MODERN PROBLEMS OF NUCLEAR ENERGY AND NUCLEAR TECHNOLOGIES

BISMUTH-BASED NANOPARTICLES AS AN EFFECTIVE RADIOSENSITIZER IN PHOTON ACTIVATION THERAPY

Not scheduled

20m

Institute of Nuclear Physics

Applied aspects of nuclear physics Applied aspects of nuclear physics

Speaker

Dildora Rasul Rasulova (Institute of nuclear physics AS RUz)

Description

The enhancement of absorbed X-ray dose in tumor cells induced by bismuth-based nanoparticles, emphasizing their role as a radiosensabilizator in Photon Activation Therapy (PAT). Bismuth (Z = 83), due to its high atomic number, biocompatibility, and strong photoelectric absorption cross-section, has emerged as a promising candidate for dose enhancement strategies in radiotherapy. Unlike another radiosensitizers, Bi nanoparticles exhibit higher density and more localized energy deposition, thereby increasing the probability of DNA double-strand breaks in tumor cell nuclei. Notably, this dose enhancement is achieved at nanoparticle concentrations substantially below the established non-toxic blood accumulation threshold in humans 800 ppm [1], with our simulations conducted at only 50 ppm.
Mathematical modeling was conducted for a single endiathel cell volume ~2 × 10-10 cm3 using a 100 kVp X-ray tube spectrum simulated via SpekPy software. Bismuth nanoparticles with an average size of 3.6 nm and a concentration of 50 ppm were considered in the system [2]. Absorbed dose distribution, photoelectric effect probabilities, and contributions from secondary electrons—including Auger and Coster-Kronig processes—were calculated for an irradiation period of one second. These simulations highlighted the dominance of low-energy electron cascades in enhancing localized radiation damage at the sub-cellular level, with photoelectrons contributing a 4.2-fold enhancement and Auger electrons providing a 2.8-fold increase [3]. The results revealed a substantial increase in absorbed dose in the presence of Bi nanoparticles compared with the control (without nanoparticles). This dose amplification is attributed mainly to photoelectric interactions and secondary electron production, confirming the efficacy of bismuth as a potential radiosensabilizator. This finding is particularly relevant in the context of PAT, where efficient dose delivery and selective tumor damage are required. The evaluation of the research underscores the therapeutic potential of Bi nanoparticles in oncology by offering localized energy amplification while minimizing systemic toxicity. Size of nanoparticles ensures potential biocompatibility and cellular uptake, reducing off-target effects. The application of bismuth as a radiosensabilizator represents an advancement over traditional metal-based sensitizers, suggesting broader clinical applicability for enhancing the therapeutic index of radiotherapy. These insights align with the ongoing search for effective nanomaterials that combine high-Z properties with biological safety, and the results encourage further preclinical and experimental studies, as well as optimization of nanoparticle concentration, irradiation parameters, and delivery methods to intoduce this approach into clinical practice.

1. Badrigilan, S., Heydarpanahi, F., Choupani, J., Jaymand, M., Samadian, H., Hoseini Ghahfarokhi, M., Webster, T.J., Tayebi, L., 2020. A review on the biodistribution, pharmacokinetics and toxicity of bismuth-based nanomaterials. Int. J. Nanomedicine. 15, 7079–7096.
2. Yu, X., Trase, I., Ren, M., Duval, K., Guo, X., Chen, Z., 2017b. Design of NP-based carriers for targeted drug delivery. ACS Nano 11 (4), 3990–4001.
3. Abdullaeva G.A., Rasulova D.R., Kulabdullaev G.A. The enhancement of X-ray absorbed dose in tumor cells via bismuth-based nanoparticles. Radiat. Phys. Chem. 2026;238:110387.