Table 3. Summary of MNP toxicity studies in in vivo rodent models via different exposure routes.

PS: polystyrene, PE: polyethylene, PET: polyethylene terephthalate, PVC: polyvinyl chloride, PA: polyamide, PP: polypropylene, TW: tire wear.

Exposure routes	Animal models	MNP types	Endpoints	Notes	References
Ingestion	Mice, rats	PS, PE, PET, PVC, PA, PP	Particle biodistribution and bioaccumulation, oxidative stress, genotoxicity, histopathological changes, pathological changes, serum biochemistry, gut barrier integrity, microbiota homeostasis, energy metabolism, locomotor activity, behavioral activity, reproductive function, developmental function, AChE activity, muscle function	Environmentally relevant MNPs; Co-exposure to MNPs and other chemicals	[187, 198, 261]
Inhalation	Mice, rats	PS, TW	Particle biodistribution and bioaccumulation, pulmonary function, bronchoalveolar lavage fluid (BALF) analysis, oxidative stress, pathological changes, AChE activity, hematological changes, serum biochemistry, locomotor activity, behavioral activity, reproductive function	Environmentally relevant MNPs	[34, 35, 147, 198-200, 265]
IP injection	Mice	PS	Particle bioaccumulation, oxidative stress, genotoxicity, AChE activity, serum biochemistry, brain biochemistry, behavioral activity, reproductive function	Co-exposure to MNP sand Zincoxide	[106, 201]
IV injection	Mice	PS	Oxidative stress, histopathological changes, oxidative stress, hepatic lipid metabolism, reproductive function, developmental function	High-fat diet fed mouse model	[266, 267]
Eye contact	Mice	PS	Eye structure, tear secretion, inflammation of the lacrimal gland and conjunctiva		[149]