title: Chemical and mechanical impact of silica nanoparticles on the phase transition behavior of phospholipid membranes in theory and experiment.
abstract: The interaction of nanoparticles (NPs) with lipid membranes is an integral step in the interaction of NPs and living cells. During particle uptake, the membrane has to bend. Due to the nature of their phase diagram, the modulus of compression of these membranes can vary by more than one order of magnitude, and thus both the thermodynamic and mechanical aspects of the membrane have to be considered simultaneously. We demonstrate that silica NPs have at least two independent effects on the phase transition of phospholipid membranes: 1), a chemical effect resulting from the finite instability of the NPs in water; and 2), a mechanical effect that originates from a bending of the lipid membrane around the NPs. Here, we report on recent experiments that allowed us to clearly distinguish both effects, and present a thermodynamic model that includes the elastic energy of the membranes and correctly predicts our findings both quantitatively and qualitatively.
authors.affiliation: Experimental Physics I, Institute of Physics and Augsburg Center for Innovative Technologies, Augsburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Westerhausen
authors.forename: F G
authors.initials: FG
authors.lastname: Strobl
authors.forename: R
authors.initials: R
authors.lastname: Herrmann
authors.forename: A T
authors.initials: AT
authors.lastname: Bauer
authors.forename: S W
authors.initials: SW
authors.lastname: Schneider
authors.forename: A
authors.initials: A
authors.lastname: Reller
authors.forename: A
authors.initials: A
authors.lastname: Wixforth
authors.forename: M F
authors.initials: MF
authors.lastname: Schneider
mesh_terms: D002462:Cell Membrane / Q000737:chemistry / Q000187:drug effects*; D042783:Endothelial Cells / Q000166:cytology; D006801:Humans; D008051:Lipid Bilayers / Q000737:chemistry; D055595:Mechanical Phenomena; D053768:Metal Nanoparticles; D008954:Models, Biological; D044367:Phase Transition / Q000187:drug effects*; D010743:Phospholipids / Q000737:chemistry*; D012824:Silicic Acid / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry* / Q000494:pharmacology*; D013816:Thermodynamics; D044366:Transition Temperature / Q000187:drug effects
chemical_list: D008051:Lipid Bilayers; D010743:Phospholipids; D012824:Silicic Acid; D012822:Silicon Dioxide