Near-Infrared Fluorescence Imaging in Preclinical Models of Glioblastoma

Abstract

Cancer is a public health problem requiring ongoing research to improve current treatments and discover novel therapies. More accurate imaging would facilitate such research. Near-infrared fluorescence has been developed as a non-invasive imaging technique capable of visualizing and measuring biological processes at the molecular level in living subjects. In this work, we evaluate the tumor activity in two preclinical glioblastoma models by using fluorochrome (IRDye 800CW) coupled to different molecules: tripeptide Arg-Gly-Asp (RGD), 2-amino-2-deoxy-D-glucose (2-DG), and polyethylene glycol (PEG). These molecules interact with pathological conditions of tumors, including their overexpression of αvβ3 integrins (RGD), elevated glucose uptake (2-DG), and enhanced permeability and retention effect (PEG). IRDye 800CW RGD gave the best in vivo fluorescence signal from the tumor area, which contrasted well with the low fluorescence intensity of healthy tissue. In the ex vivo imaging (dissected tumor), the accumulation of IRDye 800CW RGD could be appreciated at the tumor site. Glioblastoma tumors were presently detected with specificity and sensitivity by utilizing IRDye 800CW RGD, a near-infrared fluorophore combined with a marker of αvβ3 integrin expression. Further research is needed on its capacity to monitor tumor growth in glioblastoma after chemotherapy.

Keywords

• near-infrared fluorescence
• glioblastoma
• optical imaging