Physical characterization and in vivo organ distribution of coated iron oxide nanoparticles.

Citrate-stabilized iron oxide magnetic nanoparticles (MNPs) were coated with one of carboxymethyl dextran (CM-dextran), polyethylene glycol-polyethylene imine (PEG-PEI), methoxy-PEG-phosphate+rutin, or dextran. They were characterized for size, zeta potential, hysteresis heating in an alternating magnetic field, dynamic magnetic susceptibility, and examined for their distribution in mouse organs following intravenous delivery. Except for PEG-PEI-coated nanoparticles, all coated nanoparticles had a negative zeta potential at physiological pH.

Method to reduce non-specific tissue heating of small animals in solenoid coils.

Purpose: Solenoid coils that generate time-varying or alternating magnetic fields (AMFs) are used in biomedical devices for research, imaging and therapy. Interactions of AMF and tissue produce eddy currents that deposit power within tissue, thus limiting effectiveness and safety. We aim to develop methods that minimise excess heating of mice exposed to AMFs for cancer therapy experiments.

Modified Solenoid Coil That Efficiently Produces High Amplitude AC Magnetic Fields With Enhanced Uniformity for Biomedical Applications.

In this paper, we describe a modified solenoid coil that efficiently generates high amplitude alternating magnetic fields (AMF) having field uniformity (≤10%) within a 125-cm volume of interest. Two-dimensional finite element analysis (2D-FEA) was used to design a coil generating a targeted peak AMF amplitude along the coil axis of ~100 kA/m (peak-to-peak) at a frequency of 150 kHz while maintaining field uniformity to >90% of peak for a specified volume. This field uniformity was realized by forming the turns from cylindrical sections of copper plate and by adding flux concentrating rings to both ends of the coil.

Preliminary study of injury from heating systemically delivered, nontargeted dextran-superparamagnetic iron oxide nanoparticles in mice.

Aim: To assess the potential for injury to normal tissues in mice due to heating systemically delivered magnetic nanoparticles in an alternating magnetic field (AMF).

Materials & Methods: Twenty three male nude mice received intravenous injections of dextran-superparamagnetic iron oxide nanoparticles on days 1-3. On day 6, they were exposed to AMF.

A nanotube based electron microbeam cellular irradiator for radiobiology research.

A prototype cellular irradiator utilizing a carbon nanotube (CNT) based field emission electron source has been developed for microscopic image-guided cellular region irradiation. The CNT cellular irradiation system has shown great potential to be a high temporal and spatial resolution research tool to enable researchers to gain a better understanding of the intricate cellular and intercellular microprocesses occurring following radiation deposition, which is essential to improving radiotherapy cancer treatment outcomes. In this paper, initial results of the system development are reported.