Surface-charge-dependent ovarian toxicity of polystyrene microplastics: Insights into accumulation, mitochondrial damage, and macrophage polarization.
Level 5 - mechanism / opinion, no new human data
Non-clinical animal research (in vivo rat study).
PubMed 41564760 · doi:10.1016/j.jhazmat.2026.141197
What was done
Rats were orally administered polystyrene microplastics with different surface functional groups and charges (positively charged PS-NH2, pristine PS, and negatively charged PS-COOH). The study evaluated ovarian accumulation, sex hormone disruption, oxidative stress, mitochondrial structural damage, macrophage infiltration and polarization, iron accumulation, and ferroptosis pathways.
What was found
The abstract reports no numerical values. Ovarian particle accumulation ranked in the order PS-NH2 > PS > PS-COOH. All microplastics increased ovarian macrophage infiltration and iron accumulation, promoting ferroptosis. PS-NH2 exposure caused the most pronounced sex hormone imbalance, oxidative stress, and mitochondrial damage, while negatively charged PS-COOH specifically promoted pro-inflammatory M1 macrophage polarization.
Why it matters
Environmental weathering alters the surface chemistry of microplastics. Demonstrating that particle surface charge determines the extent of tissue accumulation and the specific toxic mechanism (e.g., mitochondrial damage versus M1 macrophage polarization) helps clarify reproductive toxicology risks.
Limits
The study was conducted in a rodent model, so relevance to human ovarian physiology and environmental exposure levels remains unproven. The abstract omits the sample size (n), particle dimensions, exposure concentrations, exposure duration, and all quantitative effect sizes.
Cited by
- supports Microplastics can accumulate inside the ovary.