2012 Volume 132 Issue 12 Pages 1365-1370
Nucleic acids like siRNA and pDNA are remarkable for treatment of ophthalmic diseases in posterior segment of eye such as age-related macular degeneration (AMD). However, hydrophilic and high molecule compounds are restricted in intraocular distribution through anterior segment of the eye. In addition, the ocular tissue has a blood-retinal barrier which restricts drug delivery thorough systemic administration. Therefore the invasive intravitreal injection has been generally applied for treatment of retinal diseases. The objective in this study is to prepare nucleic acid-loaded liposomes for effective gene delivery to posterior segment of eye by non-invasive ophthalmic administration such as eye-drops. The pDNA/PEI-complex loaded liposomes were prepared using detergent removal method. The obtained liposomes were lyophilized with optimal amount of a cryoprotectant to avoid changes in physical properties and, followed by adjustment of an appropriate volume and osmotic pressure as ophthalmic solution. The liposomes show high pDNA encapsulation efficiency and good cellular uptake ability in human retinal pigment epithelial cells (ARPE-19 cells). We further demonstrate that the modification of ligand which binds to specific receptor on the RPE cells to the liposomes may improve gene delivery efficacy to the posterior segment of eye by non-invasive ocular instillation.
