Gadolinium doped red-emissive carbon dots as targeted theranostic agents for fluorescence and MR imaging guided cancer phototherapy

As a new type of fluorescent agents, carbon dots (CDs) have revealed great potential in biomedical imaging applications attributed to their unique optical properties and good biocompatibility. However, engineering a versatile CDs nanoplatform integrating multifunctional imaging and therapeutic functionalities has always been an intractable challenge in targeted cancer treatment based on carbon nanomaterials. Herein, a gadolinium-doped CD conjugated with AS1411 aptamers (AS1411-Gd-CD) was prepared via facile solvothermal approach for targeted fluorescence (FL)/MR imaging guided photothermal therapy (PTT). The synthesized AS1411-Gd-CDs exhibited uniform nanostructure, good biocompatibility, strong red-fluorescence emission, significant MR contrast and efficient photothermal conversion. Benefiting from these outstanding properties, the AS1411-Gd-CDs were successfully employed in tumor-specific FL/MR dual-modal imaging in vitro and in vivo. Furthermore, under the guidance of FL/MR imaging, the AS1411-Gd-CDs demonstrated significant tumor inhibition effect owing to the outstanding photothermal effect. Thus, this study provided a versatile CDs nanoplatform as a multifunctional theranostic agent for synergistic FL/MR imaging and PTT in cancer treatment.

Automated summary

This study describes a multifunctional carbon dots (CDs) nanoplatform for cancer treatment, which integrates fluorescence imaging, magnetic resonance imaging (MRI), and photothermal therapy (PTT). By surface modification and doping with gadolinium, the synthesized CDs exhibit strong fluorescence emission, significant MRI contrast, and efficient photothermal conversion. In vitro and in vivo experiments demonstrate the excellent performance of these CDs in tumor-specific imaging and photothermal therapy under the guidance of fluorescence and MRI.