1994 Fiscal Year Final Research Report Summary
Basic study for Clinical Application of Bone Morphogenetic Protein
| Project/Area Number |
03404045
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
Orthopaedic surgery
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| Research Institution | Osaka University |
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Principal Investigator |
TAKAOKA Kunio Osaka University, School of Medicine, Assistant Professor, 医学部, 助教授 (30112048)
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| Co-Investigator(Kenkyū-buntansha) |
HASUHARA Kensaku Osaka University, School of Medicine, Assistant, 医学部, 助手 (90238915)
YOSHIKAWA Hideki Osaka University, School of Medicine, Instructor, 医学部, 講師 (60191558)
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| Project Period (FY) |
1991 – 1994
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| Keywords | Osteogenesis / Fracture repair / Osteosarcoma |
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| Research Abstract |
1. We successfully purified a bone morphogenetic protein from a murine osteosnrcoma (Dunn osteosarcoma) by biochemical procedures. The protein molecule was revenled to have molecular size of 32K daltons, homodimer structure and intense bone-inducing capacity.
2. Based on a aminoncid sequence information of a peptic frngment of the purified protein molecule, mixed oligonucleotides were synthesized to screen a c-DNA library constructed from m-RNA of Dunn osteosarcoma. Full length c-DNA of the BMP was successfully cloned. Mature region of the cloned gene encoded 146 aminoacids with seven cystein residues at positions closely beta. The molecule was also closely similar to human BMP-4.
3. The cloned geno was expressed in Chinese hamster ovary cells (CIIO cells). Protein product of the gene had intense bone-inducing nctivity and induced ectopic new bone when implanted together with carrier (pure collagen) into muscles of mice in 2 weeks.
4. In considering clinical application of the recombinant BMP to clinical practice to promote bone formation, proper carrier materinls to construct delivery systems was essential. Therefore we developed such carrier materials as less anigenic collagen derived from animal skin and a synthetic polymer (polylactic acid / polyethylene block co-polymer). These carriers worked well when mixed with r-BMP and implanted into experimental animals.
5. Special delivery system for BMP was required in primates. we found that combination of BMP carrier and porous solid materinls like hydroxyapatite, alumina ceramic or titanium was effective to induce ectopic bone formation in primate.
6. Enhanced gene expression of BMP-4 could be seen in fracture repair reaction. The expression was predominantly seen in cells locating at periosteum, bone marrow and muscles adjncent to fracture site.
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