Abstract
Purpose: :
To investigate the protective effect of basic fibroblast growth factor–loaded nanoparticles (bFGF–NPs) against photoreceptor degeneration in Royal College of Surgeons (RCS) rats.
Methods: :
To determine the localization of NPs within the retina of RCS rats, rhodamine (Rh)–labelled crosslinked gelatin NPs were injected intravitreously and visualized by confocal microscopy. Three week–old RCS rats received intravitreal injections of phosphate– buffered saline, free bFGF (bFGF; 2.5 µg), bFGF–microparticles (bFGF–MPs) (bFGF; 2.5 µg) or bFGF–NPs (bFGF; 2.5 µg). Electroretinograms (ERGs) were recorded 6 weeks after injection. At the end of the experiment, retinas were prepared for light microscopy or immunocytochemical staining with antibodies to rod opsin, S and M cone opsins, and glial fibrillary acidic protein. Cell death was examined with the TUNEL method.
Results: :
Intravitreously injected Rh–labelled bFGF–NPs were found in the outer nuclear layer of RCS rats. Amplitudes of ERG a– and b–waves in the bFGF–NPs–treated eyes were greater than those in the free bFGF– or the bFGF–MPs–treated eyes. In the bFGF–NPs–treated eyes, the number of photoreceptors was greater and the number of TUNEL–positive cells was smaller than in the free bFGF– or bFGF–MPs–treated eyes (p<0.05).
Conclusions: :
Intravitreously administered bFGF–NPs show significant protective effect against photoreceptor degeneration in RCS rats due to the targeting and the sustained release of bFGF in situ.
Keywords: retinal degenerations: cell biology • growth factors/growth factor receptors • drug toxicity/drug effects