Examples of biological models used for nanoparticle evaluation.

Approach	Biologic model	Nanoparticles	Findings	Author
In vitro	Caco-2 cells	AgNPs	Caco-2 and SW480 cell lines exposed to NPs produce cell stress and cell death	243
	SW480 cells	ZnONPs
		TiO2 NPs
	Buccal epithelial cells (TR146)	AgNPs	NPs (100 mg L−1) concentration in potable water produced cytotoxicity in oral and gastrointestinal systems, decreasing from ZnONPs to AgNPs to TiO2 NPs	83
	Human colon mucosal epithelial cells (NCM460)	ZnONPs
		TiO2 NPs
	Caco-2	AgNPs	Cell viability decreased after 24 hours exposure to concentrations of ZnONPs (3, 6, and 12 mM) and AgNPs (0.5, 1.5, and 3 mM) producing cell shape alterations, abnormal nuclear structure, membrane blebbing, and cytoplasmic deterioration	66
		ZnONPs
In vivo	Wistar rats (male/pregnant female)	AgNPs	Descendants of pregnant rats exposed to AgNPs showed an increase of glutathione peroxidase, malondialdehyde and caspase 9, on the other hand levels of glutathione decreased. Oxidative stress and apoptosis in the offspring were observed	89
	Wistar rats	AgNPs	After oral administration for 55 days, silver was found in small intestine, kidney, liver, and brain. It was also determined that AgNPs exposure changed urea nitrogen, total proteins and mean corpuscular haemoglobin in blood	248
	Wistar rats	VO2 NPs	Exposure to VO2 NPs and VO5 NPs by inhalation showed that VO2 NPs were more toxic than VO5 NPs. VO2 NPs caused an increment in the levels of oxidative stress markers such as malondialdehyde and reduced glutathione	272
		VO5 NPs
Ex vivo	Zebrafish (Danio rerio)	AgNPs	After AgNPs exposure (20 and 110 nm), high silver concentrations of 20 nm AgNPs were found in gills and intestine deposited in the basolateral membranes, disrupting Na+/K+ ionic channels	91
	Wistar rat	AgNPs	AgNPs administration in trachea isolated rings AgNPs produced a contractile effect when is administrated simultaneously with acetylcholine increasing smooth muscle contractility. Nitric oxide production due to AgNPs administration was associated with a change in the muscle tone	273
	Wistar rat	AgNPs	Perfused isolated hearts from spontaneously hypertensive rats exposed to AgNPs at cumulative and individual administrations (10 and 100 μg mL−1) produced persistent vasoconstriction due to inducible nitric oxide synthase and endothelial nitric oxide synthase reduced production	274