School of Applied Sciences, RMIT University, Melbourne, Victoria, Australia.
PLoS One. 2011;6(7):e21857. doi: 10.1371/journal.pone.0021857. Epub 2011 Jul 1.
Development of magnetic resonance imaging (MRI) contrast agents that can be readily applied for imaging of biological tissues under clinical settings is a challenging task. This is predominantly due to the expectation of an ideal MR agent being able to be synthesized in large quantities, possessing longer shelf life, reasonable biocompatibility, tolerance against its aggregation in biological fluids, and high relaxivity, resulting in better contrast during biological imaging. Although a repertoire of reports address various aforementioned issues, the previously reported results are far from optimal, which necessitates further efforts in this area. In this study, we demonstrate facile large-scale synthesis of sub-100 nm quasi-cubic magnetite and magnetite/silica core-shell (Mag@SiO2) nanoparticles and their applicability as a biocompatible T2 contrast agent for MRI of biological tissues. Our study suggests that silica-coated magnetite nanoparticles reported in this study can potentially act as improved MR contrast agents by addressing a number of aforementioned issues, including longer shelf life and stability in biological fluids. Additionally, our in vitro and in vivo studies clearly demonstrate the importance of silica coating towards improved applicability of T2 contrast agents for cancer imaging.
开发可在临床环境下用于生物组织成像的磁共振成像（MRI）造影剂是一项具有挑战性的任务。这主要是因为理想的 MRI 造影剂应具备易于大量合成、较长的保质期、合理的生物相容性、能抵抗在生物流体中聚集、高弛豫率等特性，从而在生物成像中提供更好的对比度。尽管有大量的报道涉及到上述各种问题，但之前的报道结果远非理想，这需要在该领域进一步努力。在本研究中，我们展示了简便的亚 100nm 准立方磁铁矿和磁铁矿/二氧化硅核壳（Mag@SiO2）纳米粒子的大规模合成方法，及其作为生物组织 MRI 的生物相容性 T2 造影剂的适用性。我们的研究表明，本研究中报道的涂覆有二氧化硅的磁铁矿纳米粒子可通过解决许多上述问题，包括在生物流体中的更长保质期和稳定性，潜在地作为改进的磁共振造影剂。此外，我们的体外和体内研究清楚地表明了二氧化硅涂层对改善 T2 造影剂在癌症成像中的适用性的重要性。
