Particle electrophoresis of micrometric-sized superparamagnetic particles designed for magnetic purification of cells

Sensitivity of a glassy carbon electrode covered with a chitin film improved by the addition of carbon powder

The redox activity of a chitin film on a glassy carbon electrode was remarkably improved by the addition of carbon powder to the film in the detection of ascorbic acid, flavin adenine dinucleotide (FAD) and nicotinamide adenine dinucleotide (NADH). Although oxidation of ascorbic acid using the electrode with the chitin film did not give an appreciable voltametric response, the addition of carbon powder to the film greatly improved its activity up to a 95% level of the bare carbon electrode. For FAD and NADH, an increase in each oxidation peak was observed in a similar manner. The improvement was due to electron mediation of the carbon powder contained in the film. Thus, the electrode effectively recovers the sensitivity for some biological molecules, and thus becomes a powerful device to monitor reactions between biological molecules. Because both carbon and chitin are materials with high biocompatibility, the film can be considered as cell scaffolds. Furthermore, the film immobilized on the plate has a possibility as an electrode in itself.

Blood compatibility of particulate carriers investigated by cell electrophoresis and particle electrophoresis: a preliminary report

Polyethylene glycol (PEG) and dextran were covalently coupled, or only adsorbed, to the surface of three kinds of inorganic particles in order to shield their surface and reduce their nonspecific binding to red blood cells. Surface modification as well as interaction of particles with red blood cells was followed up by particle electrophoresis. This allowed a quick evaluation of the efficiency of polymer coupling. Moreover, the nonspecific binding of particles to red blood cells was easily investigated with cell electrophoresis, showing the inhibitory effect of immobilized PEG-5000 or dextran. The electrophoretic mobility analysis presented here may be used for screening blood compatibility of particulate drug carriers and could be helpful in formulating long-living circulating particles.