scholarly journals Enhancement in the antibacterial activity of cephalexin by its delivery through star-shaped poly(ε-caprolactone)-block-poly(ethylene oxide) coated silver nanoparticles

2020 ◽  
Vol 7 (10) ◽  
pp. 201097
Author(s):  
Sana Rahim ◽  
Samina Perveen ◽  
Shakil Ahmed ◽  
Muhammad Raza Shah ◽  
Muhammad Imran Malik
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Ethylene Oxide ◽  
Inhibitory Concentration ◽  
Bacterial Cells ◽  
Force Microscopy ◽  
Atomic Force ◽  
Biofilm Destruction ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

The antibacterial activity of silver nanoparticles (AgNPs) stabilized with a four-armed star-shaped poly(ε-caprolactone)-block-poly(ethylene oxide) copolymer [St-P(CL-b-EO)] and its application as a drug delivery vehicle for cephalexin (Cp) was evaluated against pathogenic Staphylococcus aureus . The prepared AgNPs were characterized by ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, zeta sizer and atomic force microscopy (AFM). The antibacterial efficiency of Cp is enhanced several-fold by its delivery through complexation with St-P(CL-b-EO)-AgNPs, monitored by microplate assay and biofilm destruction studies. Finally, the visual destruction of bacterial cells and its biofilms by employing Cp and its conjugates at their minimum inhibitory concentration (MIC 50 ) and minimum biofilm inhibitory concentration (MBIC 50 ), respectively, is observed by topographic imaging by AFM. Enhanced antibacterial activity of St-P(CL-b-EO)-AgNPs loaded Cp is attributed to penetrative nature of the drug cargo St-P(CL-b-EO)-AgNPs towards the bacterial cell wall.

The Fabrication of Poly(Σ-caprolactone)–Poly(ethylene oxide) Sandwich Type Nanofibers Containing Sericin-Capped Silver Nanoparticles as an Antibacterial Wound Dressing

2021 ◽  
Vol 21 (5) ◽  
pp. 3041-3049
Author(s):  
Murat İnal ◽  
Zehra Gün Gök ◽  
Name Perktaş ◽  
Gozde Elif Kartal ◽  
Naciye Banu Verim ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Ethylene Oxide ◽  
Wound Dressing ◽  
Gram Positive ◽  
Gram Negative ◽  
Layer Material ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Average Size

In this study, antibacterial, synthetic poly(Σ-caprolactone)–poly(ethylene oxide) (PCL–PEO) multilayer nanofibers were produced by an electrospinning method. The material was synthesized in 3 layers. The upper–lower protective layers were produced by PCL nanofibers and the intermediate layer was produced from PEO nanofiber containing sericin-capped silver nanoparticles (S-AgNPs). The electrospinning conditions in which nano-sized, smooth, bead-free fibers were obtained was determined to be an applied voltage of 20 kV, a flow rate of 8 μL/min and a distance between the collector and the needle tip of 22 cm for the PCL layer (dissolved at a 12% g/mL concentration in a chloroform:methanol (3:2) solvent mixture) layer. For the S-AgNPs doped PEO layer (dissolved at a 3.5% g/mL concentration in water), the corresponding conditions were determined to be 20 kV, 15 μL/min and 20 cm. To characterize the three-layer material that consisted of PCL and S-AgNPs doped PEO layers, FTIR and SEM analyses were performed, and the water retention capacity, in situ degradability and antibacterial activity of the material was investigated. According to SEM analysis, the fibers obtained were found to be nano-sized, smooth and bead-free and the average size of the nanofibers forming the PCL layer was 687 nm while the average size of the fibers forming the PEO layer was 98 nm. Antibacterial activity tests were performed using gram-positive (Staphylococcus aureus ATCC 6538) and gram-negative (Escherichia coli ATCC 25922) bacteria and the resulting biomaterial was found to have antimicrobial effect on both gram-negative and gram-positive bacteria. It was determined that the 3-layer material obtained in this study can be used as a wound dressing.

Atomic Force Microscopy and Light Scattering Study of Onion-Type Micelles Formed by Polystyrene-block-poly(2-vinylpyridine) and Poly(2-vinylpyridine)-block-poly(ethylene oxide) Copolymers in Aqueous Solutions

2006 ◽  
Vol 71 (5) ◽  
pp. 723-738 ◽  
Author(s):  
Pavel Matějíček ◽  
Miroslav Štěpánek ◽  
Mariusz Uchman ◽  
Karel Procházka ◽  
Milena Špírková
Keyword(s):  
Atomic Force Microscopy ◽  
Light Scattering ◽  
Ethylene Oxide ◽  
Self Assembly ◽  
Distribution Functions ◽  
Force Microscopy ◽  
Mass Distributions ◽  
Atomic Force ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

The three-layer onion micelles formed in aqueous solution by hierarchical self-assembly of polystyrene-block-poly(2-vinylpyridine) micelles, PS-PVP, and poly(2-vinylpyridine)-block-poly(ethylene oxide) chains, PVP-PEO, were studied by a combination of light scattering (LS) and atomic force microscopy (AFM). Section analysis of AFM images of micelles deposited on mica in combination with LS data from micellar solutions provide distribution functions of sizes from which the number and mass distributions of molar masses of micelles can be evaluated. Both light scattering and AFM data reveal that the used preparation protocol yields onion micelles accompanied by an admixture of PVP-PEO micelles. It means that only a certain amount of PVP-PEO self-assembles with PS-PVP and forms onion micelles. The remaining PVP-PEO copolymer forms either small PVP-PEO micelles or participates in formation of large aggregates at longer times. The time-dependent measurements show that both onion-type and core-shell PVP-PEO micelles are fairly stable over a long time period and only a low fraction of large aggregate forms on the timescale of weeks and at longer times, the solution does not change any more.

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