Abstract

The development of new imaging agents able to differentiate tissue, organs, or pathologies more efficiently and presenting good biocompatibility motivates new studies due to its huge importance in the medical field. On the another hand, near-infrared (NIR) fluorescent probes offer advantages such as very high sensitivity, high photon penetration, low-light scattering, and minimal autofluorescence from living tissues, whereas magnetic resonance imaging (MRI) offers better resolution. In this context, this work aimed to obtain particles based on niobium oxide doped with Gd³⁺ (1, 6, and 10%) and Tm³⁺ (3%) by the nonhydrolytic sol–gel to be applied as contrast agents as well as nanoprobes for biolabelling. The structure, luminescent properties, and T1/T2 relaxivity behavior were investigated using scanning electron microscopy, X-ray diffraction, fluorimeter, FTIR and Raman spectroscopies, dynamic light scattering, and MRI techniques.

The T1 images, no contrast properties can be evidenced which is not surprising for Gd nanoparticles bigger than 10 nm. The T2 image, it can be seen that the signal decreases (increase of T2 contrast properties) as the NPs concentration increases.

中文翻译：

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掺有Tm 3+和Gd 3+离子的氧化铌用于生物多峰成像

摘要

能够更有效地区分组织，器官或病理并表现出良好生物相容性的新型显像剂的开发，因其在医学领域的重要性而引起了新的研究。另一方面，近红外（NIR）荧光探针具有诸如高灵敏度，高光子穿透，低光散射和最小的活组织自发荧光等优点，而磁共振成像（MRI）提供了更好的分辨率。在这种情况下，这项工作旨在获得基于掺有Gd ³⁺（1、6％和10％）和Tm ^3+的氧化铌的颗粒（3％）被非水解溶胶凝胶用作造影剂以及用于生物标记的纳米探针。使用扫描电子显微镜，X射线衍射，荧光计，FTIR和拉曼光谱，动态光散射和MRI技术研究了结构，发光特性和T1 / T2弛豫行为。