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Inorganic Nanoporous Nanoparticles for Tooth Bleaching
and Drug Delivery System
Kevin C.-W. Wu
吳嘉文Associate Professor
Department of Chemical Engineering
National Taiwan University
E-mail: [email protected]
Russian-Taiwanese Symposium on Nanobiology and Nanomedicine
3-5 November 2015, Novosibirsk, Russia
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About National Taiwan University
2
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Kevin C.-W. Wu
吳嘉文
Associate Professor
Department of Chemical Engineering
National Taiwan University
E-mail: [email protected]
Facebook: mesoporous
Pore = Empty = Useless?
Inorganic Nanoporous Nanoparticles for Tooth Bleaching
and Drug Delivery System
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無用之用: The Usefulness of The Useless
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Space has its usefulness with functionality
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Pore Diameter (nm)2
Mesoporous
Materials
Zeolite
MOF
ZIF
Porous glass
Classification of Porous Materials According to IUPAC
Microporous
Materials
Macroporous
Materials
MCM
SBA
FSM
Lamellar Hexagonal Cubic
50
FDU
CMK
CAR
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Inorganic Nanoporous Materials
Study in my group
Intracellular drug delivery
Tooth bleaching
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Why do we need drug carriers?
Some clinical limits of direct delivery of conventional
diagnostic and therapeutic drugs
1. Less solubility
2. Rapid clearance
3. Poor pharmacokinetics
4. High dosage
5. High side effects
6. Nonspecific targeting
1. High solubility
2. Slow clearance
3. Good pharmacokinetics
4. Low dosage
5. Low side effects
6. Specific targeting
Drug delivery systems (DDS) are designed to enhance
the availability of various therapeutic reagents to its
target site and reduce the adverse side effect.
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What is Metal-Organic-Framework (MOFs)?
‘Linking Inorganic and Organic Units by Strong Bonds’
COOH
COOH
H2BDC
+
Zn4O
Metal connector Organic linkers
FunctionalityDesignabilityDirectability
Physical propertiesof metal ion
Pore sizepore shapesurface functionality
Yaghi et al. Nature 1999, 402, 276
Zn4O(bdc)3 (MOF-5)
Ditopic linker
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The synthesis of MOF is like playing LEGO
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Library of organic linkers
Di-topic Tri-topic Poly-topic
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Library of inorganic metal connectors
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Our recent contribution to MOF
Zeolitic Imidazoate Framework-90
(ZIF-90)
H2O-based
systems
Zn(NO3)2
ICA
5 μm
200 nm
Microparticles
Nanoparticles
Water-based Synthesis of ZIF-90 with Controlled Sizes!!
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Our recent contribution to MOF JACS, in press, (2015)
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Introduction of Prussian blue
Dark blue pigment with idealized
formula Fe7(CN)18 xH2O
Widely used in painting, medicine, and
laboratory histopathology stain for iron.
In medicine, PB is used as an anitdote for heavy metal
poisoning (e.g., Cs and Tl)
The US FDA determines that 500 mg of PB is safe and
effective for treating internal contamination with heavy
metal
poisons.
Prussian blue is potential as an anticancer drug carrier
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Control of particle size of Prussian blue (PB)
Preparation of PB particles by adding polyvinylpyrrolidone (PVP)
K3[Fe(CN)6]
Partial
decomposition
Fe3+ Fe2+Reduced by PVP
K3[Fe(CN)6]Fe4[Fe(CN)6]3
Growth mechanism of PB particles
CrystEngComm, 2012, 14, 3387.
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Synthesis of solid Prussian blue (SPB) NPs
SPB
HCl
Self-
assembly
PVP
coating
Self-
etchingPVP
removal
HPB
Blue precipitates (SPB)
PVP
K3[Fe(CN)6]·3H2O
HCl solution (0.01M)
Dried@80℃
Controllable particle size: 110 nm
Interior micropores
Single-crystal of Prussian blue17
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Synthesis of hollow Prussian blue (HPB) NPs
SPB
HCl
Self-
assembly
PVP
coating
Self-
etchingPVP
removal
HPB
Interior hollow cavity
Mesopores in shell
Single-crystal of Prussian blue
HPB
SPB
PVP
HCl (1 M)
Hydrothermal
treatment@140℃
Space group: (Fm3m)
18
Angew. Chem. Int. Ed., 2012, 51, 984.
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Functionalities of hollow PB nanoparticles
Nanoparticle (~100 nm)
Easily uptaken by cancer cell
Passive targeting (EPR effect)Hollow
interior
Large space to store drug
Micropores
Absorb guest molecule by
large surface area
1. Nanoparticle morphology
3. Micropores in shell
2. Hollow cavity
Fe4[Fe(CN)6]319
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Porous structure of HPB NPs
Macropore
MicroporeMesopore
SBET = 324 m2/g
Macropore: 80 nm
Mesopore: 3-20 nm
Micropore: ~0.5 nm
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In-vitro drug loading & release
Cisplatin
(~0.5 nm)
Fast adsorption Drug got stuck in shell 21
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Confocal fluorescent images
T24 cancer cell
Healthy cell: elongated shape
HPB & cis@HPB accumulate in cytoplasm
Cell death induced by cis@HPB
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Stability & MTT assay
40%
BladderStomac
h
Endosome Blood None
High biocompatibility of HPB
Cytotoxicity of cis@HPB
High stability of HPB in pH 2-8.6
Biocompatibility of HPB Cytotoxicity of cis@HPB
70%
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Inorganic Nanoporous Materials
Study in my group
Intracellular drug delivery
Tooth bleaching
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Synthesis of mesoporous materials
Hexagonal
ArraySurfactant
Micelle
Self-assembly
Inorganic
Spices
Si(OR)4
Sol-Gel process
(OR)3Si-OHCooperative
assemblyDrying &
Calcination
Self-assembled
organic/inorganic hybrid
(Mesostructured materials)
Mesoporous
materials
A variety of inorganic species
• Siliceous
Silicon alkoxides: Si(OR)4
Layered silicate: Kanemite
Silsesquioxanes: (RO)3Si-R’-Si(OR)3
• Non-siliceous
Transition metal alkoxides: M(OR)n
Transition metal salts: MXn
Carbon: Glucose
Si +OR H2O
hydrolysis
Si +OH ROH
Si +OR
H2O
alcohol
condensation Si +O ROHSiHO Si
Si +OHwater
condensation Si +OSiHO Si Uniform and tunable pore size (2 ~ 50 nm)
High surface area (> 1000 m2/g)
Hydrophilic head
Hydrophobic tail
Cationic: CnH2n+1(CH3)3N+
Anionic: CnH2n+1R, R=COO-, SO3-
Neutral : CnH2n+1NH2
Cubic2D-HexagonalLamellar
Highly-ordered mesostructure
Gyroid
Electrostatic interaction Hydrogen-bonding
Interaction between surfactants (S) and inorganics (I) Functionalization
-COOH
-NH2
-SH
-SO3H
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Mesoporous Silica Nanoparticles (MSN)
50 - 300 nm2-5 nm
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Advantages of mesoporous silica nanoparticles (MSN)
High surface area (>1000 m2/g)
High pore volume (~1.0 cm3/g)
Uniform and tunable pore size (2-40 nm)
Abundant silanol groups (~30 %)
: Si-OH
Rigid framework
Tunable particle shape and size
External and internal surface
Multifuncationalization
: organic group A
: organic group B
: organic group C
Integratied with other NPs (e.g. Fe3O4)
A unique 2D hexagonal pore structure
: Caps
They love you !!!
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Endocytosis
Uncapping
Drug release
Intracellular Drug Delivery System
Cell membrane
: Caps
: MSN
: Drug
V
V
V
Nano-vehicle
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• Chemistry-A European Journal. 2012, 18, 7787-7792.
• Chemical Communications. 2012, 48, 6532-6534.
• ACS Applied Materials & Interfaces. 2012, 4, 6720-6727.
• Chemistry-A European Journal. 2013, 19(15), 4812-4817.
• Journal of Materials Chemistry B. 2013, 1(19), 2447-2450.
• Journal of Biomedical Materials Research: Part B - Applied Biomaterials. 2013,
102(2), 293-302.
• Chemical Communications. 2014, 50, 4148-4157. Selected as Back Cover.
• International Journal of Nanomedicine. 2014, 9(1), 2767-2778.
Our contribution in the mesoporous inorganic nanoparticles
Hollow HAp NPs Mesoporous
TiO2 NPs
Au
nanoflowers
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In vivo visualization of biodistribution of MSNs in a
see-through medaka fish (Oryzias latipes)
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In vivo toxicity and biodistribution of MSNs
Mouse is used an animal model
MRI or NIR agents are necessary Lo et al., Adv. Funct. Mater., 2009, 19, 215.
Observation of MSNs in a see-through medaka fish as a rapid
screening model for in vivo toxicity and biodistribution
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Exposure medaka fishes with FITC-MSNs
Exposure for 7 days Exposure for 28 days
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Exposure for 28 days
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Excretion for 2 days
Liver
Gill Kidney
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Comparison in liver
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Color of Tooth
Tooth structure
The tooth color is determined by
1. The color of dentine
2. The thickness of enamel
3. The color of blanket on
the enamel (hydroxyapatite)
The tooth color is yellowish
grey in general
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Removal of tooth discoloration
Mechanical polishing for
extrinsic stain
Tooth bleaching for intrinsic
stain
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Hydrogen peroxide
Bleaching agents
H2O2
(Strong free radicals can
attack stain)
OH or HO2. .
Carbamide peroxide
Sodium perborate
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Side effects of tooth bleaching:
Tooth Hypersensitivity
Alter the structure of both dentin and enamel
Damage pulp tissues
Objectives
Mn+ + H2O2 →M(n-1)+ + HOO• + H+
M(n-1)+ + H2O2 →Mn+ + HO • + OH-
Use transition metal ions to catalyze H2O2 without UV light
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Preparation of metal ion-histidine complex MSN
N
N OHNH
O
N
NOH
NH
O
Fe2+
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Preparation of tooth samples
low speed saw sonication to
remove
impurities
store it in saline
solution
0.15mM
Orange II
4,24,48,72 hrs
image analysis
400 500 600
0
2
Ab
s
Wavelength [nm]
Orange II
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Estimation of tooth color
Spectrophotometer
Colorimeter
Image analysis technique
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1 h
6 h
0 h
H2O2 MSNhis-MSN
Fe(II)-his-MSNMn(II)-his-MSN
Result: Orange II discoloration in test tubes
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Bleaching for 6 h
Only H2O2H2O2+
Fe(II)-his-MSN
Result: Orange II discoloration in tooth
H2O2+Mn(II)-his-MSN
Bleaching for 1 h
Before stain
After stain
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* P<0.05
Result: Orange II discoloration in enamel
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Mn+ + H2O2 →M(n-1)+ + HOO• + H+
M(n-1)+ + H2O2 →Mn+ + HO • + OH-
Mechanism: Fenton reaction
H2O2 + 2H+ + 2e- → H2O
H2O2 → O2 + 2H+ + 2e-
Eored = 1.776 V (1)
Eoox = -0.682 V (2)
Mn2+ + 2H2O → MnO2 + 4H+ + 2e- Eoox = -1.23 V (3)
Fe2+ → Fe3+ + e- Eoox = -0.77 V (4)
Mn2+ + H2O2
(1) + (3) = 0.546 V <
Fe2+ + H2O2
(1) + (4) = 1.006 V
Fe3+ + H2O2
(2) + (-4) = 0.088 V
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Technology Transfer
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Inorganic Nanoporous Materials
Conclusion
Intracellular drug delivery
Tooth bleaching
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Acknowledgement
Research funding
Students