In vivo imaging of cancer cells with electroporation of quantum dots and multispectral imaging

Our understanding of dissemination and growth of cancer cells is limited by our inability for long-term followup of this process in vivo. Fluorescence molecular imaging has the potential to track cancer cells with high contrast and sensitivity in living animals. For this purpose, intracellular delivery of near-infrared fluorescence quantum dots (QDs) by electroporation offers considerable advantages over organic fluorophores and other cell tagging methods. In this research we developed a multispectral imaging system that could eliminate two major parameters compromising in vivo fluorescence imaging performance, i.e., variations in the tissue optical properties and tissue autofluorescence. We demonstrated that electroporation of QDs and multispectral imaging allowed in vivo assessment of cancer development and progression in the xenograft mouse tumor model for more than 1 month, providing a powerful means to learn more about the biology of cancer and metastasis.