Jang Yeong-Ji, Liu Shuwen, Yue Huan, Park Ji Ae, Cha Hyunsil, Ho Son Long, Marasini Shanti, Ghazanfari Adibehalsadat, Ahmad Mohammad Yaseen, Miao Xu, Tegafaw Tirusew, Chae Kwon-Seok, Chang Yongmin, Lee Gang Ho
Department of Chemistry, College of Natural Sciences, Kyungpook National University, Taegu 41566, Korea.
Division of Applied RI, Korea Institute of Radiological & Medical Sciences (KIRAMS), Seoul 01812, Korea.
Diagnostics (Basel). 2020 Dec 22;11(1):2. doi: 10.3390/diagnostics11010002.
The water proton spin relaxivity, colloidal stability, and biocompatibility of nanoparticle-based magnetic resonance imaging (MRI) contrast agents depend on the surface-coating ligands. Here, poly(acrylic acid-co-maleic acid) (PAAMA) (M = ~3000 amu) is explored as a surface-coating ligand of ultrasmall gadolinium oxide (GdO) nanoparticles. Owing to the numerous carboxylic groups in PAAMA, which allow its strong conjugation with the nanoparticle surfaces and the attraction of abundant water molecules to the nanoparticles, the synthesized PAAMA-coated ultrasmall GdO nanoparticles (d = 1.8 nm and a = 9.0 nm) exhibit excellent colloidal stability, extremely low cellular toxicity, and a high longitudinal water proton spin relaxivity (r) of 40.6 smM (r/r = 1.56, where r = transverse water proton spin relaxivity), which is approximately 10 times higher than those of commercial molecular contrast agents. The effectiveness of PAAMA-coated ultrasmall GdO nanoparticles as a T MRI contrast agent is confirmed by the high positive contrast enhancements of the in vivo T MR images at the 3.0 T MR field.
基于纳米颗粒的磁共振成像（MRI）造影剂的水质子自旋弛豫率、胶体稳定性和生物相容性取决于表面包覆配体。在此，聚（丙烯酸 - 共 - 马来酸）（PAAMA）（M = ~3000 amu）被用作超小氧化钆（GdO）纳米颗粒的表面包覆配体进行研究。由于PAAMA中存在大量羧基，使其能够与纳米颗粒表面强烈结合，并吸引大量水分子至纳米颗粒，合成的PAAMA包覆的超小GdO纳米颗粒（d = 1.8 nm且a = 9.0 nm）表现出优异的胶体稳定性、极低的细胞毒性以及40.6 s mM的高纵向水质子自旋弛豫率（r）（r / r = 1.56，其中r =横向水质子自旋弛豫率），这比市售分子造影剂高出约10倍。在3.0 T MR场下，体内T MR图像的高正性对比增强证实了PAAMA包覆的超小GdO纳米颗粒作为T MRI造影剂的有效性。
