Layered gadolinium hydroxides (LGdH) have significant potential in simultaneous drug delivery and magnetic resonance imaging (MRI). In this work, we synthesized LGdH nanocomposites surface functionalised with SiO₂ nanodots (LGdH@SiO₂). We find these to have good dispersibility in cell culture medium, and a reduced tendency to aggregate compared to their uncoated analogue. Under the optimal reaction conditions, SiO₂ nanodots were evenly spread across the surface of the LGdH particles. We further intercalated ibuprofen (Ibu) and 5-fluorouracil (5FU) into LGdH@SiO₂, and explored the use of the resultant composites for drug delivery in vitro. While the SiO₂ coating could effectively reduce aggregation of the Ibu intercalate prepared by ion exchange from the parent LGdH, it was noted to increase aggregation in the case of the 5FU-loaded systems produced by coprecipitation. With a SiO₂ coating, 5FU release from the composite was almost zero-order at pH 7.4. The LGdH-5FU@SiO₂ composites can effectively inhibit the growth of A549 ​cells (a human adenocarcinoma cell line). In contrast, the Ibu-loaded materials are highly biocompatible. After SiO₂ modification, LGdH-5FU@SiO₂ retains the same proton relaxivity properties as LGdH-5FU, while LGdH-Ibu@SiO₂ becomes suitable for use as a negative contrast agent in MRI.

层状氢氧化g（LGdH）在同时给药和磁共振成像（MRI）中具有巨大潜力。在这项工作中，我们合成了用SiO ₂纳米点（LGdH @ SiO ₂）功能化的LGdH纳米复合材料。我们发现它们在细胞培养基中具有良好的分散性，并且与未包被的类似物相比，具有降低的聚集趋势。在最佳反应条件下，SiO ₂纳米点均匀分布在LGdH颗粒的表面。我们进一步将布洛芬（Ibu）和5-氟尿嘧啶（5FU）插入LGdH @ SiO _2中，并探索了所得复合物在体外药物递送中的用途。而SiO ₂涂层可以有效减少母体LGdH离子交换制得的Ibu嵌入物的聚集，在通过共沉淀产生的5FU负载系统中，这种聚集可增加聚集。使用SiO ₂涂层，在pH 7.4时，复合物中的5FU释放几乎为零级。LGdH-5FU @ SiO ₂复合材料可以有效抑制A549细胞（人类腺癌细胞系）的生长。相反，装载有Ibu的材料具有高度的生物相容性。经过SiO ₂改性后，LGdH-5FU @ SiO ₂保留了与LGdH-5FU相同的质子弛豫性，而LGdH-Ibu @ SiO ₂则适合用作MRI的阴性造影剂。