Treatment procedure of osteoradionecrosis of the jaw by E-MNC

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K10143
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57060:Surgical dentistry-related
• Research Institution: Showa University (2023); Nagasaki University (2020-2022)
• Principal Investigator: Ohba Seigo 昭和大学, 歯学部, 准教授 (80363456)
• Co-Investigator(Kenkyū-buntansha): 住田 吉慶 長崎大学, 医歯薬学総合研究科(歯学系), 教授 (50456654)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 放射線性顎骨壊死 / 組織再生 / 細胞治療

Outline of Final Research Achievements

To formulate a model of radiation-induced osteonecrosis of the jaw (ORNJ), mice were exposed to gamma irradiation and myelinated simultaneously. 5 Gy x 6 times (total 30 Gy) were exposed to the mice and all mice in the irradiated group survived until 8 weeks post-irradiation when they were sacrificed. More osteocyte-free lacunae were observed in the jawbone than ever before in which total 12Gy and 20Gy irradiation were exposed. Bone scintigraphy also showed mild inflammation at the lower jaw bone. Formulation of effectively conditioned mononuclear cells (E-MNC) therapeutics; E-MNCs are a heterogeneous cell population, and the content of M1/M2 macrophages was examined before and after cell culture; the ratio of M1/M2 was 13.1 before culture and 1.6 after culture. The collected cells were administered through the tail vein, but no clear change in local findings was observed.

Translated with DeepL.com (free version)

Free Research Field

口腔外科

Academic Significance and Societal Importance of the Research Achievements

ORNJは、放射線治療後の極めて難治性の有害事象であり、治療法の主体は腐骨除去である。傷害された顎骨が広範囲に及ぶ場合には、切除いくが大きくなり、患者のQOLを大きく損なうことになる。早期に正常な骨組織から傷害を受けて腐骨化した骨を分離して排出させることが可能になれば患者のQOLは大きく改善することになる。ORNJモデルの作出を報告した論文はマウスを用いた１編のみで、わずかに空胞骨小腔が増加した状態のものをORNJとしている。本研究では、組織学的所見のみではなく、マイクロCTや骨シンチを用いた画像学的所見を含めてORNJモデルを策定し、今後ORNJ研究分野に貢献できるものと考えられる。