Limits...
A review on potential neurotoxicity of titanium dioxide nanoparticles.

Song B, Liu J, Feng X, Wei L, Shao L - Nanoscale Res Lett (2015)

Bottom Line: However, little is known about their potential exposure and neurotoxic effects.The recognition ability, spatial memory, and learning ability of TiO2 NPs-treated rodents were significantly impaired, which meant that accumulation of TiO2 NPs in the brain could lead to neurodegeneration.However, conclusions obtained from those studies were not consistent with each other as researchers may choose different experimental parameters, including administration ways, dosage, size, and crystal structure of TiO2 NPs.

View Article: PubMed Central - PubMed

Affiliation: Guizhou Provincial People's Hospital, Guiyang, 550002, China, 17055224@qq.com.

ABSTRACT
As the rapid development of nanotechnology in the past three decades, titanium dioxide nanoparticles (TiO2 NPs), for their peculiar physicochemical properties, are widely applied in consumer products, food additives, cosmetics, drug carriers, and so on. However, little is known about their potential exposure and neurotoxic effects. Once NPs are unintentionally exposed to human beings, they could be absorbed, and then accumulated in the brain regions by passing through the blood-brain barrier (BBB) or through the nose-to-brain pathway, potentially leading to dysfunctions of central nerve system (CNS). Besides, NPs may affect the brain development of embryo by crossing the placental barrier. A few in vivo and in vitro researches have demonstrated that the morphology and function of neuronal or glial cells could be impaired by TiO2 NPs which might induce cell necrosis. Cellular components, such as mitochondrial, lysosome, and cytoskeleton, could also be influenced as well. The recognition ability, spatial memory, and learning ability of TiO2 NPs-treated rodents were significantly impaired, which meant that accumulation of TiO2 NPs in the brain could lead to neurodegeneration. However, conclusions obtained from those studies were not consistent with each other as researchers may choose different experimental parameters, including administration ways, dosage, size, and crystal structure of TiO2 NPs. Therefore, in order to fully understand the potential risks of TiO2 NPs to brain health, figure out research areas where further studies are required, and improve its bio-safety for applications in the near future, how TiO2 NPs interact with the brain is investigated in this review by summarizing the current researches on neurotoxicity induced by TiO2 NPs.

No MeSH data available.


Related in: MedlinePlus

A simple diagram of bio-distribution of Ti after TiO2 NPs exposure
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4549355&req=5

Fig4: A simple diagram of bio-distribution of Ti after TiO2 NPs exposure

Mentions: When TiO2 NPs were absorbed into circulation, they were capable of being redistributed to second organs (Fig. 4). At present, several researches have been performed to study the bio-distribution of TiO2 NPs after administrations (Table 1). In this study [73], when rats were treated with TiO2 NPs (5 mg/kg body weight) by intravenous injection, TiO2 NPs can be detected in the liver, spleen, lung, and kidney except blood cells, plasma, brain, and lymph nodes. The BALB/c female mice were exposed to TiO2 NPs at a dose of 560 mg/kg by intravenous injection (i.v.) or 5600 mg/kg by subcutaneous injection (s.c.). The TiO2 NPs were detected by energy dispersive X-ray spectroscopy (EDS) in the lung, liver, lymph node, spleen, and kidney from i.v.-administrated mice but only in the liver, lymph node, and spleen of s.c.-administrated mice, while the content of NPs was not detected in the brain [74]. Another study [75] also did not detect TiO2 NPs in the brain of male mice except blood and liver after i.v. injection. However, after hairless mice were treated with TiO2 NPs (21 nm) by dermal exposure for 60 days, significant pathological alterations were presented in the skin and liver and the NPs were also detected in the brain without pathological changes [76]. Wang et al. [16] studied the bio-distribution of TiO2 NPs (50 mg/kg) after female mice were treated with NPs by intranasal instillation every other day for 30 days. The biochemical parameters of the liver, spleen, heart, and serum were not affected by NPs as compared with the control group; while the concentration of NPs was apparently enhanced in the lung and brain regions. Another study investigated the bio-distribution of TiO2 NPs after rats were repeatedly orally administrated for 13 weeks. Even in the highest dosage group (1041.5 mg/kg BW), the Ti content in the brain was minimal with no statistical significance. Geraets et al. [77] compared the different distributions of TiO2 NPs in rats after oral and intravenous administration. The data obtained demonstrated that the Ti concentrations were not detectable in tissues, including the brain after oral administration. However, the Ti contents were detected in the liver, spleen, kidney, lung, heart, brain, thymus, and reproductive organs after intravenous injection. It could be inferred from those studies that (1) intranasal instillation might be the most effective routes for TiO2 NPs transported to the brain and (2) Ti content could be undetectable in the brain regions after intravenous injection. Undoubtedly, those conclusions drawn from abovementioned in vivo researches might not be convincing, because the translocations of TiO2 NPs into the brain would be influenced by several parameters, such as administration routes, size, dosage, and so on, which would be discussed in later chapters.Fig. 4


A review on potential neurotoxicity of titanium dioxide nanoparticles.

Song B, Liu J, Feng X, Wei L, Shao L - Nanoscale Res Lett (2015)

A simple diagram of bio-distribution of Ti after TiO2 NPs exposure
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4549355&req=5

Fig4: A simple diagram of bio-distribution of Ti after TiO2 NPs exposure
Mentions: When TiO2 NPs were absorbed into circulation, they were capable of being redistributed to second organs (Fig. 4). At present, several researches have been performed to study the bio-distribution of TiO2 NPs after administrations (Table 1). In this study [73], when rats were treated with TiO2 NPs (5 mg/kg body weight) by intravenous injection, TiO2 NPs can be detected in the liver, spleen, lung, and kidney except blood cells, plasma, brain, and lymph nodes. The BALB/c female mice were exposed to TiO2 NPs at a dose of 560 mg/kg by intravenous injection (i.v.) or 5600 mg/kg by subcutaneous injection (s.c.). The TiO2 NPs were detected by energy dispersive X-ray spectroscopy (EDS) in the lung, liver, lymph node, spleen, and kidney from i.v.-administrated mice but only in the liver, lymph node, and spleen of s.c.-administrated mice, while the content of NPs was not detected in the brain [74]. Another study [75] also did not detect TiO2 NPs in the brain of male mice except blood and liver after i.v. injection. However, after hairless mice were treated with TiO2 NPs (21 nm) by dermal exposure for 60 days, significant pathological alterations were presented in the skin and liver and the NPs were also detected in the brain without pathological changes [76]. Wang et al. [16] studied the bio-distribution of TiO2 NPs (50 mg/kg) after female mice were treated with NPs by intranasal instillation every other day for 30 days. The biochemical parameters of the liver, spleen, heart, and serum were not affected by NPs as compared with the control group; while the concentration of NPs was apparently enhanced in the lung and brain regions. Another study investigated the bio-distribution of TiO2 NPs after rats were repeatedly orally administrated for 13 weeks. Even in the highest dosage group (1041.5 mg/kg BW), the Ti content in the brain was minimal with no statistical significance. Geraets et al. [77] compared the different distributions of TiO2 NPs in rats after oral and intravenous administration. The data obtained demonstrated that the Ti concentrations were not detectable in tissues, including the brain after oral administration. However, the Ti contents were detected in the liver, spleen, kidney, lung, heart, brain, thymus, and reproductive organs after intravenous injection. It could be inferred from those studies that (1) intranasal instillation might be the most effective routes for TiO2 NPs transported to the brain and (2) Ti content could be undetectable in the brain regions after intravenous injection. Undoubtedly, those conclusions drawn from abovementioned in vivo researches might not be convincing, because the translocations of TiO2 NPs into the brain would be influenced by several parameters, such as administration routes, size, dosage, and so on, which would be discussed in later chapters.Fig. 4

Bottom Line: However, little is known about their potential exposure and neurotoxic effects.The recognition ability, spatial memory, and learning ability of TiO2 NPs-treated rodents were significantly impaired, which meant that accumulation of TiO2 NPs in the brain could lead to neurodegeneration.However, conclusions obtained from those studies were not consistent with each other as researchers may choose different experimental parameters, including administration ways, dosage, size, and crystal structure of TiO2 NPs.

View Article: PubMed Central - PubMed

Affiliation: Guizhou Provincial People's Hospital, Guiyang, 550002, China, 17055224@qq.com.

ABSTRACT
As the rapid development of nanotechnology in the past three decades, titanium dioxide nanoparticles (TiO2 NPs), for their peculiar physicochemical properties, are widely applied in consumer products, food additives, cosmetics, drug carriers, and so on. However, little is known about their potential exposure and neurotoxic effects. Once NPs are unintentionally exposed to human beings, they could be absorbed, and then accumulated in the brain regions by passing through the blood-brain barrier (BBB) or through the nose-to-brain pathway, potentially leading to dysfunctions of central nerve system (CNS). Besides, NPs may affect the brain development of embryo by crossing the placental barrier. A few in vivo and in vitro researches have demonstrated that the morphology and function of neuronal or glial cells could be impaired by TiO2 NPs which might induce cell necrosis. Cellular components, such as mitochondrial, lysosome, and cytoskeleton, could also be influenced as well. The recognition ability, spatial memory, and learning ability of TiO2 NPs-treated rodents were significantly impaired, which meant that accumulation of TiO2 NPs in the brain could lead to neurodegeneration. However, conclusions obtained from those studies were not consistent with each other as researchers may choose different experimental parameters, including administration ways, dosage, size, and crystal structure of TiO2 NPs. Therefore, in order to fully understand the potential risks of TiO2 NPs to brain health, figure out research areas where further studies are required, and improve its bio-safety for applications in the near future, how TiO2 NPs interact with the brain is investigated in this review by summarizing the current researches on neurotoxicity induced by TiO2 NPs.

No MeSH data available.


Related in: MedlinePlus