Experimental Evaluation of Radiation Response and Thermal Properties of NPs-Loaded Tissues-Mimicking Phantoms

Abstract

Many efforts have recently concentrated on constructing and developing nanoparticles (NPs) as promising thermal agent for optical hyperthermia and photothermal therapy. However, thermal energy transfer in biological tissue is a complex process involving different mechanisms such as conduction, convection, radiation. Therefore, having information about thermal properties of tissue especially when NPs are embedded in is a necessity for predicting the heat transfer during hyperthermia. In this work, the thermal properties of solid phantom based on agar in the presence of three different nanoparticles (BPSi, tNAs, GNRs) and alone were measured and reported as a function of temperature (ranging from 22 to 62 °C). The thermal response of these NPs to an 808 nm laser beam with three different powers were studied in the water comparatively. Agar and tNAs have almost constant thermal properties in the considered range. Among the three NPs, gold has the highest conductivity and diffusivity. At 62 °C BPSi NPs have the similar amount of increase for the diffusivity. The thermal parameters reported in this paper can be useful for the mathematical modeling. Irradiation of the NPs-loaded water phantom displayed the highest radiosensitivity of gold among the three mentioned NPs. However, for the higher power of irradiation, BPSi and tNAs NPs showed the increased absorption of heat during shorter time and the increased temperature gradient slope for the initial 15 s after the irradiation started. The three NPs showed different thermal and irradiation response behavior; however, this comparison study notes the worth of having information about thermal parameters of NPs-loaded tissue for pre-clinical planning.

Gold Nanoparticles-Mediated Photothermal Therapy of Pancreas Using GATE: A New Simulation Platform

“…The information about the pancreas and GNR-loaded tumor properties used in our model is available in Table 1 . According to our recent experiment [ 20 ] performed on GNR-loaded agar phantom, the diffusivity of the phantom loaded with GNRs increased around 22% at a temperature of around 62 °C compared to the one at room temperature. So, in this study, we considered the average value of diffusivity from room temperature to be 62 °C [ 20 ].…”

“…According to our recent experiment [ 20 ] performed on GNR-loaded agar phantom, the diffusivity of the phantom loaded with GNRs increased around 22% at a temperature of around 62 °C compared to the one at room temperature. So, in this study, we considered the average value of diffusivity from room temperature to be 62 °C [ 20 ]. To estimate the refractive index (RI) of pancreas tumor loaded with GNRs, the mole fraction of pancreas tumor alone and with GNR was calculated separately.…”

“…Despite many signs of progress in NPs-assisted PTT of cancer, this multifunctional approach remains a method with limited clinical applications since some obstacles hinder the translation from research to clinical practice. Furthermore, there is still a need to evaluate many factors such as the optimum concentration and size for NPs (by considering the kind of NPs) and thermal behavior-related parameters whose information is needed for precise pre-planning of NPs-assisted photothermal therapy [ 20 ]. This information can be related to the diverse biological and thermal behavior of different tissues during NPs-assisted PTT.…”

Measurement of thermal properties of biological tissues and tissue-mimicking phantom with a dual-needle sensor

“…The measurement of the physical properties of tissues of biological origin represents a crucial aspect for several areas of biomedical engineering [1]. These areas range from the research intended to realize tissue-mimicking phantoms, i.e., materials that mimic the characteristics of biological media and are worthwhile for the testing and improvement of medical systems [2]- [6], to the characterization of tissue properties aimed at optimizing diagnostic and therapeutic procedures [7], [8]. In this regard, the study of the thermal properties of biological tissues assumes a pivotal role as these properties regulate the way heat distributes within tissue, thus, they are involved in all therapies which entail a variation of the tissue temperature to treat a disease [8].…”

Editorial for Special Issue “Cancer Treatment via Nanotherapy”

“…Asadi et al evaluated the thermal response of three different NPs (black porous silicon NPs, biodegradable and excretable narrow-NIR-responsive ultrasmall-in-nano architectures, gold nanoparticles) to an 808 nm laser beam with three different powers [ 2 ]. The study found that gold nanoparticles have the highest conductivity and diffusivity and that black porous silicon-NPs have the highest radiosensitivity.…”