Colloids and Surfaces A: Physicochemical anti Engineering zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDC Aspects, 84 (1994) 113-119 0927-7757/94/$07.00 0 1994 - Elsevier Science B.V. All rights reserved. 113 Supramolecular assemblies from single-chain perfluoroalkylated phosphorylated amphiphiles Marie-Pierre Krafft*, Franqoise Giulieri, Jean G. Riess Unit& de Chimie Mokulaire, Associde au CNRS, Universite de Nice-Sophia Antipolis, Faculte’ des Sciences, 06108 Nice Cedex 2. France (Received 6 July 1993; accepted 20 September 1993) Abstract We report here that a diversity of organized supramolecular systems of various shapes and structures, including vesicles, fibers and globules, can be formed from dispersions of single-chuin perfluoroalkylated phosphocholine derivatives and dimorpholinophosphoramidates. The formation of these various aggregates can be controlled by regulating the amount of energy provided to the system. This highly versatile aggregation behavior of the fluorinated amphiphiles is in marked contrast to that of the hydrogenated analogs which only form micelles. The fluorinated aggregates have been characterized by transmission electron microscopy after freeze-fracture or negative staining and by optical microscopy. Their size has been assessed by laser light scattering spectroscopy. Key words: Electron microscopy; Fibers; Freeze-fracture; Globules; Membranes; Negative staining; Perfluoroalkylated amphiphiles; Supramolecular assemblies; Vesicles Introduction Phospholipids are the main components of bio- logical membranes. They possess two long hydro- phobic fatty acid chains and polar heads of various kinds, i.e. phosphatidylcholine, phosphatidylserine, etc. The synthesis, during the last 15 years, of more simple amphiphilic molecules which are also able to self-organize in bilayers and vesicles has opened up a new and fertile field of investigation at the interface between chemistry, physics and biology [l-3]. Synthetic membranes and vesicles can be used as models of natural membranes and for preparing drug delivering systems. The synthetic amphiphiles most investigated consist of quater- nary ammonium salts and of dialkylphosphates, sulfonates and carboxylates [4,.5]. Most of these compounds have two or three hydrophobic chains. The synthesis of perfluoroalkylated amphiphiles *Corresponding author. [ 61, such as fluorinated double- and triple-chained ammonium salts [7,8], and also more recently in our laboratory, of double-chain fluorinated gly- cerophosphatidylcholines [ 91, glycolipids [ lo] and phosphorylated sugars [ll], has also been achieved. It was shown that these amphiphiles easily allow the preparation of vesicles that are more stable and less permeable toward ions and small molecules than vesicles prepared from their hydrogenated analogs [9,10,12,13]. It must be noted again that these molecules were all bicaudal or tricaudal. In view of the stability of the vesicles obtained from such bicaudal amphiphiles the ques- tion could be legitimately asked whether the forma- tion of bilayers and vesicles from amphiphiles bearing only one fluorinated chain was possible. Single-chain amphiphiles form micelles in dilute water dispersions, but they seldom form more organized systems such as vesicles. One should note in this respect that the formation of lamellar SSDI 0927-7757(93)02681-4