ИСТИНА

Different types of nanoparticles (NP) have been shown to be biocompatible and promising for various biomedical applications [1]. In particular, iron oxide NP and nanodiamonds (ND), magnetic ND, zinc oxide, aluminum oxide, titanium dioxide and silicon NP have been proposed for their application for biomedical imaging, photodynamic therapy and targeted drug delivery [2-4]. It is presumed that in order to reach the goal these particles should be intravenously administered into the blood. In principle, NP can affect the properties of blood cells, in particular, erythrocytes such as their ability to reversibly aggregate and deform in shear flow when moving along blood vessels and capillaries. There are a few possible mechanisms of the NP interaction with erythrocytes, in particular, potential opportunity of the particles to adsorb on the cell’s membranes and their partial penetration into the internal content of the cells. All these phenomena can result to membrane rigidity and internal cell viscosity alterations which in turn lead to changing the red blood cells deformability – the ability of the cells to change their shape flexibly and reversibly by passing through the capillaries with diameter less or equal than the cells size. Another consequence of the NP interaction is that their adsorption on the surface membrane leads to a decreasing the area of possible direct cell contacts and results in impairment of erythrocytes spontaneous and reversible aggregation. In turn, both deformability and aggregation properties determine the viscosity of blood on which the blood circulation crucial depends. Thus, before clinical applications it is necessary to verify the NP on safety including regarding deformability and aggregation microrheologic parameters of the blood. In this work we tested blood samples in vitro incubated with different NP with variety of sizes and surface functionalization. The basics of laser diffractometry, diffuse light scattering aggregometry, as well as optical trapping techniques to study the effect of NP on blood microrheologic parameters are discussed [5]. To investigate the mechanisms of the NP interaction with erythrocytes we used the fluorescent microscopy and spectroscopy technique erythrocytes. Comparing of the spectra of the erythrocytes measured before and after the incubation with NP demonstrated membrane adsorption and/or intracellular penetration of some types of the NP. Using fluorescent microscopy, we obtained the images of erythrocytes samples and NP clearly showing the membrane adsorption of the latter. The effect of NP on blood microrheology are demonstrated. Incubation of blood with NP at high concentrations of the latter does negatively affect both aggregation and deformability of the cells, the effect being dependent on the particle concentration, size and surface functionalization. Basing on the measurement results one can conclude that the NP can be administered into blood in ambient conditions at low concentrations (above 30 µg/ml), without significant complication of the blood rheological conditions. However, under certain conditions, this effect can be very significant, and it is necessary to check the hemocompatibility of each type of nanoparticles in vitro. This work was supported by the Russian Scientific Foundation (Grant No. 23-45-00027) and performed according to the Development program of the Interdisciplinary Scientific and Educational School of Lomonosov Moscow State University «Photonic and Quantum technologies. Digital medicine».