Gadolinium functionalized carbon dots for fluorescence/magnetic resonance dual-modality imaging of mesenchymal stem cells

The development of multimodal nanoprobes is of great importance in nanomedicine because it integrates the advantages of each imaging modality and offers a significantly enhanced diagnostic effect. In this work, gadolinium(III) functionalized fluorescent carbon dots (Gd-CDs) are synthesized by means of a one-step hydrothermal approach. As a fluorescent nanomaterial, the obtained Gd-CDs exhibit strong and stable fluorescence with excitation-independent emission behavior. Moreover, as an MRI contrast agent, the Gd-CDs exhibited a longitudinal relaxation rate of 6.06 mM(-1) s(-1), which is significantly higher than that of the commercially available MRI agent Gadovist (4.24 mM(-1) s(-1)). In addition, the cellular experiment reveals that Gd-CDs promote the proliferation of human mesenchymal stem cells (hMSCs), which is tracked by the fluorescence/Magnetic Resonance dual-modality imaging of hMSCs by the Gd-CDs.