title: Stable polymethacrylate nanocapsules from ultraviolet light-induced template radical polymerization of unilamellar liposomes.
abstract: We employed UV-induced template polymerization to create hollow nanometer-sized polymer capsules. Homogeneous, unilamellar liposomes served as a two-dimensional template for the cross-linking of either butyl methacrylate or hydroxyethyl methacrylate with the bifunctional ethyleneglycol dimethacrylate. Different molar ratios of lipid/hydrophobic monomer/bifunctional monomer/photoinitiator were tested and dynamic light scattering revealed negligible changes of size at a defined molar ratio of 2/1/10/20, respectively. Cryo-transmission electron microscopy provided clear evidence that incorporation of the methacrylate monomers into and polymerization in the hydrophobic bilayer phase does not disrupt vesicle integrity. Moreover, after solubilization of the lipids, the polymethacrylate nanocapsules were stable at conditions needed for negative staining and could be visualized by atomic force microscopy. In contrast to previous findings, the nanocapsule size and shape did not change considerably after removal of the template phase, and the size distribution remained strictly monomodal. The employed method is not only an advance to fortify liposomes, but the nanocapsules themselves can be functionalized.
authors.affiliation: Institut de Pharmacologie et Biologie Structurale CNRS UMR5089, Toulouse F-31077, France. j.gomes@iu-bremen.de
authors.forename: Joana Filipa Pereira da Silva
authors.initials: JF
authors.lastname: Gomes
authors.forename: Andreas F-P
authors.initials: AF
authors.lastname: Sonnen
authors.forename: Astrid
authors.initials: A
authors.lastname: Kronenberger
authors.forename: Jürgen
authors.initials: J
authors.lastname: Fritz
authors.forename: Manuel Alvaro Neto
authors.initials: MA
authors.lastname: Coelho
authors.forename: Didier
authors.initials: D
authors.lastname: Fournier
authors.forename: Clara
authors.initials: C
authors.lastname: Fournier-Nöel
authors.forename: Monique
authors.initials: M
authors.lastname: Mauzac
authors.forename: Mathias
authors.initials: M
authors.lastname: Winterhalter
mesh_terms: D020285:Cryoelectron Microscopy; D005609:Free Radicals / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053769:Nanocapsules / Q000737:chemistry* / Q000648:ultrastructure*; D011109:Polymethacrylic Acids / Q000737:chemistry*; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry
chemical_list: D005609:Free Radicals; D008081:Liposomes; D053769:Nanocapsules; D011109:Polymethacrylic Acids; D014867:Water; C030613:polymethacrylic acid