This study aimed to evaluate the effects of an intratesticular injection of silver nanoparticles (AgNPs) on reproductive parameters and health of rats, and to evaluate the AgNPs biodistribution in order to develop a nanotechnological contraceptive agent for male animals. Treated animals received 220 μL of AgNPs solution (0.46 µg-Ag/ml) in each testicle and were euthanized: seven, 14, 28, and 56 days after injection. A significant decrease (p < 0.05) in the percentage of motile sperm in D7 (8.8%) was observed, comparing to the control (73.3%), D14 (86.0%), D28 (68.2%), and D56 (90.0%) groups. D7 group also presented a decrease (p < 0.05) in the percentage of normal spermatozoa. Additionally, D7 group showed an increase (p < 0.05) in abnormal midpiece and sperm head morphology compared to the Control group. Seminiferous tubules presented all germline cell types and spermatozoa for all groups. However, D7 group did not present spermatozoa in the epididymis, whereas some spermatozoa and cellular debris were visible in D14 and D28 groups. All animals presented hematological parameters, creatinine, and alanine aminotransferase values within the normal limits for Wistar rats. The percentage of silver found in the liver was always higher than in the other organs analyzed. A pioneering mathematical model is proposed, from which the half-life time of silver in the liver (17 days), spleen (23 days), lungs (30 days), and kidneys (35 days) was extracted. In conclusion, some acute and severe toxic effects were observed in sperm cells following intratesticular injection of AgNPs, although these effects were reversible. No adverse effects to general animal health were observed.

这项研究旨在评估银纳米颗粒（AgNPs）的睾丸内注射对大鼠生殖参数和健康的影响，并评估AgNPs的生物分布以开发用于雄性动物的纳米技术避孕剂。在每个睾丸中，接受治疗的动物接受220μLAgNPs溶液（0.46μg-Ag/ ml）并在注射后第7、14、28和56天实施安乐死。 与对照组（73.3％），D14（86.0％），D28（68.2％）和D56（90.0％）相比，观察到D7（8.8％）的活动精子百分比显着降低（p <0.05）。组。D7组 的正常精子百分比也降低（p <0.05）。此外，D7组显示增加（p <0.05）中段和精子头部形态异常与对照组相比。曲细精管显示所有组的所有种系细胞类型和精子。然而，D7组在附睾中没有精子，而D14和D28组中可见一些精子和细胞碎片。所有动物均表现出Wistar大鼠正常范围内的血液学参数，肌酐和丙氨酸转氨酶值。在肝脏中发现的银百分比始终高于所分析的其他器官。提出了一个开创性的数学模型，从中提取了银在肝脏（17天），脾脏（23天），肺（30天）和肾脏（35天）中的半衰期。结论，睾丸内注射AgNPs后，在精子细胞中观察到一些急性和严重的毒性作用，尽管这些作用是可逆的。没有观察到对一般动物健康的不利影响。