title: Gold-embedded photosensitive liposomes for drug delivery: triggering mechanism and intracellular release.
abstract: Liposomes embedded with gold nanoparticles show light-triggered contents release. We investigated the mechanism of the light-induced changes and functionality of the light-induced release in the cells. The real time small angle X-ray scattering (SAXS) analysis revealed time-dependent phase transitions in distearoylphosphatidylcholine (DSPC)/dipalmitoylphosphatidylcholine (DPPC) liposomes upon heating. Similar changes were observed when gold nanoparticle-embedded liposomes were exposed to the UV light: gold nanoparticles absorb light energy and transfer it to heat, thereby causing lipid phase transition from gel phase to rippled phase, and further to fluid phase. Without UV light exposure the gold nanoparticles did not affect the liposomal bilayer periodicity. The light-triggered release of hydrophilic fluorescent probe (calcein) from the gold nanoparticle-loaded liposomes was demonstrated with fluorescence-activated cell sorting after liposome internalization into the ARPE-19 cells. The liposome formulations did not decrease the cell viability in vitro. In conclusion, the light-triggered release from the liposomes is functional in the cells, and the release is triggered by thermal phase changes in the lipid bilayers.
authors.affiliation: Centre for Drug Research, University of Helsinki, Helsinki, Finland.
authors.forename: Lauri
authors.initials: L
authors.lastname: Paasonen
authors.forename: Tuomas
authors.initials: T
authors.lastname: Sipilä
authors.forename: Astrid
authors.initials: A
authors.lastname: Subrizi
authors.forename: Pasi
authors.initials: P
authors.lastname: Laurinmäki
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Butcher
authors.forename: Michael
authors.initials: M
authors.lastname: Rappolt
authors.forename: Anan
authors.initials: A
authors.lastname: Yaghmur
authors.forename: Arto
authors.initials: A
authors.lastname: Urtti
authors.forename: Marjo
authors.initials: M
authors.lastname: Yliperttula
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000009:adverse effects / Q000737:chemistry / Q000528:radiation effects; D000818:Animals; D018929:Cell Culture Techniques; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D004285:Dogs; D016503:Drug Delivery Systems / Q000379:methods*; D006046:Gold / Q000009:adverse effects / Q000737:chemistry* / Q000528:radiation effects; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007684:Kidney Tubules / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D008027:Light; D008051:Lipid Bilayers / Q000009:adverse effects / Q000737:chemistry / Q000528:radiation effects; D008081:Liposomes; D053768:Metal Nanoparticles / Q000009:adverse effects / Q000737:chemistry* / Q000528:radiation effects; D018613:Microscopy, Confocal; D044367:Phase Transition; D010713:Phosphatidylcholines / Q000009:adverse effects / Q000737:chemistry / Q000528:radiation effects; D055668:Photochemical Processes; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D053838:Scattering, Small Angle; D012995:Solubility; D014961:X-Ray Diffraction
chemical_list: D008051:Lipid Bilayers; D008081:Liposomes; D010713:Phosphatidylcholines; D015060:1,2-Dipalmitoylphosphatidylcholine; D006046:Gold; C010942:1,2-distearoyllecithin