Polyelectrolyte multilayer capsules

Shchukin DG, Ustinovich E, Sviridov DV, Lvov YM, Sukhorukov GB (2003) Photocatalytic microreactors based on Ti02-modilied polyelectrolyte multilayer capsules. Photochem Photobiol Sci 2 975-977... 

Gao CY, Liu XY, Shen JC, Mohwald H. Spontaneous deposition of horseradish peroxidase into polyelectrolyte multilayer capsules to improve its activity and stability. Chem Commun 2002 1928-1929. 

Gao CY, Moya S, Lichtenfeld H et al (2001) The decomposition process of melamine formaldehyde cores the key step in the fabrication of ultrathin polyelectrolyte multilayer capsules. Macromol Mater Eng 286 355-361... 

Antipov AA, Sukhorukov GB, Leporatti S et al (2002) Polyelectrolyte multilayer capsule permeability control. Colloids Surf A 198 535-541... 

Antipov AA, Sukhorukov GB, Donath E et al (2001) Sustained release properties of polyelectrolyte multilayer capsules. J Phys Chem B 105 2281-2284... 

Kohler K, Biesheuvel PM, Weinkamer R et al (2006) Salt-induced swelling-to-shrinking transition in polyelectrolyte multilayer capsules. Phys Rev Lett 97 188301... 

The mechanical properties of polyelectrolyte multilayer capsules have been subject of several studies using different methods. Baumler and co-workers [7] have used the micropipette technique and found that PMCs are not conserving their volume if pressure differences are applied between inside and outside of the shell. This is expected, since the shells can only be formed in first place because the membrane is permeable to low molecular weight species, the core dissolution products. They found no deformation up to a critical pressure followed by an irreversible collapse, showing that shells deform not elastically but plastically for large deformations. First quantitative estimates of the Young s modulus of the shell material were obtained by Gao and coworkers, using osmotic pressure differences between inside and outside of the shell [8,9], These authors monitored the onset of the buck-... 

KoUer K, Sukhorukov GB (2007) Heat treatment of polyelectrolyte multilayer capsules a versatile method for encapsulation. Adv Funct Mater 17 2053—2061... 

Angelatos AS, Johnston APR, Wang Y, et td. (2007) Probing the permeability of polyelectrolyte multilayer capsules via a molecultu beacon approach. Langmuir 23 4554-4562... 

A.A. Antipov, G.B. Sukhorukov, S. Leporatti, l.L. Radtchenko, E. Donath and H. Mohwald, Polyelectrolyte multilayer capsule permeability control. In 9th International Conference on Organized Molecular Films (LB9), Elsevier Science BV, Potsdam, Germany, 2000. 

Antipov, A.A., Sukhorukov, G.B., Leporatti, S., Radtchenko, I.L., Donath, E., Mohwald, H. Polyelectrolyte multilayer capsule permeability control. Coll. Surf. Physicochem. Eng. Asp. 2002,198... 

Munoz-Javier, A., Kreft, O., Semmling, M., Kempter, S., Skirtach, A.G., Bruns, O.T., del Pino, P. et al. Uptake of colloidal polyelectrolyte-coated particles and polyelectrolyte multilayer capsules by living cells. Adv. Mater. 2008, 20 (22), 4281-4287. 

Enzyme based micron sized sensing system with optical readout was fabricated by co-encapsulation of urease and dextran couple with pH sensitive dye SNARE-1 into polyelectrolyte multilayer capsules. The co-precipitation of calcium caibonate, urease, and dextran followed up by multilayer film coating and Ca- extracting by EDTA resulted in formation of 3.5-4 micron capsules, what enable the calibrated fluorescence response to urea in concentration range from 10 to 10 M. Sensitivity to urea in concentration range of 10 to 10 M was monitored on capsule assemblies (suspension) and on single capsule measurements. Urea presence can be monitored on single capsule level as illustrated by confocal fluorescent microscopy. 

J. Heuvingh, M. Zappa and A. Fery, Salt Softening of polyelectrolyte multilayer capsules, Langmuir, 21(7), 3165-3171 (2005). 

K. Koehler Temperature-Induced Rearrangements of Polyelectrolyte Multilayer Capsules. PhD thesis, Max-Planck-Institut fuer Kolloid-und Grenzflaechenforschung (2006). 

K. Koehler and G. B. Sukhorukov, Heat treatment of polyelectrolyte multilayer capsules A versatile method of encapsulation. Advanced Functional Materials, 17(13), 2053-2061 (2007). 

S. Moya, L. Daehne, A. Voigt, S. Leporatti, E. Donath and H. Moehwald, Polyelectrolyte multilayer capsules templated on biological cells Core oxidation influences layer chemistry. Colloids and Surfaces, A Physicochemical and Engineering Aspects, 183-185, 27-40 (2001). 

A. G. Skirtach, Bruno G. De Geest, Arif Mamedov, Alexei A. Antipov, Nicholas A. Kotov and Gleb B. Sukhorukov., Ultrasound stimulated release and catalysis using polyelectrolyte multilayer capsules,/. Mater. Chem., 17,1050-1054 (2007). 

Heuvingh J, Zappa M, Fery A (2005) Salt softening of polyelectrolyte multilayer capsules. Langmuir 21 3165-3171... 

Antipov AA, Sukhorakov GB. Polyelectrolyte multilayer capsules as vehicles with tunable permeability. Adv Colloid Interface Sci 2004 111(1—2) 49-61. 

Fig. 3.1. Permeation and encapsulation of FITC-dextran (M.w. 75000) into polyelectrolyte multilayer capsules. Left - pH = 10, centre - pH = 3, right - pH increased to 10 after the capsules were loaded with FITC-dextran at pH = 3. The bulk FITC-dextran was removed by washings at pH = 10. Upper - scheme, bottom - confocal images of the capsules.

Microencapsulated enzyme/dye systems Nanostructured materials Polyelectrolyte multilayer capsules Sensor system... 

Although elaborate in prepeuation, polyelectrolyte multilayer capsules are also receiving increasing attention as drug delivery systems [1]. These consist of alternating anionic and cationic polyelectrolytes, surrounding a (solution or solid) core contain-... 

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