scholarly journals Atmospheric Pressure Microplasma for Antibacterial Silver Nanoparticle/Chitosan Nanocomposites With Tailored Properties

Author(s):  
Daye Sun ◽  
Jonathan Turner ◽  
Nan Jiang ◽  
Songsong Zhu ◽  
Li Zhang ◽  
...  

<p>Room temperature atmospheric pressure microplasma (APM) was deployed for the first time for the in situ synthesis of anti-bacterial silver nanoparticle / chitosan (AgNP/CS) nanocomposites. The plasma induced liquid chemistry plays a role in the in situ formation of AgNP, the size distribution of which depends on the silver salt precursor concentration. The microplasma process has also simultaneously tailored the physical properties of the composites, rendering more crosslinked chitosan polymer network with shorter molecular chains. The formation of AgNP within the <i>in situ</i> modified chitosan has led to nanocomposites with overall improved mechanical properties and better stability in simulated body fluid. Our plasma synthesized AgNP/CS nanocomposites also demonstrate effective antibacterial properties against <i>E. Coli</i> and <i>S. Aureus</i> bacterial strains, showing their promise in potential antimicrobial applications.</p>

2019 ◽  
Author(s):  
Daye Sun ◽  
Jonathan Turner ◽  
Nan Jiang ◽  
Songsong Zhu ◽  
Li Zhang ◽  
...  

<p>Room temperature atmospheric pressure microplasma (APM) was deployed for the first time for the in situ synthesis of anti-bacterial silver nanoparticle / chitosan (AgNP/CS) nanocomposites. The plasma induced liquid chemistry plays a role in the in situ formation of AgNP, the size distribution of which depends on the silver salt precursor concentration. The microplasma process has also simultaneously tailored the physical properties of the composites, rendering more crosslinked chitosan polymer network with shorter molecular chains. The formation of AgNP within the <i>in situ</i> modified chitosan has led to nanocomposites with overall improved mechanical properties and better stability in simulated body fluid. Our plasma synthesized AgNP/CS nanocomposites also demonstrate effective antibacterial properties against <i>E. Coli</i> and <i>S. Aureus</i> bacterial strains, showing their promise in potential antimicrobial applications.</p>


2021 ◽  
Author(s):  
Elahe Pourkhosravani ◽  
fatemeh dehghan nayeri ◽  
Mitra Mohammadi Bazargani

Abstract This study sets out to compare the antibacterial and antibiofilm profiles of Ci/Ca EOs alone and in combination together against infectious bacterial strains. MIC assay was carried out to survey the effectiveness of prepared EOs by two-fold serial dilution method and MTT evaluation. Synergic antibacterial properties of EOs against target strains were studied by using checkerboard titration method. Biofilm growth and development were evaluated using CV and XTT reduction assays. Antibacterial activity was observed for EOs against both bacterial strains with stronger activity for CiEO against both bacteria. The synergistic antibacterial effect was observed only against B. subtilis. Based on the FIC index, combinations could not inhibit the growth of E. coli. The pure EOs and their combination inhibited cell attachment for both studied bacteria with stronger effect on E. coli. CV and XTT reduction assays results showed that Ci EO and its combination with CaEO had the highest antibiofilm activity at lowest MIC value 0.08% and 0.04/0.02% against biofilm formed by E. coli and B. subtilis respectively, indicating a high antibiofilm potential. Computational docking analyses also postulated that the active constituents of evaluated EOs have the potential to interact with different bacterial targets, suggested binding mode of action of EOs metabolites. By and large, synergistic anti-biofilm properties of EOs may provide further options for developing novel formula to inhibit a variety of infectious clinical and industrial strains without (or less) toxicity effects on human body.


Scientifica ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Amine Trabelsi ◽  
Mohamed Amine El Kaibi ◽  
Aïmen Abbassi ◽  
Amira Horchani ◽  
Leila Chekir-Ghedira ◽  
...  

This study aimed to determine phytochemical contents, antibacterial properties, and antibiotic modulating potential of Punica granatum leaf extracts: hexane, chloroform, ethyl acetate, ethanol, and aqueous extracts as well as an extract enriched with total oligomer flavonoids (TOFs). The TOF extract contained the highest value of phenols and flavonoids. Rutin, luteolin, gallic acid, and ellagic acid were determined by HPLC analysis of this extract. The antibacterial activity was assayed by the disc diffusion method and microdilution method against Staphylococcus aureus and Escherichia coli standard ATCC strains and clinical isolates resistant strains. The TOF extract was the most active against all tested strains. The checkerboard method was used for the determination of synergy between two antibiotics (amoxicillin and cefotaxime) and P. granatum leaf extracts. The best synergistic interaction was found with TOF extract combined with amoxicillin for penicillin-resistant E. coli and penicillin-resistant S. aureus. These results can be assigned to tannins, flavonoids, and phenolic acids found in P. granatum leaf extracts. Pomegranate leaf extracts or active compounds isolated from these extracts could be used to fight the emergence and spread of resistant bacterial strains.


2019 ◽  
Vol 4 (1) ◽  
pp. 6-20 ◽  
Author(s):  
Panagiota Moutsatsou ◽  
Karen Coopman ◽  
Stella Georgiadou

Background: Within the healthcare industry, including the care of chronic wounds, the challenge of antimicrobial resistance continues to grow. As such, there is a need to develop new treatments that can reduce the bioburden in wounds. Objective: The present study is focused on the development of polyaniline (PANI) / chitosan (CH) nanofibrous electrospun membranes and evaluates their antibacterial properties. Methods: To this end, experimental design was used to determine the electrospinning windows of both pure chitosan and PANI/CH blends of different ratios (1:3, 3:5, 1:1). The effect of key environmental and process parameters (relative humidity and applied voltage) was determined, as well as the effect of the PANI/CH ratio in the blend and the molecular interactions between PANI and chitosan that led to jet stability. Results: The nanofibrous mats were evaluated regarding their morphology and antibacterial effect against model gram positive and gram negative bacterial strains, namely B. subtilis and E. coli. High PANI content mats show increased bactericidal activity against both bacterial strains. Conclusion: The blend fibre membranes combine the materials’ respective properties, namely electrical conductivity, biocompatibility and antibacterial activity. This study suggests that electrospun PANI/CH membranes are promising candidates for healthcare applications, such as wound dressings.


The Analyst ◽  
2019 ◽  
Vol 144 (16) ◽  
pp. 4887-4896 ◽  
Author(s):  
Mariyemu Tuergong ◽  
Patima Nizamidin ◽  
Abliz Yimit ◽  
Rena Simayi

The optical gas adsorption behaviors of [Zn2(bdc)2(dpNDI)]n membranes were studied for the first time. Under UV light irradiation, they exhibited a greater adsorption response to xylene gas with adsorption capacity of 6.46 μg cm−2 per unit surface.


Author(s):  
Gilles Schnee ◽  
Mathilde Farenc ◽  
Leslie Bitard ◽  
Aurelien Vantomme ◽  
Alexandre Welle ◽  
...  

New ligand platforms of the type p- or m-Ph{-CR(3,6-tBu2Flu)(Cp)}2 (para-, R = Me (2a), H (2b); meta-, R = Me (2c)) were synthesized via nucleophilic addition of the 3,6-tBu2-fluorenyl-anion onto the parent phenylene-bridged difulvenes (1a‒c). The corresponding discrete homodinuclear zirconium and hafnium bis(dichloro ansa-metallocene) complexes, Ph[{-CR(3,6-tBu2Flu)(Cp)}MCl2]2 (p-, R = Me (3a-Zr2, 3a-Hf2), R = H (3b-Zr2); m-, R = Me (3c-Zr2) were prepared by salt metathesis reactions. An attempt to generate in situ a heterodinuclear complex 3a-Zr-Hf was also undertaken. For the first time, Atmospheric Pressure PhotoIonization (APPI) mass-spectrometric data were obtained for all dinuclear compounds and found to be in excellent agreement with the simulated ones. Preliminary studies on the catalytic performances of these dinuclear complexes, upon activation with MAO, in ethylene homopolymerization and ethylene/1-hexene copolymerization revealed a few differences as compared to those of the monometallic analogues. In particular, slightly lower molecular weights and greater formation of short methyl and ethyl branches were obtained with the dinuclear systems.


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4322
Author(s):  
Xiang He ◽  
Ruyue Liu ◽  
Huiqing Liu ◽  
Ruixiao Wang ◽  
Zhenhao Xi ◽  
...  

In order to replace traditional wound treatments such as sutures, tissue adhesives with strong wet tissue adhesion and biocompatibility have attracted more attention to the applications of non-invasive wound closure. Herein, inspired by tunicate adhesive protein, a series of 2,3,4-trihydroxybenzaldehyde (TBA)-modified chitosan hydrogels (CS-TBA-Fe) were prepared by easily mixing the solutions of chitosan-FeCl3 and TBA via the Schiff-base reaction and the coordination between Fe3+ and pyrogallol groups. The gelation time was greatly shortened to only several seconds after induced even trace Fe3+. The hydrogel (CS-TBA-Fe) exhibited ~12-fold enhanced wet tissue adhesion strength (60.3 kPa) over the commercial fibrin glue. Meanwhile, the hydrogel also showed robust adhesion to various substrates such as wood, PMMA, and aluminum. The swelling ratio and rheological property can be simply controlled by changing the concentrations of chitosan, TBA, and Fe3+. Moreover, the hydrogel displayed a rapid and highly efficient self-healing ability and an excellent antibacterial activity against E. coli. The overall results show that the CS-TBA-Fe hydrogel with enhanced wet adhesiveness will be a promising tissue adhesive material.


2021 ◽  
Author(s):  
Qian Zou ◽  
Yinuo Gai ◽  
Xiaotang Gai ◽  
Siwei Xiong ◽  
Nanjun Wei ◽  
...  

Abstract The surgical masks have been essential consumables for public in the COVID-19 pandemic. However, long-time wearing masks will make wearers feel uncomfortable and massive discarded non-biodegradable masks lead to a heavy burden on our environment. In this paper, we adopt degradable chitosan@silver (CS@Ag) core-shell fibers and plant fibers to prepare an eco-friendly mask with excellent thermal comfort, self-sterilization, and antiviral effects. The thermal network of CS@Ag core-shell fibers highly improves the in-plane thermal conductivity of masks, which is 4.45 times higher than that of commercial masks. Because of the electrical conductivity of Ag, the fabricated mask can be electrically heated to warm the wearer in a cold environment and disinfect COVID-19 facilely at room temperature. Meanwhile, the in-situ reduced silver nanoparticles (AgNPs) endow the mask with superior antibacterial properties. Therefore, this mask shows a great potential to address the urgent need for a thermally comfortable, antibacterial, antiviral, and eco-friendly mask.


Author(s):  
Soudabeh Alizadeh Matboo ◽  
Shahram Nazari ◽  
Ali Niapour ◽  
Mehdi Vosoughi Niri ◽  
Esrafil Asgari ◽  
...  

Abstract This study investigated the bacterial removal using TiO2 nanoparticles (NPs) modified with poly-amidoamine dendrimer macromolecule (PAMAM, G3). The PAMAM G3/TiO2 (nanohybrid) was used to specify antibacterial properties via broth microdilution (MBC-Minimum Bactericidal Concentration and MIC-Minimum Inhibitory Concentration- determination), paper disc diffusion, and surface plate count methods. The nanohybrid was characterized via the different techniques. The effects of different factors including initial bacteria count, run time, solution pH, and the nanohybrid concentration were studied. The nanohybrid cytotoxicity was studied on AGS and MKN45 cells line by MTT assay. It was revealed that the nanohybrid was effective in intercepting both bacterial strains growth. The MIC value for S. aureus and E. coli were determined to be 4 and 2 μg/mL, respectively. The MBC value for both strains were calculated to be 32 μg/mL. The results showed removal efficiency of 100% for S. aureus and E. coli bacteria in optimum situation. The decrease in cell viability in the dosage of 32 μg/mL after 72 h treatment for AGS and MKN45 cells line were shown to be 6.2 and 4.6%, respectively. The nanohybrid was able to decrease the S. aureus and E. coli count in solution, which meets the drinking water criterions aligned with WHO guidelines.


Sign in / Sign up

Export Citation Format

Share Document