Intrathecal Delivery Of Folate Conjugated Near-Infrared Quantum Dots For Targeted In Vivo Imaging Of Gliomas In Mice Brains

Folate acid receptors (FR) are overexpressed in various tumor types, and this makes them excellent targets for tumor localization. From the literature, folate-modified quantum dots (QDs) have the potential to effectively target and monitor brain tumors in vivo. Here we report the high tumor targeting efficacy of folate acid (FA) labeled near-infrared (NIR) QDs with their maximum emission at 800 nm. After coupling QD800-PEG (CdSeTe/ZnS) with FA, we used the orthotopic transplantation mouse model with folate-rich U87MG to test targeted fluorescence imaging of the tumor after intrathecal delivery. The results show that the tumor uptake of QD800-FA is much higher than that of QD800. The semiquantitative analysis of the region of interest (ROI) showed a higher tumor uptake of 90.9 +/- 0.6%ID/g of QD800-FA as compared to 24.8 +/- 1.6%ID/g of QD800. At the end point of our study, 6 weeks after injection, we could still observe fluorescence signals from the mouse brain.