. 2017 Jun 1;91(9):2967–3010. doi: 10.1007/s00204-017-1993-y

Table 2.

In vivo studies on SiNPs toxicity

Type of SiNPs	Exposure route	Primary particle size	Source	Species and Strain	Exposure dose	Exposure duration	Organ(s)/sample(s)	Effect(s)/endpoint(s)	Assay (s)/method(s)	Results	References
C-SiNPs	Oral	20 and 100 nm	E&B Nanotech	Rat; SD (female and male)	500 and 1000 mg/kg bw	1 h–10 days	Animal	Clinical signs	Observation	No animal death	Lee et al. (2014)
							Lungs, liver, brain, kidneys, testis and spleen	Tissue distribution	Molybdenum blue method	NPs detected in lungs, liver, spleen and kidneys
							Lungs, liver, brain, kidneys, testis and spleen	NP Localization	TEM	NPs detected in the nuclei of hepatocytes
							Urine and feces	Excretion kinetics	Molybdenum blue method	Most NPs excreted via feces
C-SiNPs	Oral	20 and 100 nm (uncoated or l-arginine coated)	E&B Nanotech	Mice; C57BL/6	750 mg/kg bw	Daily for 14 days	Blood	WBCs count	Serum analyzer	Increase	Kim et al. (2014b)
							Blood	Pro-inflammatory response(s)	Multiplex analysis	Differential expression of cytokines
							Spleen	Oxidative stress	DCFH-DA assay	Increase
								Oxidative stress	SOD and GPx assay	No effect
								Oxidative stress	Griess reagent/NO production	Increase
C-SiNPs	Oral	12 nm	ABC Nanotech	Rat; SD	Acute-1959 and 2061; Sub-acute-489.8, 979.5, 1959; Sub-chronic: 244.9, 489.8 and 975.9 mg/kg bw	Acute—14 days Sub-acute—daily for 14 days Sub-chronic: daily for 13 w	Blood	Blood cell count	Hematoanalyzer	No effect	Yun et al. (2015)
							Blood	Organ damage bio-markers	Serum analyzer	No effect
							Urine	Urinalysis	Urine analyzer	No effect
							Eye	Ophthalmology	Morphological examination	No effect
							Major organs	Tissue distribution	ICP-MS	NPs not detected
							Urine and feces	Excretion kinetics	ICP-MS	Most NPs excreted via feces
C-SiNPs	Oral gavage	20 and 80 nm, coated with l-arginine	E&B Nanotech	Rats; Crl:CD(SD)	500, 1000 and 2000 mg/kg bw	Daily for 90 days	Animal	Clinical signs	Observation	No animal death	Kim et al. (2014c)
							Blood	Blood cell count	Hematoanalyzer	No effect
							Blood	Organ damage bio-markers	Serum analyzer	No effect
							Eye	Ophthalmology	Observation of ocular fundus	No effect
							All major organs	Necropsy	Weighing organs	No effect
							All major organs	Histopathology	H & E staining	No effect
C-SiNPs	Intratracheal	9,15, 30 and 55 nm	AkzoNobel AB	Rat; Wistar (female)	360 µg in 500 ml of saline	3 days	Blood	Blood cell count	Hematoanalyzer	Increase of polymorphonulcear neutrophils and lymphocytes	Maser et al. (2015)
							Lungs	Histopathology	H & E staining	Mild increase of granulomatous inflammation
							Lungs	Genotoxicity	Comet assay	No effect
							Bone marrow	Genotoxicity	Micronucleus test	No effect
C-SiNPs	Dermal	20 nm, coated with l-arginine	E&B Nanotech	Rat; Sprague–Dawley (SD)	500 mg, 1000 mg, and 2000 mg/kg bw	Daily for 90 days	Animal	Clinical signs	Observation	No animal death	Ryu et al. (2014)
							Blood	Blood cell count	Hematoanalyzer	No effect
							Blood	Organ damage bio-markers	Serum analyzer	No effect
							All major organs	Necropsy	Organ weighing	No effect
							All major organs	Histopathology	H & E staining	No effect
C-SiNPs	Dermal	20 and 100 nm (uncoated or l-arginine coated)	E&B Nanotech	Rat	2000 (coated) and 1000 mg/kg bw(uncoated)	Daily for 28 d	Brain	Blood–brain barrier damage	Evans blue staining	No effect	Shim et al. (2014)
C-SiNPs	Dermal	20 and 100 nm (uncoated or l-arginine coated)	E&B Nanotech	Rat	2000 (coated) and 1000 mg/kg bw(uncoated)	Daily for 28 d	Brain	Tissue distribution	TEM-EDX	NPs not detected	Shim et al. (2014)
C-SiNPs	Intraperitoneal	50 nm	Polysciences	Mice; Male tuck ordinary	0.25 mg/kg bw	24 h	Blood	Blood cell count	Hematoanalyzer	Increase of leukocytes	Nemmar et al. (2016)
							Blood	Organ damage bio-markers	Serum analyzer	Increase of CK, ALT and AST
							Lungs, heart, liver, kidneys, and brain	Oxidative stress	LPO, SOD and catalase assay	Increase
								Pro-inflammatory response(s)	ELISA	Differential expression of IL-6, TNF-α and IL-1β
								Genotoxicity	Comet assay	Increase
C-SiNPs	Intravenous	64 nm	Laboratory synthesis	Mice; ICR (male and female)	0, 29.5, 103.5, and 177.5 mg/kg bw	14 days	Blood	Organ damage bio-markers	Serum analyzer	Increase of LDH, ALT and AST	Yu et al. (2013)
							Liver, spleen, kidneys, heart, lungs, and brain	Histopathology	H & E staining	Tissue damages observed
								CD-68 positive cells	CD-68 staining	Increase in liver and spleen
								NP localization	TEM	NPs detected in liver macrophages and in the endothelial cells of lungs and kidneys
								Tissue distribution	ICP-OES	Si detected in liver and lungs
S-SiNPs	Intratracheal	50 nm, with or without amine modification	Laboratory synthesis	Mice; C57BL/6 (male)	4 and 20 mg/kg bw	24 h	Lungs	Inflammation	BALF cell count and LDH assay	Dose-dependent increase of total cell number, macrophages, neutrophils and LDH release	Morris et al. (2016)
S-SiNPs	Intratracheal	50 nm, with or without amine modification	Laboratory synthesis	Mice; C57BL/6 (male)	4 and 20 mg/kg bw	24 h	Lungs	Oxidative stress	ROS/RNS production	Dose-dependent increase	Morris et al. (2016)
S-SiNPs	Intratracheal	58 nm	Laboratory synthesis	Mice; C57 (male)	2 mg/kg bw	Once every 3 days for 45 days	Testis	Histopathology	H & E staining	Decrease in mature sperm and primary spermatocytes	Zhang et al. (2016)
								Meiotic regulating factors	Western blot	Cell cycle arrest observed
								Oxidative stress	DCFH-DA assay	Increase
							Sperm	Quality evaluation	Microscopy	No effect
S-SiNPs	Intratracheal	43 nm	Laboratory synthesis	Mice; BALB/c(female)	0, 7, 21, and 35 mg/kg bw	Once every 3 days for 15 days	Lungs, liver and heart	Histopathology	H & E staining	Increase of Inflammation	Yang et al. (2016)
								Organ damage bio-markers	Serum analyzer	Increase of BUN, CREA, uric acid, and AST
								NP localization	TEM	NPs detected in cytoplasm and lysosomes
								Macrophage activation	Immunohistochemistry	Increase
								Inflammatory response	Multiplex flow cytometry	Increase of IL-8, TNF-α and IL-6	Duan et al. (2014a, b)
S-SiNPs	Intravenous	62 nm	Laboratory synthesis	Mice; ICR	29.5, 103.5, and 177.5 mg/kg bw	14 days	Heart	Autophagy	LC3 and VEGFR2 positive staining	Increase of LC3
									TEM	Increase of autophagic ultrastructures
									Cell cytoskeleton staining	Weakening of F actin
									MMP measurements	Dose-dependent decrease
									LC3-II/LC3-I ratio	Increase
M-SiNPs	Intragastrical	Spherical 83 nm, short rods (AR 1.75) and long rods (AR 5)	Laboratory synthesis	Mice; ICR (male)	40 mg/kg bw	14 days	Blood	Blood cell count	Hematoanalyzer	No effect	Li et al. (2015)
							Blood	Organ damage bio-markers	Serum analyzer	Increase of LDH release and CREA
							Liver, kidneys, spleen, lungs and small intestine	Histopathology	H & E staining	Gross tissue damage in kidneys
							Liver, kidneys, spleen, lungs and small intestine	Tissue distribution and excretion kinetics	ICP-OES and TEM	shape-dependent distribution and clearance in organs
M-SiNPs	Intravenous	1.5 (short rods) and 5 (long rods) aspect ratio; standard or PEGylated	Laboratory synthesis	Mice	20 mg/kg bw	2 h, 24 h and 7 days	Blood	Blood cell count	Hematoanalyzer	No effect	Huang et al. (2011)
							Blood	Organ damage bio-markers	Serum analyzer	Increase of TBIL, CREA and BUN
							Liver, spleen, lungs and kidneys	Histopathology	DAPI	Gross tissue damage in kidneys
							Liver, spleen, lungs and kidneys	Tissue distribution	ICP-OES	PEGylation reduced distribution in liver and spleen
							Urine and feces	Excretion kinetics	TEM/EDX	Short rods cleared rapidly than long rods
M-SiNPs	Intraperitoneal	~198 nm	Laboratory synthesis	Mice; BALB/C	150, 300, and 600 mg/kg bw	2 and 12 days	Blood	Organ damage bio-markers	Serum analyzer	Increase of AST, ALT BUN and CREA	Chen et al. (2015)
							Kidneys	Histopathology	H & E staining	Detection of renal interstitial fibrosis
							Kidneys	Tissue damage	Masson’s trichrome staining	Dose and time-dependent increase in kidney injury
Pr-SiNPs (NM 200 & 201), Py-SiNPs (NM 202 & 203)	Oral gavage	18–24 nm	JRC repository	Rat; SD (male)	5, 10, and 20 mg/kg bw	0, 24, and 45 h	Blood	Oxidative stress	LPO assay	No effect	Tarantini et al. (2015a, b)
							Liver, kidneys, spleen, intestine, blood and bone marrow	Histopathology	H & E staining	No effect
							Liver, kidneys, spleen, intestine, blood and bone marrow	Genotoxicity	Alkaline, FpG modified comet assay and micronucleus test	No effect
Pr-SiNPs (NM 200)	Oral gavage	10–15 nm	JRC repository	Rat; Wistar	100, 300, or 1000 mg/kg bw at a dose volume of 10 mL/kg bw	Daily for 14 days (from gestation period 6–19)	Animal	Clinical signs	Observation	No animal death	Hofmann et al. (2015)
							Animal	Body weight	Observation	No effect
							Gravid uterus	Necropsy	Cesarean	No effect
							Fetus	Fetus gross damage	Morphological examinations	No effect
Py-SiNPs	Exposure via food	7 nm and NM 202 (10–25 nm)	JRC repository	Rat; SD	Sub-acute: 100, 1000,2500 mg/kg bw Sub-chronic: 2500 mg/kg bw	Sub-acute: daily for 28 days Sub-chronic: daily for 84 days	Blood	Organ damage bio-markers	Serum analyzer	No effect	Zande et al. (2014)
							Blood	Plasma IgG and IgM and cytokine analysis	ELISA	No effect
							Liver	Transcriptomic analysis	mRNA quantification kit	No effect
							Liver, jejunum, kidneys and spleen	Histopathology	H & E staining	Presence of fibrosis in the liver of NM 202 treated rats
							Liver, spleen, lungs, brain and testis	Tissue distribution	ICP-MS	NM 202 detected in lungs, kidneys and spleen; SAS only in the spleen
Py-SiNPs	Intravenous	13 ± 5 nm	Vekton Ltd	Rat; Wistar	7 mg/kg bw	7, 30 and 60 days	Blood	Hemodynamics	Blood pressure measurement and heart rate	No effect	Zhuravskii et al. (2016)
								Blood cell count	Hematoanalyzer	No change
								Organ damage bio-markers	Serum analyzer	Increase of ALP at 7 d
							Liver, heart, spleen, lungs and kidneys	Tissue distribution	Atomic absorption spectrometry	Si detected in liver, lungs and spleen
								NP localization	SEM	NPs detected in hepatocytes
								Histopathology	H & E staining	Induction of fibrosis
SiNPs	Oral gavage	70 nm, 300 and 1000 nm with or without carboxyl or amine groups	Micromod Partikeltechnologie	Mice; BALB/c	2.5 mg/mouse	Daily for 28 days	Blood	Blood cell count	Hematoanalyzer	No effect	Yoshida et al. (2014)
							Blood	Organ damage bio-markers	Serum analyzer	No effect
							All major organs	Histopathology	H & E staining	No effect
							Intestine	Intestinal absorption	Evented gut sac analysis	Absorption of coated 70 nm SiNPs
SiNPs	Oral gavage	10–15 nm	TECNAN	Rat; Wistar (male)	333.3 mg/kg bw	Daily for 5 days	Animal	Clinical signs	Observation	Symptoms of vomiting and severe lethargy	Hassankhani et al. (2014)
							Blood	Organ damage bio-markers	Serum analyzer	Increase
							Kidneys, lungs and testis	Histopathology	H & E staining	Tissue damage observed
SiNPs	Intratracheal	Three SiNPs (30, 60, and 90 nm) and one fine-sized silica (600 nm)	Laboratory synthesis	Rat; Wistar (male)	2,5 and 10 mg/kg bw	Daily for 16 days	Blood and Heart	Blood cell count	Hematoanalyzer	Increase of WBCs & platelets and decrease of hemoglobin &RBCs	Du et al. (2013)
								Oxidative stress	LPO, GSH, SOD and GSH-Px assay	Increase of MDA formation
								Oxidative stress	NO/NOS	Increase of NO and decrease of NOS
								Pro-Inflammatory response(s)	ELISA	Increase of TNF-a, IL-1b and IL-6
								Tissue distribution	ICP-OES	NPs detected in heart
SiNPs in paints	Oropharyngeal	19 nm	SiNPs	Mice; BALB/c mice	20 µg/aspiration	Once a week for 5 w	Lungs	Inflammation	BALF Cell count	Increase of macrophages and neutrophils	Smulders et al. (2014)
								Pro-inflammatory response(s)	ELISA	No effect
								Tissue distribution	ICP-MS	NPs detected in lungs
SiNPs	Intranasal	10 and 80 nm SiNPs	Nanoamor	Rat; Wistar (male)	150 µg/50 µl PBS/rat	Daily for 30 days	Brain	Oxidative stress	LPO assay	Increase of MDA formation	Parveen et al. (2015)
									Xylenol orange assay	Increase of H₂O₂ levels
									GSH depletion	Increase
									SOD, CAT and GPx levels	Increase
								Pro-Inflammatory response(s)	RT-PCR and ELISA	Increase TNF-α, IL-1β and MCP-1
								Nuclear binding activity	Immuno blot analysis	Increase
								Tissue distribution	ICP-OES	Si detected in frontal cortex, corpus striatum and hippocampus
SiNPs	Topical	70 nm, 300 and 1,000 nm	Micromod Partikeltechnologie	Mice; BALB/c	250 mg/ear	Daily for 28 days	Skin	Apoptosis	TUNEL staining	Increase	Nabeshi et al. (2011b)
	Topical				250 mg/ear	Daily for 28 days	Animal	Tissue distribution	In vivo Imaging	70 nm SiNPs detected around the liver
	Intravenous				30 mg/kg bw	24 h		Tissue distribution	In vivo Imaging	70 nm SiNPs detected around the liver
	Intravenous				30 mg/kg bw	24 h		NP internalization	TEM	70 nm SiNPs detected in cytoplasm and nucleus of the parenchymal hepatocytes (liver)
SiNPs	Intravenous	15 nm	Sigma-Aldrich	Rat; SD (male)	50 mg/kg bw	48 h	Blood	Blood cell count	Hematoanalyzer	Increase of WBC, lymphocytes, monocytes and neutrophils	Chen et al. (2013)
							Liver	CD-68 positive cells	CD-68 staining	Increase
								Oxidative stress	GSH and SOD assay	Increase
								Injury bio-markers	Proton-NMR spectroscopic analysis	Increase

JRC Joint research commission, TEM Transmission electron microscopy, WBCs White blood cells, ICP-MS Inductively coupled plasma mass spectrometry, H & E Hematoxylin and eosin, EDX Energy dispersive X-ray spectroscopy, ELISA Enzyme linked immuno sorbent Assay, CD Cluster of differentiation, ICP-OES Inductively coupled plasma optical emission spectroscopy, BALF Bronchoalveolar lavage fluid, VEGFR Vascular endothelial growth factor receptor, MMP Mitochondrial membrane potential, DAPI-4′,6-diamidino-2-phenylindole, dilactate, SEM Scanning electron microscopy, TUNEL Terminal deoxynucleotidyl transferase dUTP nick end labeling, NMR Nuclear magnetic resonance