Multicolor imaging of lymphatic function with two nanomaterials: quantum dot-labeled cancer cells and dendrimer-based optical agents

Aim: The lymphatics, critical conduits of metastases, are difficult to study because of their size and location. Two approaches to lymphatic imaging have been employed; cancer cell labeling provides information on cell migration and metastasis and macromolecular contrast agents enable visualization of the lymphatic drainage and identification of sentinel lymph node. Only one of these approaches is typically employed during an imaging examination. Here, we demonstrate the combined use of both approaches. Method: In this study, we simultaneously visualize migration of quantum dot-labeled melanoma cells and the lymphatics using optically labeled dendrimers in vivo. Results: The appropriate use of two nanomaterials, quantum dots and dendrimers, enabled the simultaneous tracking of cancer cells within draining lymphatics. Conclusion: This technique could enable better understanding of lymph node metastasis.