title: A New Route to Liposil Formation by an Interfacial Sol-Gel Process Confined by Lipid Bilayer.
abstract: We report a new and simple approach to prepare a class of silica-reinforced liposomes with hybrid core-shell nanostructures. The amphiphilic natural structure of lipids was exploited to sequester hydrophobic molecules, namely precursor TEOS and pyrene, in the hydrophobic midplane of liposomal bilayer assemblies in the aqueous phase. Subsequent interfacial hydrolysis of TEOS at the bilayer/water interface and ensuing condensation within the hydrophobic interstices of the lipid bilayer drives silica formation in situ, producing a novel class of silica-lipid hybrid liposils. Structural characterization by scanning- and transmission electron microscopy confirm that the liposils so generated preserve closed topologies and size-monodipersity of the parent lecithin liposomes, and DSC-TGA and XRD measurements provide evidence for the silica coating. Monitoring fluorescence measurements using embedded pyrene yield detailed information on microenvironment changes, which occur during sol-gel process and shed light on the structural evolution during silica formation. We envisage that liposils formed by this simple, new approach, exploiting the hydrophobic core of the lipid bilayer to spatially localize silica-forming precursors enables preparation of stable liposils exhibiting capacity for cargo encapsulation, bicompatibility, and fluorescence monitoring, more generally opening a window for construction of stable, functional hybrid materials.
authors.affiliation: School of Materials Science & Engineering, Shaanxi Normal University , Xi'an 710062, China.
authors.forename: Shukun
authors.initials: S
authors.lastname: Shen
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry & Chemical Engineering, Shaanxi Normal University , Xi'an 710119, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Yang
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry & Chemical Engineering, Shaanxi Normal University , Xi'an 710119, China.
authors.forename: Yaxing
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry & Chemical Engineering, Shaanxi Normal University , Xi'an 710119, China.
authors.forename: Jian-Gang
authors.initials: JG
authors.lastname: Chen
authors.affiliation: School of Materials Science & Engineering, Shaanxi Normal University , Xi'an 710062, China.
authors.forename: Shaofei
authors.initials: S
authors.lastname: Song
authors.affiliation: School of Materials Science & Engineering, Shaanxi Normal University , Xi'an 710062, China.
authors.forename: Daodao
authors.initials: D
authors.lastname: Hu
authors.affiliation: Department of Applied Science, University of California , Davis, California 95616, United States.
authors.forename: Atul
authors.initials: A
authors.lastname: Parikh
mesh_terms: D000818:Animals; D002152:Calorimetry, Differential Scanning; D002645:Chickens; D008051:Lipid Bilayers / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D044367:Phase Transition; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D008051:Lipid Bilayers; D012821:Silanes; C040733:tetraethoxysilane; D012822:Silicon Dioxide
keywords: fluorescent probe; interfacial sol−gel process; lipid bilayers; liposomes and vesicles; local molecular microenvironment