Preparation of dual-modal nanoprobe for fluorescent-magnetic imaging with manganese-doped carbon quantum dots and imaging study in tumor bearing mice / 中华核医学与分子影像杂志

ABSTRACT

Objective@#To prepare manganese-doped carbon quantum dots (Mn-CDs) dual-modal nanoprobe for fluorescent-magnetic imaging, and evaluate its characteristics and potential on fluorescence imaging and MRI.@*Methods@#Mn-CDs were synthesized at 150 ℃. The form, diameter, component, fluorescent capability, T1 relaxation rate, stability and cytotoxicity of Mn-CDs in vivo were verified. The fluorescence imaging of HO-8910 tumor-bearing mice was performed on small animal imager, and the whole-body enhanced imaging was performed on 3.0 T MRI scanner. One-way analysis of variance was used to analyze the data.@*Results@#The Mn-CDs with the diameter of (4.64±0.85) nm showed a well-defined spherical morphology. The fluorescent spectra of Mn-CDs exhibited that the excitation maximum was at 360 nm and the emission maximum was at 440 nm. The T1 relaxation rate was (3.26±0.04) mmol·L-1·s-1. The Mn-CDs had good stability of fluorescent and magnetic imaging capability at 0, 0.25, 0.5, 0.75, 1.0 and 2 months at room temperature with no significant differences of fluorescent and magnetic signals (F=1.566 and 0.987, both P>0.05). After injection of 200 μl Mn-CDs (15 g/L), mice were all alive and had no viscera damage. The tumor could be observed obviously on fluorescence imaging at 5 min. Enhanced MRI showed that the tumor was unevenly enhanced and Mn-CDs were mainly cleared away through urinary system.@*Conclusion@#Mn-CDs are stable and have good potential on fluorescence imaging and MRI, which provides a promising multimodal imaging method for tumor detection and monitoring.