Effects of hydroxyl-functionalized multiwalled carbon nanotubes on sperm health and testes of Wistar rats

Carbon nanotubes (CNTs) are promising candidates for various applications including biomedical purposes. Owing to their remarkable physical, mechanical, electrical and chemical properties, CNTs have become an area of intense research and industrial activity in recent years. Therefore, toxicity and risk assessment studies are becoming increasingly important. The present study was designed to assess the effects of hydroxyl-functionalized multiwalled CNTs (OH-f MWCNTs) on sperm health and testes of adult Wistar rats. Animals were treated with different doses of OH-f MWCNTs (0.4, 2.0 and 10.0 mg/kg) along with a control group receiving only vehicle. Assessments after 15 alternate intraperitoneal doses revealed dose-related adverse effects on many endpoints tested. Results of the study showed significant impairment of sperm health at 2.0 and 10.0 mg/kg. Histology of testes demonstrated degeneration of germinal epithelium and loss of germ cells in the treatment groups. The exposure resulted in increased oxidative stress in testes in a dose-dependent manner. The findings of the study demonstrate that CNTs are potentially harmful for male reproductive health.