CC BY
3*
ALT'23 The 30th International Conference on Advanced Laser Technologies
B-O-7
Iron oxide nanoparticles coated with a photosensitizer for phototherapy: experimental study of local intracellular heating
A. Ryabova12, D. Pominova12, I. Markova2, A. Nikitin3, P. Ostroverhov3, E. Plotnikova4, N. Morozova4, I. Romanishkin1, M. Abakumov3, A. Pankratov4, R. Steiner2, V. Loschenov12
1-Prokhorov General Physics Institute of the Russian Academy of Sciences, 119991 Russia, Moscow, Vavilov-38 2- National research nuclear university MEPHI, Moscow, Russia
3- National University of Science and Technology "MISIS", Moscow, Russia
4-National University of Science and Technology "MISIS", Moscow, Russia
5- National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, P. A. Hertsen
Moscow Oncology Research Institute, Moscow, Russia
Iron oxide nanoparticles (IONPs) are promising for diagnosis and therapy: they can be coated with a photosensitizer for photodynamic therapy, laser or magnetic heating of IONPs can be used for controlled drug release or phototherapy [1]. Temperature measurement for cell organelles containing NPs during phototherapy is important, but complex and challenging. Fluorescent thermometers are reliable tools for measuring temperature fluctuations in nano-volumes, given their advantages such as fast response, high sensitivity and spatial resolution, ease of use and non-destructive detection [2].
In this work we performed an experimental study of the emergence of "hot spots" of IONPs ensembles of different sizes and shapes during laser scanning with the estimation of heat distribution over the cell volume using the fluorescence thermometry based on rhodamine B (RhB) lifetime measurement. In order to interpret the experimental data obtained, numerical simulations of the scattering and absorption cross sections of the studied IONPs and their ensembles, as well as the field enhancement and heating during the interaction with the excitation electromagnetic radiation were performed using the finite-difference time-domain method. Depending on the IONPs shape and their location in space, a significant change in the spatial distribution of the EM field near the IONPs surface was observed. The local heating of IONPs in an ensemble reaches sufficiently high values; the relative change was about 35°C for Fe2O3 NPs. Nevertheless, all the studied IONPs water colloids showed heating by no more than 10°C. The heating temperature of the ensemble depends on the thermal conductivity of the medium, on which the heat dissipation depends. When capturing IONPs inside the cell into lysosomes - lipid sacs with lower thermal conductivity, the situation was different. As a result, so-called "hot spots" with temperature over 100°C can appear inside cells around the accumulation of IONPs in vesicles. The distribution of "hot spots" determines the thermal response of the entire biosample. It should have a certain effect on the cell death mechanism through hyperthermia and the lysosomes destruction response.
The work was supported by the RFBR, grant 21-52-12030.
[1] S.K. Sharma, N. Shrivastava, F. Rossi, L.D. Tung, N.T.K. Thanh. Nanoparticles-Based Magnetic and Photo Induced Hyperthermia for Cancer Treatment, Nano Today, vol.29, p.100795 (2019).
[2] J. Zhou, B. del Rosal, D. Jaque, S. Uchiyama, D. Jin. Advances and Challenges for Fluorescence Nanothermometry. Nat Methods 2020, vol.17,
pp. 967-980 (2020).
