Usefulness of acellular dermal matrix graft on the tissue regeneration in rabbits

ABSTRACT

PURPOSE: The present study was aimed to examine the effect of acellular dermal matrix (AlloDerm(R)) grafted to the experimental tissue defect on tissue regeneration. MATERIALS AND METHODS: Male albino rabbits were used. Soft tissue defects were prepared in the external abdominal oblique muscle. The animals were then divided into 3 groups by the graft material used no graft, autogenous dermis graft, and AlloDerm(R) graft. The healing sites were histologically examined at weeks 4 and 8 after the graft. In another series, critical sized defects with 8-mm diameter were prepared in the right and left iliac bones. The animals were then divided into 5 groups no graft, grafted with autogenous iliac bone, AlloDerm(R) graft, AlloDerm(R) graft impregnated with rhBMP-2, and AlloDerm(R) graft with rhTGF-beta(1). The healing sites of bone defect were investigated with radiologic densitometry and histological evaluation at weeks 4 and 8 after the graft. RESULTS: In the soft tissue defect, normal healing was seen in the group of no graft. Inflammatory cells and foreign body reactions were observed in the group of autogenous dermis graft, and the migration of fibroblasts and the formation of vessels into the collagen fibers were observed in the group of AlloDerm(R) graft. In the bone defect, the site of bone defect was healed by fibrous tissues in the group of no graft. The marked radiopacity and good regeneration were seen in the group of autogenous bone graft. There remained the traces of AlloDerm(R) with no satisfactory results in the group of AlloDerm(R) graft. In the groups of the AlloDerm(R) graft with rhBMP-2 or rhTGF-beta(1), there were numerous osteoblasts in the boundary of the adjacent bone which was closely approximated to the AlloDerm(R) with regeneration features. However, the fibrous capsule also remained as in the group of AlloDerm(R) graft, which separated the AlloDerm(R) and the adjacent bone. CONCLUSIONS: These results suggest that AlloDerm(R) can be useful to substitute the autogenous dermis in the soft tissue defect. However, it may not be useful as a bone graft material or a carrier, since the bone defect was not completely healed by the bony tissue, regardless of the presence of osteogenic factors like rhBMP-2 or rhTGF-beta(1).