The impact of orally administered gadolinium orthovanadate GdVO4:Eu3+ nanoparticles on the state of phospholipid bilayer of erythrocytes

Objectives: To assess the state of phospholipid bilayer of red blood cells (RBCs) in rats orally exposed to gadolinium orthovanadate GdVO4:Eu3+ nanoparticles (VNPs) during two weeks using fluorescent probes - ortho-hydroxy derivatives of 2,5-diaryl-1,3-oxazole. Methods: Steady-state fluorescence spectroscopy: a study by the environment-sensitive fluorescent probes - 2-(2'-OH- phenyl)-5-phenyl-1,3-oxazole (probe O1O) and 2-(2'-OH-phenyl)-phenanthro [9,10]-1,3-oxazole (probe PH7). Results: No significant changes are detected in the spectra of the fluorescent probes bound to the RBCs from the rats orally exposed to nanoparticles in comparison with the corresponding spectra of the probes bound to the cells from the control group of animals. This indicates that, in case of the rats orally exposed to nanoparticles, no noticeable changes in physico-chemical properties (i.e., in the polarity and the proton-donor ability) are observed in the lipid membranes of RBCs in the region, where the probes locate. Conclusions: No changes in the physical and chemical properties of the erythrocyte membranes are detected in the region from glycerol backbones of phospholipids to the center of the phospholipid bilayer in the rats orally exposed to VNPs during 2 weeks.