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Accueil du site > Productions scientifiques > Séminaires à PHENIX > 2010 > Séminaire 29.11.2010 - 10h45

Séminaire 29.11.2010 - 10h45

par Guillaume Mériguet - 10 décembre 2010

Un séminaire intitulé

Nano-Scale Compartmentation in Self-Assembled Molecular Systems : Surface Hemimicelles,Vesicles, Emulsions and Microbubbles

aura lieu le lundi 29 novembre 2010 à 10h45 dans la bibliothèque du laboratoire PECSA (Bat F, 7e étage, porte 754), présenté par Marie-Pierre Krafft (Systèmes Organisés Fluorés à Finalités Thérapeutiques (SOFFT) - Institut Charles Sadron - Strasbourg).

Résumé

PDF - 158.5 ko

Fluorinated chains (F-chains) are chemically more stable and have lower intermolecular interactions than any of their hydrogenated counterparts. The combination of their extreme hydrophobicity and pronounced lipophobic character is unique, causing fluorinated amphiphiles (F-amphiphiles) to segregate into stable nano- and micro-sized assemblies. [1] [2]

By imposing the orientation of F-amphiphiles at interfaces, F-chains promote formation of original organized systems. Semifluorinated alkanes CnF2n+1CmH2m+1 (FnHm diblocks) form stable hexagonal lattices of monodisperse, circular hemimicelles when deposited as monolayers at the air/water interface [3] or onto solid substrates. [4] [5]. These hemimicelles can coexist with a monolayer of phospholipids. [6] Spherical vesicles of octyltrimethylammonium perfluorooctanoate C7F15COO- C8H17N+(CH3)3 spontaneously convert over time into polyhedral vesicles. [7] Most remarkable is the fact that the facetted vesicles’ bilayers remain in the fluid state.

F-amphiphiles impact on the properties of organized systems. Vesicles made from combinations of phospholipids (PL) and FnHm diblocks are more stable towards the release of hydrophilic encapsulated probes than vesicles made of PL solely. [8] [9] Their kinetics of fusion is also dramatically hindered. FnHm diblocks strongly stabilize PL-based fluorocarbon emulsions destined as O2-carriers, by reinforcing the interfacial film. [10]. Other examples of organized systems and interfaces stabilized by F-compounds include microbubbles for O2 delivery and ultrasound diagnosis, [11] and new lung surfactant substitutes. [12] Partially fluorinated PL also form compartmented vesicles, which allows control of the intra-bilayer polymerization of hydrophobic monomers. [13]


[1] M.P. Krafft, J. Riess Chem. Rev., 2009, 109, 1714.

[2] M.P. Krafft, J. Riess J. Polym. Sci. Part A : Polym. Chem. (Highlight), 2007, 45, 1185

[3] P. Fontaine, M. Goldmann, P. Muller, M.-C. Fauré, O. Kolovanov, M.P. Krafft, J. Am. Chem. Soc. 2005, 127, 512.

[4] M. Maaloum, P. Muller, M.P. Krafft, Angew. Chem. Int. Ed. 2002, 41, 4331.

[5] G. Zhang, P. Marie, M. Maaloum, P. Muller, N. Benoit, M.P. Krafft, J. Am. Chem. Soc. 2005, 127, 10412

[6] M. Maaloum, P. Muller, M.P. Krafft, Langmuir 2003, 20, 2261.

[7] A. Gonzalez-Perez, M. Schmutz, G. Waton, M. J. Romero, M.P. Krafft, J. Am. Chem. Soc. 2007, 129, 756.

[8] Y. Ferro, M.P. Krafft, Biochim. Biophys. Acta 2002, 1581, 11

[9] M. Schmutz, B. Michels, P. Marie, M.P. Krafft, Langmuir 2003, 19, 4889.

[10] S. Marie Bertilla, J.L. Thomas, P. Marie, M.P. Krafft, Langmuir 2004, 20, 3920

[11] S. Rossi, G. Waton, T.F. Vandamme, M.P. Krafft, Langmuir 2010, 26, 1649

[12] F. Gerber, M.P. Krafft, T.F. Vandamme, M. Goldmann, P. Fontaine, Angew. Chem. Int. Ed. 2005, 44, 2749.

[13] M.P. Krafft, L. Schieldknecht, P. Marie, F. Giulieri, et al., Langmuir 2001, 17, 2872.