Evaluation of bFGF collagen composite sponge promoting vascular ingrowth in orbital implantation by 99Tcm-MDP scan / 中华实验眼科杂志

ABSTRACT

Background Intraorbital implantation of coralline porous hydroxyapatite (CHA) is a favorable cosmetic method after enucleation.However,the low degree of vascularizatiou in implant results in implant infection and exposure.Studies showed that a collagen composite sponge treated by basic fibroblast growth factor (bFGF/ collagen composite sponge) can promote angiogenesis.However,whether bFGF/collagen composite sponge improves the vascularization of CHA implants is unclear.Objective This study was to investigate the accelerating effect of bFGF collagen composite sponge on vascularization of orbital implant made of CHA using 99Tcm-methylene diphosphate (MDP) scan.Methods Forty-five New Zealand rabbits were randomly assigned to 3 groups.Evisceration of eyeball was performed on the left eyes of rabbits,and naked CHA,collagen composite sponge wrapped CHA and bFGF/collagen composite sponge wrapped CHA were implanted into the orbit respectively in 3 groups.99Tcm-MDP of 3 mCi was injected in the rabbits via ear vein in 2,4,6,8 and 12 weeks,and the vascular enhancement intensity on implants was observed 3 hours after injection.The ratio of average radioactive count from the area of interest with the same size between the left eyes and the right eyes was calculated.The implants were extracted for histopathological examination in the 12 weeks.Results As the lapse of postoperative time,the inflammation response gradually disappeared and no exposure of implants was seen during the 12-week duration.A similar vascular development strength was found in the area of interest among the 3 groups 2 weeks after surgery.However,the vascular development was significantly enhanced in the left eyes compared the right eyes from 4 to 6 weeks,with the highest intensity in the 8th week in the naked CHA group and collagen composite sponge wrapped CHA group.In the bFGF/ collagen composite sponge wrapped CHA group,the strongest image was in the 6th week after operation.The ratios of average radioactive count between the left eyes and the right eyes were significantly higher in the bFGF/collagen somposite sponge wrapped CHA group compared with the naked CHA group and collagen composite sponge wrapped CHA group (all at P＜0.05),and ratios of average radioactive count of the collagen composite sponge wrapped CHA group was significantly higher than that of the naked CHA group (all at P＜0.05).New blood vessels ingrowed toward the center of the implants through the coralline porous under the optical microscope.Conclusions Both bFGF (20 μg)/collagen composite sponge and collagen composite sponge can accelerate the ingrowth of vessel in the CHA,but the promoting effect of bFGF collagen composite sponge is prominent.