Tracking of macrophages.

Tumor development is mainly driven by aberrant growth of cancer cells, but the contribution of the microenvironment to tumor progression is increasingly well understood.

Being able to gain insights into the recruitment and persistence of bone marrow derived cells into tumor tissue is important for the understanding of tumor heterogeneity.

MSOT technology can be leveraged for tracking the tumor distribution of NIR-labeled bone marrow derived macrophages.

Bone marrow cells were isolated from the femur of a BALB/c nude mouse and differentiated into macrophages by tumor cell conditioned media. Cells were then labeled using the CellVue® NIR 815 cell labeling kit and injected systemically (0.5×106 cells) in a BALB/c nude mouse bearing an orthotopic 4T1 breast tumor. MSOT imaging was performed before and after injection (10 min. and 24 hrs).

Macrophage accumulation in tumor was visualized after 24 hrs.
B:Determination of the key components within the MSOT data by PCA/ICA analysis confirmed that the main signal consisted of labeled cells.
C:Quantification of macrophage signal by linear regression showed a significant accumulation of cells after 24 hrs.