ИСТИНА

Nanoparticles (NPs) have strong potential for diagnostic and therapeutic applications in all industries, especially in medicine. Commonly it is intended to administer NP into human body by injecting them into the bloodstream. However, nowadays, there is no evidence confirming that this will not negatively influence the blood constitution and circulation and, consequently, the patient’s health. That is why it is important to characterize the RBCs interaction in the presence of NPs. In contrast to our previous works [1], in which the interaction of a certain type of NP, namely titanium dioxide, with RBC was studied, in this paper, the influence of different NPs on the characteristic time of RBCs pair aggregates (doublets) formation, the aggregation and disaggregation forces of RBCs was additionally studied using laser tweezers. Laser tweezers were used to capture and manipulate individual RBCs in order to measure the parameters of RBCs pair aggregation. An optical trap is a region of constriction of an acutely focused laser beam. The principle of operation of the laser tweezers is based on the use of forces acting on the cells under study from the laser beam. [2]. Blood samples were drawn from a healthy donor and were stabilized with EDTA to prevent blood clotting. After that they were incubated with different NPs: TiO2, nonfunctionalized nanodiamonds (NDs) and magnetic nanodiamonds (MNDs) in concentration of 40 µg/ml. All experiments were carried out within 3 hours after blood sampling The obtained result show that the presence of any type of investigated nanoparticles in human blood leads to an increase in all measured parameters of RBC pair aggregation (fig. 1-3). Based on our results, it can be concluded that incubation of nanoparticles with human blood results in a decrease of RBC aggregation rate. At the same time, the forces of aggregate formation and destruction become higher. Legend: • NDs (2 hours) - blood with the addition of nanodiamonds and incubation for 2 hours • NDs (1 hour) - blood with the addition of nanodiamonds and incubation for 1 hour • TiO2 - blood with the addition of TiO2 Hombitan and incubation for 1 hour • MNDs - blood with the addition of MND incubation for 1 hour This work was supported by the Russian Science Foundation (Grant No. 20-45-08004) 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». [1] Neznanov A.I. et al., “Effect of titanium dioxide nanoparticles on human red blood cells microrheologic properties: in vitro studies by laser techniques”. Book of abstracts of International Symposium on Optics & Biophotonics within Saratov Fall Meeting (SMF-2019), Saratov, 28.09.2019-02.10.2019. [2] Ermolinskiy P.B. et al., “Interaction of erythrocytes in the process of pair aggregation in blood samples from patients with arterial hypertension and healthy donors: measurements with laser tweezers”, J. of Biomedical Photonics & Eng. 4(3), 030303 (2018)