Distribution and histologic effects of intravenously administered amorphous nanosilica particles in the testes of mice

• Published in: Biochemical and biophysical research communications 2012-04, Vol.420 (2), p.297-301
• Main Authors: Morishita, Yuki, Yoshioka, Yasuo, Satoh, Hiroyoshi, Nojiri, Nao, Nagano, Kazuya, Abe, Yasuhiro, Kamada, Haruhiko, Tsunoda, Shin-ichi, Nabeshi, Hiromi, Yoshikawa, Tomoaki, Tsutsumi, Yasuo
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; Animals; Biodistribution; BLOOD; CONSUMER PRODUCTS; DIFFUSION BARRIERS; HEALTH HAZARDS; IN VITRO; IN VIVO; Injections, Intravenous; Male; MICE; Mice, Inbred BALB C; Microscopy, Electron, Transmission; Nanomaterials; Nanoparticles - administration & dosage; NANOSTRUCTURES; PARTICLE SIZE; Reproductive toxicity; Safety; Silicon Dioxide - administration & dosage; Silicon Dioxide - pharmacokinetics; SPERMATOCYTES; TESTES; Testis - metabolism; Testis - ultrastructure; TOXICITY; TRANSMISSION ELECTRON MICROSCOPY; VENTILATION BARRIERS
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2012.02.153

► There is rising concern regarding the potential health risks of nanomaterials. ► Few studies have investigated the effect of nanomaterials on the reproductive system. ► Here, we evaluated the intra-testicular distribution of nanosilica particles. ► We showed that nanosilica particles can penetrate the blood-testis barrier. ► These data provide basic information on ways to create safer nanomaterials. Amorphous nanosilica particles (nSP) are being utilized in an increasing number of applications such as medicine, cosmetics, and foods. The reduction of the particle size to the nanoscale not only provides benefits to diverse scientific fields but also poses potential risks. Several reports have described the in vivo and in vitro toxicity of nSP, but few studies have examined their effects on the male reproductive system. The aim of this study was to evaluate the testicular distribution and histologic effects of systemically administered nSP. Mice were injected intravenously with nSP with diameters of 70nm (nSP70) or conventional microsilica particles with diameters of 300nm (nSP300) on two consecutive days. The intratesticular distribution of these particles 24h after the second injection was analyzed by transmission electron microscopy. nSP70 were detected within sertoli cells and spermatocytes, including in the nuclei of spermatocytes. No nSP300 were observed in the testis. Next, mice were injected intravenously with 0.4 or 0.8mg nSP70 every other day for a total of four administrations. Testes were harvested 48h and 1week after the last injection and stained with hematoxylin–eosin for histologic analysis. Histologic findings in the testes of nSP70-treated mice did not differ from those of control mice. Taken together, our results suggest that nSP70 can penetrate the blood-testis barrier and the nuclear membranes of spermatocytes without producing apparent testicular injury.