Figure 1. Time course of radioactivity remaining after intravitreal injection of ¹²⁵I-labeled pigment epithelium-derived factor (PEDF)-impregnated nanoparticles in rat vitreous. Five ml of the suspension of ¹²⁵I-labeled PEDF impregnated NPs were injected into the vitreous of male Wistar rats (n=28, postnatal week 5). The remaining radioactivity determined by a gamma counter was 76.1±8, 59.1±6.2, 27.7±13.1, 27.3±8.5, 9.1±10.7, 6.6±4.0, and 1.8±1.0 on Day 1, 3, 7, 10, 14, 21, and 28. Data are shown as the mean±SD (n=4 in each group).