title: Efficient electroporation of liposomes doped with pore stabilizing nisin.
abstract: BACKGROUND
  Liposomes have a long history as passive and active drug carriers. Recently, a few methods have been realized to control the release from liposomes, including heating, ultrasound and laser.
  
  
  OBJECTIVE
  We report on a new approach to drive release from liposomes using electric fields.
  
  
  METHODS
  Liposomes were manufactured containing a high concentration of (quenched) 5-6 carboxyfluorescein dye. Nisin, a well-known amphiphilic peptide lantibiotic that works by stabilizing pores formed in cell membranes, was mixed in solution inside or outside the liposomes. The liposomes were then electroporated using a range of voltages, and assayed for increases in fluorescence due to release of dye. Release was measured against positive and negative controls, with positive control release driven by a strong detergent.
  
  
  RESULTS
  Our results demonstrate that the addition of nisin significantly reduces the electric field required to release the contents of liposomes, from 2000 V/m to approximately 200 V/m. This result proves that, in principle, electroporation (EP) of liposomes doped with small amounts of amphiphilic pore stabilizing peptides may be a practical means to drive release of liposomal contents in vivo.
  
  
  CONCLUSIONS
  Drug delivery from liposomes doped with amphiphilic peptides using EP is feasible. This technique could be developed into a potent adjuvant to tumor ablation using irreversible EP.
authors.affiliation: Department of Translational Imaging, The Methodist Hospital Research Institute, Houston, TX 77030, USA.
authors.forename: Jiang
authors.initials: J
authors.lastname: Yi
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Barrow
authors.forename: Nam
authors.initials: N
authors.lastname: Yu
authors.forename: Brian E
authors.initials: BE
authors.lastname: O'Neill
mesh_terms: D018274:Electroporation / Q000379:methods*; D005452:Fluoresceins; D005456:Fluorescent Dyes; D008081:Liposomes / Q000378:metabolism; D009561:Nisin / Q000737:chemistry*
chemical_list: D005452:Fluoresceins; D005456:Fluorescent Dyes; D008081:Liposomes; D009561:Nisin; C024098:6-carboxyfluorescein