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1.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360535

RESUMO

The aims of this study were to develop the magnolol-chitosan films and study the positive effect of the combination of magnolol and chitosan. The addition of magnolol made the magnolol-chitosan films exhibit higher density (1.06-1.87 g/cm3), but the relatively lower water vapor permeability (12.06-7.36 × 10-11·g·m-1·s-1·Pa-1) and water content (16.10-10.64%). The dense and smooth surface and cross-section of magnolol-chitosan films were observed by environmental scanning electron microscopy (ESEM) images. The interaction of magnolol and chitosan was observed by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). After the addition of magnolol, the antioxidant capacity of magnolol-chitosan films was increased from 18.99 to 82.00%, the growth of P. aeruginosa was inhibited and the inhibition percentage of biofilm formation was increased from 30.89 to 86.04%. We further verified that the application of magnolol-chitosan films on chilled pork significantly reduced the increases in pH value, inhibited the growth of microorganisms and extended the shelf life. Results suggest that magnolol had a positive effect on magnolol-chitosan films and could be effectively applied to pork preservation.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Compostos de Bifenilo/farmacologia , Quitosana/química , Conservação de Alimentos/métodos , Lignanas/farmacologia , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Embalagem de Alimentos/métodos , Carne de Porco/análise , Infecções por Pseudomonas/microbiologia , Suínos
2.
ACS Appl Mater Interfaces ; 13(33): 38979-38989, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433249

RESUMO

Chronic infections caused by Pseudomonas aeruginosa pose severe threats to human health. Traditional antibiotic therapy has lost its total supremacy in this battle. Here, nanoplatforms activated by the clinical microenvironment are developed to treat P. aeruginosa infection on the basis of dynamic borate ester bonds. In this design, the nanoplatforms expose targeted groups for bacterial capture after activation by an acidic infection microenvironment, resulting in directional transport delivery of the payload to bacteria. Subsequently, the production of hyperpyrexia and reactive oxygen species enhances antibacterial efficacy without systemic toxicity. Such a formulation with a diameter less than 200 nm can eliminate biofilm up to 75%, downregulate the level of cytokines, and finally promote lung repair. Collectively, the biomimetic design with phototherapy killing capability has the potential to be an alternative strategy against chronic infections caused by P. aeruginosa.


Assuntos
Antibacterianos/química , Verde de Indocianina/química , Nanocápsulas/química , Fármacos Fotossensibilizantes/química , Polímeros/química , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/radioterapia , Células A549 , Animais , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Composição de Medicamentos , Liberação Controlada de Fármacos , Sinergismo Farmacológico , Humanos , Verde de Indocianina/farmacologia , Raios Infravermelhos , Masculino , Metacrilatos/química , Camundongos Endogâmicos BALB C , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Polietilenoglicóis/química , Pseudomonas aeruginosa/efeitos dos fármacos
3.
Molecules ; 26(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200763

RESUMO

The development of new antimicrobial strategies that act more efficiently than traditional antibiotics is becoming a necessity to combat multidrug-resistant pathogens. Here we report the efficacy of laser-light-irradiated 5,10,15,20-tetrakis(m-hydroxyphenyl)porphyrin (mTHPP) loaded onto an ethylcellulose (EC)/chitosan (Chs) nanocomposite in eradicating multi-drug resistant Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans. Surface loading of the ethylcelllose/chitosan composite with mTHPP was carried out and the resulting nanocomposite was fully characterized. The results indicate that the prepared nanocomposite incorporates mTHPP inside, and that the composite acquired an overall positive charge. The incorporation of mTHPP into the nanocomposite enhanced the photo- and thermal stability. Different laser wavelengths (458; 476; 488; 515; 635 nm), powers (5-70 mW), and exposure times (15-45 min) were investigated in the antimicrobial photodynamic therapy (aPDT) experiments, with the best inhibition observed using 635 nm with the mTHPP EC/Chs nanocomposite for C. albicans (59 ± 0.21%), P. aeruginosa (71.7 ± 1.72%), and S. aureus (74.2 ± 1.26%) with illumination of only 15 min. Utilization of higher doses (70 mW) for longer periods achieved more eradication of microbial growth.


Assuntos
Antibacterianos/química , Celulose/análogos & derivados , Quitosana/química , Nanocompostos/química , Porfirinas/química , Piridonas/química , Pirróis/química , Animais , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Linhagem Celular , Celulose/química , Chlorocebus aethiops , Lasers , Luz , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Células Vero
4.
Molecules ; 26(12)2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34205355

RESUMO

Rottlerin is a natural product consisting of chalcone and flavonoid scaffolds, both of which have previously shown quorum sensing (QS) inhibition in various bacteria. Therefore, the unique rottlerin scaffold highlights great potential in inhibiting the QS system of Pseudomonas aeruginosa. Rottlerin analogues were synthesised by modifications at its chalcone- and methylene-bridged acetophenone moieties. The synthesis of analogues was achieved using an established five-step synthetic strategy for chalcone derivatives and utilising the Mannich reaction at C6 of the chromene to construct morpholine analogues. Several pyranochromene chalcone derivatives were also generated using aldol conditions. All the synthetic rottlerin derivatives were screened for QS inhibition and growth inhibition against the related LasR QS system. The pyranochromene chalcone structures displayed high QS inhibitory activity with the most potent compounds, 8b and 8d, achieving QS inhibition of 49.4% and 40.6% and no effect on bacterial growth inhibition at 31 µM, respectively. Both compounds also displayed moderate biofilm inhibitory activity and reduced the production of pyocyanin.


Assuntos
Acetofenonas/farmacologia , Benzopiranos/farmacologia , Produtos Biológicos/farmacologia , Percepção de Quorum/efeitos dos fármacos , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Flavonoides/farmacologia , Testes de Sensibilidade Microbiana/métodos , Pseudomonas aeruginosa/efeitos dos fármacos , Piocianina/farmacologia
5.
J Enzyme Inhib Med Chem ; 36(1): 1509-1520, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34238110

RESUMO

In the present study, a series of azo derivatives (TR-1 to TR-9) have been synthesised via the diazo-coupling approach between substituted aromatic amines with phenol or naphthol derivatives. The compounds were evaluated for their therapeutic applications against alpha-glucosidase (anti-diabetic) and pathogenic bacterial strains E. coli (gram-negative), S. aureus (gram-positive), S. aureus (gram-positive) drug-resistant strain, P. aeruginosa (gram-negative), P. aeruginosa (gram-negative) drug-resistant strain and P. vulgaris (gram-negative). The IC50 (µg/mL) of TR-1 was found to be most effective (15.70 ± 1.3 µg/mL) compared to the reference drug acarbose (21.59 ± 1.5 µg/mL), hence, it was further selected for the kinetic studies in order to illustrate the mechanism of inhibition. The enzyme inhibitory kinetics and mode of binding for the most active inhibitor (TR-1) was performed which showed that the compound is a non-competitive inhibitor and effectively inhibits the target enzyme by binding to its binuclear active site reversibly.


Assuntos
Antibacterianos/farmacologia , Compostos Azo/farmacologia , Inibidores Enzimáticos/farmacologia , Hipoglicemiantes/farmacologia , Simulação de Acoplamento Molecular , alfa-Glucosidases/metabolismo , Antibacterianos/síntese química , Antibacterianos/química , Compostos Azo/síntese química , Compostos Azo/química , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Escherichia coli/efeitos dos fármacos , Hipoglicemiantes/síntese química , Hipoglicemiantes/química , Cinética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Pseudomonas aeruginosa/efeitos dos fármacos , Saccharomyces cerevisiae/enzimologia , Staphylococcus aureus/efeitos dos fármacos
6.
J Chem Phys ; 154(20): 204201, 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34241187

RESUMO

Pseudomonas aeruginosa is an opportunistic human pathogen implicated in both acute and chronic diseases, which resists antibiotic treatment, in part by forming physical and chemical barriers such as biofilms. Here, we explore the use of confocal Raman imaging to characterize the three-dimensional (3D) spatial distribution of alkyl quinolones (AQs) in P. aeruginosa biofilms by reconstructing depth profiles from hyperspectral Raman data. AQs are important to quorum sensing (QS), virulence, and other actions of P. aeruginosa. Three-dimensional distributions of three different AQs (PQS, HQNO, and HHQ) were observed to have a significant depth, suggesting 3D anisotropic shapes-sheet-like rectangular solids for HQNO and extended cylinders for PQS. Similar to observations from 2D imaging studies, spectral features characteristic of AQs (HQNO or PQS) and the amide I vibration from peptide-containing species were found to correlate with the PQS cylinders typically located at the tips of the HQNO rectangular solids. In the QS-deficient mutant lasIrhlI, a small globular component was observed, whose highly localized nature and similarity in size to a P. aeruginosa cell suggest that the feature arises from HHQ localized in the vicinity of the cell from which it was secreted. The difference in the shapes and sizes of the aggregates of the three AQs in wild-type and mutant P. aeruginosa is likely related to the difference in the cellular response to growth conditions, environmental stress, metabolic levels, or other structural and biochemical variations inside biofilms. This study provides a new route to characterizing the 3D structure of biofilms and shows the potential of confocal Raman imaging to elucidate the nature of heterogeneous biofilms in all three spatial dimensions. These capabilities should be applicable as a tool in studies of infectious diseases.


Assuntos
Biofilmes/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Quinolonas/farmacologia , Biofilmes/crescimento & desenvolvimento , Microscopia Confocal , Quinolonas/química , Análise Espectral Raman
7.
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
8.
BMC Genomics ; 22(1): 572, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34311706

RESUMO

BACKGROUND: Pseudomonas aeruginosa is a ubiquitous environmental microorganism and also a common cause of infection. Its ability to survive in many different environments and persistently colonize humans is linked to its presence in biofilms formed on indwelling device surfaces. Biofilm promotes adhesion to, and survival on surfaces, protects from desiccation and the actions of antibiotics and disinfectants. RESULTS: We examined the genetic basis for biofilm production on polystyrene at room (22 °C) and body temperature (37 °C) within 280 P. aeruginosa. 193 isolates (69 %) produced more biofilm at 22 °C than at 37 °C. Using GWAS and pan-GWAS, we found a number of accessory genes significantly associated with greater biofilm production at 22 °C. Many of these are present on a 165 kb region containing genes for heavy metal resistance (arsenic, copper, mercury and cadmium), transcriptional regulators and methytransferases. We also discovered multiple core genome SNPs in the A-type flagellin gene and Type II secretion system gene xpsD. Analysis of biofilm production of isolates of the MDR ST111 and ST235 lineages on stainless-steel revealed several accessory genes associated with enhanced biofilm production. These include a putative translocase with homology to a Helicobacter pylori type IV secretion system protein, a TA system II toxin gene and the alginate biosynthesis gene algA, several transcriptional regulators and methytransferases as well as core SNPs in genes involved in quorum sensing and protein translocation. CONCLUSIONS: Using genetic association approaches we discovered a number of accessory genes and core-genome SNPs that were associated with enhanced early biofilm formation at 22 °C compared to 37 °C. These included a 165 kb genomic island containing multiple heavy metal resistance genes, transcriptional regulators and methyltransferases. We hypothesize that this genomic island may be associated with overall genotypes that are environmentally adapted to survive at lower temperatures. Further work to examine their importance in, for example gene-knockout studies, are required to confirm their relevance. GWAS and pan-GWAS approaches have great potential as a first step in examining the genetic basis of novel bacterial phenotypes.


Assuntos
Biofilmes , Farmacorresistência Bacteriana Múltipla , Pseudomonas aeruginosa , Antibacterianos/farmacologia , Genótipo , Humanos , Infecções por Pseudomonas , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/genética , Percepção de Quorum
9.
NPJ Biofilms Microbiomes ; 7(1): 59, 2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244523

RESUMO

Microbial biofilms are involved in a number of infections that cannot be cured, as microbes in biofilms resist host immune defenses and antibiotic therapies. With no strict biofilm-antibiotic in the current pipelines, there is an unmet need for drug candidates that enable the current antibiotics to eradicate bacteria in biofilms. We used high-throughput screening to identify chemical compounds that reduce the intracellular c-di-GMP content in Pseudomonas aeruginosa. This led to the identification of a small molecule that efficiently depletes P. aeruginosa for c-di-GMP, inhibits biofilm formation, and disperses established biofilm. A combination of our lead compound with standard of care antibiotics showed improved eradication of an implant-associated infection established in mice. Genetic analyses provided evidence that the anti-biofilm compound stimulates the activity of the c-di-GMP phosphodiesterase BifA in P. aeruginosa. Our work constitutes a proof of concept for c-di-GMP phosphodiesterase-activating drugs administered in combination with antibiotics as a viable treatment strategy for otherwise recalcitrant infections.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , GMP Cíclico/análogos & derivados , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Transdução de Sinais/efeitos dos fármacos , Animais , Antibacterianos/química , Cromatografia Líquida de Alta Pressão , GMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Descoberta de Drogas , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Sequenciamento de Nucleotídeos em Larga Escala , Camundongos , Espectrometria de Massas em Tandem , Transcriptoma
10.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203313

RESUMO

The paper presents a synthesis of poly(l-lactide) with bacteriostatic properties. This polymer was obtained by ring-opening polymerization of the lactide initiated by selected low-toxic zinc complexes, Zn[(acac)(L)H2O], where L represents N-(pyridin-4-ylmethylene) tryptophan or N-(2-pyridin-4-ylethylidene) phenylalanine. These complexes were obtained by reaction of Zn[(acac)2 H2O] and Schiff bases, the products of the condensation of amino acids and 4-pyridinecarboxaldehyde. The composition, structure, and geometry of the synthesized complexes were determined by NMR and FTIR spectroscopy, elemental analysis, and molecular modeling. Both complexes showed the geometry of a distorted trigonal bipyramid. The antibacterial and antifungal activities of both complexes were found to be much stronger than those of the primary Schiff bases. The present study showed a higher efficiency of polymerization when initiated by the obtained zinc complexes than when initiated by the zinc(II) acetylacetonate complex. The synthesized polylactide showed antibacterial properties, especially the product obtained by polymerization initiated by a zinc(II) complex with a ligand based on l-phenylalanine. The polylactide showed a particularly strong antimicrobial effect against Pseudomonas aeruginosa, Staphylococcus aureus, and Aspergillus brasiliensis. At the same time, this polymer does not exhibit fibroblast cytotoxicity.


Assuntos
Poliésteres/química , Polímeros/química , Zinco/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Aspergillus/efeitos dos fármacos , Quelantes/química , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
11.
Molecules ; 26(12)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34198596

RESUMO

Staphylococcus aureus (Gram-positive) and Pseudomonas aeruginosa (Gram-negative) bacteria represent major infectious threats in the hospital environment due to their wide distribution, opportunistic behavior, and increasing antibiotic resistance. This study reports on the deposition of polyvinylpyrrolidone/antibiotic/isoflavonoid thin films by the matrix-assisted pulsed laser evaporation (MAPLE) method as anti-adhesion barrier coatings, on biomedical surfaces for improved resistance to microbial colonization. The thin films were characterized by Fourier transform infrared spectroscopy, infrared microscopy, and scanning electron microscopy. In vitro biological assay tests were performed to evaluate the influence of the thin films on the development of biofilms formed by Gram-positive and Gram-negative bacterial strains. In vitro biocompatibility tests were assessed on human endothelial cells examined for up to five days of incubation, via qualitative and quantitative methods. The results of this study revealed that the laser-fabricated coatings are biocompatible and resistant to microbial colonization and biofilm formation, making them successful candidates for biomedical devices and contact surfaces that would otherwise be amenable to contact transmission.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Flavonoides/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Biofilmes/crescimento & desenvolvimento , Materiais Revestidos Biocompatíveis/química , Flavonoides/química , Lasers/normas , Testes de Sensibilidade Microbiana/métodos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Propriedades de Superfície
12.
Int J Mol Sci ; 22(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200185

RESUMO

Segmented polyurethane ionomers find prominent applications in the biomedical field since they can combine the good mechanical and biostability properties of polyurethanes (PUs) with the strong hydrophilicity features of ionomers. In this work, PU ionomers were prepared from a carboxylated diol, poly(tetrahydrofuran) (soft phase) and a small library of diisocyanates (hard phase), either aliphatic or aromatic. The synthesized PUs were characterized to investigate the effect of ionic groups and the nature of diisocyanate upon the structure-property relationship. Results showed how the polymer hard/soft phase segregation was affected by both the concentration of ionic groups and the type of diisocyanate. Specifically, PUs obtained with aliphatic diisocyanates possessed a hard/soft phase segregation stronger than PUs with aromatic diisocyanates, as well as greater bulk and surface hydrophilicity. In contrast, a higher content of ionic groups per polymer repeat unit promoted phase mixing. The neutralization of polymer ionic groups with silver or zinc further increased the hard/soft phase segregation and provided polymers with antimicrobial properties. In particular, the Zinc/PU hybrid systems possessed activity only against the Gram-positive Staphylococcus epidermidis while Silver/PU systems were active also against the Gram-negative Pseudomonas aeruginosa. The herein-obtained polyurethanes could find promising applications as antimicrobial coatings for different kinds of surfaces including medical devices, fabric for wound dressings and other textiles.


Assuntos
Materiais Biocompatíveis/farmacologia , Transição de Fase , Poliuretanos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Prata/química , Staphylococcus epidermidis/efeitos dos fármacos , Zinco/química , Teste de Materiais , Resistência à Tração
13.
Int J Mol Sci ; 22(13)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201818

RESUMO

Pseudomonas aeruginosa is an opportunistic human pathogen that has become a nosocomial health problem worldwide. The pathogen has multiple drug removal and virulence secretion systems, is resistant to many antibiotics, and there is no commercial vaccine against it. Yersinia pestis is a zoonotic pathogen that is on the Select Agents list. The bacterium is the deadliest pathogen known to humans and antibiotic-resistant strains are appearing naturally. There is no commercial vaccine against the pathogen, either. In the current work, novel compounds based on metallacarborane cage were studied on strains of Pseudomonas aeruginosa and a Yersinia pestis substitute, Yersinia enterocolitica. The representative compounds had IC50 values below 10 µM against Y. enterocolitica and values of 20-50 µM against P. aeruginosa. Artificial generation of compound-resistant Y. enterocolitica suggested a common mechanism for drug resistance, the first reported in the literature, and suggested N-linked metallacarboranes as impervious to cellular mechanisms of resistance generation. SEM analysis of the compound-resistant strains showed that the compounds had a predominantly bacteriostatic effect and blocked bacterial cell division in Y. enterocolitica. The compounds could be a starting point towards novel anti-Yersinia drugs and the strategy presented here proposes a mechanism to bypass any future drug resistance in bacteria.


Assuntos
Antibacterianos/farmacologia , Boranos/química , Compostos Organometálicos/farmacologia , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Yersiniose/tratamento farmacológico , Yersinia enterocolitica/efeitos dos fármacos , Humanos , Infecções por Pseudomonas/microbiologia , Yersiniose/microbiologia
14.
Int J Mol Sci ; 22(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202773

RESUMO

In recent years, antimicrobial photodynamic therapy (aPDT) has received increasing attention as a promising tool aimed at both treating microbial infections and sanitizing environments. Since biofilm formation on biological and inert surfaces makes difficult the eradication of bacterial communities, further studies are needed to investigate such tricky issue. In this work, a panel of 13 diaryl-porphyrins (neutral, mono- and di-cationic) was taken in consideration to photoinactivate Pseudomonas aeruginosa. Among cationic photosensitizers (PSs) able to efficiently bind cells, in this study two dicationic showed to be intrinsically toxic and were ruled out by further investigations. In particular, the dicationic porphyrin (P11) that was not toxic, showed a better photoinactivation rate than monocationic in suspended cells. Furthermore, it was very efficient in inhibiting the biofilms produced by the model microorganism Pseudomonas aeruginosa PAO1 and by clinical strains derived from urinary tract infection and cystic fibrosis patients. Since P. aeruginosa represents a target very difficult to inactivate, this study confirms the potential of dicationic diaryl-porphyrins as photo-activated antimicrobials in different applicative fields, from clinical to environmental ones.


Assuntos
Biofilmes/efeitos dos fármacos , Biofilmes/efeitos da radiação , Luz , Porfirinas/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/efeitos da radiação , Antibacterianos/química , Antibacterianos/farmacologia , Cátions , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/química
15.
Molecules ; 26(11)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199966

RESUMO

Nanfeng mandarins (Citrus reticulata Blanco cv. Kinokuni), Xunwu mandarins (Citrus reticulata Blanco), Yangshuo kumquats (Citrus japonica Thunb) and physiologically dropped navel oranges (Citrus sinensis Osbeck cv. Newhall) were used as materials to extract peel essential oils (EOs) via hydrodistillation. The chemical composition, and antibacterial and antioxidant activities of the EOs were investigated. GC-MS analysis showed that monoterpene hydrocarbons were the major components and limonene was the predominate compound for all citrus EOs. The antibacterial testing of EOs against five different bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium) was carried out using the filter paper method and the broth microdilution method. Kumquat EO had the best inhibitory effect on B. subtilis, E. coli and S. typhimurium with MIC (minimum inhibitory concentration) values of 1.56, 1.56 and 6.25 µL/mL, respectively. All citrus EOs showed the antioxidant activity of scavenging DPPH and ABTS free radicals in a dose-dependent manner. Nanfeng mandarin EO presented the best antioxidant activity, with IC50 values of 15.20 mg/mL for the DPPH assay and 0.80 mg/mL for the ABTS assay. The results also showed that the antibacterial activities of EOs might not be related to their antioxidant activities.


Assuntos
Antibacterianos/química , Antioxidantes/química , Citrus/química , Óleos Voláteis/farmacologia , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Bacillus subtilis/efeitos dos fármacos , Citrus/classificação , Destilação , Relação Dose-Resposta a Droga , Escherichia coli/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Óleos Vegetais/química , Óleos Vegetais/isolamento & purificação , Óleos Vegetais/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Salmonella typhimurium/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
16.
Molecules ; 26(13)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206777

RESUMO

Previous studies have revealed the numerous biological activities of the fruits of Illicium verum; however, the activities of its leaves and twigs have remained undiscovered. The study aimed to investigate the phytochemical components and antibacterial activity of the various extracts from the leaves and twigs of Illicium verum. The herbal extracts were prepared by supercritical CO2 extraction (SFE) and 95% ethanol extraction, followed by partition extraction based on solvent polarity. Analysis of antimicrobial activity was conducted through the usage of nine clinical antibiotic- resistant isolates, including Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. Among the tested samples, the SFE extracts exhibited broader and stronger antibacterial activities against the test strains, with a range of MIC between 0.1-4.0 mg/mL and MBC between 0.2-4.5 mg/mL. Observations made through scanning electron microscopy revealed potential mechanism of the antimicrobial activities involved disruption of membrane integrity of the test pathogens. Evaluation of the chemical composition by gas chromatography-mass spectrometry indicated the presence of anethole, anisyl aldehyde, anisyl acetone and anisyl alcohol within the SFE extracts, demonstrating significant correlations with the antibacterial activities observed. Therefore, the leaves and twigs of Illicium verum hold great potential in being developed as new natural antibacterial agents.


Assuntos
Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Illicium/química , Extratos Vegetais/análise , Extratos Vegetais/farmacologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/ultraestrutura , Antibacterianos/análise , Anti-Infecciosos/análise , Membrana Celular/efeitos dos fármacos , Membrana Celular/ultraestrutura , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Gasosa , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Extratos Vegetais/química , Folhas de Planta/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/ultraestrutura , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/ultraestrutura
17.
Int J Mol Sci ; 22(13)2021 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-34281254

RESUMO

Silver nanoparticles (AgNPs) have been imposed as an excellent antimicrobial agent being able to combat bacteria in vitro and in vivo causing infections. The antibacterial capacity of AgNPs covers Gram-negative and Gram-positive bacteria, including multidrug resistant strains. AgNPs exhibit multiple and simultaneous mechanisms of action and in combination with antibacterial agents as organic compounds or antibiotics it has shown synergistic effect against pathogens bacteria such as Escherichia coli and Staphylococcus aureus. The characteristics of silver nanoparticles make them suitable for their application in medical and healthcare products where they may treat infections or prevent them efficiently. With the urgent need for new efficient antibacterial agents, this review aims to establish factors affecting antibacterial and cytotoxic effects of silver nanoparticles, as well as to expose the advantages of using AgNPs as new antibacterial agents in combination with antibiotic, which will reduce the dosage needed and prevent secondary effects associated to both.


Assuntos
Antibacterianos/uso terapêutico , Nanopartículas Metálicas/uso terapêutico , Prata/uso terapêutico , Animais , Antibacterianos/administração & dosagem , Antibacterianos/química , Infecções Bacterianas/tratamento farmacológico , Linhagem Celular , Desenvolvimento de Medicamentos , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Humanos , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Nanotecnologia , Pseudomonas aeruginosa/efeitos dos fármacos , Prata/administração & dosagem , Prata/química , Staphylococcus aureus/efeitos dos fármacos
18.
Photochem Photobiol Sci ; 20(8): 985-996, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34275118

RESUMO

Chronic lung infections are among the most diffused human infections, being often associated with multidrug-resistant bacteria. In this framework, the European project "Light4Lungs" aims at synthesizing and testing an inhalable light source to control lung infections by antimicrobial photoinactivation (aPDI), addressing endogenous photosensitizers only (porphyrins) in the representative case of S. aureus and P. aeruginosa. In the search for the best emission characteristics for the aerosolized light source, this work defines and calculates the photo-killing action spectrum for lung aPDI in the exemplary case of cystic fibrosis. This was obtained by applying a semi-theoretical modelling with Monte Carlo simulations, according to previously published methodology related to stomach infections and applied to the infected trachea, bronchi, bronchioles and alveoli. In each of these regions, the two low and high oxygen concentration cases were considered to account for the variability of in vivo conditions, together with the presence of endogenous porphyrins and other relevant absorbers/diffusers inside the illuminated biofilm/mucous layer. Furthermore, an a priori method to obtain the "best illumination wavelengths" was defined, starting from maximizing porphyrin and light absorption at any depth. The obtained action spectrum is peaked at 394 nm and mostly follows porphyrin extinction coefficient behavior. This is confirmed by the results from the best illumination wavelengths, which reinforces the robustness of our approach. These results can offer important indications for the synthesis of the aerosolized light source and definition of its most effective emission spectrum, suggesting a flexible platform to be considered in further applications.


Assuntos
Espectro de Ação , Antibacterianos/química , Antibacterianos/farmacologia , Pulmão/microbiologia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Aerossóis , Biofilmes/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Porfirinas/química , Porfirinas/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos da radiação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/efeitos da radiação
19.
Molecules ; 26(13)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34279375

RESUMO

Infection is the major reason that people die from burns; however, traditional medical dressings such as gauze cannot restrain bacterial growth and enhance the healing process. Herein, an organic- and inorganic-base hydrogel with antibacterial activities was designed and prepared to treat burn wounds. Oxidized dextran (ODex) and adipic dihydrazide grafted hyaluronic acid (HA-ADH) were prepared, mixed with quaternized chitosan (HACC) and silver nanoparticles to fabricate Ag@ODex/HA-ADH/HACC hydrogel. The hydrogel, composed of nature biomaterials, has a good cytocompatibility and biodegradability. Moreover, the hydrogel has an excellent antibacterial ability and presents fast healing for burn wounds compared with commercial Ag dressings. The Ag@ODex/HA-ADH/HACC hydrogel will be a promising wound dressing to repair burn wounds and will significantly decrease the possibility of bacterial infection.


Assuntos
Antibacterianos/química , Queimaduras/terapia , Quitosana/análogos & derivados , Hidrogéis/química , Nanopartículas Metálicas/química , Cicatrização , Adipatos/química , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bandagens , Queimaduras/tratamento farmacológico , Linhagem Celular , Dextranos/química , Hidrogéis/farmacologia , Hidrogéis/uso terapêutico , Masculino , Camundongos , Pseudomonas aeruginosa/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Prata/química , Staphylococcus aureus/efeitos dos fármacos
20.
Int J Mol Sci ; 22(11)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34073939

RESUMO

An amphipathic α-helical peptide, Hp1404, was isolated from the venomous gland of the scorpion Heterometrus petersii. Hp1404 exhibits antimicrobial activity against methicillin-resistant Staphylococcus aureus but is cytotoxic. In this study, we designed antimicrobial peptides by substituting amino acids at the 14 C-terminal residues of Hp1404 to reduce toxicity and improve antibacterial activity. The analog peptides, which had an amphipathic α-helical structure, were active against gram-positive and gram-negative bacteria, particularly multidrug-resistant Acinetobacter baumannii, and showed lower cytotoxicity than Hp1404. N-phenyl-1-naphthylamine uptake and DisC3-5 assays demonstrated that the peptides kill bacteria by effectively permeating the outer and cytoplasmic membranes. Additionally, the analog peptides inhibited biofilm formation largely than Hp1404 at low concentrations. These results suggest that the analog peptides of Hp1404 can be used as therapeutic agents against A. baumannii infection.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escorpiões/química , 1-Naftilamina/análogos & derivados , 1-Naftilamina/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos/efeitos adversos , Peptídeos Catiônicos Antimicrobianos/química , Benzotiazóis/metabolismo , Biofilmes/efeitos dos fármacos , Carbocianinas/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Escherichia coli/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Conformação Proteica em alfa-Hélice , Pseudomonas aeruginosa/efeitos dos fármacos , Salmonella/efeitos dos fármacos
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