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Tissue distribution and excretion kinetics of orally administered silica nanoparticles in rats.

Lee JA, Kim MK, Paek HJ, Kim YR, Kim MK, Lee JK, Jeong J, Choi SJ - Int J Nanomedicine (2014)

Bottom Line: Size-dependent excretion kinetics were apparent and the smaller 20 nm particles were found to be more rapidly eliminated than the larger 100 nm particles.In vivo, silica nanoparticles were found to retain their particulate form, although more decomposition was observed in kidneys, especially for 20 nm particles.These findings will be of interest to those seeking to predict potential toxicological effects of silica nanoparticles on target organs.

View Article: PubMed Central - PubMed

Affiliation: Department of Food Science and Technology, Seoul Women's University, Seoul, Republic of Korea.

ABSTRACT

Purpose: The effects of particle size on the tissue distribution and excretion kinetics of silica nanoparticles and their biological fates were investigated following a single oral administration to male and female rats.

Methods: Silica nanoparticles of two different sizes (20 nm and 100 nm) were orally administered to male and female rats, respectively. Tissue distribution kinetics, excretion profiles, and fates in tissues were analyzed using elemental analysis and transmission electron microscopy.

Results: The differently sized silica nanoparticles mainly distributed to kidneys and liver for 3 days post-administration and, to some extent, to lungs and spleen for 2 days post-administration, regardless of particle size or sex. Transmission electron microscopy and energy dispersive spectroscopy studies in tissues demonstrated almost intact particles in liver, but partially decomposed particles with an irregular morphology were found in kidneys, especially in rats that had been administered 20 nm nanoparticles. Size-dependent excretion kinetics were apparent and the smaller 20 nm particles were found to be more rapidly eliminated than the larger 100 nm particles. Elimination profiles showed 7%-8% of silica nanoparticles were excreted via urine, but most nanoparticles were excreted via feces, regardless of particle size or sex.

Conclusion: The kidneys, liver, lungs, and spleen were found to be the target organs of orally-administered silica nanoparticles in rats, and this organ distribution was not affected by particle size or animal sex. In vivo, silica nanoparticles were found to retain their particulate form, although more decomposition was observed in kidneys, especially for 20 nm particles. Urinary and fecal excretion pathways were determined to play roles in the elimination of silica nanoparticles, but 20 nm particles were secreted more rapidly, presumably because they are more easily decomposed. These findings will be of interest to those seeking to predict potential toxicological effects of silica nanoparticles on target organs.

No MeSH data available.


Tissue distributions of silica nanoparticles in rats after a single oral administration.Notes: (A) Oral administration of 500 mg/kg of 20 nm nanoparticles in males. (B) Oral administration of 500 mg/kg of 20 nm nanoparticles in females. (C) Oral administration of 500 mg/kg of 100 nm in males. (D) Oral administration of 500 mg/kg of 100 nm in females. (E) Oral administration of 1,000 mg/kg of 20 nm nanoparticles in males. (F) Oral administration of 1,000 mg/kg of 20 nm nanoparticles in females. (G) Oral administration of 1,000 mg/kg of 100 nm in males. (H) Oral administration of 1,000 mg/kg of 100 nm in females. There are statistically significant differences between columns labeled (a) and columns labeled (b) (P<0.05).Abbreviation: Si, silicon.
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f2-ijn-9-251: Tissue distributions of silica nanoparticles in rats after a single oral administration.Notes: (A) Oral administration of 500 mg/kg of 20 nm nanoparticles in males. (B) Oral administration of 500 mg/kg of 20 nm nanoparticles in females. (C) Oral administration of 500 mg/kg of 100 nm in males. (D) Oral administration of 500 mg/kg of 100 nm in females. (E) Oral administration of 1,000 mg/kg of 20 nm nanoparticles in males. (F) Oral administration of 1,000 mg/kg of 20 nm nanoparticles in females. (G) Oral administration of 1,000 mg/kg of 100 nm in males. (H) Oral administration of 1,000 mg/kg of 100 nm in females. There are statistically significant differences between columns labeled (a) and columns labeled (b) (P<0.05).Abbreviation: Si, silicon.

Mentions: The biodistribution of silica nanoparticles was examined in brain, kidneys, liver, lungs, spleen, and ovaries/testes. Total Si concentrations in tissues were analyzed, as described above, by determining increases in total Si levels in silica-administered rats versus untreated controls. Si levels were found to be significantly higher in kidneys, liver, lungs, and spleen of treated rats regardless of dose, particle size, or sex (Figure 2). Notably, high Si concentrations were found in kidneys and livers at 6 hours to 3 days post-administration, whereas elevated Si levels were detected at 6 hours to 2 days in lungs and spleens. Silica nanoparticles did not accumulate significantly in brains, ovaries, or testes. Furthermore, tissue distributions were similar regardless of particle size or sex. The increases in Si concentrations that were found are summarized in Table 2. Increases in Si concentrations in the GI tract (esophagus, stomach, and intestine) were not detected at 7 days post-administration.


Tissue distribution and excretion kinetics of orally administered silica nanoparticles in rats.

Lee JA, Kim MK, Paek HJ, Kim YR, Kim MK, Lee JK, Jeong J, Choi SJ - Int J Nanomedicine (2014)

Tissue distributions of silica nanoparticles in rats after a single oral administration.Notes: (A) Oral administration of 500 mg/kg of 20 nm nanoparticles in males. (B) Oral administration of 500 mg/kg of 20 nm nanoparticles in females. (C) Oral administration of 500 mg/kg of 100 nm in males. (D) Oral administration of 500 mg/kg of 100 nm in females. (E) Oral administration of 1,000 mg/kg of 20 nm nanoparticles in males. (F) Oral administration of 1,000 mg/kg of 20 nm nanoparticles in females. (G) Oral administration of 1,000 mg/kg of 100 nm in males. (H) Oral administration of 1,000 mg/kg of 100 nm in females. There are statistically significant differences between columns labeled (a) and columns labeled (b) (P<0.05).Abbreviation: Si, silicon.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4279759&req=5

f2-ijn-9-251: Tissue distributions of silica nanoparticles in rats after a single oral administration.Notes: (A) Oral administration of 500 mg/kg of 20 nm nanoparticles in males. (B) Oral administration of 500 mg/kg of 20 nm nanoparticles in females. (C) Oral administration of 500 mg/kg of 100 nm in males. (D) Oral administration of 500 mg/kg of 100 nm in females. (E) Oral administration of 1,000 mg/kg of 20 nm nanoparticles in males. (F) Oral administration of 1,000 mg/kg of 20 nm nanoparticles in females. (G) Oral administration of 1,000 mg/kg of 100 nm in males. (H) Oral administration of 1,000 mg/kg of 100 nm in females. There are statistically significant differences between columns labeled (a) and columns labeled (b) (P<0.05).Abbreviation: Si, silicon.
Mentions: The biodistribution of silica nanoparticles was examined in brain, kidneys, liver, lungs, spleen, and ovaries/testes. Total Si concentrations in tissues were analyzed, as described above, by determining increases in total Si levels in silica-administered rats versus untreated controls. Si levels were found to be significantly higher in kidneys, liver, lungs, and spleen of treated rats regardless of dose, particle size, or sex (Figure 2). Notably, high Si concentrations were found in kidneys and livers at 6 hours to 3 days post-administration, whereas elevated Si levels were detected at 6 hours to 2 days in lungs and spleens. Silica nanoparticles did not accumulate significantly in brains, ovaries, or testes. Furthermore, tissue distributions were similar regardless of particle size or sex. The increases in Si concentrations that were found are summarized in Table 2. Increases in Si concentrations in the GI tract (esophagus, stomach, and intestine) were not detected at 7 days post-administration.

Bottom Line: Size-dependent excretion kinetics were apparent and the smaller 20 nm particles were found to be more rapidly eliminated than the larger 100 nm particles.In vivo, silica nanoparticles were found to retain their particulate form, although more decomposition was observed in kidneys, especially for 20 nm particles.These findings will be of interest to those seeking to predict potential toxicological effects of silica nanoparticles on target organs.

View Article: PubMed Central - PubMed

Affiliation: Department of Food Science and Technology, Seoul Women's University, Seoul, Republic of Korea.

ABSTRACT

Purpose: The effects of particle size on the tissue distribution and excretion kinetics of silica nanoparticles and their biological fates were investigated following a single oral administration to male and female rats.

Methods: Silica nanoparticles of two different sizes (20 nm and 100 nm) were orally administered to male and female rats, respectively. Tissue distribution kinetics, excretion profiles, and fates in tissues were analyzed using elemental analysis and transmission electron microscopy.

Results: The differently sized silica nanoparticles mainly distributed to kidneys and liver for 3 days post-administration and, to some extent, to lungs and spleen for 2 days post-administration, regardless of particle size or sex. Transmission electron microscopy and energy dispersive spectroscopy studies in tissues demonstrated almost intact particles in liver, but partially decomposed particles with an irregular morphology were found in kidneys, especially in rats that had been administered 20 nm nanoparticles. Size-dependent excretion kinetics were apparent and the smaller 20 nm particles were found to be more rapidly eliminated than the larger 100 nm particles. Elimination profiles showed 7%-8% of silica nanoparticles were excreted via urine, but most nanoparticles were excreted via feces, regardless of particle size or sex.

Conclusion: The kidneys, liver, lungs, and spleen were found to be the target organs of orally-administered silica nanoparticles in rats, and this organ distribution was not affected by particle size or animal sex. In vivo, silica nanoparticles were found to retain their particulate form, although more decomposition was observed in kidneys, especially for 20 nm particles. Urinary and fecal excretion pathways were determined to play roles in the elimination of silica nanoparticles, but 20 nm particles were secreted more rapidly, presumably because they are more easily decomposed. These findings will be of interest to those seeking to predict potential toxicological effects of silica nanoparticles on target organs.

No MeSH data available.