title: Rapid and efficient cell labeling with a MRI contrast agent by electroporation in the presence of protamine sulfate.
abstract: OBJECTIVE
  To investigate various protocols for magnetic labeling of human cancer cells with ferumoxides with a view to developing an effective and fast technique for potential clinical use in MRI.
  
  
  METHODS
  Transfection methods utilizing poly-L-lysine and protamine sulfate (PS), electroporation, and combination of PS with electroporation were evaluated in this in vitro study.
  
  
  RESULTS
  Although transfection was more effective in terms of uptake rates (95-100%) and intracellular iron concentrations (4.01-7.34 pg/cell), all transfection agents required prolonged incubation. By contrast, electroporation yielded fast labeling but with a lower efficacy (68-75%, 1.63-2.59 pg/cell). The addition of PS to electroporation increased the labeling efficacy (80-91%, 2.84-4.16 pg/cell) and protected cell viability. This combined method also resulted in the best T(2)*-shortening effect in the in vitro cellular MRI.
  
  
  CONCLUSIONS
  The combined PS-electroporation method provides a fast and efficient protocol for ferumoxide-based cellular imaging and therapeutic procedure.
authors.affiliation: Institute for Medical Science & Technology (IMSaT), School of Engineering, Physics & Mathematics, University of Dundee, Dundee, UK.
authors.forename: Lijun
authors.initials: L
authors.lastname: Wang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Wang
authors.forename: Tim G
authors.initials: TG
authors.lastname: Frank
authors.forename: Stuart I
authors.initials: SI
authors.lastname: Brown
authors.forename: Sandy A
authors.initials: SA
authors.lastname: Chudek
authors.forename: Alfred
authors.initials: A
authors.lastname: Cuschieri