The ciliary smooth muscle electrotransfer: basic principles and potential for sustained intraocular production of therapeutic proteins

Abstract

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.

Non-viral gene therapy for GDNF production in RCS rat: the crucial role of the plasmid dose

“…At PN87, no statistical difference could be detected in the a-wave (17.1±3.2 vs 24.5±4.9 mV) and b-wave (83±7 vs 110±14 mV) amplitude between the two groups ( Figure 7 Higher pVAX2 --rGDNF dose results in lower neuroprotective effects We have recently published that using ciliary muscle ET, protein production in the ocular media could be increased either by increasing the plasmid dose or by performing multi-sites treatment. 42 We therefore evaluated the effect of increased dose of GDNF using two ET of 15 or 30 mg of pVAX2 --rGDNF, or pVAX2 as control, and analyses were performed at PN70. For all measured parameters, no differences were observed between eyes treated with two ET of either 15 or 30 mg of the naked pVAX2 plasmid.…”

“…42 Its efficacy was shown over the shortterm 41,43,44 and mid-term 44 in two rat models of intraocular inflammation, by using secreted tumor necrosis factor-a soluble Posterior segment containing the sclera (sc), the choroid (ch) and the retina (ret) was discarded and the lens (l) was carefully removed from the rest of anterior segment. (a3) Anterior segment explants made of the cornea (co), the iris (ir) and the ciliary body (cb), the latter containing the transfected ciliary muscle fibers, were incubated for 15 additional minutes at 37 1C in conditioning medium before being cultured ex vivo.…”

“…42 Comparison was thus performed between a total amount of 30 and 60 mg of plasmid using two ET of 15 and 30 mg at distinct sites. 42 Increasing the dose of non-coding plasmid or using two control ET did not induce any statistical difference at each level of analysis at PN70.…”

“…In the ciliary muscle electrotransfer (ET) technique, a focal electric field is applied to transfer plasmid DNA into ciliary muscle fibers, 41,42 which are turned into a biofactory for the secretion of any molecular weight proteins for several months, mainly into the vitreous. 42 This technique was shown to be efficient on the shortterm 41,43,44 and mid-term 44 to deliver anti-tumor necrosis factor molecules in two rat models of intraocular inflammation.…”

“…42 This technique was shown to be efficient on the shortterm 41,43,44 and mid-term 44 to deliver anti-tumor necrosis factor molecules in two rat models of intraocular inflammation.…”