Fluorescein-labeled polymeric nanoparticles functionalized with a targeting peptide (in green) are internalized into MCF-7 (from breast tumor) and U87 (from glioblastoma) spheroids that express the NRP-1 receptor (in red). The nanoparticles are observed inside the U87 cells (white arrow). Scale bar are 200 µm and 20 µm (in the big magnification).

Authors: Lorena Simón-Gracia, Ines Diaz Bessone, Kadri Toome