The biological activity of γ-Fe₂O₃ magnetic nanoparticles (MNPs), obtained by the laser target evaporation technique, was studied, with a focus on their possible use in biosensor applications. The biological effect of the MNPs was investigated in vitro on the primary cultures of human dermal fibroblasts. The effects of the MNPs contained in culture medium or MNPs already uptaken by cells were evaluated for the cases of the fibroblast’s proliferation and secretion of cytokines and collagen. For the tests related to the contribution of the constant magnetic field to the biological activity of MNPs, a magnetic system for the creation of the external magnetic field (having no commercial analogues) was designed, calibrated, and used. It was adapted to the size of standard 24-well cell culture plates. At low concentrations of MNPs, uptake by fibroblasts had stimulated their proliferation. Extracellular MNPs stimulated the release of pro-inflammatory cytokines (Interleukin-6 (IL-6) and Interleukin-8 (IL-8) or chemokine (C-X-C motif) ligand 8 (CXCL8)) in a concentration-dependent manner. However, the presence of MNPs did not increase the collagen secretion. The exposure to the uniform constant magnetic field (H ≈ 630 or 320 Oe), oriented in the plane of the well, did not cause considerable changes in fibroblasts proliferation and secretion, regardless of presence of MNPs. Statistically significant differences were detected only in the levels of IL-8/CXCL8 release.

Dendritic cells (DCs), loaded with tumor antigens, are widely investigated as a potential therapeutic tool for cancer treatment. CCR7 plays the key role in DCs migration to lymph nodes for the anti-tumor immune response activation. The purpose of this study was to investigate the effect of different compositions for DC maturation on the CCR7 expression. Materials and methods. DCs were derived from peripheral blood monocytes in medium supplemented with GM-CSF and IL-4. Five different compounds were used for stimulation of DCs maturation. The expression of CCR7 was evaluated by flow cytometry. Results and discussion. The highest level of CCR7 expression was seen when the ‘‘cytokine cocktail” (TNF+IL-1+IL-6+PGE2) or the poly I:C were used for the stimulation of cell maturation. At the same time, the immunosuppressive effect of PGE2 and poly I:C cannot be excluded. Therefore, additional investigations of functionality of DCs after induced maturation are required.

The aim of the work — study the effect of clopidogrel on platelets under conditions of mandibular bone injury. Materials and methods of research. The experiment was carried out on 40 white nonlinear rats, which were divided into two groups. The animals in the experimental group were injected with the anticoagulant clopidogrel intraperitoneally daily for 7 days prior to operation and until the moment of withdrawal from the experiment (1, 3 and 7 days after injury). Operations in control group animals were conducted without clopidogrel injection. Platelet parameters such as absolute platelet count, mean platelet volume, large platelet ratio and thrombocrit were determined and platelet aggregation activity was analysed. The results of the study. Intraperitoneal administration of clopidogrel with and without bone injury changes both the functional properties of platelets and platelet parameters of the general blood test, consumption of different platelets occurs. Conclusions. The following conclusions were made based on the results of the work: intraperitoneal administration of clopidogrel leads to complete blocking of platelet aggregation function; Surgery performed on the background of such therapy is accompanied by a more intensive consumption of platelets than without an antiplatelet agent; against the background of the use of clopidogrel, there is a uniform consumption of platelets of different volumes, while during surgical intervention in the absence of an antiplatelet agent, smaller and more mature platelets are predominantly recruited; bone tissue trauma stimulates aggregation activity during the early postoperative period even with complete preoperative blocking of platelets with clopidogrel.