Development and application of cell viability imaging using MEMRI

2016 Fiscal Year Final Research Report

• Project/Area Number: 24300167
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Biomedical engineering/Biological material science
• Research Institution: National Institutes for Quantum and Radiological Science and Technology
• Principal Investigator: Aoki Ichio 国立研究開発法人量子科学技術研究開発機構, 放射線医学総合研究所 分子イメージング診断治療研究部, チームリーダー (10319519)
• Co-Investigator(Kenkyū-buntansha): 田畑 泰彦 京都大学, 再生医科学研究所, 教授 (50211371) ; 齋藤 茂芳 大阪大学, 医学(系)研究科(研究院), 助教 (40583068)
• Project Period (FY): 2012-04-01 – 2017-03-31
• Keywords: MRI / 造影剤 / マンガン / 機能性 / プローブ / 低pH / がん

Outline of Final Research Achievements

We performed in vitro and in vivo MRI experiments with Mn2+ to investigate whether manganese-enhanced MRI (MEMRI) can be used to detect cell alterations as an early-phase tumor response after radiotherapy. MEMRI was successfully used to detect cell alterations as an early-phase cellular response after tumor radiotherapy (Cancer Res. 2013). Also, we reported an nano-MRI contrast agent that rapidly amplifies MRI signals in response to pH. We confined Mn2+ within pH-sensitive calcium phosphate (CaP) nanoparticles. At a low pH, such as in solid tumors, the CaP disintegrates and releases Mn2+. Binding to proteins increases the relaxivity of Mn2+ and enhances the contrast. We show that these nanoparticles could rapidly and selectively enhanced solid tumors, identify low pH regions within the tumor (Nat Nanotechnol. 2016).

Free Research Field

磁気共鳴イメージング