NFR-seminar 2010
Silica nanoparticles in inflammatory
responses: Importance of exposure conditions,
particle characteristics, involvement of particle
uptake and mechanisms
Maurizio Gualtieri, Tonje Skuland, Marit Låg, Per
Schwarze, Tore-Geir Iversen* Johan Øvrevik, and
Magne Refsnes
Norwegian Institute of Public Health; *Institute of
Cancer Research, UiO
Copyright Maurizio Gualtieri
Outline:
• NPs and exposure conditions: behavior
and biological responses
• NPs surface properties and biological
responses
• NPs-related inflammatory responses:
- importance of NPs uptake
- possible signaling pathway
Definition of NPs
Ultrafine particles and
Nanoparticles (NPs)
- Nanoparticles:
engineered particlesfrom 1-100 nmeter
0.01
0.1
10
100
- Small particles have
a much larger
surface area than
larger particles
Suh et al. (in press)
Particulate matter, PM10 and PM2.5
1
1000
2.5
2500
10 µm
10000 nm
Medium properties: modification of particles
properties
(apolipoproteins)
(5) Advanced Drug Delivery Reviews 61 (2009) 428–437
Presence of proteins/BSA in the medium
prevents particles agglomeration
100 -/-
2000
100 +/-
100 +/+
With increase of the BSA
concentration the NP sizes
are more stable with time
1800
1600
1200
1000
800
600
400
200
0
0
0,5
1
1,5
2
2,5
3
time (h)
500 -/-
700
The sub-micron silica
particles are more stable
and less influenced by
BSA
500 +/-
500 +/+
600
500
d. nm
d. nm
1400
400
300
200
100
0
0
0,5
1
1,5
time (h)
2
2,5
3
Medium composition and biological responses
6
Cntl
30
50
100
200
500
IL6 (Fold increase)
5
4
3
2
1
0
BSA -/-
BSA +/-
BSA +/+
Increasing the concentration of BSA there is a reduction in
pro-inflammatory protein release, the effect is larger for
silica NPs than for submicron silica particles.
The importance of particle size for cytokine
responses: a complex relationship in the
small-sized area
30nm
30
50nm
100nm
200nm
500nm
200 nm SiNPs induce a dosedependent IL-6 release higher than
other SiNPs (200 nm > 30 nm ~ 50 nm
~ 100nm > 500nm)
20
15
10
5
30nm
16
0
0
50
100
150
200
50nm
100nm
200nm
500nm
14
Si NP (ug/ml)
200 nm SiNPs induce a dosedependent IL-8 release higher than
other SiNPs (200 nm > 30 nm ~ 50
nm ~100nm > 500nm)
IL-8 (fold increase)
IL-6 (fold increase)
25
12
10
8
6
4
2
0
0
50
100
SiNP [ ] (ug/ml)
150
200
- Surface-doping modified 50 nm
SiNPs pro-inflammatory effects.
-IL-8 release induced by RhodamineSiNPs >> Rhod-Si-NH2 > Rhod-SiCOOH
IL-8 (fold increase)
Surface doping of silica NPs and modification
of cytokine responses
9
8
7
6
5
4
3
2
1
0
untreated
RhodamineSi
Rhod-SiCOOH
Rhod-Si-NH2
-plain SiNPs~ plain Si-NH2 > plain SiCOOH
IL-8 (fold increase)
2
1,5
1
0,5
0
Untreated
50 nm plain
SiNP
50 nm COOH
50 nm -NH2
Is uptake required for initiating cellular
responses?
Important questions:
• How are the uptake
patterns in the NP size
area and for larger
particles?
• Different mechanisms In
macrophages versus
epithelial cells?
• Is the uptake required for
the responses, or are the
responses initiated at the
plasma membrane?
• Will uptake be required
for some responses, not
for others?
Nanoparticles
Agglomerated
Inhibitors
Particle uptake
Signals from
the plasma
membrane
signals
s
IL-8 mRNA
↑
IL-8
IL-8
Importance of silica-NP uptake on cytokine release
Red  Rhodamine-Si nanoparticles; Blue  early endosome; Green  late endosome
• No cellular uptake of rhodamine-silica NPs at 45 min and 3 h
• IL-8 mRNA expression increases from 60 to 90 min
• Uptake does not seem to be required for the cytokine (IL-8) expression
Signaling pathways in SiNP-induced cytokine
response
anti.-TGF
TAPI-1
AG1478/anti-EGFR
SB202190/SP6000125
siRNA p65
Inhibition of silica-NP-induced IL-8 with different
inhibitors of signalling pathways and silica NPinduced phosphorylation patterns of the respective
signaling molecules
Signaling pathways in SiNP-induced cytokine
response
anti.-TGF
TAPI-1
AG1478/anti-EGFR
SB202190/SP6000125
• The silica NP-induced IL8/IL-6 expression is
mediated via the
MAPKinases and the NFkB
activation
siRNA p65
• TACE and EGFR activation
seems to be involved
Inhibition of silica-NP-induced IL-8 with different
inhibitors of signalling pathways and silica NPinduced phosphorylation patterns of the respective
signaling molecules
Manuscripts:
• The importance of the agglomeration state of
amorphous silica NPs for cytokine responses and
cytotoxicity in bronchial epithelial cells (BEAS-2B)
•Silica NPs in cytokine release and cytotoxicity:
Signalling through EGF-receptor, MAP-kinases and
NFkB
•The importance of surface modification and size for
silica-NP-induced cytokine release and cytotoxicity in
lung cells
NFR-seminar 2010
THANK YOU FOR THE ATTENTION!!!
Silica nanoparticles in inflammatory responses:
Importance of exposure conditions, particle characteristics
and involvement of particle uptake and mechanisms
Maurizio Gualtieri, Tonje Skuland, Marit Låg, Per
Schwarze, Tore-Geir Iversen* Johan Øvrevik, and Magne
Refsnes
Norwegian Institute of Public Health; *Institute of Cancer
Research, UiO