Orally administered fluorescent nanosized polystyrene particles affect cell viability, hormonal and inflammatory profile, and behavior in treated mice.
Level 5 - mechanism / opinion, no new human data
Animal model and in vitro experimental study
PubMed 35405220 · doi:10.1016/j.envpol.2022.119206
What was done
Mice were orally administered fluorescent polystyrene (PS) nanoparticles to evaluate systemic biodistribution, organ accumulation, and toxicological outcomes. Researchers assessed testicular accumulation, serum testosterone, splenocyte interleukin secretion (IL-12p35 and IL-23), spleen cell viability and DNA damage, behavioral anxiety responses, and hippocampal expression of apoptotic and inflammatory genes (*Bax*, *Nlrp3*). An in vitro cochlear explant model was also evaluated to examine particle interaction with inner ear cells.
What was found
The abstract reports no numerical values, effect sizes, exposure doses, or sample sizes. Qualitatively, PS nanoparticles crossed the digestive barrier and accumulated in various organs. In cochlear explants, PS aggregates formed in hair cells. Male mice showed particle accumulation in the testicular interstitial compartment alongside a statistically significant reduction in testosterone, increased splenic secretion of IL-12p35 and IL-23, decreased splenocyte viability, elevated spleen DNA damage, and anxiogenic behavioral responses. Female mice showed increased hippocampal expression of *Bax* and *Nlrp3*.
Why it matters
The study shows that ingested nanoplastics can cross the gut barrier to accumulate in tissues and trigger sex-dependent endocrine, immunologic, and neurobehavioral toxicity in a mammalian model.
Limits
The abstract provides no sample sizes (n), dosing concentrations, or quantitative effect estimates. As an animal and in vitro study, the findings cannot be directly extrapolated to human health or typical environmental exposure levels without clinical or epidemiological validation.
Cited by
- supports When inner ear tissue is exposed to micro- and nanoplastics, they are preferentially taken up by hair cells.