title: Utilizing targeted gene therapy with nanoparticles binding alpha v beta 3 for imaging and treating choroidal neovascularization.
abstract: OBJECTIVE
  The integrin αvβ3 is differentially expressed on neovascular endothelial cells. We investigated whether a novel intravenously injectable αvβ3 integrin-ligand coupled nanoparticle (NP) can target choroidal neovascular membranes (CNV) for imaging and targeted gene therapy.
  
  
  METHODS
  CNV lesions were induced in rats using laser photocoagulation. The utility of NP for in vivo imaging and gene delivery was evaluated by coupling the NP with a green fluorescing protein plasmid (NP-GFPg). Rhodamine labeling (Rd-NP) was used to localize NP in choroidal flatmounts. Rd-NP-GFPg particles were injected intravenously on weeks 1, 2, or 3. In the treatment arm, rats received NP containing a dominant negative Raf mutant gene (NP-ATPμ-Raf) on days 1, 3, and 5. The change in CNV size and leakage, and TUNEL positive cells were quantified.
  
  
  RESULTS
  GFP plasmid expression was seen in vivo up to 3 days after injection of Rd-NP-GFPg. Choroidal flatmounts confirmed the localization of the NP and the expression of GFP plasmid in the CNV. Treating the CNV with NP-ATPμ-Raf decreased the CNV size by 42% (P<0.001). OCT analysis revealed that the reduction of CNV size started on day 5 and reached statistical significance by day 7. Fluorescein angiography grading showed significantly less leakage in the treated CNV (P<0.001). There were significantly more apoptotic (TUNEL-positive) nuclei in the treated CNV.
  
  
  CONCLUSIONS
  Systemic administration of αvβ3 targeted NP can be used to label the abnormal blood vessels of CNV for imaging. Targeted gene delivery with NP-ATPμ-Raf leads to a reduction in size and leakage of the CNV by induction of apoptosis in the CNV.
authors.affiliation: Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Hani
authors.initials: H
authors.lastname: Salehi-Had
authors.forename: Mi In
authors.initials: MI
authors.lastname: Roh
authors.forename: Andrea
authors.initials: A
authors.lastname: Giani
authors.forename: Toshio
authors.initials: T
authors.lastname: Hisatomi
authors.forename: Shintaro
authors.initials: S
authors.lastname: Nakao
authors.forename: Ivana K
authors.initials: IK
authors.lastname: Kim
authors.forename: Evangelos S
authors.initials: ES
authors.lastname: Gragoudas
authors.forename: Demetrios
authors.initials: D
authors.lastname: Vavvas
authors.forename: Samira
authors.initials: S
authors.lastname: Guccione
authors.forename: Joan W
authors.initials: JW
authors.lastname: Miller
mesh_terms: D000818:Animals; D017209:Apoptosis; D020256:Choroidal Neovascularization / Q000235:genetics* / Q000628:therapy*; D042783:Endothelial Cells / Q000378:metabolism; D005799:Genes, Dominant; D015316:Genetic Therapy / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D039302:Integrin alphaVbeta3 / Q000235:genetics* / Q000378:metabolism*; D007834:Lasers; D008028:Light Coagulation; D008264:Macrophages / Q000378:metabolism; D008297:Male; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D051381:Rats; D012235:Rhodamines / Q000494:pharmacology
chemical_list: D039302:Integrin alphaVbeta3; D012235:Rhodamines; D049452:Green Fluorescent Proteins