Dual-modal polypeptide-containing contrast agents for magnetic resonance/fluorescence imaging

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Molecular Imaging

Background:

• Dual-modal magnetic resonance/fluorescent imaging (MRI/FI) is crucial for accurate tumor diagnosis.
• Developing targeted imaging agents with high sensitivity and specificity is essential to improve MRI/FI quality.
• Polypeptide-based contrast agents offer potential for targeted tumor imaging.

Purpose of the Study:

• To synthesize and characterize novel dual-modal MRI/FI agents for targeted tumor imaging.
• To evaluate the tumor-targeting capabilities, cell uptake, and cytotoxicity of the developed agents.
• To assess the in vivo performance of the agents for enhanced tumor visualization using MRI and FI.

Main Methods:

• Synthesis of two novel polypeptide-based derivatives: RGD-Gd-DTPA-RhB and YIGSR-Gd-DTPA-RhB.
• Characterization of the agents, including relaxivity, cell uptake, and cytotoxicity assays.
• In vitro and in vivo evaluation of MRI and fluorescent imaging performance in B16F10 melanoma models.

Main Results:

• Both RGD-Gd-DTPA-RhB and YIGSR-Gd-DTPA-RhB exhibited high relaxivity and good tumor-targeting properties.
• The agents demonstrated low cell cytotoxicity and effective red fluorescence in B16F10 melanoma cells.
• In vivo studies showed high uptake in B16F10 melanoma, leading to enhanced and prolonged MRI/FI of tumors in mice.

Conclusions:

• YIGSR-Gd-DTPA-RhB and RGD-Gd-DTPA-RhB are effective dual-modal agents for targeted tumor MRI/FI.
• These agents show significant potential for improving in vivo tumor detection and diagnosis.
• The developed polypeptide-based derivatives offer a promising platform for advanced molecular imaging applications.