State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University , Changchun 130012, People's Republic of China.
Department of Oral Pathology, School and Hospital of Stomatology, Jilin University , Changchun 130021, People's Republic of China.
ACS Appl Mater Interfaces. 2016 Sep 7;8(35):22942-52. doi: 10.1021/acsami.6b07997. Epub 2016 Aug 25.
Iron oxide (Fe3O4), polydopamine (PDA), and in particular their composites are examples of the safest nanomaterials for developing multifunctional nanodevices to perform noninvasive tumor diagnosis and therapy. However, the structures and performances of Fe3O4-PDA nanocomposites should be further perfected to enhance the theranostic efficiency. In this work, we demonstrate the fabrication of PDA-capped Fe3O4 (Fe3O4@PDA) superparticles (SPs) employing preassembled Fe3O4 nanoparticles (NPs) as the cores. Owing to the collective effect of preassembled Fe3O4 NPs, the superparamagnetism and photothermal performance of Fe3O4@PDA SPs are greatly enhanced, thus producing nanodevices with improved magnetic resonance imaging (MRI)-guided photothermal efficiency. Systematical studies reveal that the molar extinction coefficient of the as-assembled Fe3O4 SPs is 3 orders of magnitude higher than that of individual Fe3O4 NPs. Also due to the high aggregation degree of Fe3O4 NPs, the T2-weighted MRI contrast is greatly enhanced for the SPs with r2 relaxivity of 230.5 mM(-1) s(-1), which is ∼2.5 times larger than that of individual Fe3O4 NPs. The photothermal stability, physiological stability, and biocompatibility, as well as the photothermal performance of Fe3O4 SPs, are further improved by enveloping with PDA shell.
氧化铁（Fe3O4）、聚多巴胺（PDA），特别是它们的复合材料，是开发用于进行非侵入性肿瘤诊断和治疗的多功能纳米器件的最安全的纳米材料之一。然而，为了提高治疗效果，Fe3O4-PDA 纳米复合材料的结构和性能还需要进一步完善。在这项工作中，我们采用预先组装的 Fe3O4 纳米颗粒（NPs）作为核，制备了聚多巴胺（PDA）包覆的 Fe3O4（Fe3O4@PDA）超粒子（SPs）。由于预先组装的 Fe3O4 NPs 的协同作用，Fe3O4@PDA SPs 的超顺磁性和光热性能得到了极大的增强，从而产生了具有改进的磁共振成像（MRI）引导光热效率的纳米器件。系统研究表明，组装后的 Fe3O4 SP 的摩尔消光系数比单个 Fe3O4 NPs 高 3 个数量级。此外，由于 Fe3O4 NPs 的高聚集度，SPs 的 T2 加权 MRI 对比大大增强，其 r2 弛豫率为 230.5 mM(-1) s(-1)，是单个 Fe3O4 NPs 的 2.5 倍。通过包裹 PDA 壳，进一步提高了 Fe3O4 SP 的光热稳定性、生理稳定性、生物相容性和光热性能。
