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 (ZnO:Eu 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 ZnO:Eu NPs. Microscopic evaluation based on immunofluorescence and histopathological studies were also conducted. Results showed that ZnO:Eu 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 ZnO:Eu NPs were able to accumulate in the testis with no negative impact on sperm parameters, tissue architecture or the integrity of the BTB.

Biodegradable Zinc Oxide Nanoparticles Doped with Iron as Carriers of Exogenous Iron in the Living Organism

“…), route of administration and dose may strongly affect their behavior in the organism. Our previous studies reported efficient absorption of orally administered, zinc-based nanoparticles [ 33 , 34 , 35 , 36 ]. Hilty et al also reported that nanosized Fe/Zn compounds presented higher bioavailability, compared to standard FeSO 4 [ 40 ].…”

“…ZnO:Fe nanoparticles were prepared using microwave hydrothermal technique [ 33 , 34 , 35 , 36 ]. Two starting compounds as the iron ions source were used to obtain two kinds of samples: ZnO:Fe containing only Fe 3+ ions and ZnO:Fe 3+ enriched with Fe 2+ ions.…”

“…However, the use of iron-doped nanoparticles as potential carriers of exogenous iron to the living organism is novelty. According to our previous studies, zinc-based nanoparticles provide a safe, biodegradable, fast and very efficient transport system for orally given substances to key organs [ 33 , 34 , 35 , 36 ]. Promising results of mentioned studies prompted the start of research on zinc-based nanoparticles doped with iron.…”

Perspectives of Nanoparticles in Male Infertility: Evidence for Induced Abnormalities in Sperm Production

“…Sundarraj et al [90] observed the accumulation of NPs in the testis of mice after iron oxide NP (25 and 50 mg/kg) exposure, documenting the ability of these NPs to cross the BTB and accumulate in the testicular tissue as demonstrated by the presence of iron content. Oral administration of fluorescent europium doped ZnO NPs to mice for 14 days showed their accumulation in testes, indicating the penetration of these NPs through the BTB [91]. Similarly, after intragastric administration of TiO2 NPs at the concentration of 2.5, 5 and 10 mg/kg BW in male mice for 90 days, it was observed that NPs crossed the BTB, reached the testes and then accumulated, inducing testicular toxicity resulting in poor quality of sperm, changes in hormone level and testicular lesions [92].…”

Adverse Effects of some of the Most Widely used Metal Nanoparticles on the Reproductive System

“…These effects are as reduction and loss of cells in seminiferous tubules in testicular tissue. In fact, these nanoparticles are able to degenerate and decrease cell types in the seminiferous tubules (such as spermatogonia, primary spermatocyte, spermatid and sperm cells), outer part of the tubules (such as leydig, fibroblast cells and blood vesicles), seminiferous epithelium and tubule are diameters (128).…”