Bioconjugation of luminescent silicon quantum dots to gadolinium ions for bioimaging applications
Bioconjugation of luminescent silicon quantum dots to gadolinium ions for bioimaging applications
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DOI：
10.1039/c2nr31002c
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发表时间：
2012-01-01
期刊：
影响因子：
6.7
通讯作者：
Prasad, Paras N.
中科院分区：
文献类型：
--
作者：
Erogbogbo, Folarin;Chang, Ching-Wen;Prasad, Paras N.
发光成像剂和MRI造影剂是合理设计用于生物成像应用的多功能纳米结构的理想组分。发光的生物相容性硅量子点（SiQD）和钆螯合物可以分别应用于荧光显微镜和MRI。在这里，我们报告的第一个合成的纳米复合物，将硅量子点和钆离子（Gd 3+）的生物应用。该纳米结构由PEG化胶束组成，其核心中具有疏水SiQD，共价结合至DOTA螯合的Gd 3+。动态光散射显示这些纳米结构的半径为85 nm，这与描绘半径范围为25至60 nm的电子显微镜结果一致。细胞摄取的探针验证，它们保持其光学特性内的细胞内环境。纳米结构的磁共振弛豫率为2.4 mM（-1）s（-1）（以Gd 3+浓度计），计算得出每个纳米结构约为6000 mM（-1）s（-1）。新开发的探针的这些理想的光学和弛豫特性为SiQD在未来的多模态应用（如肿瘤成像）中的使用打开了大门。
Luminescent imaging agents and MRI contrast agents are desirable components in the rational design of multifunctional nanoconstructs for biological imaging applications. Luminescent biocompatible silicon quantum dots (SiQDs) and gadolinium chelates can be applied for fluorescence microscopy and MRI, respectively. Here, we report the first synthesis of a nanocomplex incorporating SiQDs and gadolinium ions (Gd3+) for biological applications. The nanoconstruct is composed of a PEGylated micelle, with hydrophobic SiQDs in its core, covalently bound to DOTA-chelated Gd3+. Dynamic light scattering reveals a radius of 85 nm for these nanoconstructs, which is consistent with the electron microscopy results depicting radii ranging from 25 to 60 nm. Cellular uptake of the probes verified that they maintain their optical properties within the intracellular environment. The magnetic resonance relaxivity of the nanoconstruct was 2.4 mM(-1) s(-1) (in terms of Gd3+ concentration), calculated to be around 6000 mM(-1) s(-1) per nanoconstruct. These desirable optical and relaxivity properties of the newly developed probe open the door for use of SiQDs in future multimodal applications such as tumour imaging.