Antibacterial activity of copper salts against microorganisms isolated from chronic infected wounds

Indexación: Web of Science: Scopus; Scielo.Background: The antimicrobial activity of copper (Cu+2) is recognized and used as an antimicrobial agent. Aim: To evaluate the antimicrobial activity of copper against microorganisms obtained from chronic cutaneous wound infections. Material and Methods: Five chemical products that contained copper particles in their composition were tested (zeolite, silica, acetate, nitrate and nanoparticle of copper). The antimicrobial activity against antibiotic resistant strains usually isolated from chronic cutaneous wound infections was determined for two of the products with better performance in copper release. Results: The minimal inhibitory and minimal bactericidal concentrations of copper acetate and nitrate were similar, fluctuating between 400-2,000 mu g/ml. Conclusions: The studied copper salts show great potential to be used to control both gram positive and gram negative, antibiotic resistant bacteria isolated from wound infections.http://ref.scielo.org/jh7v9

Fabrication and assessment of bifunctional electrospun poly(L-lactic acid) scaffolds with bioglass and zinc oxide nanoparticles for bone tissue engineering

Electrospun scaffolds based on poly(L-lactic acid) (PLLA) with bioglass (n-BG) and zinc oxide (n-ZnO), and mixture of both, were developed to design bifunctional biomaterials with enhanced bioactive and biocidal properties. The presence of n-BG increased the fiber diameter of the pure PLA from 1.5 ± 0.3 μm to 3.0 ± 0.8 μm for 20 wt%. ZnO and the mixed nanoparticles did not significantly affect the morphology. The mechanical properties decreased with the presence of nanoparticles. Scaffolds based on PLA/n-BG promoted hydroxyapatite (HA) formation in simulated body fluid (SBF) that was inhibited with the presence of ZnO. Notably, mixed particles produced bioactivity although at longer times. The incorporation of n-ZnO produced a biocidal capacity against S. aureus in the polymeric scaffold, reaching a viability reduction of 60 % after 6 h of exposure. When both types of nanoparticles were combined, the bacterial viability reduction was 30 %. Pure PLA scaffolds and the composites with n-BG showed good ST-2 bone marrow-derived cell line viability, scaffolds with n-BG (pure or mixture) presented lower viability. Results validated the use of both n-BG and n-ZnO fillers for the development of novel bifunctional PLA-based scaffolds with both bioactive and biocidal properties for bone tissue engineering applications.P.A. Zapata acknowledge the financial support of Direccion de Investigacion Científica y Tecnologica, Universidad de Santiago de Chile (DICYT) project: 052241ZR_DAS. D. Canales thanks the financial support of FONDECYT under postdoctoral project No. 3210810. Finally, D. Canales is immensely grateful to Katharina Schuhladen, Sonja Kuth, Lena Vogt, Irem Unalam, and Florian Ruther, members of Institute of Biomaterials of University of Erlangen-Nuremberg, for their support in the mechanical and biological analysis

Mechano‐Optical Characterization of Extrusion Flow Instabilities in Styrene‐Butadiene Rubbers: Investigating the Influence of Molecular Properties and Die Geometry

The extrusion flow instabilities of two commercial styrene-butadiene rubbers are investigated as they vary in isomer content (1,4-cis, 1,4-trans, and 1,2 con- formation) of the butadiene monomer and the molecular architecture (linear, branched). The investigated samples have similar multimodal molecular weight distribution. Two geometries of extrusion dies, slit and round capillary, are compared in terms of the type and the spatial characteristics of the flow instabilities. The latter are quantified using three methods: a highly pressure sensitive slit die, online and offline optical analysis. The highly pressure- sensitive slit die has three piezoelectric pressure transducers (Δt ≈ 10−3 s and Δp ≈ 10−5 bar) placed along the die length. The characteristic frequency (fChar.) of the flow instabilities follows a power law behavior as a function of shear\ua0rate to a 0.5 power for both materials, f Char. ∝ γ app.. A qualitative model is used\ua0to predict the spatial characteristic wavelength (λ) of the flow instabilities from round capillary to slit dies and vice versa. Slip velocities (Vs) are used to quantify the slippage at slit and round capillary dies as well

Data for: Novel magnetic CoFe2O4 /layered double hydroxide nanocomposites for recoverable anionic adsorbents for water treatment.

Original data from the adsorption experiments from the different particles studie

Polymer Degradation and Stability

768

Data for: Novel magnetic CoFe2O4 /layered double hydroxide nanocomposites for recoverable anionic adsorbents for water treatment.

Original data from the adsorption experiments from the different particles studiedTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Modifying the electrical behaviour of polypropylene/carbon nanotube composites by adding a second nanoparticle and by annealing processes

The effect of different nanoparticles on the geometrical percolation transition of multi-wall carbon nanotubes (CNT) in polypropylene (PP) composites was studied. Our results show that the electrical conductivity of PP/CNT composites (around 2 vol%) can be tuned depending on the characteristic of the third component. Non-conductive layered silica fillers disrupt the CNT percolated network reducing the electrical conductivity of the composite. Spherical nanoparticles otherwise, either copper metal or silica-based, decrease the percolation threshold down to 0.5 vol% of CNT. These results cannot be explained by previous theories about the effect of a second particle on the electrical behaviour of polymer/CNT composites such as the interparticle bridging or the excluded volume. The effect of annealing in the melt was further analyzed and our results show that depending on the concentration and the type of filler, the electrical conductivity of the composites can be increased several orders of magnitude