Table 1.

Overview of recent toxicity studies of ZnO NPs with different models.

ZnO NPs Dosage	Toxicity Classification	Species/Cell Type	Exposure/Assay	Observations	Ref.
0.05, 0.2 mg/kg	Acute toxicity	Mice	Single intravenous exposure	Accumulation to spleen, liver and lungs; increase of 8-OHdG. LD50: 0.3 mg/kg	[5]
9.38, 18.75, 37.50, 75.00, 150.00 mg/kg	Acute toxicity	Mice	Intraperitoneal injection for 5 d and 10 d	Histopathological damage to kidneys, spleen, heart, and brain; effects on hematological and biochemical parameters. LD50: 299.9 mg/kg	[6]
31.25, 125, 500 mg/kg	Subchronic toxicity	Rat	Oral gavage for 90 d	Inflammatory damage to stomach, pancreas, eye, prostate gland tissues.	[7]
2000 mg/kg	Teratogenicity	Rat	Oral gavage	Fetal malformation, skeletal dysplasia and spinal insufficiency.	[8]
0.245, 245.26 mg/kg	Mutagenicity	Chicks	Intraperitoneal injection for 2 d	Induction of micronucleus, binucleus and heteromorphus in erythrocytes.	[9]
1 µg/mL	Carcinogenic risk	Mice embryonic fibroblasts	Exposure for 2 and 12 weeks	Upregulation of the early biomarkers of carcinogenesis, MTH1.	[10]
10 mg/kg	Nephrotoxicity	Mice	Single intraperitoneal injection	Renal tubule and glomerulus damage, increase of serum creatinine and blood urea nitrogen; HIF-1α-mediated apoptosis and autophagy.	[11]
600, 1000 mg/kg	Cardiotoxicity	Rat	Oral gavage for 5 d	Increase of troponin-T, creatine kinase-MB, myoglobin, TNF-α, IL-6, cardiac calcium concentration, DNA damage and Caspase-3 activity.	[12]
5.6 mg/kg	Neurotoxicity	Mice	Intraperitoneal injection 3 times per week for 28 d	Damage to blood brain barrier; disorder of nerve cell arrangement; neuronal degeneration; nistenite loss.	[13]
350 mg/kg	Immunotoxicity	Rat	Oral gavage for 28 d	Increase of MDA, IL-1β, TNF-α, TLR4 and TLR6; increase of apoptotic bodies and tingible body macrophages; appearance of abnormal thymocytes;	[14]
100 mg/kg	Reproductive toxicity	Mice	Oral gavage for 3 d	Induction of oxidative stress and apoptosis; weight loss of male mice testicular; activation of Shh pathway in ovaries; Caspase-related uteri injury.	[15]