Dual Magnetic Particle Imaging and Akaluc Bioluminescence Imaging for Tracking Cancer Cell Metastasis

Area of Science:

• Biomedical Engineering
• Oncology
• Medical Imaging

Background:

• Magnetic Particle Imaging (MPI) enables tracking and quantification of superparamagnetic iron oxide nanoparticle (SPIO)-labeled cells.
• Bioluminescence Imaging (BLI) using the Akaluc reporter gene provides insights into cell viability.
• Combining MPI and BLI can offer a more comprehensive understanding of cancer cell dynamics.

Purpose of the Study:

• To explore the synergistic combination of MPI and BLI for a holistic assessment of cancer cell fate in vivo.
• To evaluate the utility of this multimodal imaging approach in tracking tumor growth, cell viability, and metastasis in a mouse model.

Main Methods:

• Akaluc-expressing 4T1Br5 breast cancer cells were labeled with SPIO nanoparticles (Synomag-D).
• Cells were injected into the mammary fat pads (MFP) of nude mice.
• Longitudinal BLI and MPI were performed, followed by ex vivo analysis of primary tumors and metastatic sites.

Main Results:

• BLI signal in the MFP increased significantly, correlating with tumor growth.
• MPI signal decreased over time due to SPIO dilution in proliferating cells, indicating cell division.
• Both imaging modalities detected secondary metastases, but in different anatomical locations, highlighting complementary detection capabilities.

Conclusions:

• Akaluc BLI complements MPI for longitudinal cell tracking, providing measures of cell viability and detecting distant metastases.
• This multimodal imaging strategy enhances the understanding of metastatic mechanisms and cancer cell fate.
• The combined approach holds promise for evaluating novel cancer therapeutics and improving preclinical research.