title: A novel liposome-based therapy to reduce complement-mediated injury in revascularized tissues.
abstract: BACKGROUND
  Ischemia/reperfusion (IR) injury is an unavoidable consequence of tissue transplantation or replantation that often leads to inflammation and cell death. Excessive complement activation following IR induces endothelial cell injury, altering vascular and endothelial barrier function causing tissue dysfunction. To mitigate the IR response, various systemic anti-complement therapies have been tried. Recently, we developed a localized therapy that uses biotinylated fusogenic lipid vesicles (BioFLVs) to first incorporate biotin tethers onto cell membranes, which are then used to bind therapeutic fusion proteins containing streptavidin (SA) resulting in the decoration of cell membranes. The therapy is applied in two steps using solutions delivered intra-arterially.
  
  
  METHODS
  Alteration of formulation, concentration and duration of incubation of BioFLVs were conducted to demonstrate the ability of the system to modulate biotin tether incorporation in cultured cells. Using a rat hind limb model, the ability of BioFLVs to decorate endothelium of femoral vessels with FITC-labeled SA for 48 h of reperfusion was demonstrated. The feasibility of a BioFLV-based anti-complement therapy was tested in cultured cells using SA fused with vaccinia virus complement control protein (SA-VCP), a C3 convertase inhibitor. Human ovarian carcinoma (SKOV-3) cells were incubated with BioFLVs first and then with SA-VCP. To activate complement the cells were treated with a SKOV-3-specific antibody (trastuzumab) and incubated in human serum.
  
  
  RESULTS
  Decoration of cells with SA-VCP effectively reduced complement deposition.
  
  
  CONCLUSIONS
  We conclude that BioFLV-mediated decoration of cell membranes with anti-complement proteins reduces complement activation and deposition in vitro and has the potential for application against inappropropriate complement activation in vivo.
authors.affiliation: Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky 40292, USA.
authors.forename: Ledia
authors.initials: L
authors.lastname: Goga
authors.forename: Sathnur B
authors.initials: SB
authors.lastname: Pushpakumar
authors.forename: Gustavo
authors.initials: G
authors.lastname: Perez-Abadia
authors.forename: Paul
authors.initials: P
authors.lastname: Olson
authors.forename: Gary
authors.initials: G
authors.lastname: Anderson
authors.forename: Chirag V
authors.initials: CV
authors.lastname: Soni
authors.forename: John H
authors.initials: JH
authors.lastname: Barker
authors.forename: Claudio
authors.initials: C
authors.lastname: Maldonado
mesh_terms: D000818:Animals; D019921:Biotinylation; D002478:Cells, Cultured; D003171:Complement Pathway, Classical; D003165:Complement System Proteins / Q000502:physiology*; D004730:Endothelium, Vascular / Q000378:metabolism; D006801:Humans; D008081:Liposomes / Q000008:administration & dosage*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D015427:Reperfusion Injury / Q000517:prevention & control*
chemical_list: D008081:Liposomes; D003165:Complement System Proteins