Tissue reaction after implantation of Spongostan, as the carrier of xenogenic bone morphogenetic protein. Experimental study.

Reconstruction or filling of bone defects, especially in the maxillofacial region, often requires use of biomaterials. An implant should fasten healing of the bone gap or it should replace autogenic bone grafts. The combination of bone morphogenetic proteins with suitable carrier may fulfill these requirements. Proteins causing differentiation of mesenchymal cells in chondroblasts and osteoblasts were called Bone Morphogenetic Proteins--BMPs. The authors extracted BMP from bovine bones and placed it into collagen carrier formed from generally accessible hemostatic sponge--Spongostan. The implants were grafted into rat femoral muscle pouches in order to trace the tissue response. Pathologic examinations were performed 3, 6 and 8 weeks after implantation. On the basis on macroscopic and microscopic examinations it was stated that collagen sponge speckled with BMP caused minimal tissue response and evolved characteristic thin connective tissue capsule formation around the implant. The connective tissue penetrated spongious structure of the implant, filling the spaces, which became growing due to sponge resorption. Characteristic hyalinization and sparse chondroblasts were visible 8 weeks after implantation.