Morphological aspects of restoring a rat's eye socket defect with elastin-based biomaterial

The purpose of the study is to identify morphological aspects of replacement of xenogenic decellularized elastin matrix (DXEM) transplanted into a bone defect of the upper wall of the rat's eye socket. Materials and Methods. The experiment was performed on 60 Wistar rats, which produced a 7x4 mm defect in the upper edge of the orbit. DXEM was placed in the defect zone, in the experimental group (n=30). The size was similar to the defect and was fixed with a suture material-silk 50 microns. Soft tissues were sutured in layers in the control group (n=30). Tissue excision was performed after 1, 3 and 12 months. Histological, immunohistochemical and electron microscopic methods were used. Results. DXEM was gradually replaced by bone tissue against the background of a pronounced reaction of CD68+/MMP-9+ macrophages. This indicated its resorption and lysis. Osteogenesis occurred endesmally, periostally, which was preceded by centripetal migration of endothelial kidneys with subsequent differentiation into hemocapillaries and growth of loose fibrous connective tissue with progenitor cells. The microenvironment could contribute to differentiation of progenitor cells in the osteogenic direction and osteogenesis represented by reticulin fibers, TGFb, sulfated glycosaminoglycans in the control group, the defect remained open throughout the experiment. Conclusion. Decellularized biomaterial based on elastin matrix has osteoconductive and osteoinductive characteristics and can serve as an adequate biomimetic for bone defects restoration.