Kunihiro Musashi

Experimental proliferative vitreoretinopathy in rabbits by delivery of bioactive proteins with gelatin microspheres

Graphical abstract Figure. No caption available. &NA; Proliferative vitreoretinopathy (PVR) is a challenging pathological condition, often causing failure of retinal detachment surgery. The purpose of this study was to evaluate the feasibility of a delivery system of bioactive proteins using anionic and cationic gelatin microspheres and to establish a new PVR model in rabbits by intraocular sustained delivery of basic fibroblast growth factor (bFGF) and interferon‐beta (IFN&bgr;). Anionic and cationic gelatin microspheres were prepared and immersed in bFGF and IFN&bgr; solution, respectively, to yield a polyion complex between gelatin matrix and a bioactive protein. The bFGF‐impregnated microspheres were injected into the subretinal space in rabbit eyes. At week 2, the IFN&bgr;‐impregnated microspheres also were injected into the same space. Control eyes received gelatin microspheres without bFGF or IFNß, or both. The eyes then were observed for 8 weeks by ophthalmoscopy, fundus photography, and fluorescein angiography. The eyes also were evaluated histologically. In the group with both bFGF and IFN&bgr;, the number of eyes with more severe PVR increased over time. Histologic examination showed retinal folds. In contrast, no proliferative changes were seen in any control groups. Subretinal implantation of bFGF and IFN&bgr;‐impregnated gelatin microspheres induced reproducible PVR in rabbit eyes. This study guaranteed delivery of bioactive proteins with gelatin microspheres.