrene sheets and optimize conversion using additional stabilizers such as cetyltrimethyl ammonium bromide, dioctadecyldimethyl ammonium bromide, or soybean lecithin during nanoparticles synthesis. Methodology included dynamic light scattering, determination of wettability, ellipsometry of spin-coated films, scanning electron microscopy, and determination of colony forming unities (log CFU/mL) of bacteria after 1 h interaction with the coatings. The additional lipids and surfactants indeed improved nanoparticle synthesis, substantially increasing the conversion rates by stabilizing the monomer droplets in dispersion during the polymerization. The coatings obtained by spin-coating or casting of the nanoparticles dispersions onto silicon wafers were hydrophilic with contact angles increasing with the amount of the cationic polymer in the nanoparticles. Against Escherichia coli and Staphylococcus aureus, bacteria cell counts were reduced by approximately 7 logs upon interaction with the coatings, revealing their potential for several biotechnological and biomedical applications.
Assuntos
Antibacterianos/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Nanopartículas/química , Polímeros/farmacologia , Coloides , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanopartículas/ultraestrutura , Polietilenos/farmacologia , Polimetil Metacrilato/farmacologia , Compostos de Amônio Quaternário/farmacologia , Solventes , Staphylococcus aureus/efeitos dos fármacos , Tensoativos/farmacologiaRESUMO
Topical nitric oxide (NO) delivery has been shown to accelerate wound healing. However, delivering NO to wounds at appropriate rates and doses requires new biomaterial-based strategies. Here, we describe the development of supramolecular interpolymer complex hydrogels comprising PEO-PPO-PEO (F127) micelles embedded in a poly(acrylic acid) (PAA) matrix, with S-nitrosoglutathione (GSNO) molecules dissolved in the hydrophilic domain. We show that PAA:F127/GSNO hydrogels start releasing NO upon hydration at rates controlled by their rates of water absorption. SAXS measurements indicate that the supramolecular structure of the hydrogels retains long-range order domains of F127 micelles. The PAA/F1227 hydrogels displayed dense morphologies and reduced rates of hydration. The NO release rates remain constant over the first 200â¯min, are directly correlated with the hydration rates of the PAA:F127/GSNO hydrogels, and can be modulated in the range of 40â¯nmol/gâ¯h to 1.5⯵mol/gâ¯h by changing the PAA:F127 mass ratio. Long-term NO-release profiles over 5â¯days are governed by the first-order exponential decay of GSNO, with half-lives in the range of 0.5-3.4â¯days. A preliminary in vivo study on full-thickness excisional wounds in mice showed that topical NO release from the PAA:F127/GSNO hydrogels is triggered by exudate absorption and leads to increased angiogenesis and collagen fiber organization, as well as TGF-ß, IGF-1, SDF-1, and IL-10 gene expressions in the cicatricial tissue. In summary, these results suggest that hydration-controlled NO release from topical PAA:F127/GSNO hydrogels is a potential strategy for enhancing wound healing. STATEMENT OF SIGNIFICANCE: The topical delivery of nitric oxide (NO) to wounds may provide significant beneficial results and represent a promising strategy to treat chronic wounds. However, wound dressings capable of releasing NO after application and allowing the modulation of NO release rates, demand new platforms. Here, we describe a novel strategy to overcome these challenges, based on the use of supramolecular poly(acrylic acid) (PAA):F127 hydrogels charged with the NO donor S-nitrosoglutathione (GSNO) from whereby the NO release can be triggered by exudate absorption and delivered to the wound at rates controlled by the PAA:F127 mass ratio. Preliminary in vivo results offer a proof of concept for this strategy by demonstrating increased angiogenesis; collagen fibers organization; and TGF-ß, IGF-1, SDF-1, and IL-10 gene expressions in the cicatricial tissue after topical treatment with a PAA:F127/GSNO hydrogel.
Assuntos
Resinas Acrílicas , Hidrogéis , Óxido Nítrico , Polietilenos , Polipropilenos , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões , Resinas Acrílicas/farmacocinética , Resinas Acrílicas/farmacologia , Animais , Citocinas/biossíntese , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Hidrogéis/química , Hidrogéis/farmacocinética , Hidrogéis/farmacologia , Camundongos , Micelas , Óxido Nítrico/química , Óxido Nítrico/farmacocinética , Óxido Nítrico/farmacologia , Polietilenos/química , Polietilenos/farmacocinética , Polietilenos/farmacologia , Polipropilenos/química , Polipropilenos/farmacocinética , Polipropilenos/farmacologia , S-Nitrosoglutationa/química , S-Nitrosoglutationa/farmacocinética , S-Nitrosoglutationa/farmacologia , Ferimentos e Lesões/tratamento farmacológico , Ferimentos e Lesões/metabolismo , Ferimentos e Lesões/patologiaRESUMO
UNLABELLED: Recent data have shown that synthetic polymers and nanomaterials display phenotypic effects in cells and signal transduction mechanisms involved in inflammation, differentiation, proliferation, and apoptosis. AIM: This article aims to investigate the effect of poly(ethylene oxide)-poly(propylene oxide) (PEO-PPO) block copolymers with a wide range of biomedical and pharmaceutical applications on apoptosis and/or cell immortalization, by flow cytometry and multiplex RT-PCR for bax, bcl-2, and human telomerase reverse transcriptase (hTERT). RESULTS: PEO-PPO amphiphiles upregulated bax and hTERT and induced apoptosis of two human hepatoma cell lines. CONCLUSIONS: PEO-PPO block copolymers-considered safe for human use-can drastically alter gene expression profiles of genes related to apoptosis/cell proliferation.
Assuntos
Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/patologia , Polietilenos/farmacologia , Polipropilenos/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Tensoativos/farmacologia , Telomerase/genética , Proteína X Associada a bcl-2/genética , Antineoplásicos/química , Antineoplásicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Polietilenos/química , Polipropilenos/química , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Tensoativos/química , Células Tumorais CultivadasRESUMO
Polyelectrolyte multilayers (PEMs) with different polycation/polyanion pairs are fabricated by the layer-by-layer technique employing synthetic, natural, and both types of polyelectrolytes. The impact of the chemical composition of PEMs on cell adhesion is assessed by studying cell shape, spreading area, focal contacts, and cell proliferation for the A549 cell line. Cells exhibit good adhesion on PEMs containing natural polycations and poly(sodium 4-styrenesulfonate) (PSS) as polyanion, but limited adhesion is observed on PEMs fabricated from both natural polyelectrolytes. PEMs are then assembled, depositing a block of natural polyelectrolytes on top of a stiffer block with PSS as polyanion. Cell adhesion is enhanced on top of the diblock PEMs compared to purely natural PEMs. This fact could be explained by the interdigitation between polyelectrolytes from the two blocks. Diblock PEM assembly provides a simple means to tune cell adhesion on biocompatible PEMs.
Assuntos
Adesão Celular/efeitos dos fármacos , Polietilenos/farmacologia , Polilisina/farmacologia , Polímeros/farmacologia , Compostos de Amônio Quaternário/farmacologia , Ácidos Sulfônicos/farmacologia , Células A549 , Resinas Acrílicas/química , Resinas Acrílicas/farmacologia , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Forma Celular/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Adesões Focais/efeitos dos fármacos , Adesões Focais/fisiologia , Humanos , Polietilenoimina/química , Polietilenoimina/farmacologia , Polietilenos/química , Polilisina/química , Polímeros/química , Compostos de Amônio Quaternário/química , Relação Estrutura-Atividade , Ácidos Sulfônicos/química , Propriedades de SuperfícieRESUMO
The growing challenge of antimicrobial resistance to antibiotics requires novel synthetic drugs or new formulations for old drugs. Here, cationic nanostructured particles (NPs) self-assembled from cationic bilayer fragments and polyelectrolytes are tested against four multidrug-resistant (MDR) strains of clinical importance. The non-hemolytic poly(diallyldimethylammonium) chloride (PDDA) polymer as the outer NP layer shows a remarkable activity against these organisms. The mechanism of cell death involves bacterial membrane lysis as determined from the leakage of inner phosphorylated compounds and possibly disassembly of the NP with the appearance of multilayered fibers made of the NP components and the biopolymers withdrawn from the cell wall. The NPs display broad-spectrum activity against MDR microorganisms, including Gram-negative and Gram-positive bacteria and yeast.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Polietilenos/farmacologia , Compostos de Amônio Quaternário/farmacologiaRESUMO
Silver is used worldwide in dressings for wound management. Silver has demonstrated great efficacy against a broad range of microorganisms, but there is very little data about the systemic absorption and toxicity of silver in vivo. In this study, the antimicrobial effect of the silver-coated dressing (SilverCoat(®)) was evaluated in vitro against the most common microorganisms found in wounds, including Pseudomonas aeruginosa, Candida albicans, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus and Klebsiella pneumoniae. We also performed an excisional skin lesion assay in mice to evaluate wound healing after 14 days of treatment with a silver-coated dressing, and we measured the amount of silver in the blood, the kidneys and the liver after treatment. Our data demonstrated that the nylon threads coated with metallic silver have a satisfactory antimicrobial effect in vitro, and the prolonged use of these threads did not lead to systemic silver absorption, did not induce toxicity in the kidneys and the liver and were not detrimental to the normal wound-healing process.