Ylenia Miele1, Anne-Françoise Mingotaud2, Enrico Caruso3, Miryam C Malacarne3, Lorella Izzo4, Barbara Lonetti5, Federico Rossi6. 1. Department of Chemistry and Biology, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy. 2. Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III - Paul Sabatier, 118 Rte de Narbonne, F-31062 Toulouse cedex 9, France. 3. Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J. H. Dunant, 3, 21100 Varese, Italy. 4. Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J. H. Dunant, 3, 21100 Varese, Italy. Electronic address: lorella.izzo@uninsubria.it. 5. Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III - Paul Sabatier, 118 Rte de Narbonne, F-31062 Toulouse cedex 9, France. Electronic address: lonetti@chimie.ups-tlse.fr. 6. Department of Earth, Environmental and Physical Sciences - DEEP Sciences - Pian dei Mantellini 44, 53100 Siena, Italy.
Abstract
BACKGROUND: In recent years, there has been a growing interest in the formation of copolymer-lipid hybrid self-assemblies, which allow combining and improving the main features of pure lipid-based and copolymer-based systems known for their potential applications in the biomedical field. As the most common method used to obtain giant vesicles is electroformation, most systems so far used low Tg polymers for their flexibility at room temperature. METHODS: Copolymers used in the hybrid vesicles have been synthesized by a modified version of the ATRP, namely the Activators ReGenerated by Electron Transfer ATRP and characterized by NMR and DSC. Giant hybrid vesicles have been obtained using electroformation and droplet transfer method. Confocal fluorescence microscopy was used to image the vesicles. RESULTS: Electroformation enabled to obtain hybrid vesicles in a narrow range of compositions (15 mol% was the maximum copolymer content). This range could be extended by the use of a droplet transfer method, which enabled obtaining hybrid vesicles incorporating a methacrylate-based polymer in a wide range of compositions. Proof of the hybrid composition was obtained by fluorescence microscopy using labeled lipids and copolymers. CONCLUSIONS: This work describes for the first time, to the best of our knowledge, the formation of giant hybrid polymer/lipid vesicles formed with such a content of a polymethylmethacrylate copolymer, the glass temperature of which is above room temperature. GENERAL SIGNIFICANCE: This work shows that polymer structures, more complex than the ones mostly employed, can be possibly included in giant hybrid vesicles by using the droplet transfer method. This will give easier access to functionalized and stimuli-responsive giant vesicles and to systems exhibiting a tunable permeability, these systems being relevant for biological and technological applications.
BACKGROUND: In recent years, there has been a growing interest in the formation of copolymer-lipid hybrid self-assemblies, which allow combining and improving the main features of pure lipid-based and copolymer-based systems known for their potential applications in the biomedical field. As the most common method used to obtain giant vesicles is electroformation, most systems so far used low Tgpolymers for their flexibility at room temperature. METHODS:Copolymers used in the hybrid vesicles have been synthesized by a modified version of the ATRP, namely the Activators ReGenerated by Electron Transfer ATRP and characterized by NMR and DSC. Giant hybrid vesicles have been obtained using electroformation and droplet transfer method. Confocal fluorescence microscopy was used to image the vesicles. RESULTS: Electroformation enabled to obtain hybrid vesicles in a narrow range of compositions (15 mol% was the maximum copolymer content). This range could be extended by the use of a droplet transfer method, which enabled obtaining hybrid vesicles incorporating a methacrylate-based polymer in a wide range of compositions. Proof of the hybrid composition was obtained by fluorescence microscopy using labeled lipids and copolymers. CONCLUSIONS: This work describes for the first time, to the best of our knowledge, the formation of giant hybrid polymer/lipid vesicles formed with such a content of a polymethylmethacrylate copolymer, the glass temperature of which is above room temperature. GENERAL SIGNIFICANCE: This work shows that polymer structures, more complex than the ones mostly employed, can be possibly included in giant hybrid vesicles by using the droplet transfer method. This will give easier access to functionalized and stimuli-responsive giant vesicles and to systems exhibiting a tunable permeability, these systems being relevant for biological and technological applications.