title: Energy transfer cassettes in silica nanoparticles target intracellular organelles.
abstract: Lipophilic energy transfer cassettes like 1 and 2 are more conveniently synthesized than the corresponding hydrophilic compounds, but they are not easily used in aqueous media. To overcome the latter issue, cassettes 1 and 2 were separately encapsulated in silica nanoparticles (ca. 22 nm) which freely disperse in aqueous media. Photophysical properties of the encapsulated dyes 1-SiO(2) and 2-SiO(2) were recorded. The nanoparticles 1-SiO(2) permeated into Clone 9 rat liver cells and targeted only the ER. A high degree of energy transfer was observed in this organelle such that most of the light fluoresced from the acceptor part, i.e. the particles appeared red. Silica nanoparticles 2-SiO(2) also permeated into Clone 9 rat liver cells and they targeted mitochondria but were also observed in endocytic vesicles (lysosomes or endosomes). In these organelles they fluoresced red and red/green respectively. Thus the cargo inside the nanoparticles influences where they localize in cells, and the environment of the nanoparticles in the cells changes the fluorescent properties of the encapsulated dyes. Neither of these findings were anticipated given that silica nanoparticles of this type are generally considered to be non-porous.
authors: Department of Chemistry, Texas A&M University, College Station, TX 77842, USA.
authors: Jiney
authors: J
authors: Jose
authors: Aurore
authors: A
authors: Loudet
authors: Yuichiro
authors: Y
authors: Ueno
authors: Liangxing
authors: L
authors: Wu
authors: Hsiang-Yun
authors: HY
authors: Chen
authors: Dong Hee
authors: DH
authors: Son
authors: Rola
authors: R
authors: Barhoumi
authors: Robert
authors: R
authors: Burghardt
authors: Kevin
authors: K
authors: Burgess
mesh_terms: D000042:Absorption; D000818:Animals; D001692:Biological Transport; D002214:Capsules; D004735:Energy Transfer; D008099:Liver / Q000166:cytology; D053758:Nanoparticles / Q000737:chemistry*; D015388:Organelles / Q000378:metabolism*; D051381:Rats; D012822:Silicon Dioxide / Q000737:chemistry* / Q000378:metabolism*; D014867:Water / Q000737:chemistry
chemical_list: D002214:Capsules; D014867:Water; D012822:Silicon Dioxide