title: Porous nanoparticle supported lipid bilayers (protocells) as delivery vehicles.
abstract: Mixing liposomes with hydrophilic particles induces fusion of the liposome onto the particle surface. Such supported bilayers have been studied extensively as models of the cell membrane, while their applications in drug delivery have not been pursued. In this communication, we report liposome fusion on mesoporous particles as a synergistic means to simultaneously load and seal cargo within the porous core. We find fusion of a cationic lipid (DOTAP) on an anionic silica particle loads an anionic fluorescent dye (calcein) into the particle to a concentration exceeding 100x that in the surrounding medium. The loaded "protocell" particles are taken up efficiently by Chinese hamster ovary cells, where, due to a reduced pH within endosomal compartments, calcein is effectively released. Compared to some other nanoparticle systems, protocells provide a simple construct for cargo loading, sealing, delivery, and release. They promise to serve as useful vectors in nanomedicine.
authors.affiliation: Center for Micro-Engineered Materials, University of New Mexico, Albuquerque, New Mexico 87106, USA.
authors.forename: Juewen
authors.initials: J
authors.lastname: Liu
authors.forename: Alison
authors.initials: A
authors.lastname: Stace-Naughton
authors.forename: Xingmao
authors.initials: X
authors.lastname: Jiang
authors.forename: C Jeffrey
authors.initials: CJ
authors.lastname: Brinker
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D008051:Lipid Bilayers / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D014677:Pharmaceutical Vehicles; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry
chemical_list: D008051:Lipid Bilayers; D014677:Pharmaceutical Vehicles; D012822:Silicon Dioxide