title: Novel delivery of oligonucleotides using a topical hydrogel tissue sealant in a murine partial nephrectomy model.
abstract: OBJECTIVE
  Ischemia/reperfusion injury is a leading cause of renal damage and antisense gene therapy has been shown to ameliorate its effects. However, this approach has been limited by current delivery methods that require high concentrations of intravenous nucleic acids lacking specificity for targeting tissues. To overcome these limitations we developed a novel murine partial nephrectomy model to evaluate polyethylene-glycol (PEG) hydrogel tissue sealant as a topical oligonucleotide delivery system.
  
  
  METHODS
  A total of 18 male C57BL/6 mice underwent left partial nephrectomy with vascular occlusion. Hydrogel primer and then sealant were applied to the cut surface and photopolymerized. Using this method 16 additional mice received hydrogel primer mixed with Cy5 labeled fluorescent oligonucleotide (10 to 100 microg). Kidneys were harvested at various time points and assessed for oligonucleotide penetration using fluorescence microscopy.
  
  
  RESULTS
  A survival rate of 100% (34 subjects) was obtained using this mouse model of partial nephrectomy. PEG hydrogel provided adequate protection against renal hematoma and intraperitoneal blood. Fluorescent images revealed that 50 microg was the minimum dose resulting in complete progressive cellular penetration with time. In addition to direct diffusion from the application site, movement of oligonucleotide through the subcapsular space into the cortex was an observed mechanism of distribution.
  
  
  CONCLUSIONS
  A murine partial nephrectomy model was successfully created using PEG hydrogel. In addition to achieving hemostasis, hydrogel served as a successful depot for delivering oligonucleotides throughout the kidney.
authors.affiliation: Department of Surgery, University of Arizona, Tucson 85724-5077, USA.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Ramakumar
authors.forename: Hardeep
authors.initials: H
authors.lastname: Phull
authors.forename: Todd
authors.initials: T
authors.lastname: Purves
authors.forename: Joel
authors.initials: J
authors.lastname: Funk
authors.forename: Duan
authors.initials: D
authors.lastname: Copeland
authors.forename: Judith B
authors.initials: JB
authors.lastname: Ulreich
authors.forename: Li-Wen
authors.initials: LW
authors.lastname: Lai
authors.forename: Yeong-Hau Howard
authors.initials: YH
authors.lastname: Lien
mesh_terms: D000818:Animals; D003182:Complement C5 / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000379:methods; D006400:Hematocrit; D006490:Hemostatics / Q000008:administration & dosage* / Q000493:pharmacokinetics; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000008:administration & dosage* / Q000493:pharmacokinetics; D007668:Kidney / Q000098:blood supply*; D007672:Kidney Cortex / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009392:Nephrectomy / Q000379:methods*; D009841:Oligonucleotides / Q000008:administration & dosage* / Q000493:pharmacokinetics; D015427:Reperfusion Injury / Q000517:prevention & control*; D014018:Tissue Distribution
chemical_list: D003182:Complement C5; D006490:Hemostatics; D009841:Oligonucleotides; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate