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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.


Related in: MedlinePlus

TEM images of silica nanoparticles before administration and liver and kidney tissues collected at 48 hours after the oral administration of 20 nm or 100 nm sized nanoparticles.Notes: (A) Higher magnification of the tissues where nanoparticles are present, indicated by arrow. (B) TEM-EDS images show the presence of Si in the particulate forms in the tissues.Abbreviations: EDS, energy dispersive spectroscopy; Si, silicon; SiO2, silica; TEM, transmission electron microscopy.
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f3-ijn-9-251: TEM images of silica nanoparticles before administration and liver and kidney tissues collected at 48 hours after the oral administration of 20 nm or 100 nm sized nanoparticles.Notes: (A) Higher magnification of the tissues where nanoparticles are present, indicated by arrow. (B) TEM-EDS images show the presence of Si in the particulate forms in the tissues.Abbreviations: EDS, energy dispersive spectroscopy; Si, silicon; SiO2, silica; TEM, transmission electron microscopy.

Mentions: TEM analysis of organs from silica-administered rats was carried out to confirm tissue distributions and to determine the biological fates of nanoparticles in target tissues. As shown in Figure 3, silica nanoparticles of both 20 nm and 100 nm were observed in liver, and these had the same spherical morphology and particle sizes observed prior to administration (Table 1). In particular, differently sized silica nanoparticles were localized in hepatocytes as well as in nuclei. On the other hand, irregular particle shapes were observed in kidneys, and more so in rats treated with 20 nm silica nanoparticles. TEM-EDS confirmed the presence of Si in the particulate forms in livers and kidneys.


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)

TEM images of silica nanoparticles before administration and liver and kidney tissues collected at 48 hours after the oral administration of 20 nm or 100 nm sized nanoparticles.Notes: (A) Higher magnification of the tissues where nanoparticles are present, indicated by arrow. (B) TEM-EDS images show the presence of Si in the particulate forms in the tissues.Abbreviations: EDS, energy dispersive spectroscopy; Si, silicon; SiO2, silica; TEM, transmission electron microscopy.
© Copyright Policy
Related In: Results  -  Collection

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

f3-ijn-9-251: TEM images of silica nanoparticles before administration and liver and kidney tissues collected at 48 hours after the oral administration of 20 nm or 100 nm sized nanoparticles.Notes: (A) Higher magnification of the tissues where nanoparticles are present, indicated by arrow. (B) TEM-EDS images show the presence of Si in the particulate forms in the tissues.Abbreviations: EDS, energy dispersive spectroscopy; Si, silicon; SiO2, silica; TEM, transmission electron microscopy.
Mentions: TEM analysis of organs from silica-administered rats was carried out to confirm tissue distributions and to determine the biological fates of nanoparticles in target tissues. As shown in Figure 3, silica nanoparticles of both 20 nm and 100 nm were observed in liver, and these had the same spherical morphology and particle sizes observed prior to administration (Table 1). In particular, differently sized silica nanoparticles were localized in hepatocytes as well as in nuclei. On the other hand, irregular particle shapes were observed in kidneys, and more so in rats treated with 20 nm silica nanoparticles. TEM-EDS confirmed the presence of Si in the particulate forms in livers and kidneys.

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.


Related in: MedlinePlus