Prospects for nanomedicine in treating age-related macular degeneration

Polyion complex (PIC) micelles have a size range of tens of nanometers formed through electrostatic interaction. In experimental choroidal neovascularization (CNV) in rats, the PIC micelle accumulates to the CNV lesions and is retained. PIC micelles can be used for effective drug delivery to CNV. A novel dendritic photosensitizer encapsulated by a polymeric-micelle formulation was employed for an effective photodynamic therapy for age-related macular degeneration. With its highly selective accumulation on experimental CNV lesions, this treatment resulted in a remarkably efficacious CNV occlusion with minimal unfavorable phototoxicity. Gene therapy is a promising approach to treat age-related macular degeneration. A ternary complex, composed of a core containing DNA packaged with cationic peptides and enveloped in the anionic dendrimer phthalocyanine, has been developed, which provides the photosensitizing action. Subconjunctival injection of the ternary complex followed by laser irradiation resulted in transgene expression only in the laser-irradiated site in rats.