title: The ciliary smooth muscle electrotransfer: basic principles and potential for sustained intraocular production of therapeutic proteins.
abstract: BACKGROUND
  We have developed a nonviral gene therapy method based on the electrotransfer of plasmid in the ciliary muscle. These easily accessible smooth muscle cells could be turned into a biofactory for any therapeutic proteins to be secreted in a sustained manner in the ocular media.
  
  
  METHODS
  Electrical conditions, design of electrodes, plasmid formulation, method and number of injections were optimized in vivo in the rat by localizing β-galactosidase expression and quantifying reporter (luciferase) and therapeutic (anti-tumor necrosis factor) proteins secretion in the ocular media. Anatomical measurements were performed via human magnetic resonance imaging to design a human eye-sized prototype that was tested in the rabbit.
  
  
  RESULTS
  In the rat, transscleral injection of 30 µg of plasmid diluted in half saline (77 mM NaCl) followed by application of eight square-wave electrical pulses (15 V, 10 ms, 5.3 Hz) using two platinum/iridium electrodes, an internal wire and an external sheet, delivered plasmid efficiently to the ciliary muscle fibers. Gene transfer resulted in a long-lasting (at least 5 months) and plasmid dose-/injection number- dependent secretion of different molecular weight proteins mainly in the vitreous, without any systemic exposure. Because ciliary muscle anatomical measurements remained constant among ages in adult humans, an integrated device comprising needle-electrodes was designed and manufactured. Its usefulness was validated in the rabbit.
  
  
  CONCLUSIONS
  Plasmid electrotransfer to the ciliary muscle with a suitable medical device represents a promising local and sustained protein delivery system for treating posterior segment diseases, avoiding repeated intraocular injections.
authors.affiliation: INSERM, U872 Physiopathology of Ocular Diseases: Therapeutic innovations, Paris, France. elodie_touchard@yahoo.fr
authors.forename: Elodie
authors.initials: E
authors.lastname: Touchard
authors.forename: Laura
authors.initials: L
authors.lastname: Kowalczuk
authors.forename: Carole
authors.initials: C
authors.lastname: Bloquel
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Naud
authors.forename: Pascal
authors.initials: P
authors.lastname: Bigey
authors.forename: Francine
authors.initials: F
authors.lastname: Behar-Cohen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001082:Aqueous Humor / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D002924:Ciliary Body / Q000378:metabolism*; D018274:Electroporation / Q000379:methods*; D005123:Eye / Q000033:anatomy & histology / Q000378:metabolism; D005260:Female; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D006801:Humans; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D023421:Models, Animal; D009130:Muscle, Smooth / Q000378:metabolism*; D010957:Plasmids; D011817:Rabbits; D051381:Rats; D011917:Rats, Inbred Lew; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
chemical_list: D008156:Luciferases; D001616:beta-Galactosidase