Nanoscale physics

Physical description of near-field interaction of nanoparticles with microorganisms
Rusinchuk N.1, Lozovski V.1,2, Lysenko V.2
1 Institute of High Technologies, Taras Shevchenko National University of Kyiv, Glushkova ave., 4g, Kyiv-03187, Ukraine. 
E-mail: n.m.rusinchuk@gmail.com
2V.E. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
Nowadays nanoparticles are widely used in biomedicine, where their interactions with living cells or microorganisms occur. It is important to understand mechanisms of these interactions and to describe them theoretically. In our previous works we proposed models that allow explaining interaction between the nanoparticles and viruses and to explain experimental results on antiviral and virucidal action of nanoparticles [1]. However, these models cannot be applied to explain the results of experiments on interaction of nanoparticles with microorganisms. Hence, the task of the work was to develop a model that would describe the near-field interaction of nanoparticles with microorganisms whose size is much larger than hundreds of nanometers. To do this, it was shown that the interaction of nanoparticles with microorganisms can be considered at several levels: the interaction of nanoparticles with the surface of the microorganism, the interaction of nanoparticles with intracellular organelles, and the interaction of nanoparticles with intracellular DNA during replication. It was shown that the DNA molecule from the point of view of nanophysics is a complex nanoparticle with built-in polarization, and therefore the model of interaction of two nanoparticles with certain modifications can be applied to description of such interaction. It also was shown that the whole microorganism from the point of view of nanophysics interacts with the nanoparticle primarily due to the structure of its surface (i.e. shell), while the internal structure affects this interaction slightly and can be represented in the model as a certain additional gain or weakening. This makes it possible to consider the interaction of a nanoparticle with microorganisms as the interaction of a nanoparticle with a nanostructured surface of some curvature. It has been shown that the method of the pseudo-vacuum Green's function can be used to describe such an interaction with satisfactory accuracy.
This work was supported by National Research Foundation of Ukraine, Project 2020.02/0352. 

1.	Lozovski, V.Z., Lysenko, V.S., Rusinchuk, N.M. Near-field interaction explains features of antiviral action of non-functionalized nanoparticles // Adv Nat Sci: Nanosci Nanotech.-2020.-11.- No. 015014.