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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.


Excretion kinetics of silica nanoparticles.Notes: (A) Excretion of 20 nm silica nanoparticles via urine in males. (B) Excretion of 20 nm silica nanoparticles via urine in females. (C) Excretion of 100 nm silica nanoparticles via urine in males. (D) Excretion of 100 nm silica nanoparticles via urine in females. (E) Excretion of 20 nm silica nanoparticles via feces in males. (F) Excretion of 20 nm silica nanoparticles via feces in females. (G) Excretion of 100 nm silica nanoparticles via feces in males. (H) Excretion of 100 nm silica nanoparticles via feces in females. There are statistically significant differences between columns labeled (a), columns labeled (b), and columns labeled (c) (P<0.05).Abbreviation: Si, silicon.
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f4-ijn-9-251: Excretion kinetics of silica nanoparticles.Notes: (A) Excretion of 20 nm silica nanoparticles via urine in males. (B) Excretion of 20 nm silica nanoparticles via urine in females. (C) Excretion of 100 nm silica nanoparticles via urine in males. (D) Excretion of 100 nm silica nanoparticles via urine in females. (E) Excretion of 20 nm silica nanoparticles via feces in males. (F) Excretion of 20 nm silica nanoparticles via feces in females. (G) Excretion of 100 nm silica nanoparticles via feces in males. (H) Excretion of 100 nm silica nanoparticles via feces in females. There are statistically significant differences between columns labeled (a), columns labeled (b), and columns labeled (c) (P<0.05).Abbreviation: Si, silicon.

Mentions: The excretion kinetics of silica nanoparticles was evaluated by measuring increases in Si levels in urine and feces. Significantly, higher Si concentrations in urine were detected, regardless of sex, at 1–2 days and 1–5 days after administering 20 nm silica nanoparticles at 500 or 1,000 mg/kg, respectively (Figure 4). However, elimination in urine was slower after the administration of 100 nm particles, which produced elevated Si levels at 1–3 days and 1–6 days at doses of 500 and 1,000 mg/kg, respectively. A similar tendency was found for fecal excretion profiles; Si concentrations were elevated at 1–3 days and at 1–4 days after the administration of 20 nm and 100 nm nanoparticles, respectively, at doses of 500 and 1,000 mg/kg, showing size-dependent elimination kinetics. It is worth noting that much higher Si levels were detected in feces than in urine. Table 3 summarizes the total excretion values of differently sized silica nanoparticles. We estimate that 7%–8% of nanoparticles were excreted in urine and 75%–80% via feces. Particle size and sex were not found to influence excretion values.


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)

Excretion kinetics of silica nanoparticles.Notes: (A) Excretion of 20 nm silica nanoparticles via urine in males. (B) Excretion of 20 nm silica nanoparticles via urine in females. (C) Excretion of 100 nm silica nanoparticles via urine in males. (D) Excretion of 100 nm silica nanoparticles via urine in females. (E) Excretion of 20 nm silica nanoparticles via feces in males. (F) Excretion of 20 nm silica nanoparticles via feces in females. (G) Excretion of 100 nm silica nanoparticles via feces in males. (H) Excretion of 100 nm silica nanoparticles via feces in females. There are statistically significant differences between columns labeled (a), columns labeled (b), and columns labeled (c) (P<0.05).Abbreviation: Si, silicon.
© Copyright Policy
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC4279759&req=5

f4-ijn-9-251: Excretion kinetics of silica nanoparticles.Notes: (A) Excretion of 20 nm silica nanoparticles via urine in males. (B) Excretion of 20 nm silica nanoparticles via urine in females. (C) Excretion of 100 nm silica nanoparticles via urine in males. (D) Excretion of 100 nm silica nanoparticles via urine in females. (E) Excretion of 20 nm silica nanoparticles via feces in males. (F) Excretion of 20 nm silica nanoparticles via feces in females. (G) Excretion of 100 nm silica nanoparticles via feces in males. (H) Excretion of 100 nm silica nanoparticles via feces in females. There are statistically significant differences between columns labeled (a), columns labeled (b), and columns labeled (c) (P<0.05).Abbreviation: Si, silicon.
Mentions: The excretion kinetics of silica nanoparticles was evaluated by measuring increases in Si levels in urine and feces. Significantly, higher Si concentrations in urine were detected, regardless of sex, at 1–2 days and 1–5 days after administering 20 nm silica nanoparticles at 500 or 1,000 mg/kg, respectively (Figure 4). However, elimination in urine was slower after the administration of 100 nm particles, which produced elevated Si levels at 1–3 days and 1–6 days at doses of 500 and 1,000 mg/kg, respectively. A similar tendency was found for fecal excretion profiles; Si concentrations were elevated at 1–3 days and at 1–4 days after the administration of 20 nm and 100 nm nanoparticles, respectively, at doses of 500 and 1,000 mg/kg, showing size-dependent elimination kinetics. It is worth noting that much higher Si levels were detected in feces than in urine. Table 3 summarizes the total excretion values of differently sized silica nanoparticles. We estimate that 7%–8% of nanoparticles were excreted in urine and 75%–80% via feces. Particle size and sex were not found to influence excretion values.

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.