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Thermal- and pH-Dependent Size Variable Radical Nanoparticles and Its Water Proton Relaxivity for Metal-free MRI Functional Contrast Agents
https://repo.qst.go.jp/records/48303
https://repo.qst.go.jp/records/48303b5a31e8e-ed51-421f-ba83-9582beb66997
| Item type | 学術雑誌論文 / Journal Article(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2017-08-21 | |||||
| タイトル | ||||||
| タイトル | Thermal- and pH-Dependent Size Variable Radical Nanoparticles and Its Water Proton Relaxivity for Metal-free MRI Functional Contrast Agents | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
| 資源タイプ | journal article | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Morishita, Kosuke
× Morishita, Kosuke× Murayama, Shuhei× Araki, Takeru× Aoki, Ichio× Karasawa, Satoru× 村山 周平× 青木 伊知男 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | For development of the metal-free MRI contrast agents, we prepared the supra-molecular organic radical, TEMPO-UBD, carrying TEMPO radical, as well as the urea, alkyl group, and phenyl ring, which demonstrate self-assembly behaviors using noncovalent bonds in an aqueous solution. In addition, TEMPO-UBD has the tertiary amine and the oligoethyleneglycol chains (OEGs) for the function of pH and thermal responsiveness. By DLS and TEM imaging, the resulting self-assembly was seen to form the spherical nano-particles 10 – 150 nm in size. On heating, interestingly, the nano-particles showed a lower critical solution temperature (LCST) behavior having two-step variation. This double-LCST behavior is the first such example among the supra-molecules. To evaluate of the ability as MRI contrast agents, the values of proton (1H) longitudinal relaxivity (r1) were determined using MRI apparatus. In conditions below and above CAC at pH 7.0, the distinguishable r1 values were estimated to be 0.17 and 0.21 mM(-1)s(1), indicating the suppression of fast tumbling motion of TEMPO moiety in a nano-particle. Furthermore, r1 values became larger in the order of pH 7.0 > 9.0 > 5.0. Those thermal and pH dependencies indicated the possibility of metal-fee MRI functional contrast agents in the future. | |||||
| 書誌情報 |
J. Org. Chem. 巻 81, 号 18, p. 8351-8362, 発行日 2016-08 |
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| 出版者 | ||||||
| 出版者 | ACS | |||||
| DOI | ||||||
| 識別子タイプ | DOI | |||||
| 関連識別子 | 10.1021/acs.joc.6b01509 | |||||
