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Maxillary sinus floor bone augmentation using recombinant human bone morphogenetic protein-2 (RhBMP-2) and absorbable collagen sponge (ACS) in goats
022-B2 Distraction osteogenesis and BMP
1 l. Maxillary Sinus Floor Bone Augmentation Using Recombinant Human Bone Morphogenefic Protein-2 (RhBMP-2) and Absorbable Collagen Sponge (ACS) in Goats
Kirker-Head, C. A. 1, Nevins, R. 2, Palmer, R. 3, Nevins, M. 2, Schelling, S. 1, Graham, 1).3, Roscioli, A. 1 l Orthopaedic Research Laboratory, Tufts University School of Veterinary Medicine, 2Institute for Advanced Dental Studies, 3Genetics Institute, Massachusetts, U.S.A. This study assessed the efficacy, safety and technical feasibility of inducing bone formation in an animal model of maxillary sinus floor augmentation (MSFA) using an rhBMP-2/ACS implant. Bilateral maxillary sinus floor elevation procedures were surgically performed in 6 adult goats. Each goat was implanted with rhRMP-2 (1.7 mg)/ACS in one sinus and a negative control (buffer/ACS) in the contralateral sinus. Two animals were sacrificed at 4, 8, and 12 weeks. Bone formation was evaluated using computed tomography (CT), gross pathologic and histologic analyses. Goats also received daily physical exams, hematologic profiling, and serologic screening for antibodies to the bovine origin ACS. CT scans documented non-osseous radiopacity in both sinuses immediately post-implantation. RhBMP-2/ACS implants subsequently demonstrated increasing radio-opacity while the control implants' radio-opacity remained unchanged or decreased. Histologic examination at 4 weeks revealed exuberant robust neo-osteogenesis at rhBMP-2/ACS implant sites whereas fibrous tissue was observed in the contralateral control sinuses. No inflammatory response, residual ACS or cartilage was identifiable in either treatment group. By 12 weeks, dense isolated trabeculae and bone marrow were locally present at rhBMP-2/ACS implant sites. Very little new bone had formed in the control sinuses. No anti-bovine collagen antibodies were detected at 5 or 14 days post-operatively. In summary, rhBMP-2/ACS imp!ants induced substantive new bone without adverse sequelae. The animal model proved to be a realistic representation of the MSFA procedure as performed clinically in humans. RhBMP-2/ACS implants may be an acceptable alternative to bone grafts and bone substitutes for MSFA procedures in humans.
12. Bone Transplantation in Irradiated Rat Calvalia
Takekawa, M., Matsuda, M., Ohotubo, S., Kita, S. Department of OMS, Asahikawa Med. Coll., Asahikawa, Japan The purpose of this study was to determine the proper time for bone transplantation after irradiation treatment. Autogenous illiac bone transplantations were carried out in
77
rat parietal bones two and four weeks after irradiation (60Co, total 22.4 Gy). The same bone transplantation in rats without irradiation was performed as a control. Samples from the each group at 1, 2, 4 and 6 weeks after the transplantation were prepared for scanning electron and conventional light microscopy. New bone formation was seen in all groups one week after transplantation. In the group that received the transplantion two weeks after irradiation, the proliferation of mesenchyma! cells, the formation of blood vessels and subsequent new bone formation were noticeably reduced. The group that had the transplantation four weeks after irradiation showed a similar healing process to the control, although the new bone formation in the early stage after the transplantation was a little delayed. We have concluded that when bone transplantion is done soon after irradiation, primary new bone formation and incorporation are delayed as compared with the control.
13. Bone Formation by Culture-Expanded Bone Marrow Cells Exposed to Growth Factors in vitro and in vivo
Higashinakagawa, M., Asahina, L, Enonwto, S. Second Department of Oral and Maxillofacial Surgery, Tokyo Medical and Dental University Background: Bone marrow cells have the capacity to differentiate into bone or cartilage under appropriate conditions. Previous studies have described that some scaffolds which are able to sustain cells, such as porous hydroxyapatite, are osteoinductive when combined with bone marrow cells. On the other hand, it is known that certain growth factors such as bone morphogenic proteins and fibroblast growth factors have the potential to enhance osteoblastic characteristics in vitro. We tried to expand the number of bone marrow cells under the influence of growth factors with appropriate scaffolds in vitro, and examined the bone-forming potential of these materials with osteogenic cells in vivo. Methods: Primary cell cultures of rat bone marrow were used. The cells were sustained in scaffolds made of porous hydroxyapatite and were cultured for one to two weeks with or without growth factors. These materials including the cells were then implanted subcutaneously into syngenic rats for various amounts of time, and then the rats were sacrificed for histological evaluation. Results: Bone formation was observed two to three weeks after the implantation. New bone formation was first observed on the surface, and then it penetrated deeper into the materials. Growth factors enhanced new bone formation. Conclusions: Our data suggests that the combination of bone marrow cells and certain scaffolds would be useful for repairing bone defects. Bone marrow cells cultured with growth factors in appropriate scaffolds could have the potential to induce new bone formation.
1 l. Maxillary Sinus Floor Bone Augmentation Using Recombinant Human Bone Morphogenefic Protein-2 (RhBMP-2) and Absorbable Collagen Sponge (ACS) in Goats
Kirker-Head, C. A. 1, Nevins, R. 2, Palmer, R. 3, Nevins, M. 2, Schelling, S. 1, Graham, 1).3, Roscioli, A. 1 l Orthopaedic Research Laboratory, Tufts University School of Veterinary Medicine, 2Institute for Advanced Dental Studies, 3Genetics Institute, Massachusetts, U.S.A. This study assessed the efficacy, safety and technical feasibility of inducing bone formation in an animal model of maxillary sinus floor augmentation (MSFA) using an rhBMP-2/ACS implant. Bilateral maxillary sinus floor elevation procedures were surgically performed in 6 adult goats. Each goat was implanted with rhRMP-2 (1.7 mg)/ACS in one sinus and a negative control (buffer/ACS) in the contralateral sinus. Two animals were sacrificed at 4, 8, and 12 weeks. Bone formation was evaluated using computed tomography (CT), gross pathologic and histologic analyses. Goats also received daily physical exams, hematologic profiling, and serologic screening for antibodies to the bovine origin ACS. CT scans documented non-osseous radiopacity in both sinuses immediately post-implantation. RhBMP-2/ACS implants subsequently demonstrated increasing radio-opacity while the control implants' radio-opacity remained unchanged or decreased. Histologic examination at 4 weeks revealed exuberant robust neo-osteogenesis at rhBMP-2/ACS implant sites whereas fibrous tissue was observed in the contralateral control sinuses. No inflammatory response, residual ACS or cartilage was identifiable in either treatment group. By 12 weeks, dense isolated trabeculae and bone marrow were locally present at rhBMP-2/ACS implant sites. Very little new bone had formed in the control sinuses. No anti-bovine collagen antibodies were detected at 5 or 14 days post-operatively. In summary, rhBMP-2/ACS imp!ants induced substantive new bone without adverse sequelae. The animal model proved to be a realistic representation of the MSFA procedure as performed clinically in humans. RhBMP-2/ACS implants may be an acceptable alternative to bone grafts and bone substitutes for MSFA procedures in humans.
12. Bone Transplantation in Irradiated Rat Calvalia
Takekawa, M., Matsuda, M., Ohotubo, S., Kita, S. Department of OMS, Asahikawa Med. Coll., Asahikawa, Japan The purpose of this study was to determine the proper time for bone transplantation after irradiation treatment. Autogenous illiac bone transplantations were carried out in
77
rat parietal bones two and four weeks after irradiation (60Co, total 22.4 Gy). The same bone transplantation in rats without irradiation was performed as a control. Samples from the each group at 1, 2, 4 and 6 weeks after the transplantation were prepared for scanning electron and conventional light microscopy. New bone formation was seen in all groups one week after transplantation. In the group that received the transplantion two weeks after irradiation, the proliferation of mesenchyma! cells, the formation of blood vessels and subsequent new bone formation were noticeably reduced. The group that had the transplantation four weeks after irradiation showed a similar healing process to the control, although the new bone formation in the early stage after the transplantation was a little delayed. We have concluded that when bone transplantion is done soon after irradiation, primary new bone formation and incorporation are delayed as compared with the control.
13. Bone Formation by Culture-Expanded Bone Marrow Cells Exposed to Growth Factors in vitro and in vivo
Higashinakagawa, M., Asahina, L, Enonwto, S. Second Department of Oral and Maxillofacial Surgery, Tokyo Medical and Dental University Background: Bone marrow cells have the capacity to differentiate into bone or cartilage under appropriate conditions. Previous studies have described that some scaffolds which are able to sustain cells, such as porous hydroxyapatite, are osteoinductive when combined with bone marrow cells. On the other hand, it is known that certain growth factors such as bone morphogenic proteins and fibroblast growth factors have the potential to enhance osteoblastic characteristics in vitro. We tried to expand the number of bone marrow cells under the influence of growth factors with appropriate scaffolds in vitro, and examined the bone-forming potential of these materials with osteogenic cells in vivo. Methods: Primary cell cultures of rat bone marrow were used. The cells were sustained in scaffolds made of porous hydroxyapatite and were cultured for one to two weeks with or without growth factors. These materials including the cells were then implanted subcutaneously into syngenic rats for various amounts of time, and then the rats were sacrificed for histological evaluation. Results: Bone formation was observed two to three weeks after the implantation. New bone formation was first observed on the surface, and then it penetrated deeper into the materials. Growth factors enhanced new bone formation. Conclusions: Our data suggests that the combination of bone marrow cells and certain scaffolds would be useful for repairing bone defects. Bone marrow cells cultured with growth factors in appropriate scaffolds could have the potential to induce new bone formation.