title: Carbon nanotubes as intracellular carriers for multidrug resistant cells studied by capillary electrophoresis-laser-induced fluorescence.
abstract: Fluorescently labeled carbon nanotube probes (CNTP) are prepared by derivatizing oxidized (o)-MWNTs with a fluorescein dye. Capillary electrophoresis coupled with laser-induced fluorescence (CE-LIF) detection is used to separate and detect CNTP in multidrug-resistant cells (K562A) and the parent cells (K562S). CE-LIF and flow cytometry investigation reveal that the CNTP can traverse the membranes in both cell lines without being pumped out by P-glycoprotein. The CE-LIF method is also useful for quantitative analysis of CNT in single cells, enabling drug delivery and multidrug resistance (MDR) studies. Moreover, toward quantifying the intracellular uptake of oxidized (o)-SWNTs with anchored Rhodamine123 (Rho123), fluorescence-quenching of Rho123 is measured by micellar electrokinetic chromatography coupled with LIF detection. Enhanced uptake of Rho123 in multidrug-resistant leukemia cells can be achieved with the aid of the o-SWNTs carriers. Besides being able to overcome MDR, o-SWNTs are shown to be excellent intracellular carriers possessing large adsorption capacity and prolonged release ability. Finally, it is demonstrated that o-SWNTs are safe for biological applications at concentrations of up to 40 microg/mL.
authors.affiliation: National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, P.R., China. snowmaplecher@126.com
authors.forename: Ruibin
authors.initials: R
authors.lastname: Li
authors.forename: Hanfa
authors.initials: H
authors.lastname: Zou
authors.forename: Hua
authors.initials: H
authors.lastname: Xiao
authors.forename: Renan
authors.initials: R
authors.lastname: Wu
mesh_terms: D000327:Adsorption; D002462:Cell Membrane / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004337:Drug Carriers / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D016503:Drug Delivery Systems; D018432:Drug Resistance, Multiple / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D019075:Electrophoresis, Capillary; D005434:Flow Cytometry; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D006801:Humans; D020014:K562 Cells; D007834:Lasers; D037742:Nanotubes, Carbon / Q000737:chemistry*; D020112:Rhodamine 123 / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D014018:Tissue Distribution
chemical_list: D004337:Drug Carriers; D005456:Fluorescent Dyes; D037742:Nanotubes, Carbon; D020112:Rhodamine 123