title: Spectroscopic characterization of  protein-wrapped single-wall carbon  nanotubes and quantification of their  cellular uptake in multiple cell  generations.
abstract: We study the spectral characteristics of bovine serum albumin (BSA) protein conjugated single-wall carbon nanotubes (SWNTs), and quantify their uptake by macrophages. The binding of BSA onto the SWNT surface is found to change the protein structure and to increase the doping of the nanotubes. The G-band Raman intensity follows a well-defined power law for SWNT concentrations of up to 33 microg ml(-1) in aqueous solutions. Subsequently, in vitro experiments demonstrate that incubation of BSA-SWNT complexes with macrophages affects neither the cellular growth nor the cellular viability over multiple cell generations. Using wide spot Raman spectroscopy as a fast, non-destructive method for statistical quantification, we observe that macrophages effectively uptake BSA-SWNT complexes, with the average number of nanotubes internalized per cell remaining relatively constant over consecutive cell generations. The number of internalized SWNTs is found to be approximately 30 10(6) SWNTs/cell for a 60 mm(-2) seeding density and approximately 100 x 10(6) SWNTs/cell for a 200 mm(-2) seeding density. Our results show that BSA-functionalized SWNTs are an efficient molecular transport system with low cytotoxicity maintained over multiple cell generations.
authors.affiliation: Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK.
authors.forename: Cristina
authors.initials: C
authors.lastname: Bertulli
authors.forename: Harry J
authors.initials: HJ
authors.lastname: Beeson
authors.forename: Tawfique
authors.initials: T
authors.lastname: Hasan
authors.forename: Yan Yan S
authors.initials: YY
authors.lastname: Huang
mesh_terms: D000042:Absorption; D000818:Animals; D002138:Calibration; D002417:Cattle; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004705:Endocytosis / Q000187:drug effects; D006801:Humans; D008264:Macrophages / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000633:toxicity; D061848:Optical Imaging; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D013010:Sonication; D013059:Spectrum Analysis, Raman
chemical_list: D037742:Nanotubes, Carbon; D012710:Serum Albumin, Bovine