Figure 2

Penetration of topically applied Alexa Fluor 488-labeled P60 (5 µg) and P78 in ATs across a diabetic (>300 mg/dL glucose) Ins2^Akita mouse eye. (A) Cross-section of a mouse eye 2 h after receiving the eye drops. The fluorescently labeled peptides were visible on the corneal surface and in the ciliary body (CB), RPE/Choroid (RPE/ch) and retina (n = 8). (B) Cross-sections of the corneal epithelium 1–4 h after treatment with eye drops containing dialyzed unconjugated Alexa Fluor 488 label (control), labeled P60, P78 or PEDF. Controls receiving dialyzed unconjugated Alexa Fluor 488 alone indicate that most of the free label was removed during dialysis. Labeled P60 penetrated the cornea earlier than P78, and most of the larger full-length PEDF (50 kDa) remained at the corneal epithelium (n = 5) (scale bar = 50 µmol/L). (C) Distribution of labeled P60 and P78 in the retina, 2 h after eye drops were given. The fluorescently labeled peptides were visible in the RPE/choroid, vitreous and vasculature of the inner retina (arrows) and in some retinal cells (arrowheads). RPE/Ch: RPE-choroidal complex (n = 4) (scale bar = 50 µmol/L).