Reconstruction of orbital floor defect with polylacticglycolide acid/recombinant human bone morphogenetic protein 2 compound implanted material in sheep

Abstract

To study the effect and safety of polylacticglycolide acid copolymer (PLGA) and recombinant human bone morphogenetic protein 2 (rhBMP-2) as implanted biomaterials for reconstruction orbital floor defects in sheep and find the relationship between implant materials degradation and orbital floor defects restoration. Nine sheep (eighteen eyes) with orbital floor defect were divided into three groups randomly. Group A was the control without treatment. Group B was treated with PLGA and group C was received PLGA/rhBMP-2. Cosmetic appearances and complications were observed after surgery. CT scan, 3D reconstruction, defect area measurement and histological examination were performed on a week, three months and six months after operation. No complication was observed. The CT examinations showed that orbital floor defect in group C was almost disappeared by six months, however in group A and group B only partially orbital floor defect was repaired. Histological examinations showed that all materials were absorbed on six months. The orbit defects in group A were replaced by fiber tissue. The defect areas in group B were consisted of bone tissue in the peripheral and fiber tissue in the center. In group C the reconstructed areas were replaced by bone tissue, loose connective tissue and mucosal epithelia layers. The thick of 0.5 mm PLGA/rhBMP-2 sheet is a good substitute material of bone graft and may be used for orbital fracture defect reconstruction in clinic in the future.