Development of a novel radiosensitizer with inorganic nanoparticles

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K07752
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Kobe University
• Principal Investigator: Nishimura Hideki 神戸大学, 医学研究科, 客員准教授 (80444610)
• Co-Investigator(Kenkyū-buntansha): 佐々木 良平 神戸大学, 医学部附属病院, 教授 (30346267) ; 赤坂 浩亮 神戸大学, 医学研究科, 医学研究員 (20707161)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: ナノ粒子 / 過酸化チタン / 放射線増感

Outline of Final Research Achievements

The development of potentially safe radiosensitizing agents is essential to enhance the treatment outcomes of radioresistant cancers. The titanium peroxide nanoparticle (TiOxNP) was originally produced using the titanium dioxide nanoparticle, and it showed excellent reactive oxygen species (ROS) generation in response to ionizing radiation. Surface coating the TiOxNPs with polyacrylic acid (PAA) showed low toxicity to the living body and excellent radiosensitizing effect on cancer cells. Herein, we evaluated the mechanism of radiosensitization by PAA-TiOxNPs in comparison with gold nanoparticles (AuNPs). PAA-TiOxNPs showed a significantly more radiosensitizing effect than that of AuNPs. A comparison of the types and amounts of ROS generated showed that hydrogen peroxide generation by PAA-TiOxNPs was the major factor that contributed to the nanoparticle radiosensitization.

Free Research Field

放射線腫瘍学

Academic Significance and Societal Importance of the Research Achievements

今日の臨床のがん治療の現場において、有機的な化合物で放射線増感剤として認識され、広く臨床使用されているものはない。そのため、その現状を打破する画期的なアイデアとして無機ナノ粒子に着目し、開発を進めてきた。これまで世界的にも金ナノ粒子の効果が期待されてきたが、我々が開発した過酸化チタンナノ粒子は金ナノ粒子よりも過酸化水素の産生が協力であり、より強い放射線増感効果を示すことを世界で初めて実証した。今後は臨床応用を目指して、毒性の評価や有効性の非臨床試験などを一歩一歩進めていく。