title: Direct gene transfer with compacted DNA nanoparticles in retinal pigment epithelial cells: expression, repeat delivery and lack of toxicity.
abstract: OBJECTIVE
  To evaluate the safety of compacted DNA nanoparticles (NPs) in retinal pigment epithelial (RPE) cells.
  
  
  METHODS
  Enhanced GFP expression cassettes controlled by the RPE-specific vitelloform macular dystrophy promoter were constructed with and without a bacterial backbone and compacted into NPs formulated with polyethylene glycol-substituted lysine 30-mers. Single or double subretinal injections were administered in adult BALB/c mice. Expression levels of enhanced GFP, proinflammatory cytokines and neutrophil/macrophage mediators, and retinal function by electroretinogram were evaluated at different time-points postinjection.
  
  
  RESULTS
  Immunohistochemistry and real-time PCR demonstrated that NPs specifically transfect RPE cells at a higher efficiency than naked DNA and similar results were observed after the second injection. At 6 h postinjections, a transient inflammatory response was observed in all cohorts, including saline, indicating an adverse effect to the injection procedure. Subsequently, no inflammation was detected in all experimental groups.
  
  
  CONCLUSIONS
  This study demonstrates the safety and efficacy of NP-mediated RPE gene transfer therapy following multiple subretinal administrations.
authors.affiliation: Department of Cell Biology, University of Oklahoma Health Sciences Center, BMSB 781, 940 Stanton L Young Blvd, Oklahoma City, OK 73104, USA.
authors.forename: Zongchao
authors.initials: Z
authors.lastname: Han
authors.forename: Adarsha
authors.initials: A
authors.lastname: Koirala
authors.forename: Rasha
authors.initials: R
authors.lastname: Makkia
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Cooper
authors.forename: Muna I
authors.initials: MI
authors.lastname: Naash
mesh_terms: D000818:Animals; D004247:DNA / Q000008:administration & dosage / Q000235:genetics*; D004847:Epithelial Cells / Q000378:metabolism*; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry*; D055213:Retinal Pigment Epithelium / Q000166:cytology*
chemical_list: D049452:Green Fluorescent Proteins; D004247:DNA