title: Carbon nanotube-enhanced thermal destruction of cancer cells in a noninvasive radiofrequency field.
abstract: BACKGROUND
  Single-walled carbon nanotubes (SWNTs) have remarkable physicochemical properties that may have several medical applications. The authors have discovered a novel property of SWNTs-heat release in a radiofrequency (RF) field-that they hypothesized may be used to produce thermal cytotoxicity in malignant cells.
  
  
  METHODS
  Functionalized, water-soluble SWNTs were exposed to a noninvasive, 13.56-megahertz RF field, and heating characteristics were measured with infrared thermography. Three human cancer cell lines were incubated with various concentrations of SWNTs and then treated in the RF field. Cytotoxicity was measured by fluorescence-activated cell sorting. Hepatic VX2 tumors in rabbits were injected with SWNTs or with control solutions and were treated in the RF field. Tumors were harvested 48 hours later to assess viability.
  
  
  RESULTS
  The RF field induced efficient heating of aqueous suspensions of SWNTs. This phenomenon was used to produce a noninvasive, selective, and SWNT concentration-dependent thermal destruction in vitro of human cancer cells that contained internalized SWNTs. Direct intratumoral injection of SWNTs in vivo followed by immediate RF field treatment was tolerated well by rabbits bearing hepatic VX2 tumors. At 48 hours, all SWNT-treated tumors demonstrated complete necrosis, whereas control tumors that were treated with RF without SWNTs remained completely viable. Tumors that were injected with SWNTs but were not treated with RF also were viable.
  
  
  CONCLUSIONS
  The current results suggested that SWNTs targeted to cancer cells may allow noninvasive RF field treatments to produce lethal thermal injury to the malignant cells. Now, the authors are developing SWNTs coupled with cancer cell-targeting agents to enhance SWNT uptake by cancer cells while limiting uptake by normal cells.
authors.affiliation: Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Gannon
authors.forename: Paul
authors.initials: P
authors.lastname: Cherukuri
authors.forename: Boris I
authors.initials: BI
authors.lastname: Yakobson
authors.forename: Laurent
authors.initials: L
authors.lastname: Cognet
authors.forename: John S
authors.initials: JS
authors.lastname: Kanzius
authors.forename: Carter
authors.initials: C
authors.lastname: Kittrell
authors.forename: R Bruce
authors.initials: RB
authors.lastname: Weisman
authors.forename: Matteo
authors.initials: M
authors.lastname: Pasquali
authors.forename: Howard K
authors.initials: HK
authors.lastname: Schmidt
authors.forename: Richard E
authors.initials: RE
authors.lastname: Smalley
authors.forename: Steven A
authors.initials: SA
authors.lastname: Curley
mesh_terms: D000818:Animals; D002470:Cell Survival; D006801:Humans; D017745:Incineration; D008113:Liver Neoplasms / Q000628:therapy*; D037742:Nanotubes, Carbon / Q000009:adverse effects; D011817:Rabbits; D000078702:Radiofrequency Therapy; D014407:Tumor Cells, Cultured
chemical_list: D037742:Nanotubes, Carbon