The removal of zinc and lead from aqueous dilute solutions by polymer-enhanced ultrafiltration process using unmodified starch as a new binding polymer was studied. Experiments were performed to determine the effects of transmembrane pressure, pH, concentration of metal ions on the retention and permeate flux. The performance of the proposed new binding polymer was compared to that of polyethyl...

Stem cell transfection agents have traditionally included lipofectamine, but newer agents include polyethyleneimine-coated magnetic ferro-ferric oxide nanoparticles. This study was done to compare these two methods in transfecting cultured ratmesenchymal stem cells. Magnetic ferro-ferric oxide nanoparticles were coated with polyethyleneimine using co-precipitation of alkali metal ions, forming ...

The siRNA transfection efficiency of nanoparticles (NPs), composed of a superparamagnetic iron oxide core modified with polycationic polymers (poly(hexamethylene biguanide) or branched polyethyleneimine), were studied in CHO-K1 and HeLa cell lines. Both NPs demonstrated to be good siRNA transfection vehicles, but unmodified branched polyethyleneimine (25 kD) was superior on both cell lines. How...

Magnetic particles are used for medical and pharmaceutical purposes such as delivery systems for drugs, genes, and radionuclides. In this study, the technique of chemical co-precipitation in aqueous solution was applied for the synthesis of iron-based magnetic particles. The size and size distribution of magnetic particles were determined by photon correlation spectroscopy. Oxygen-free conditio...

The apparent Michaelis constant, K(M), for glutamate oxidase (GluOx) immobilised on Pt electrodes increased systematically with enzyme loading. The effect was due, at least in part, to electrostatic repulsion between neighbouring oxidase molecules and the anionic substrate, glutamate (Glu). This understanding has allowed us to increase the Glu sensitivity of GluOx-based amperometric biosensors ...

BACKGROUND AND METHODS A new amphiphilic comb-shaped copolymer (SP) was synthesized by conjugating poly(styrene-co-maleic anhydride) with low molecular weight polyethyleneimine for gene delivery. Fourier transform infrared spectrum, (1)H nuclear magnetic resonance, and gel permeation chromatography were used to characterize the graft copolymer. RESULTS The buffering capability of SP was simil...

Picric acid (PA) explosive is a hazard to public safety and health, so the sensitive and selective detection of PA is very important. In the present work, polyethyleneimine stabilized Ag nanoclusters were successfully used for the sensitive and selective quantification of PA on the basis of fluorescence quenching. The quenching efficiency of Ag nanoclusters is proportional to the concentration ...