Functional activity of animal bone marrow cells after their treatment with nanocomplexes

Abstract

Background. Previously, the antitumor activity of nanocomplexes (NCs) containing nanoparticles of rare earth metal orthovanadates GdYEuVO4 and cholesterol has been approved when applied in 9:1 ratio (the cells-to-NCs), which can be considered as a conditionally therapeutic dose. Therefore, studying the potential risks of NCs exposure in terms of functional activity of hematopoietic progenitor cells is relevant. Рurpose – determining a toxic effect of NCs on functional activity of hematopoietic cells of bone marrow (BM). Materials and Methods. The study was performed in BM cells of CBA/H mice. Nanocomplexes were synthesized at Institute for Scintillation Materials of the National Academy of Sciences of Ukraine. BM cells with NCs were incubated in the ratios as follows: 9BM:1NCs; 1BM:1NCs; 1BM:9NCs, followed by assessing the number of apoptotic/necrotic cells in BM using FITC Annexin V Apoptosis Detection Kit I (BD, USA) by means of “FACS Calibur” flow cytometer (“BD”, USA). Hematopoietic progenitor cells of BM were functionally evaluated in vivo by determining the content of colony-forming units of the spleen (CFUs) and the number of myelokaryocytes in lethally irradiated recipients on day 8 after administering BM cells, pre-incubated with NCs. Survival of irradiated recipient mice after BM administration was recorded 12 days long. Results and discussion. The dose-dependent effect of functional potential in- hibition for BM hematopoietic progenitor cells under NCs influence has been established. Although, in vitro processing the BM cells with a conditionally therapeutic dose of NCs (9BM:1NCs) before administration to irradiated animal caused remodeling of cell membranes and contributed to apoptotic manifes- tations, but it did not lead to strong changes in their colony-forming potential and did not reduce the number of BM cells in animals if compared with the introduced BM cells without NCs treatment. Increasing the NCs concentration five- and tenfold significantly reduced the colony-forming potential of BM cells, caused BM hypoplasia and a crucial reduction in the survival of recipient animals, indicating possible toxic effects of this compound when administered at high concentrations. Conclusions. The toxic effect of NCs is detected only when certain concen- trations, significantly exceeding the conditionally therapeutic dose previously determined when treating the experimental oncology diseases, are used.