Green Synthesis of Copper Nanoparticles utilising the Maillard Reaction

A new approach for the fabrication copper nanoparticles by a wet chemical reduction method is reported. The natural resources arginine as amino compound and several monosaccharides (xylose, ribose, galactose and glucose) react characteristically performing an Amadori rearrangement followed by a Maillard type reaction. This reaction carried out in an aqueous solution ensures an environmentally friendly way of reducing copper(II) ions leading to the formation of the desired nanoparticles. By changing the concentration of the amino acid, simultaneously acting as a complexing agent, it is possible to tune the size of the resulting nano particles to a certain degree down to 3 nm. This nontoxic and facile preparation route with quantitative yield opens a wide field of applications ranging from electronics to medical approaches.

Membrane action of polyhexamethylene guanidine hydrochloride revealed on smooth muscle cells, nerve tissue and rat blood platelets: A biocide driven pore-formation in phospholipid bilayers

A well-known cationic biocide of guanidine polymer family, polyhexamethylene guanidine hydrochloride (PHMG) has been tested against smooth muscle cells isolated from swine myometrium, synaptosomes of rat brain nerve terminals and rat blood platelets for the membrane action. It was established that PHMG blocked the activity of Na⁺,K⁺-ATPase of smooth muscle cells plasma membrane by 82.2 ± 0.9% at a concentration of 7 ppm, whilst a dose-dependent depolarization of synaptosomes and platelets became appreciable at 100-500 ppm. Comparative studies by the methods of mass spectrometry (MALDI-TOF and PDMS-TOF), viscosimetry, dynamic light scattering and model phospholipid membranes revealed PHMG oligomers with various number of repeat units (8-16) that formed K⁺-selective potential-dependent pores in sterol-free phosphatidylethanolamine-containing phospholipid bilayers at a concentration of 1 ppm. Obtained results suggest that besides acidic lipids and membrane proteins phosphatidylethanolamine and cholesterol are the other major factors responsible for the differences between PHMG-induced plasma membrane depolarization of microbial and eukaryotic cells and thus, diverse modes of PHMG membrane action.

Synthesis and Adsorption Properties of 4-Vinylpyridine and Styrene Copolymer In Situ Immobilized on Silica Surface

Copolymer of 4-vinylpyridine with styrene was in situ immobilized on silica gel surface via the heterogeneous radical polymerization. Anchorage of the copolymer on the surface layer was confirmed by IR spectroscopy. The quantity of copolymer on the silica gel surface was evaluated as 25.73 wt.% by TG and DSC-MS analysis. "Islet" location of polymer layer on the silica surface was confirmed by the scanning electron microscopy. A high adsorption activity of silica gel with immobilized copolymer towards microquantitatives of Cu(II), Cd(II), Pb(II), Fe(III), and Ni(II) ions in steady state conditions as well as of Ni(II) ions in dynamic regime was found.