1
W. J. Parak
Inorganic Nanoparticles -From Synthesis to Biological Applications
(biological) Applications- Light-addressable electrodes- Phagokinetic tracks (motility assay)- Drug delivery- Smart Sensors
Organo-metallic synthesis of inorganic nanoparticles + phase transfer to aqueous solution- synthesis - properties- hybrid materials- phase transfer
Bioconjugation- model-system DNA-Au- particles with single molecules- particles saturated with molecules- introduction of functional groups- transfer to other particles / molecules- polymer capsules
2
CdSe magic-size nanocrystals
S. Kudera, M. Zanella, C. Giannini, A. Rizzo, Y. Li, G. Gigli, R. Cingolani, G. Ciccarella, W. Spahl, W. J. Parak, L. Manna, "Sequential growth of magic-size CdSe nanocrystals", Advanced Materials 19, 548-552 (2007).
3
Hybrid materials: two functionalities within one particle
FePt@CdS
(adopted from the synthesis protocol of H. Gu et al., JACS, 2004)
FePt
one material grown on top of another ? potentially two functionalities within of particle (e.g. fluorescent + magnetic)
M. Zanella, A. Falqui, S. Kudera, L. Manna, W. Parak, in preparation
many material combinations are possible: FePt@(CdS, ZnS, PbS, CdSe, ZnSe, PbSe) ? very general synthesis route
but: are properties of the original materials retained?? to our experience: slightly reduced magnetic moment + strongly quenched fluorescence
problems with this concept for hybrid particles: hydrophobic, decreased performance of functionality ? surface modification
4
Transfer to aqueous solution: Polymer coating procedure
works for all particles with hydrophobic stabilizer chains
wrap particles in an amphiphilic polymer shell
T. Pellegrino, L. Manna, S. Kudera, D. Koktysh, A. Rogach, S. Keller, J.Rädler, G. Natile, W. J. Parak, Nanoletters 4, 703-707 (2004)
5
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6
Direct embedding of functional groups in the polymer shell
Cheng-An J. Lina, Ralph A. Sperling, Jimmy K. Li, Ting-Ya Yang, Pei-Yun Li, Marco Zanella, Walter H. Chang, Wolfgang J. Parak , submitted to SMALL
functional group:- PEG- organic fluorophore- sugar- biotin- ....
we can directly incorporate functional groups into the polymer shell without the need for post bioconjugated chemistry
7
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Cheng-An J. Lina, Ralph A. Sperling, Jimmy K. Li, Ting-Ya Yang, Pei-Yun Li, Marco Zanella, Walter H. Chang, Wolfgang J. Parak , submitted to SMALL
Direct embedding of functional groups in the polymer shell
8
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R. A. Sperling, T. Pellegrino, J. K. Li, W. H. Chang, W. J. Parak, Advanced Functional Materials, 16, 943-948 (2006). Cheng-An J. Lina, Ralph A. Sperling, Jimmy K. Li, Ting-Ya Yang, Pei-Yun Li, Marco Zanella, Walter H. Chang, Wolfgang J. Parak , submitted to SMALL
General bioconjugation (with controlled number of single molecules)
9
Commonly used quantum-dot based FRET assemblies
hydrophobicallycapped quantum
dot
ligand exchange +linkage of recognition site (occupied by organic fluorophore)
polymer-coating / PEGylation +linkage of recognition site (occupied by organic fluorophore)
qdot excitationradiation-less energy transfer (FRET)
acceptor (organic dye)
emission
competitive displacement of dye-
labeled analyte with analyte
-: low colloidal stability+: close acceptor / donor distance
+: high colloidal stability-: big acceptor / donor distance
donor (qdot) emission
10
Polymer with embedded organic fluorophoresSample purification with gel electrophoresis
FS
+-
1
2
3
Polymer coating yields next to polymer-coated particles also some empty micells!
María Theresa Fernández-Argüelles, Aleksey Yakovlev, Camilla Luccardini, Ralph Sperling, Stéphane Gaillard, James Lin, Alfredo Sanz Medel, Walther Chang, Jean-Maurice Mallet, Jean-Marie Brochon, Anne Feltz, Martin Oheim, Wolfgang Parak, Nanoletters, in press.
11
FRET of acceptor embedded in polymer around donor
0
20000
40000
60000
80000
100000
0 10 20 30
01234567
500 600 700 800
? [nm]
I(? )
slow bands
01234567
500 600 700 800
? [nm]
I(? )
fast bands
María Theresa Fernández-Argüelles, Aleksey Yakovlev, Camilla Luccardini, Ralph Sperling, Stéphane Gaillard, James Lin, Alfredo Sanz Medel, Walther Chang, Jean-Maurice Mallet, Jean-Marie Brochon, Anne Feltz, Martin Oheim, Wolfgang Parak, NanoLetters, in press.
1.78xPAQD
2.14xPAQD
2.51xPAQD
101xPQD
?[ns]
sample
+-1
5FS
234
1xPA
1xPAQD4xPAQD8xPAQD
1xPQD
12
Polymer capsules as multifunctional containers
form polyelectrolyte onion-shells (PSS/PAH) around template + dissolve templateload with fluorescent (+ magnetic + metallic) nanocrystals + biological molecules
= loading of a "container" with particles of different functionality (see work of G. Decher, H. Möhwald)
capsule preparation by group of G. Sukhorukov
positively charged negatively
charged
load can be embedded into interior of capsules by - impregnation of the template core-swelling + shrinking of the mesh of the walls at different pH? transport container
functional nanoparticles can be embedded into wall of capsules by electrostatic attraction? functionality
size of capsule: ? msize of nanoparticles: nm
13
Targeted local delivery and release Capsule uptake by living cells
MCF-7 cells
„hard“ capsules(template core not removed)walls labeled with dye
„soft“ capsules(template core removed)walls labeled with dye
"hard" and "soft" capsules are ingested by the cells; the "soft" capsules are deformed
A. Muñoz_Javier, S. Kempter, O. Kreft, M. Semmling, A. Skirtach, O. Bruns, J. Rädler, J. Käs, G. Sukhorukov, C. Plank, W. Parak, in preparation
confocal microscopy: Maximilian Semmling
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Targeted local delivery and release - Magnetic direction of capsules
B. Zebli, A. S. Susha, G. B. Sukhorukov, A. L. Rogach, W. J. Parak, Langmuir 21, 4262-4265 (2005).
A
B C
Magnet
CBA
distance AC: 11 mmdistance BC: 5 mm
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Targeted local delivery and release Capsule opening with a light pointer
A. Skirtach, A. Munoz Javier, O. Kreft, K. Köhler, A. Piera Alberola, H. Möhwald, W. J. Parak , G. Sukhorukov, Angewandte Chemie, 2006
16
Emissionspectra (Fluorescence) of SNARF-Dextrane in Solution (pH 2 to 11)
0
2000
4000
6000
8000
10000
12000
510 520 530 540 550 560 570 580 590 600 610 620 630 640 650 660 670 680 690 700 710 720 730 740 750
nm
pH 2.0
pH 3.0
pH 4.0
pH 5.0
pH 6.0
pH 7.0
pH 8.0
pH 9.0
pH 10.0
pH 11.0
O. Kreft, A. Munoz Javier, G. Sukhorukov, W. J. Parak, Journal of Materials Chemistry, in press
Capsules as intracellular sensors: pH-sensitive capsules
wavelength (nm)
fluo
resc
ence
inte
nsity
(a.u
.)acidic pH:
green fluorescence
embed sensitive dyes (e.g. pH sensitive, Ca sensitive) in polymer capsules ?- dye is protected against degradation, cell is protected from free dye ? long term measurements- many dye molecules are embedded in one capsule ? sensitivity- dye is confined to capsules ? localization
SNARF: pH sensitive dye
capsule preparation by
group of G. Sukhorukov
alkaline pH: red fluorescence
17
Capsules as intracellular sensors: pH-sensitive capsules
0 min 30 min
60 min 180 min
acidic pH: green fluorescence
alkaline pH: red fluorescence
capsules in extracellular medium: alkaline environment
capsules ingested by cells in endosomes: acidic environment
O. Kreft, A. Munoz Javier, G. Sukhorukov, W. J. Parak, Journal of Materials Chemistry, in press
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Capsules as intracellular sensors: multiplexed measurements?
problem: release of capsules for endosome to cytoplasm
capsules can carry fluorescence molecules at two disctinct positions:
cavity ? ion sensitive dyewall ? spectral barcode ? quantum dots
19
pH = 6
pH = 9
pH = 6
pH = 9
phase contrast
SNARFgreen-
channelred-
channel
wall labelAlexa488-
channelTRITC-channel overlay
Capsules as intracellular sensors: multiplexed measurements?
O. Kreft, A. Munoz Javier, G. Sukhorukov, W. J. Parak, Journal of Materials Chemistry, in press
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Acknowledgement
Ralf SperlingStefan Kudera
Tim LiedlAlmudena Muñoz Javier
Bernd ZebliMarco Zanella
Maite Fernandez ArgüellesChristian Kirchner
Maximilian SemmlingFeng Zhang
Pablo del Pino
Hermann Gaub
Teresa PellegrinoLiberato Manna
A. Paul AlivisatosCarolyn A. Larabell
Josef Käs
Alicia PieraSusi KempterJoachim Rädler
Jimmy LiJames LinWalter Chang
Alfredo Sanz Medel
Christian StollFred Lisdat
Oliver KreftAndrei SkirtachMathieu BedardGleb Sukhorukov
Birgit BußmannTobias SchraderStephan MalkmusMarkus Braun
Aleksey YakovlevCamilla LuccardiniStéphane GaillardJean-Maurice MalletJean-Claude BrochonAnne FeltzMartin Oheim
Eric DulkeithMoritz RinglerThomas KlarAndrei SushaAndrey RogachJochen Feldmann
Oliver Bruns