The use of magnetic nanoparticles in thermal therapy monitoring and screening: Localization and imaging (invited)

Abstract

Magnetic nanoparticles have many diagnostic and therapeutic applications. A method termed magnetic spectroscopy of nanoparticle Brownian motion (MSB) was developed to interrogate in vivo the microscopic environment surrounding magnetic nanoparticles. We can monitor several effects that are important in thermal therapy and screening including temperature measurement and the bound state distribution. Here we report on simulations of nanoparticle localization. Measuring the spatial distribution of nanoparticles would allow us to identify ovarian cancer much earlier when it is still curable or monitor thermal therapies more accurately. We demonstrate that with well-designed equipment superior signal to noise ratio (SNR) can be achieved using only two harmonics rather than using all the harmonics containing signal. Alternatively, smaller magnetic field amplitudes can be used to achieve the same SNR. The SNR is improved using fewer harmonics because the noise is limited.

Remote Hyperthermia, Drug Delivery and Thermometry: The Multifunctional Platform Provided by Nanoparticles

“…At this point it is interesting to emphasize that both magnetic and metallic nanoparticles can be used not only to produce heat but also to provide the thermometric property, optical or magnetic, to build a remote and suitable nanothermometer. Nanosized cubic ferrites can be used as remotely-driven heaters [41] while providing remote temperature sensing using temperaturedependent magnetic properties [32][33][34][35]. Likewise, the metallic nanoparticle-based platform can be used for remote heating [44][45][46] as well as for remote temperature sensing [47,48].…”

“…The thermometric property of magnetic-based nanothermometers proposed up to date is either based on magnetization [33][34][35] or susceptibility [32] measurements. Similarly to the optical approaches magnetic-based nanothermometry relies on remote excitation as well as on remote detection of the thermometric magnetic property.…”

“…As far as the clinical use is concerned the drawbacks of the actual optical-based nanothermometers rely on biocompatibility (usual semiconductor-based core nanoprobes or dye-based shell moieties are toxic), robustness (typical bleaching of organic-based shell moieties) or temperature accuracy (no better than 0.3°C nowadays), or even combination of these factors. Moreover, due to limitations imposed by living tissues on the optical penetration of light (optical therapeutic window in the 700-1100 nm wavelength range), noninvasive clinical use of optical excitation and signal pickup is a huge challenge, not yet solved, except for very special therapeutic applications, as for instance the photodynamic therapy for treatment (heating monitoring) ofof magnetic nanoprobes for remote assessing site-targeted temperatures [32][33][34][35]. Typical magnetic nanoprobes are surface-functionalized cubic ferrites, such as magnetite and maghemite nanoparticles [32][33][34][35][36].…”

“…Moreover, due to limitations imposed by living tissues on the optical penetration of light (optical therapeutic window in the 700-1100 nm wavelength range), noninvasive clinical use of optical excitation and signal pickup is a huge challenge, not yet solved, except for very special therapeutic applications, as for instance the photodynamic therapy for treatment (heating monitoring) ofof magnetic nanoprobes for remote assessing site-targeted temperatures [32][33][34][35]. Typical magnetic nanoprobes are surface-functionalized cubic ferrites, such as magnetite and maghemite nanoparticles [32][33][34][35][36]. Actually, up to date, for noninvasively clinical use the available data favour magnetic nanothermometry as compared to optical nanothermometry.…”

Simulations of magnetic nanoparticle Brownian motion

“…2 Magnetic spectroscopy of Brownian motion (MSB) uses particle dynamics to gather information about the microscopic environments the particles inhabit. 3 A therapeutic method called hyperthermia damages unwanted cells (e.g., in cancer treatment) by depositing energy from particles that are unable to rotate in time with oscillating fields due to viscous drag or anisotropic energy barriers. 4 In each of these techniques, it is necessary to understand the rotational dynamics of the particles in magnetic fields.…”