title: Cellular uptake and cytotoxicity of octahedral rhenium cluster complexes.
abstract: Cellular uptake behavior of a novel class of octahedral rhenium cluster compounds, hexahydroxo complexes K(4)[{Re(6)S(8)}(OH)(6)].8H(2)O (1) and K(4)[{Re(6)Se(8)}(OH)(6)].8H(2)O (2), was evaluated in human cervical adenocarcinoma HeLa cells. Confocal microscopy and flow cytometry studies demonstrated that rhenium cluster 1 was not internalized into cell, while rhenium cluster 2 was. Conjugation of a polymer to rhenium cluster 1, namely the derivative K(4)[{Re(6)S(8)}(OH)(5)L] (3) (L is amphiphilic diblock copolymer MPEG550-CH(2)CONH-GlyPheLeuGlyPheLeu-COO(-)), considerably enhanced cellular uptake in a concentration-dependent manner and was predominantly localized in the cytoplasm and nucleus upon incubation time. The uptake of rhenium cluster 2 was mediated by energy-dependent endocytosis, whereas rhenium cluster 3 was directly ingested into cells by cell-fusion-like mechanism. According to the cytotoxicity evaluation test, both rhenium clusters 2 and 3 did not exhibit acute cytotoxic effects up to 50 microM, at the practical concentration level of biological applications. It is, therefore, expected that the rhenium cluster complexes can be promising potential candidates as diagnostic agents for medical treatment.
authors.affiliation: Division of Nano Sciences BK21, Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Republic of Korea.
authors.forename: Soo-Jin
authors.initials: SJ
authors.lastname: Choi
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Brylev
authors.forename: Jing-Zhe
authors.initials: JZ
authors.lastname: Xu
authors.forename: Yuri V
authors.initials: YV
authors.lastname: Mironov
authors.forename: Vladimir E
authors.initials: VE
authors.lastname: Fedorov
authors.forename: Youn Soo
authors.initials: YS
authors.lastname: Sohn
authors.forename: Sung-Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Choy
mesh_terms: D001692:Biological Transport; D002470:Cell Survival; D002614:Chelating Agents / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D005260:Female; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D009942:Organometallic Compounds / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity*; D012211:Rhenium / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity*
chemical_list: D002614:Chelating Agents; D009942:Organometallic Compounds; D012211:Rhenium