Dose dependent intra-testicular accumulation of silver nanoparticles triggers morphometric changes in seminiferous tubules and Leydig cells and changes the structural integrity of spermatozoa chromatin.

Citrate-coated silver nanoparticles were synthesized in one step method using tri-sodium citrate and silver nitrate at pH 6.1. After synthesis, the resulting silver nano-suspension was characterized using UV-visible spectroscopy, dynamic light scattering, high resolution-scanning electron microscopy, energy dispersive x-ray spectroscopy and fourier transform infrared-spectroscopy. The particles were intraperitoneally injected into Swiss albino male mice for a period of one complete spermatogenic cycle. The LD was determined following the procedure of Dixon's Up-and-Down method. The intra-testicular level of silver was measured using the technique of inductively coupled plasma-mass spectrometry. The intra-testicular location of accumulated nanoparticles was observed using auto-metallography. The cytology and volume of Leydig cells were assessed and analysed. Following the exposure to silver nanoparticles, it was found that accumulation of nanoparticles inside the seminiferous tubules is a dose-dependent process. The deposition of silver agglomerate induced morphometric changes in the lumen of seminiferous tubules and Leydig cells. The exposure also caused significant changes at the level of structural integrity of sperm chromatin material and variable damages to sperm DNA.