Novel nanotechnology-based drug delivery in photodynamic therapy for age-related macular degeneration
Yasuhiro Tamaki
Department of Ophthalmology,
School of Medicine,
University of Tokyo
mailing address; 7-3-1, Hongo,
Bunkyo-ku, Tokyo, 113-8655, Japan
Abstract:
Exudative age-related macular degeneration (AMD), a condition caused by choroidal neovascularization (CNV), is a major cause of legal blindness in western countries. Even with the recent advent of several treatment options such as photodynamic therapy (PDT) and anti-vascular endothelial growth factor therapy,their efficacy is still limited.PDT, which utilizes cytotoxic singlet oxygen produced by photoirradiation of a photosensitizer, is a promising treatment for CNV, and is effective at reducing the relative risk of visual acuity loss; however, it requires expensive treatments and is ineffective for some groups of patient. Polyion complex (PIC) micelle has a size range of tens of nanometersthrough electrostatic interaction with oppositely charged block copolymers, which accumulates to the CNV lesions in animal models, and can be used for effective drug delivery to CNV.In this study, we have developed an effective PDT for AMD employing a supramolecularnanomedical device, i.e. a novel dendritic PS, dendrimerporphyrin (DP), incorporated into a PIC micelle.With its highly selective accumulation on experimental CNV lesions, this treatment resulted in a remarkably efficacious CNV occlusion with minimal unfavorable phototoxicity. PDT employing a DP incorporated into a PIC micelle can be a promising treatment for AMD.
