CdTe quantum dots as fluorescent nanotools for in vivo glioblastoma imaging

Glioblastoma (GBM) is the most aggressive and infiltrating primary tumor of the central nervous system (CNS), showing a variety of mutations and a high degree of vascularity, cell polymorphism, and nuclear atypia. GBM treatment often recurs to surgical resection, but such protocol lacks efficacy since complete tumor removal is not entirely successful due to invasive cells that cannot be detected at the moment of the surgery. Here, we describe a new in vivo targeting and imaging method for GBM detection in an orthotropic mouse model using fluorescent CdTe quantum dots (CdTe QDs) conjugated to anti-glial fibrillary acidic protein (anti-GFAP). We conjugated and optimized red-emitting CdTe QDs to anti-GFAP to label GBM (U87 cell line) in vivo. The in vivo tumor growth was visualized by the hematoxylin and eosin staining and showed the successful delivery of GBM cells into the mouse brain parenchyma. CdTe/anti-GFAP QDs were injected into the tumor region, and their uptake by tumor cells was visualized by fluorescence microscopy, showing a specific dual labeling with vimentin-immunoreactive GBM. The results reported here provide new perspectives for using CdTe QDs in GBM detection, suggesting their potential application in imaging-guided surgery and a potential fluorescent tool to be applied in the monitoring of 3D tumor glial cultures.