Transfer of orally administered ZnO:Eu nanoparticles through the blood-testis barrier: the effect on kinetic sperm parameters and apoptosis in mice testes.

ABSTRACT

Zinc-based nanoparticles are promising materials for various applications, including in biomedicine. The aim of our study was to determine the effect of fluorescent europium-doped zinc oxide nanoparticles (ZnOEu NPs) on sperm parameters, cell apoptosis and integrity of the blood-testis barrier (BTB) in mice. Nanostructures were orally administered to adult mice (n = 34). Animals were sacrificed after 3 h, 24 h, 7 d and 14 d following oral administration. Sperm was collected and analysed for viability and kinetic parameters. Collected testes were quantitatively analysed for accumulation of ZnOEu NPs. Microscopic evaluation based on immunofluorescence and histopathological studies were also conducted. Results showed that ZnOEu NPs were able to overcome the BTB with their subsequent accumulation in the testis. No toxic or pro-apoptotic effects of nanoparticles on the male reproductive system were observed. The results suggested that ZnOEu NPs were able to accumulate in the testis with no negative impact on sperm parameters, tissue architecture or the integrity of the BTB.