ИСТИНА

In the last decade, different types of nanoparticles (NP) have been proposed as biocompatible and promising for various applications in many fields of life sciences. In particular, iron (iii) oxide nanoparticles (Fe2O3) and carbon NP - nanodiamonds (ND), titanium dioxide (TiO2) and silicon NP, nanotubes and fullerenes have been proposed for using in Theranostic Applications – biomedical imaging and photodynamic therapy, direct drug delivery and etc. [1]. It is presumed that in order to reach the target these particles would be intravenously administered into blood. However, so far there is little information on the interaction of NP with major blood components. It can be assumed that NP can affect the red blood cells (RBCs) properties such as their ability to reversibly aggregate and deform in shear flow when propagating along blood vessels and capillaries. These alterations can impair blood rheology and, as a result, increase the risk of development of cardiovascular diseases and even mortality during medical application of NP. The aim of our work was to study in vitro and in vivo the effect of NP on blood microrheology – aggregation and deformability properties of the cells. Laser diffractometry, diffuse light scattering aggregometry, as well as optical trapping [2] were used to study various aspects of the interaction of NP with rat and human red blood cells (RBC). It is expected that the results of the study of the interaction of NP with RBC and other blood cells in vitro can provide a basis for determining their cytotoxicity without conducting experiments with animals in vivo. When accomplished, this test may significantly reduce the need for experiments with animals when studying the effect of NPs on the human organism. To investigate the interaction between the NPs and RBCs, namely, to study sorption onto the membrane and cellular penetration, we performed experiments using the fluorescence laser confocal microscopy. All experimental results were obtained on EDTA stabilized human and rat blood samples incubated with NP of different sizes and surface functionalization in different concentrations for in vitro and in vivo conditions. It was shown that 45 min-long incubation of RBCs 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. The alterations in the microrheological properties are more significant for higher NP concentrations and more pronounced for non-functionalized particles in comparison with Fe2O3 particles functionalized with porphyrin (fig. 1c) and carboxylated ND. We demonstrated that the effects on blood microrheological properties of NP incubated with blood (in vitro) and administrated intravenously into laboratory animals (in vivo) are similar. Basing on the results one can conclude that the NP can be administered into blood in ambient conditions at low concentrations (33 µg/ml), without significant complication of the blood rheological conditions. However, controlling the RBCs microrheological properties is necessary during treatment. We can conclude that it is not possible to make a general conclusion about the effect of the nanoparticles on the rheological properties of RBC. 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.