title: The influence of ligand organization on the rate of uptake of gold nanoparticles by colorectal cancer cells.
abstract: We have explored the uptake of different hydrophilic mono- and dual-ligand gold nanoparticles in colorectal cancer cells in vitro and find that the rate of uptake is dependent on the structural organization of the ligands on the surface of the particles rather than their charge or chemical properties. Gold nanoparticles with 50%PEG-NH(2)/50% glucose are taken up eighteen fold faster than nanoparticles carrying only PEG-NH(2) or glucose. Glutathione-coated gold particles are by far the most efficiently internalized; however, glucose-glutathione dual-ligand nanoparticles are taken up at a thirty fold reduced rate. We found furthermore that the rates are influenced by the cell density and concentration of glucose in the growth medium. Rather than being internalized through a conventional receptor-mediated mechanism the particles appear to be taken up by the cells via an energy-independent diffusion across the cell membrane through pre-existing pores or openings in the lipid bi-layer created by ligands on the gold nanoparticles.
authors.affiliation: Centre for Investigative and Diagnostic Oncology, Department of Natural Sciences, School of Health and Social Sciences, Middlesex University, The Burroughs, London NW4 4BT, UK. t.lund@mdx.ac.uk
authors.forename: Torben
authors.initials: T
authors.lastname: Lund
authors.forename: Martina F
authors.initials: MF
authors.lastname: Callaghan
authors.forename: Phil
authors.initials: P
authors.lastname: Williams
authors.forename: Mark
authors.initials: M
authors.lastname: Turmaine
authors.forename: Christof
authors.initials: C
authors.lastname: Bachmann
authors.forename: Tom
authors.initials: T
authors.lastname: Rademacher
authors.forename: Ivan M
authors.initials: IM
authors.lastname: Roitt
authors.forename: Richard
authors.initials: R
authors.lastname: Bayford
mesh_terms: D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D004705:Endocytosis; D005947:Glucose / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006046:Gold / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D008024:Ligands; D006046:Gold; D005978:Glutathione; D005947:Glucose