Histomorphometric evaluation of bone healing capacity of epigallocatechin-3-gallate-loaded Î²-TCP bone substitute in rabbit calvarial defects

Park, Jin Woo

Abstract

This study investigated the effect of epigallocatechin-3-gallate (EGCG)-loaded microporous Î²-tricalcium phosphate (Î²-TCP) bone substitute in the bone healing of rabbit calvarial defects. New bone formation induced by Î²-TCP incorporating two different dose of EGCG [1 mg EGCG/200 mg Î²-TCP (TCP-1), 10 mg EGCG/200 mg Î²-TCP (TCP-10)] was compared with unloaded Î²-TCP (TCP-0). Calvarial defects 8 mm diameter created in 14 adult male New Zealand White rabbits were filled with three types of bone substitutes. The amount of newly formed bone was evaluated histomorphometrically at 4 and 8 weeks after implantation. The TCP-1 group exhibited increased bone healing capacity and numerous blood vessel formation compared with the other two groups. New bone formation was observed in the cental area of TCP-1 filled defects at 8 weeks. Histomorphometric analysis revealed significantly greater newly formed bone area in the TCP-1 group when compared with unloaded TCP-0 (p < 0.05 at 4 and 8 weeks) and 10 mg EGCG-loaded TCP-10 groups (p < 0.05 at 8 weeks). No difference was observed in new bone area between TCP-0 and TCP-10 groups. These results suggest that local delivery of 1 mg EGCG to Î²-TCP bone substitute by simple adsorption promotes bone regeneration in the healing of rabbit calvarial osseous defect and higher EGCG dose (in this study, 10 mg per defect) does not exert any positive effect on bone healing capacity of Î²-TCP. Thus, local delivery of EGCG to Î²-TCP bone substitute seems to be an effective approach for the treatment of osseous defects.