Dose-dependent effects of nanoscale graphene oxide on reproduction capability of mammals

In vivo dose-dependent effects of nanoscale graphene oxide (NGO) sheets on reproduction capability of Balb/C mice were investigated. Biodistribution study of the NGO sheets (intravenously injected into male mice at dose of ∼2000 μg/mL or 4 mg/kg of body weight) showed a high graphene uptake in testis. Hence, in vivo effects of the NGO sheets on important characteristics of spermatozoa (including their viability, morphology, kinetics, DNA damage and chromosomal aberration) were evaluated. Significant in vivo effects was found at the injected concentrations ≥200 μg/mL after (e.g., ∼45% reduction in sperm viability and motility at 2000 μg/mL). Observation of remarkable DNA fragmentations and chromosomal aberrations of the spermatozoa after ∼8 weeks from the first weekly injection were assigned to the involvement of the NGO in spermatogenesis of the mice. The uptake of the NGO in the testis could also increase the generation of reactive oxygen species in semen of the mice. Moreover, semen of the NGO-treated mice (containing the damaged spermatozoa) might disturb the hormone secretion and pregnant functionality of female mice (∼44, 35 and 59% reduction in fertility, gestation ability and multi-production capability) and also viability of the next generation (∼15% reduction in postnatal viability of delivered pups).