title: Time-resolved luminescence microscopy of bimetallic lanthanide helicates in living cells.
abstract: The cellular uptake mechanism and intracellular distribution of emissive lanthanide helicates have been elucidated by time-resolved luminescence microscopy (TRLM). The helicates are non-cytotoxic and taken up by normal (HaCat) and cancer (HeLa, MCF-7) cells by endocytosis and show a late endosomal-lysosomal cellular distribution. The lysosomes predominantly localize around the nucleus and co-localize with the endoplasmatic reticulum. The egress is slow and limited, around 30% after 24 h. The first bright luminescent images can be observed with an external concentration gradient of 5 microM of the Eu(III) helicate [Q = 0.21, tau = 2.43 ms], compared to >10 microM when using conventional luminescence microscopy. Furthermore, multiplex labeling could be achieved with the Tb(III) [Q = 0.11, tau = 0.65 ms], and Sm(III) [Q = 0.0038, tau = 0.030 ms] analogues.
authors.affiliation: Laboratory of Lanthanide Supramolecular Chemistry, Ecole Polytechnique Fédérale de Lausanne, BCH 1404, 1015 Lausanne, Switzerland.
authors.forename: Bo
authors.initials: B
authors.lastname: Song
authors.forename: Caroline D B
authors.initials: CD
authors.lastname: Vandevyver
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Chauvin
authors.forename: Jean-Claude G
authors.initials: JC
authors.lastname: Bünzli
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival; D004705:Endocytosis / Q000187:drug effects; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism*; D028581:Lanthanoid Series Elements / Q000032:analysis* / Q000737:chemistry*; D049449:Luminescence; D049408:Luminescent Agents / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D008853:Microscopy; D009942:Organometallic Compounds / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism; D013194:Staining and Labeling; D013997:Time Factors
chemical_list: D028581:Lanthanoid Series Elements; D049408:Luminescent Agents; D009942:Organometallic Compounds