Effect of Collagen Gel with Growth Factor and Wrapping Materials on Fibrovascularization of Porous Orbital Implant

ABSTRACT

PURPOSE: To determine the effect of bFGF complexed collagen gel, which allows constant release of bFGF along with biodegradation of the collagen gel. The specific study purpose was to determine whether it can accelerate the fibrovascular ingrowth into wrapped HA-coated porous alumina and to verify the safety of new wrapping materials. Synthetic polyester-urethane (Neuropatch(R)) and lyophilized bovine pericardium (Lyoplant(R)) were compared to donor sclera for the fibrovascular ingrowth into HA-coated porous alumina. METHODS: The experimental and control groups, each consisting of 9 rabbits were wrapped with each wrapping materials (3 rabbits per wrapping material). The experimental group underwent pretreatment of bFGF-collagen gel while the control group did not. The fibrovascular ingrowth was compared at 2 and 4 weeks after implantation. Western blot analysis was conducted at 4 weeks using antibodies against CD141 and laminin. The rate of fibrovascular ingrowth was fastest in orbital implant wrapped with Lyoplant(R). RESULTS: Histopathologic examinations at 2 weeks showed no differences in distance and percentage area of fibrovascular ingrowth. Histopathologic examinations at 4 weeks showed that pretreatment of bFGF-collagen gel increased the fibrovascular ingrowth in the experimental group. Western blot analysis on experimental group also showed that the expressions of CD141 and laminin were increased by bFGF-collagen gel, thereby indicating that the fibrovascular proliferations were accelerated by bFGF released from the complex. CONCLUSIONS: bFGF-collagen gel increased the rate and degree of fibrovascular growth into hydroxyapatite-coated porous alumina by releasing bFGF as the collagen gel biodegraded. Both Lyoplant(R) and Neuropatch(R) were evaluated as safe for substitution of the donor sclera.