[Development of artificial implant bone].
This study tested the hypothesis that a significant amount of the new bone produced by heterotopic periosteal grafts is derived osteoinductively because proliferating periosteal cells express the bone morphogenetic protein (BMP). Rabbit ulnar and radial periosteum were autografted as free grafts (FGs) to the forelimb musculature, and as millipore diffusion chambers grafts (MDCGs) to the rectus abdominus muscle. The sections were immunostained with monoclonal antibody against recombinant human (rh) BMP-2. Sections from FGs recovered 5 to 28 days postoperatively exhibited cartilage and bone; fibrous tissue, cartilage, bone, and osteochondroid differentiated within MDCGs. Although BMP-2 was expressed by mesenchymal cells, osteoblasts, osteocytes, and osteoclasts, none of the MDCGs produced the osteoinductive signature of transmembrane bone formation. These observations indicated that the larger fraction of the new bone produced by heterotopic periosteal autografts is derived from the graft cells. As the artificial implant bone, 1) the freeze-dried bone, 2) autoclaved bone, 3) sintered bone, 4) hydroxyapatite, and 5) titanium metal were used. Sprague-Dawley rats (aged 8 weeks) were used, the parietal bone was cut off, they were treated to freeze-dried bone, autoclaved bone and sintered bone. Then each treated bone was reimplanted. The grafts were harvested at 1, 2, 3, and 5 weeks postoperatively, the specimens were observed with a scanning electron microscope and a conventional light microscope. All of the treated bone were able to bone union, especially in the sintered bone and autoclaved bone, the blood vessels and the bone formation were produced at extremely early stage. In implantation of the non-living body materials, bone formation and revascularization was inhibited. We think that bone transplantation after irradiation should be done after recovery from the radiation damage to the periosteal cells and the blood vessels.
Kita
S
S
Department of Oral and Maxillofacial Surgery, Asahikawa Medical College, Japan.
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000378:metabolism / Q000502:physiology; D018786:Bone Substitutes; D002454:Cell Differentiation; D002455:Cell Division; D006801:Humans; D006882:Hydroxyapatites; D016348:Osseointegration; D010521:Periosteum / Q000166:cytology / Q000378:metabolism / Q000637:transplantation; D019736:Prostheses and Implants; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D016042:Transplantation, Heterotopic
C525718:BMP2 protein, human; C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D018786:Bone Substitutes; D006882:Hydroxyapatites; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2