scholarly journals Cotton Fabric Modified with a PAMAM Dendrimer with Encapsulated Copper Nanoparticles: Antimicrobial Activity

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7832
Author(s):  
Desislava Staneva ◽  
Daniela Atanasova ◽  
Ani Nenova ◽  
Evgenia Vasileva-Tonkova ◽  
Ivo Grabchev
Keyword(s):  
Antimicrobial Activity ◽  
Visible Light ◽  
Copper Nanoparticles ◽  
Copper Ions ◽  
Pamam Dendrimer ◽  
Eosin Y ◽  
Ambient Conditions ◽  
Paramagnetic Resonance ◽  
Textile Materials ◽  
Antimicrobial Materials

A new methodology for modifying textile materials with dendrimers containing nanoparticles was developed. This involved a combination of eosin Y and N-methyldiethanolamine (MDEA) for reducing the copper ions in the dendrimer complex by enabling a photochemical reaction under visible light and ambient conditions. The conversion of copper ions into nanoparticles was monitored using scanning electron microscopy (SEM) and by performing colorimetric, fluorescence, and electron paramagnetic resonance (EPR) studies. Regardless of the concentration of the photoinitiator eosin Y, it discolored completely upon illumination. Three types of cotton fabrics were compared as antimicrobial materials against Bacillus cereus. One of the fabrics was dyed with a first-generation PAMAM dendrimer which had been functionalized with eight 1,8-naphthalimide fluorophores. Another fabric was dyed with a dendrimer–copper complex, and the third was treated by conversion of the complex into copper nanoparticles encapsulated into the dendrimer. An enhancement in the antimicrobial activity of the textiles was achieved at higher dendrimer concentrations, under illumination with visible light. The fabric modified with the copper nanoparticles encapsulated inside the dendrimer exhibited the best antibacterial activity because it had two photosensitizers (PS), as both 1,8-naphthalimide fluorophores and copper nanoparticles were contained in the dendrimer molecules. The presence of oxygen and suitable illumination activated the photosensitizers to generate the reactive oxygen species (singlet oxygen (1O2) and other oxygenated products, e.g., anion radicals, hydroxyl radicals, and hydrogen peroxide) responsible for destroying the bacteria.

scholarly journals New Poly(Propylene Imine) Dendrimer Modified with Acridine and Its Cu(II) Complex: Synthesis, Characterization and Antimicrobial Activity

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3020 ◽  
Author(s):  
Paula Bosch ◽  
Desislava Staneva ◽  
Evgenia Vasileva-Tonkova ◽  
Petar Grozdanov ◽  
Ivanka Nikolova ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Copper Ions ◽  
Spectral Characteristics ◽  
Dilution Method ◽  
Pathogenic Microorganisms ◽  
Paramagnetic Resonance ◽  
Poly Propylene ◽  
New Compounds ◽  
First Time

A second-generation poly(propylene imine) dendrimer modified with acridine and its Cu(II) complex have been synthesized for the first time. It has been found that two copper ions form complexes with the nitrogen atoms of the dendrimeric core by coordinate bonds. The new compounds have been characterized by nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), fourier-transform infrared spectroscopy (FTIR) and fluorescence spectroscopy. The spectral characteristics of the modified dendrimer have been measured in different organic solvents, and a negative fluorescence solvatochromism has been observed. The antimicrobial activity of the dendrimers has been tested against model pathogenic microorganisms in agar and by broth dilution method. The cotton fabric treated with both dendrimers has been evaluated towards pathogenic microorganisms. The obtained modified cotton fabrics have been shown to hamper bacterial growth and to prevent biofilm formation. Dendrimer cytotoxicity has been investigated in vitro in the model HEp-2 cell line.

Rhodamines as Photocatalyst in Organic Synthesis

2020 ◽  
Vol 07 ◽  
Author(s):  
Avik K. Bagdi ◽  
Papiya Sikdar
Keyword(s):  
Visible Light ◽  
Organic Synthesis ◽  
Organic Dyes ◽  
Transition Metal Catalysts ◽  
Visible Light Photocatalysis ◽  
Eosin Y ◽  
Organic Transformations ◽  
The Sustainable Development ◽  
Mechanistic Pathway ◽  
Green Model

Abstract:: Organic synthesis under environment friendly conditions has great impact in the sustainable development. In this context, visible light photocatalysis has emerged as a green model as this offers an energy-efficient pathway towards the organic transformation. Different transition-metal catalysts (Ir-, Ru-, Cu- etc) and organic dyes (eosin Y, rose bengal, methylene blue etc) are well-known photocatalysts in organic synthesis. Apart from the well-known organophotoredox catalysts, rhodamines (Rhodamine B and Rhodamine 6G) have been also employed as efficient photocatalysts for different organic transformations. In this review, we will focus on the photocatalysis by rhodamines in organic synthesis. Mechanistic pathway of the methodologies will also be discussed. We believe this review will stimulate the employment of rhodamines in the visible light photocatalysis for efficient organic transformations in the future.

scholarly journals Antimicrobial Property of Polypropylene Composites and Functionalized Copper Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1694
Author(s):  
Noemi Jardón-Maximino ◽  
Gregorio Cadenas-Pliego ◽  
Carlos A. Ávila-Orta ◽  
Víctor Eduardo Comparán-Padilla ◽  
Luis E. Lugo-Uribe ◽  
...  
Keyword(s):  
Copper Nanoparticles ◽  
Crystallization Process ◽  
Copper Ions ◽  
Antimicrobial Property ◽  
Aminobutyric Acid ◽  
New Materials ◽  
Melt Mixing ◽  
Polypropylene Composites ◽  
And Staphylococcus Aureus ◽  
Thermal Stability Of

Copper nanoparticles (CuNPs) functionalized with polyethyleneimine (PEI) and 4-aminobutyric acid (GABA) were used to obtain composites with isotactic polypropylene (iPP). The iPP/CuNPs composites were prepared at copper concentrations of 0.25–5.0 wt % by melt mixing, no evidence of oxidation of the CuNP was observed. Furthermore, the release of copper ions from iPP/CuNPs composites in an aqueous medium was studied. The release of cupric ions was higher in the composites with 2.5 and 5.0 wt %. These composites showed excellent antibacterial activity (AA) toward Pseudomona aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). The incorporation of CuNP into the iPP polymeric matrix slightly decreased the thermal stability of the composite material but improved the crystallinity and the storage modulus. This evidence suggests that CuNPs could work as nucleating agents in the iPP crystallization process. The iPP/CuNPs composites presented better AA properties compared to similar composites reported previously. This behavior indicates that the new materials have great potential to be used in various applications that can be explored in the future.

Highly chemoselective deoxygenation of N-heterocyclic N-oxides under transition metal-free conditions

2021 ◽  
Vol 19 (16) ◽  
pp. 3735-3742
Author(s):  
Se Hyun Kim ◽  
Ju Hyeon An ◽  
Jun Hee Lee
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Eosin Y ◽  
Metal Free ◽  
Simple Protocol

Here, we provide an operationally simple protocol for the highly chemoselective deoxygenation of various functionalized N-heterocyclic N-oxides under visible light-mediated photoredox conditions with Na2-eosin Y as an organophotocatalyst.

Visible-light-initiated Catalyst-free Oxidative Cleavage of Triaryl-Substituted Alkenes C=C Bonds under Ambient Conditions

2021 ◽  
Author(s):  
Wenjing Li ◽  
Shun Li ◽  
Lihua Luo ◽  
Yichen Ge ◽  
Jiaqi Xu ◽  
...  
Keyword(s):  
Visible Light ◽  
Room Temperature ◽  
Ambient Air ◽  
Oxidative Cleavage ◽  
Ambient Conditions ◽  
Blue Led ◽  
Catalyst Free

The catalyst-free oxidative cleavage of (Z)-triaryl-substituted alkenes bearing pyridyl motif with ambient air under irradiation of blue LED at room temperature has been developed. The reaction was facile and scalable,...

scholarly journals Evaluation of New Antimicrobial Materials Incorporating Ethyl Lauroyl Arginate or Silver into Different Matrices, and Their Safety in Use as Potential Packaging

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 355
Author(s):  
Sofía Manso ◽  
Magdalena Wrona ◽  
Jesús Salafranca ◽  
Cristina Nerín ◽  
María José Alfonso ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Aspergillus Flavus ◽  
Salmonella Enterica ◽  
Inductively Coupled Plasma ◽  
Food Packaging ◽  
Effective Solution ◽  
Inductively Coupled ◽  
Antimicrobial Materials ◽  
Icp Ms ◽  
Plasma Mass Spectrometry

A big challenge for today’s industry is antimicrobial preservation and the safety of food. An effective solution to this problem can be a modern invention such as antimicrobial packaging. In the presented research the antimicrobial activity of two new active films incorporating silver, as IONPURE IPL, and ethyl lauroyl arginate (LAE) were evaluated, by employing a low-density polyethylene (LDPE) matrix and a biofilm material, respectively. Additionally, LAE was also incorporated into polystyrene (PS) pads by two different methods: by spraying and by immersion of the PS pads into an aqueous LAE solution. LDPE films containing silver did not show any antimicrobial activity against Escherichia coli and Aspergillus flavus, whereas the biofilm containing LAE reduced the growth of Salmonella enterica but did not inhibit Aspergillus flavus. The active PS pads, both sprayed and immersed in LAE solution, also showed antimicrobial activity, causing a reduction of 99.99% of Pseudomonas putida growth. Thermal treatment at 180 °C for 6 and 15 min did not modify the antimicrobial activity of LAE against Salmonella enterica. Moreover, inductively coupled plasma-mass spectrometry (ICP-MS) analysis was performed to check the migration of silver from developed material intended for food packaging applications into food simulant.

scholarly journals Protein-Engineered Polymers Functionalized with Antimicrobial Peptides for the Development of Active Surfaces

2021 ◽  
Vol 11 (12) ◽  
pp. 5352
Author(s):  
Ana Margarida Pereira ◽  
Diana Gomes ◽  
André da Costa ◽  
Simoni Campos Dias ◽  
Margarida Casal ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptides ◽  
Recombinant Dna ◽  
Biological Properties ◽  
Resistant Bacteria ◽  
Recombinant Dna Technology ◽  
Free Standing ◽  
Microbial Cell Factories ◽  
Cell Factories ◽  
Antimicrobial Materials

Antibacterial resistance is a major worldwide threat due to the increasing number of infections caused by antibiotic-resistant bacteria with medical devices being a major source of these infections. This suggests the need for new antimicrobial biomaterial designs able to withstand the increasing pressure of antimicrobial resistance. Recombinant protein polymers (rPPs) are an emerging class of nature-inspired biopolymers with unique chemical, physical and biological properties. These polymers can be functionalized with antimicrobial molecules utilizing recombinant DNA technology and then produced in microbial cell factories. In this work, we report the functionalization of rPBPs based on elastin and silk-elastin with different antimicrobial peptides (AMPs). These polymers were produced in Escherichia coli, successfully purified by employing non-chromatographic processes, and used for the production of free-standing films. The antimicrobial activity of the materials was evaluated against Gram-positive and Gram-negative bacteria, and results showed that the polymers demonstrated antimicrobial activity, pointing out the potential of these biopolymers for the development of new advanced antimicrobial materials.

scholarly journals Gold Nanoparticles Synthesis and Antimicrobial Effect on Fibrous Materials

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1067
Author(s):  
Behnaz Mehravani ◽  
Ana Isabel Ribeiro ◽  
Andrea Zille
Keyword(s):  
Gold Nanoparticles ◽  
Antimicrobial Properties ◽  
Antimicrobial Effect ◽  
Environmental Concerns ◽  
Fibrous Materials ◽  
Barrier Material ◽  
Future Studies ◽  
Textile Materials ◽  
Promising Strategy ◽  
Antimicrobial Materials

Depositing nanoparticles in textiles have been a promising strategy to achieve multifunctional materials. Particularly, antimicrobial properties are highly valuable due to the emergence of new pathogens and the spread of existing ones. Several methods have been used to functionalize textile materials with gold nanoparticles (AuNPs). Therefore, this review highlighted the most used methods for AuNPs preparation and the current studies on the topic in order to obtain AuNPs with suitable properties for antimicrobial applications and minimize the environmental concerns in their production. Reporting the detailed information on the functionalization of fabrics, yarns, and fibers with AuNPs by different methods to improve the antimicrobial properties was the central objective. The studies combining AuNPs and textile materials have opened valuable opportunities to develop antimicrobial materials for health and hygiene products, as infection control and barrier material, with improved properties. Future studies are needed to amplify the antimicrobial effect of AuNPs onto textiles and minimize the concerns related to the synthesis.

Eosin Y photoredox catalyzed net redox neutral reaction for regiospecific annulation to 3-sulfonylindoles via anion oxidation of sodium sulfinate salts

2018 ◽  
Vol 16 (4) ◽  
pp. 536-540 ◽  
Author(s):  
Rajendra S. Rohokale ◽  
Shrikant D. Tambe ◽  
Umesh A. Kshirsagar
Keyword(s):  
Visible Light ◽  
Eosin Y ◽  
Cascade Cyclization ◽  
Neutral Reaction ◽  
Neutral Process ◽  
Radical Cascade

An eosin Y photoredox catalyzed net redox neutral process for 3-sulfonylindoles via the anionic oxidation of sodium sulfinate salts and its radical cascade cyclization with 2-alkynyl-azidoarenes was developed with visible light as a mediator.

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