We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Comparing the effects and mechanisms of exposure to polystyrene nanoplastics with different functional groups on the male reproductive system
Summary
Scientists exposed male mice to polystyrene nanoparticles with different surface charges (unmodified, negatively charged, and positively charged) and found all three types damaged reproductive health by reducing sperm count, increasing sperm defects, and disrupting testicular tissue. The positively charged (amino-modified) nanoparticles were the most toxic, causing the greatest reproductive damage. This is important because as plastics age in the environment, they develop different surface charges that may make them more harmful to reproductive health than pristine plastic particles.
After aging in the environment, some nanoplastics will carry different charges and functional groups, thereby altering their toxicological effects. To evaluate the potential impact of aging of nanoplastics on the mammalian reproductive system, we exposed C57BL/6 male mice to a dose of 5 mg/kg/d polystyrene nanoparticles (PS-NPs) with different functional groups (unmodified, carboxyl functionalized and amino functionalized) for 45 days for this study. The results suggest that PS-NPs with different functional groups triggered oxidative stress, a decreased in the testis index, disruption of the outer wall of the seminiferous tubules, reduction in the number of spermatogonia cells and sperm counts, and an increased in sperm malformations. We performed GO and KEGG enrichment analysis on the differentially expressed proteins, and found they were mainly enriched in protein transport, RNA splicing and mTOR signaling. We confirmed that the PI3K-AKT-mTOR pathway is over activated, which may lead to reduction of spermatogonia stem cells by over differentiation. Strikingly, PS-NPs with functional group modifications are more toxic than those of unmodified polystyrene, and that PS-NPs with positively charged amino modifications are the most toxic. This study provides a new understanding for correctly evaluating the toxicological effects of plastic aging, and of the mechanism responsible for the reproductive toxicity caused by nanoplastics.