title: Poly-(amidoamine) dendrimers with a precisely core positioned sulforhodamine B molecule for comparative biological tracing and profiling.
abstract: We report on a simple robust procedure for synthesis of generation-4 poly-(amidoamine) (PAMAM) dendrimers with a precisely core positioned single sulforhodamine B molecule. The labelled dendrimers exhibited high fluorescent quantum yields where the absorbance and fluorescence spectrum of the fluorophore was not affected by pH and temperature. Since the stoichiometry of the fluorophore to the dendrimer is 1:1, we were able to directly compare uptake kinetics, the mode of uptake, trafficking and safety of dendrimers of different end-terminal functionality (carboxylated vs. pyrrolidonated) by two phenotypically different human endothelial cell types (the human brain capillary endothelial cell line hCMEC/D3 and human umbilical vein endothelial cells), and without interference of the fluorophore in uptake processes. The results demonstrate comparable uptake kinetics and a predominantly clathrin-mediated endocytotic mechanism, irrespective of dendrimer end-terminal functionality, where the majority of dendrimers are directed to the endo-lysosomal compartments in both cell types. A minor fraction of dendrimers, however, localize to endoplasmic reticulum and the Golgi apparatus, presumably through the recycling endosomes. In contrast to amino-terminated PAMAM dendrimers, we confirm safety of carboxylic acid- and pyrrolidone-terminated PAMAM dendrimers through determination of cell membrane integrity and comprehensive respiratory profiling (measurements of mitochondrial oxidative phosphorylation and determination of its coupling efficiency). Our dendrimer core-labelling approach could provide a new conceptual basis for improved understanding of dendrimer performance within biological settings.
authors.affiliation: Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark.
authors.forename: Lin-Ping
authors.initials: LP
authors.lastname: Wu
authors.affiliation: Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Mario
authors.initials: M
authors.lastname: Ficker
authors.affiliation: Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Søren L
authors.initials: SL
authors.lastname: Mejlsøe
authors.affiliation: Genome Integrity Unit, Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Arnaldur
authors.initials: A
authors.lastname: Hall
authors.affiliation: Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Valentina
authors.initials: V
authors.lastname: Paolucci
authors.affiliation: Department of Chemistry, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Jørn B
authors.initials: JB
authors.lastname: Christensen
authors.affiliation: CosmoPHOS Ltd, 77 Tsimiski Street, GR-54622 Thessaloniki, Greece.
authors.forename: Panagiotis N
authors.initials: PN
authors.lastname: Trohopoulos
authors.affiliation: School of Medicine, Pharmacy and Health, Durham University, Queen's Campus, Stockton-on-Tees TS17 6BH, UK. Electronic address: moein.moghimi@gmail.com.
authors.forename: Seyed M
authors.initials: SM
authors.lastname: Moghimi
mesh_terms: D002460:Cell Line; D050091:Dendrimers / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology* / Q000378:metabolism; D005456:Fluorescent Dyes / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D055442:Metabolome; D061848:Optical Imaging; D012235:Rhodamines / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism
chemical_list: D050091:Dendrimers; D005456:Fluorescent Dyes; C104700:PAMAM Starburst; D012235:Rhodamines; C022027:lissamine rhodamine B
keywords: Cytotoxicity; Dendrimers; Endothelial cells; Fluorescent probes; Nanomaterials