Nanobubbles in pulsed laser fields for anticancer therapy: in search of adequate models and simulation approaches

Kostyukov, A. S.; Isaev, I. L.; Ershov, A. E.; Gerasimov, V. S.; Polyutov, S. P.; et al. // Journal Of Physics D-applied Physics//

We numerically investigate the conditions for the laser-induced formation of nanobubbles in aqueous medium around plasmonic nanoparticles (NPs) bound to the malignant cell membranes that is considered as the method of their irreversible damage. We proposed employing the versatile and accessible simulation software as a research tool based on the finite volume method underlying the ANSYS Fluent package and supplemented with our user-defined functions that adapt it to solution of the stated problems. This adaptation allows to verify the model using experimental data for the same conditions. We determined the conditions for the pressure growth on the cell membrane at the initial moment of bubble formation significantly exceeding the threshold of irreversible damage. The model can be used for investigation of hydrodynamic effects accompanying irradiation of plasmonic NPs using both different types of pulsed lasers and ideally absorbing NPs with resonance in the hemoglobin spectral transparency range, as well as to uncover previously unknown effects. They include the conditions for localization of a damaging factor non-affecting the normal cells, the conditions for generation of ultrahigh pressure pulse that enables to damage the cell membrane and precedes formation of thin vapor shell around NPs, which, unlike large bubbles, requires registration using highly sensitive experimental measurements. An extensive overview of key publications summarizing the state-of-art in this area is presented.