comparison of toxicity of cdse: zns quantum dots on male reproductive system in different stages of development in mice

background: quantum dots (qds) are new types of fluorescent materials for biological labeling. qds toxicity study is an essential requirement for future clinical applications. therefore, this study aimed to evaluate cytotoxic effects of cdse: zns qds on male reproductive system. materials and methods: in this experimental study, the different concentrations of cdse: zns qds (10, 20 and 40 mg/kg) were injected to 32 male mice (adult group) and 24 pregnant mice (embryo group) on day 8 of gestation. the histological changes of testis and epididymis were studied by a light microscopy, and the number of seminiferous tubules between two groups was compared. one-way analysis of variance (one-way anova) using the statistical package for the social sciences (spss, spss inc., usa) version 16 were performed for statistical analysis. results: in adult group, histological studies of testis tissues showed a high toxicity of cdse: zns in 40 mg/kg dose followed by a decrease in lamina propria; destruction in interstitial tissue; deformation of seminiferous tubules; and a reduction in number of spermatogonia, spermatocytes, and spermatids. however, there was an interesting result in fetal testis development, meaning there was no significant effect on morphology and structure of the seminiferous tubules and number of sperm stem cells. also histological study of epididymis tissues in both groups (adult and embryo groups) showed no significant effect on morphology and structure of tubule and epithelial cells, but there was a considerable reduction in number of spermatozoa in the lumen of the epididymal duct in 40 mg/kg dose of adult group. conclusion: the toxicity of qds on testicular tissue of the mice embryo and adult are different before and after puberty. due to lack of research in this field, this study can be an introduction to evaluate the toxicity of qds on male reproduction system in different stages of development.