For Peer Review Only
Quantitative biokinet
ics of titanium dioxide nanoparticles
after oral administration in rats (Part 2)
Journal:
Nanotoxicology
Manuscript ID
TNAN-2016-0177.R2
Manuscript Type:
Original Article
Date Submitted by the Author:
n/a
Complete List of Authors:
Kreyling, Wolfgang; Helmholtz Center Munich – German Research Center
for Environmental Health, Comprehensive Pneumology Center, Institute of
Lung Biology and Disease; Helmholtz Center Munich – German Research
Center for Environmental Health, Institute of Epidemiology 2
Holzwarth, Uwe; Joint Research Centre, Institute for Health and Consumer
Protection
Schleh, Carsten; Helmholtz Center Munich – German Research Center for
Environmental Health, Comprehensive Pneumology Center, Institute of
Lung Biology and Disease
Kozempel, Ján; Joint Research Centre, Institute for Health and Consumer
Protection
Wenk, Alexander; Helmholtz Center Munich – German Research Center for
Environmental Health, Comprehensive Pneumology Center, Institute of
Lung Biology and Disease
Haberl, Nadine; Helmholtz Center Munich – German Research Center for
Environmental Health , Comprehensive Pneumology Center, Institute of
Lung Biology and Disease
Hirn, Stephanie; Helmholtz Zentrum München – German Research Center
for Environmental Health, Comprehensive Pneumology Center, Institute of
Lung Biology and Disease
Schäffler, Martin; Helmholtz Center Munich – German Research Center for
Environmental Health, Comprehensive Pneumology Center, Institute of
Lung Biology and Disease
Lipka, Jens; Helmholtz Zentrum Munchen Deutsches Forschungszentrum
fur Umwelt und Gesundheit, Comprehensive Pneumology Center, Institute
of Lung Biology and Disease
URL: http://mc.manuscriptcentral.com/tnan
Nanotoxicology
For Peer Review Only
Semmler-Behnke, Manuela; Helmholtz Zentrum München – German
Research Center for Environmental Health, Comprehensive Pneumology
Center, Institute of Lung Biology and Disease
Gibson, Neil; Joint Research Centre, Institute for Health and Consumer
Protection
Keywords:
Size-selected, radiolabeled titanium dioxide nanoparticles, gavage, gut-
absorption, accumulation in secondary organs and tissues, different
biokinetics pattern after gavage versus intravenous injection
Abstract:
The biokinetics of a size-selected fraction (70nm median size) of
commercially available and 48V-radiolabeled [48V]TiO2 nanoparticles has
been investigated in female Wistar-Kyoto rats at retention timepoints 1h,
4h, 24h and 7days after oral application of a single dose of an aqueous
[48V]TiO2-nanoparticle suspension by intra-esophageal instillation. A
completely balanced quantitative body clearance and biokinetics in all
organs and tissues was obtained by applying typical [48V]TiO2-
nanoparticle doses in the range of 30–80 µg•kg-1 bodyweight, making use
of the high sensitivity of the radiotracer technique.
The [48V]TiO2-nanoparticle content was corrected for nanoparticles in the
residual blood retained in organs and tissue after exsanguination and for
48V-ions not bound to TiO2-nanoparticles. Beyond predominant fecal
excretion about 0.6% of the administered dose passed the gastro-
intestinal-barrier after -h and about 0.05% were still distributed in the
body at day-7, with quantifiable [48V]TiO2-nanoparticle organ
concentrations present in liver (0.09ng•g-1), lungs (0.10ng•g-1), kidneys
(0.29ng•g-1), brain (0.36ng•g-1), spleen (0.45ng•g-1), uterus (0.55ng•g-
1) and skeleton (0.98ng•g-1). Since chronic, oral uptake of TiO2 particles
(including a nano-fraction) by consumers has continuously increased in the
past decades , the possibility of chronic accumulation of such biopersistent
nanoparticles in secondary organs and the skeleton raises questions about
the responsiveness of their defense capacities, and whether these could be
leading to adverse health effects in the population at large.
After normalizing the fractions of retained [48V]TiO2-nanoparticles to the
fraction that passed the gastro-intestinal-barrier and reached systemic
circulation the biokinetics was compared to the biokinetics determined after
IV-injection (Part 1). Since the biokinetics patterns differ largely IV-
injection is not an adequate surrogate for assessing the biokinetics after
oral exposure to TiO2 nanoparticles.
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1
Quantitative biokinetics of titanium dioxide nanoparticles after oral
1
application in rats (Part 2)
2
Wolfgang G. Kreyling*
#§
, Uwe Holzwarth
+
, Carsten Schleh*
1
, Ján Kozempel
+2
, Alexander Wenk*
3
, 3
Nadine Haberl*, Stephanie Hirn*, Martin Schäffler*, Jens Lipka*, Manuela Semmler-Behnke*
4
, 4
Neil Gibson
+
. 5
* Helmholtz Zentrum München – German Research Center for Environmental Health, 6
Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Ingolstaedter 7
Landstrasse 1, D-85764 Neuherberg / Munich, Germany 8
#
Helmholtz Center Munich – German Research Center for Environmental Health, Institute of 9
Epidemiology 2, Ingolstaedter Landstrasse 1, D-85764 Neuherberg / Munich, Germany 10
+
European Commission, Joint Research Centre, Directorate F – Health, Consumers and Reference 11
Materials, Via E. Fermi 2749, I-21027 Ispra (VA), Italy 12
13
§
Corresponding author: 14
Dr. Wolfgang G. Kreyling 15
Institute of Epidemiology 2 16
Helmholtz Centre Munich, German Research Center for Environmental Health 17
D-85764 Neuherberg / Munich 18
Germany 19
Email: kreyling@helmholtz-muenchen.de 20
Phone: +49-89-2351-4817 21
22
KEYWORDS 23
1
Current address: Abteilung Gesundheitsschutz, Berufsgenossenschaft Holz und Metall, D-81241
München, Germany
2
Current address: Czech Technical University in Prague, Faculty of Nuclear Sciences and Physical
Engineering, Břehová 7, CZ-11519 Prague 1, Czech Republic
3
Current address: Dept. Infrastructure, Safety, Occupational Protection, German Research Center
for Environmental Health, D-85764 Neuherberg / Munich, Germany
4
Current address: Bavarian Health and Food Safety Authority, D-85764 Oberschleissheim,
Germany
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Size-selected, radiolabeled titanium dioxide nanoparticles; gavage; gut-absorption; accumulation in 24
secondary organs and tissues; different biokinetics pattern after gavage versus intravenous injection 25
26
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ABSTRACT 27
The biokinetics of a size-selected fraction (70nm median size) of commercially available and
48
V-28
radiolabeled [
48
V]TiO
2
nanoparticles has been investigated in female Wistar-Kyoto rats at retention 29
timepoints 1h, 4h, 24h and 7days after oral application of a single dose of an aqueous [
48
V]TiO
2
-30
nanoparticle suspension by intra-esophageal instillation. A completely balanced quantitative body 31
clearance and biokinetics in all organs and tissues was obtained by applying typical [
48
V]TiO
2
-32
nanoparticle doses in the range of 30–80 µg•kg
-1
bodyweight, making use of the high sensitivity of 33
the radiotracer technique. 34
The [
48
V]TiO
2
-nanoparticle content was corrected for nanoparticles in the residual blood retained in 35
organs and tissue after exsanguination and for
48
V-ions not bound to TiO
2
-nanoparticles. Beyond 36
predominant fecal excretion about 0.6% of the administered dose passed the gastro-intestinal-barrier 37
after -h and about 0.05% were still distributed in the body at day-7, with quantifiable [
48
V]TiO
2
-38
nanoparticle organ concentrations present in liver (0.09ng•g
-1
), lungs (0.10ng•g
-1
), kidneys 39
(0.29ng•g
-1
), brain (0.36ng•g
-1
), spleen (0.45ng•g
-1
), uterus (0.55ng•g
-1
) and skeleton (0.98ng•g
-1
). 40
Since chronic, oral uptake of TiO
2
particles (including a nano-fraction) by consumers has 41
continuously increased in the past decades , the possibility of chronic accumulation of such 42
biopersistent nanoparticles in secondary organs and the skeleton raises questions about the 43
responsiveness of their defense capacities, and whether these could be leading to adverse health 44
effects in the population at large. 45
After normalizing the fractions of retained [
48
V]TiO
2
-nanoparticles to the fraction that passed the 46
gastro-intestinal-barrier and reached systemic circulation the biokinetics was compared to the 47
biokinetics determined after IV-injection (Part 1). Since the biokinetics patterns differ largely IV-48
injection is not an adequate surrogate for assessing the biokinetics after oral exposure to TiO
2
49
nanoparticles. 50
51
52
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