Detection of magnetic nanoparticles with magnetoencephalography

Superconducting quantum interference devices (SQUIDs) have been widely utilized in biomedical applications due to their extremely high sensitivity to magnetic signals. The present study explores the feasibility of a new type of nanotechnology-based imaging method using standard clinical magnetoencephalographic (MEG) systems equipped with SQUID sensors. Previous studies have shown that biological targets labeled with non-toxic, magnetized nanoparticles can be imaged by measuring the magnetic field generated by these particles. In this work, we demonstrate that (1) the magnetic signals from certain nanoparticles can be detected without magnetization using standard clinical MEG, (2) for some types of nanoparticles, only bound particles produce detectable signals, and (3) the magnetic field of particles several hours after magnetization is significantly stronger than that of un-magnetized particles. These findings hold promise in facilitating the potential application of magnetic nanoparticles to in vivo tumor imaging. The minimum amount of nanoparticles that produce detectable signals is predicted by theoretical modeling and computer simulation.

[1]  R. Ilmoniemi,et al.  Magnetoencephalography-theory, instrumentation, and applications to noninvasive studies of the working human brain , 1993 .

[2]  H. Bryant,et al.  A biomagnetic system for in vivo cancer imaging , 2005, Physics in medicine and biology.

[3]  W. Weitschies,et al.  Magnetic nanoparticle relaxation measurement as a novel tool for in vivo diagnostics , 2002 .

[4]  Q. Pankhurst,et al.  Applications of magnetic nanoparticles in biomedicine , 2003 .

[5]  Ralph Weissleder,et al.  Tat peptide-derivatized magnetic nanoparticles allow in vivo tracking and recovery of progenitor cells , 2000, Nature Biotechnology.

[6]  P. Wust,et al.  Magnetic fluid hyperthermia (MFH): Cancer treatment with AC magnetic field induced excitation of biocompatible superparamagnetic nanoparticles , 1999 .

[7]  D. Leslie-Pelecky,et al.  Iron oxide nanoparticles for sustained delivery of anticancer agents. , 2005, Molecular pharmaceutics.

[8]  Jeff W M Bulte,et al.  Iron oxide MR contrast agents for molecular and cellular imaging , 2004, NMR in biomedicine.

[9]  K. Uutela,et al.  Detecting and Correcting for Head Movements in Neuromagnetic Measurements , 2001, NeuroImage.

[10]  Christoph Alexiou,et al.  Magnetic Drug Targeting—Biodistribution of the Magnetic Carrier and the Chemotherapeutic agent Mitoxantrone after Locoregional Cancer Treatment , 2003 .

[11]  C. Alexiou,et al.  Medical applications of magnetic nanoparticles. , 2006, Journal of nanoscience and nanotechnology.

[12]  Richard M. Leahy,et al.  Electromagnetic brain mapping , 2001, IEEE Signal Process. Mag..

[13]  N. Hamasaki,et al.  Magnetic immunoassays utilizing magnetic markers and a high-T/sub c/ SQUID , 2005, IEEE Transactions on Applied Superconductivity.

[14]  R Hergt,et al.  Use of magnetic nanoparticle heating in the treatment of breast cancer. , 2005, IEE proceedings. Nanobiotechnology.

[15]  J. Mazziotta,et al.  Brain Mapping: The Methods , 2002 .

[16]  R. Hari,et al.  10 – Magnetoencephalographic Characterization of Dynamic Brain Activation: Basic Principles and Methods of Data Collection and Source Analysis , 2002 .