Complex particle systems for biological and technical applications

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Complex particle systems for biological and
technical applications

• Petr Štepánek
• Cestmír Konák
• Karel Ulbrich
• Institute of Macromolecular Chemistry
• Prague,CZ

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INSTITUTE OF MACROMOLECULAR CHEMISTRY ACADEMY OF
SCIENCES OF THE CZECH REPUBLIC
110 scientists, 55 students, 50 technicians
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Department of supramolecular polymer systems

• 4 DLS dynamic light scattering instruments
• SLS static light scattering
• zeta potential measurement
• birefringence (order-disorder transition)
• SAXS-WAXS - new Molmet instrument
• AFM dry and wet, small and large resolution
• ellipsometry
• GPC 5 detectors (RI, Mw, UV, viscosity,
  evaporative)
• MALDI-TOF
• EPR

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Research related to Biosons

1. DNA/poly(Lysine) complexes, coated with pHPMA
2. Polyamide nanoparticles coated with PEO
3. Thermosensitive NIPAM particles stabilized by
   surfactants
4. Diblock copolymer microemulsions

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1. Coating of Polyelectrolyte Complexes
DNA/Poly(L-lysine) Complexes coated by covalent
attachment of PolyN-(2-hydroxypropyl)methacrylam
ide grafted with thiazolidine-2-thione (TT)

• delivery through the cell membrane
• targetting antibodies
• coating to prevent elimination from the blood
  stream
• semitelechelic or multivalent copolymer

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PolyN-(2-hydroxypropyl)methacrylamide grafted
with thiazolidine-2-thione (TT)
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Coating kinetics
Coating Polymer Structure Mw g mol-1 Mw/Mn Rh nm Reactive groups mol.
2 pHPMA-TT 45 200 1.72 6.5 7

• complexes unstable
• (fast addition of PLL)
• model system latex

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Size of complexes
DNA/PLL
Latex
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BIOSONS - We need latex with NH2 and COOH (
electroneutral)
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2. Biodegradability of disulfide bonds

• Biodegradability of the disulfide bond with
  glutathione is especially interesting for the
  drug, protein or DNA delivery
• Extracellular level of glutathione is much lower
  than the intracellular level.
• Stable systems during transport outside the cell,
  disintegration after internalization in the
  target cell.

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Glutathione L-?-glutamyl-L-cysteinyl
glycine
1,4-Dithio-DL-threitol (DTT)

S-S
HS
G
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Scheme of nanocoating - degradation
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Biodegradable nanocoatings
Latex coated with PolyN-(2-hydroxypropyl)methacry
lamide with thiazolidine-2-thione (TT)
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Poly(ethylene oxide)-coated Polyamide
Nanoparticles Degradable by Glutathione
Micelle-like nanoparticles

• polyamide-type core poly(adipoyl
  chloride-alt-cystamine)
• disulfide bonds in the main chain
• degradation products are fragments of low
  molecular weight
• shell poly(ethylene oxide) monomethyl ether
  Mw 2000 and 5000

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Proposed mechanism of degradation

• irreversible chemical degradation of unimers (in
  equilibrium with nanoparticles) with glutathione
  into low-molecular-weight fragments
• release of new unimers from particles
  progressive dissolution

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Characteristics of micelle-like nanoparticles at
37 oC.
Sample Mw ? 10-7 Rh nm PDI ?m g cm-3 CAC ? 103 mg mL-1
SS2 2.44 44 ? 1 0.15 0.12 5.5
SS5 6.10 60 ? 2 0.16 0.11 7.5
Solution tlf / SS2 h tlf / SS5 h
Phosphate buffered saline 99 76
Phosphate buffered saline with oxidized glutathione (GSSG) 43 26
Phosphate buffered saline with reduced glutathione (GSH) 9.9 9.6
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3. Thermosensitive NIPAM particles stabilized by
surfactants
PNIPA undergoes a coil-to-globule transition at
32 ?C
Preparation of nanoparticles by temperature jump
from 25 ?C to 40 ?C of a solution of PNIPA with a
surfactant (e.g., SDS)
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Results
The surfactant concentrations cSR ? 5 ? 10-4 g
mL-1 are not able to prevent intermolecular
aggregation hence, PNIPA aggregates form
well-defined nanoparticles.
Hysteresis due to kinetics of nanoparticle
dissolution
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Characteristics of nanoparticles at 40 oC M?
122 000, cPNIPA 5 x 10-4 and cSR 5 x 10-5 g
mL-1
Surfactant Mw g mol-1 Rg nm Rh nm ?Rh/Rh
SDS 1.28 x 107 17.7 24.6 0.17
CTAB 1.37 x 107 19.5 26.8 0.15
HDP 1.39 x 107 25.1 33.5 0.23
F68 4.2 x 108 62.9 83.9 0.07
B98 5.67 x 108 86.8 112 0.10
B97 8.55 x 108 116 136 0.09
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4. Diblock Copolymer Microemulsions
copolymer A-B
solvent ? good for A, bad for B solvent ß good
for B, bad for A
N. Dan and M. Tirrell, Macromolecules 1993, 26,
637
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Experimental
A poly(octylstyrene) ? heptane (C7) B
poly(butyl methacrylayte) ß dimethylformamide
A-B
immiscible
Mw Mw/Mn fOS
OB3 23 k 1.04 0.49
OB5 35 k 1.19 0.61
polymer non soluble at room temperature
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Solvents miscible at elevated temperature ?
polymer soluble
Dynamic light scattering
heptane - DMF
OB5, c 3, fDMF 15
75.3 oC
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Hollow micelles OB5, c 5 , fDMF 15
9.4 nm
SAXS
q0
DMF
heptane
12.4 nm
aggregation number 62 DMF in
microemulsion 7 polymer in microemulsion
2.8 DMF missing 8
polymer missing 2.2
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Macrophase separation
v11 c22
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Small-angle neutron scatteringPS-PB 16-79, 10,
CX/ 10 DMF, 25oC
d
CX
? 0.66
best fit sphere R 16 nm
s 0.15
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Entangled hollow spheres PS-PB 16-79, 10, CX/
10 DMF, 25oC
24 nm
PB
PB
16 nm
PB
PB
PB
PB
73 nm
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The End
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Diblock copolymer with two isorefractive
immiscible solvents
cyclohexane CX dimethylformamide DMF TC 48.2
oC, wc 36 wt.
PS- PB(16-79) poly(styrene-butadiene) PS-
PEP(43-41) poly(styrene-Hisoprene)
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Viscosity of solutions, 5 polymer, 12 DMF,
T25oC
PS-PEP in CX/DMF
POS-PBuMA in C7/DMF liquid
t 0
viscosity 1 cP
viscosity 10 000 cP
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Microphase separation local structure
Order-disorder transition birfringence does not
work nCX 1.426 nDMF 1.430
CX
PEP
PS
DMF
PEP
d
CX
DMF
CX
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Small-angle neutron scatteringPS-PEP 43-41, 3,
CX/12DMF, 25oC
q0
q0 0.008 A-1
?3
d 4?/?3q0 50 nm (never lamellar)
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Small-angle neutron scatteringPS-PEP 43-41, 3,
CX/12DMF, 25oC
q0 0.008 A-1
d 4?/?3q0 70 nm
form factor cylinders R 14.9 nm ? 0.18
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Small-angle neutron scatteringPS-PEP 43-41, 3,
CX/12DMF, 25oC
q0
q0 0.008 A-1
?3
d 4?/?3q0 52 nm
form factor cylinders R 14.9 nm ? 0.18
-1.52

• -1/m 0.66 R M?
• chains at the interface
• are only slightly extended

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Small-angle neutron scatteringPS-PB 16-79, 10,
CX/ 10 DMF, 25oC
d
CX
? 0.66
best fit sphere R 16 nm
s 0.15
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Entangled hollow spheres PS-PB 16-79, 10, CX/
10 DMF, 25oC
24 nm
PB
PB
16 nm
PB
fDMF 6.4
simple cubic
PB
PB
PB
crosslink PB
3 DMF missing
73 nm
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Ultra small-angle neutron scatteringPS-PEP
43-41, 3, CX/12DMF, 25oC
-4
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Ultra small-angle neutron scatteringPS-PEP
43-41, 3, CX/12DMF, 25oC
-4
fit with spherical objects grain size d 2.1 µm
SANS Saclay, F DCD at NRI in Rež, CZ DCD at GKSS,
Geesthacht, D ( detector at 5 km in pinhole
configuration)
interfacial signal from excess solvent
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The End
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Synthesized by polycondensation of cystamine
dihydrochloride with adipoyl chloride and
poly(ethylene oxide) monomethyl ether in the
presence of base and subsequent self-assembling
of the polymer in water.
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Surfactants Abbreviation CMC mM CMC mg mL-1 Mw g mol-1
Sodium dodecyl sulfat SDS 8.1 2.3 288.38
Cetyltrimethylammonium bromide CTAB 1.00 0.387 384.44
Cetylpyridinium chloride CPC 0.11 0.035 320.00
Pluronic F-68 F68 5.45 45.8 8 400
Polyoxoethylene(20) oleyl ether Brie 98, B98 lt0.025 1150
Polyoxoethylene(10) oleyl ether Brie 97, B97 lt0.025 709