Distribution of nanoparticles in the pregnant rat: the morphologic and spectroscopic study

Abstract

The nanoparticles (NP) applications in industry and biomedicine are growing despite of superficial understanding about the mechanisms of NP biological interactions and the possible toxicity. The beneficial NP applications in medicine, as well as potential adverse effects, first of all depend on the NP accumulation and localization in the organism. The human in pre-natal stages is more sensitive to toxic materials than the adult organism and, therefore, it is physiologically protected from harmful agents by the selective transport across the placental barrier. However, there is a lack of studies on the NP penetration through this barrier and the accumulation in foetus. In this study fluorescence spectroscopy and confocal microscopy methods were employed to investigate the distribution of polyethylene glycol (PEG) coated semiconductor quantum dots (QD) in the pregnant rat model. The main results indicate that QD are systemically distributed in the body and can be found in all the investigated organs, including placenta and uterus 3 h after the intraperitoneal injection. However, QD could not be detected in the foetal tissues (embryo, yolk sac placenta, umbilical cord). The study shows that QD mainly accumulate in the maternal blood sinuses of the placenta and the QD passage to the foetus is prevented by the placental barrier.