Numerical Simulation of Enhancement of Superficial Tumor Laser Hyperthermia with Silicon Nanoparticles

Abstract

Biodegradable and low-toxic silicon nanoparticles (SiNPs) have potential in different biomedical applications. Previous experimental studies revealed the efficiency of some types of SiNPs in tumor hyperthermia. To analyse the feasibility of employing SiNPs produced by the laser ablation of silicon nanowire arrays in water and ethanol as agents for laser tumor hyperthermia, we numerically simulated effects of heating a millimeter-size nodal basal-cell carcinoma with embedded nanoparticles by continuous-wave laser radiation at 633 nm. Based on scanning electron microscopy data for the synthesized SiNPs size distributions, we used Mie theory to calculate their optical properties and carried out Monte Carlo simulations of light absorption inside the tumor, with and without the embedded nanoparticles, followed by an evaluation of local temperature increase based on the bioheat transfer equation. Given the same mass concentration, SiNPs obtained by the laser ablation of silicon nanowires in ethanol (eSiNPs) are characterized by smaller absorption and scattering coefficients compared to those synthesized in water (wSiNPs). In contrast, wSiNPs embedded in the tumor provide a lower overall temperature increase than eSiNPs due to the effect of shielding the laser irradiation by the highly absorbing wSiNPs-containing region at the top of the tumor. Effective tumor hyperthermia (temperature increase above 42 °C) can be performed with eSiNPs at nanoparticle mass concentrations of 3 mg/mL and higher, provided that the neighboring healthy tissues remain underheated at the applied irradiation power. The use of a laser beam with the diameter fitting the size of the tumor allows to obtain a higher temperature contrast between the tumor and surrounding normal tissues compared to the case when the beam diameter exceeds the tumor size at the comparable power.

Monitoring of optical properties of tumors during laser plasmon photothermal therapy

“…We emphasize that the model was simplified due to the uniform distribution of particles in the tumor volume that contributed to a high absorption coefficient of tumor tissue at a wavelength of 808 nm. This simplification is widely used by many authors to simulate the propagation of laser radiation and heat in similar tasks [22, 65–68]. Our results agree with previous simulations [68–70], demonstrating stronger skin heating than a tumor without additional absorbers in the form of plasmonic nanoparticles or dyes.…”

Enhancement of skin tumor laser hyperthermia with Ytterbium nanoparticles: numerical simulation

“…The researchers used the Monte Carlo technique and Beer's law in their study to estimate the thermal production of tissue and GNPs when exposed to laser irradiation. Sokolovskaya et al [23] carried out a study to assess the viability of utilizing silicon nanoparticles (SiNPs) generated through laser ablation of silicon nanowire arrays in water and ethanol for laser tumor HT. The numerical simulations were performed to analyze the impact of continuous-wave laser radiation at a wavelength of 633 nm on heating a millimeter-sized nodal basal-cell carcinoma that contained embedded nanoparticles.…”

Effect of bio-tissue deformation behavior due to intratumoral injection on magnetic hyperthermia

“…[1][2][3] The most important factor for the success of therapy is to control the treatment temperature for tumor region within a range from 42 • C to 46 • C, in which malignant cells can be damaged due to their thermal sensitivity while healthy cells can survive. [4,5] However, the treatment temperature distribution inside the tumor region should be determined by many factors, and the most two important elements are the power dissipation for magnetic nanoparticles (MNPs) and the nanofluid concentration distribution inside the tumor region. [6,7] The heat dissipated by the MNPs is primarily determined by the characteristics of the applied magnetic field and MNPs.…”