LAUSR

Abstract Wet type age-related macular degeneration results in the reduction and loss of eyesight and is closely correlated with angiogenesis. Small interfering siRNA (siRNA) is a functional nucleic acid used as a knockdown tool to control target gene expression in a sequence-dependent manner. In contrast, siRNA can potently inhibit angiogenesis in an “independent” manner via its interaction with Toll-like receptor 3. In this study, siRNA was conjugated with ultra-small gold nanoparticles to prevent the distribution of siRNA outside the eye, and the usefulness of this mini-carrier with siRNA against angiogenesis was investigated. Thiolated siRNA (siRNA-hexaethyleneglycol-SH) was conjugated to the surface of gold nanoparticles through a coordinate bond. The nanoparticles were small (approximately 10 nm in diameter) and carried approximately 7.6 siRNA molecules oriented vertically. These nanoparticles suppressed luciferase gene expression in a cell line stably expressing luciferase. The siRNA-gold nanoparticles inhibited tube formation by human endothelial cells on Matrigel efficiently. These siRNA-gold nanoparticles may be useful for treating angiogenesis resulting from age-related macular degeneration.