title: Single-walled carbon nanotubes are a new class of ion channel blockers.
abstract: Here we identify a novel class of biological membrane ion channel blockers called single-walled carbon nanotubes (SWNTs). SWNTs with diameter distributions peaked at approximately 0.9 and 1.3 nm, C60 fullerenes, multi wall nanotubes (MWNTs), and hyperfullerenes (nano-"onions") were synthesized by several techniques and applied to diverse channel types heterologously expressed in mammalian cells. External as-fabricated and purified SWNTs blocked K+ channel subunits in a dose-dependent manner. Blockage was dependent on the shape and dimensions of the nanoparticles used and did not require any electrochemical interaction. SWNTs were more effective than the spherical fullerenes and, for both, diameter was the determining factor. These findings postulate new uses for SWNTs in biological applications and provide unexpected insights into the current view of mechanisms governing the interaction of ion channels with blocking molecules.
authors.affiliation: Department of Physiology and Biophysics, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA.
authors.forename: Ki Ho
authors.initials: KH
authors.lastname: Park
authors.forename: Manish
authors.initials: M
authors.lastname: Chhowalla
authors.forename: Zafar
authors.initials: Z
authors.lastname: Iqbal
authors.forename: Federico
authors.initials: F
authors.lastname: Sesti
mesh_terms: D000818:Animals; D016466:CHO Cells; D002244:Carbon / Q000737:chemistry*; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D037741:Fullerenes / Q000737:chemistry; D007473:Ion Channels / Q000037:antagonists & inhibitors* / Q000737:chemistry; D007477:Ions / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008954:Models, Biological; D008958:Models, Molecular; D036103:Nanotechnology; D026902:Potassium Channel Blockers / Q000737:chemistry*; D015221:Potassium Channels / Q000737:chemistry; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014162:Transfection
chemical_list: D037741:Fullerenes; D007473:Ion Channels; D007477:Ions; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D011993:Recombinant Fusion Proteins; D002244:Carbon