title: Stable and fluid multilayer phospholipid-silica thin films: mimicking active multi-lamellar biological assemblies.
abstract: Phospholipid-based nanomaterials are of interest in several applications including drug delivery, sensing, energy harvesting, and as model systems in basic research. However, a general challenge in creating functional hybrid biomaterials from phospholipid assemblies is their fragility, instability in air, insolubility in water, and the difficulty of integrating them into useful composites that retain or enhance the properties of interest, therefore limiting there use in integrated devices. We document the synthesis and characterization of highly ordered and stable phospholipid-silica thin films that resemble multilamellar architectures present in nature such as the myelin sheath. We have used a near room temperature chemical vapor deposition method to synthesize these robust functional materials. Highly ordered lipid films are exposed to vapors of silica precursor resulting in the formation of nanostructured hybrid assemblies. This process is simple, scalable, and offers advantages such as exclusion of ethanol and no (or minimal) need for exposure to mineral acids, which are generally required in conventional sol-gel synthesis strategies. The structure of the phospholipid-silica assemblies can be tuned to either lamellar or hexagonal organization depending on the synthesis conditions. The phospholipid-silica films exhibit long-term structural stability in air as well as when placed in aqueous solutions and maintain their fluidity under aqueous or humid conditions. This platform provides a model for robust implementation of phospholipid multilayers and a means toward future applications of functional phospholipid supramolecular assemblies in device integration.
authors.affiliation: Center for Biomedical Engineering, Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131, USA.
authors.forename: Gautam
authors.initials: G
authors.lastname: Gupta
authors.forename: Srinivas
authors.initials: S
authors.lastname: Iyer
authors.forename: Kara
authors.initials: K
authors.lastname: Leasure
authors.forename: Nicole
authors.initials: N
authors.lastname: Virdone
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Dattelbaum
authors.forename: Plamen B
authors.initials: PB
authors.lastname: Atanassov
authors.forename: Gabriel P
authors.initials: GP
authors.lastname: López
mesh_terms: D040761:Biomimetic Materials / Q000138:chemical synthesis / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D010743:Phospholipids / Q000138:chemical synthesis / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D010743:Phospholipids; D017640:Silicates; D012822:Silicon Dioxide