Practical bioinstrumentation developments for AC magnetic field-mediated magnetic nanoparticle heating applications.

Abstract

Heat dissipation during magnetization reversal processes in magnetic nanoparticles (MNP), upon exposure to alternating magnetic fields (AMF), has been extensively studied in relation to applications in magnetic fluid hyperthermia (MFH). This current paper demonstrates the design, fabrication, and evaluation of an efficient instrument, operating on this principle, for use as (i) a non-contact, in vitro, real-time temperature monitor; (ii) a drug release analysis system (DRAS); (iii) a high flux density module for AMF-mediated MNP studies; and (iv) an in vivo coil setup for real-time, whole body thermal imaging. The proposed DRAS is demonstrated by an AMF-mediated drug release proof-of-principle experiment. Also, the technique described facilitates non-contact temperature measurements of specific absorption rate (SAR) as accurately as temperature measurements using a probe in contact with the sample. Numerical calculations estimating the absolute and root mean squared flux densities, and other MNP - AMF studies suggest that the proposed stacked planar coil module could be employed for calorimetry. Even though the proposed in vivo coil setup could be used for real-time, whole body thermal imaging (within the limitations due to issues of penetration depth), further design effort is required in order to enhance the energy transfer efficiency.