LAUSR

Despite extensive research in drug development, brain cancer is still lacking an efficacious cure due to the inability to deliver current therapeutics to the brain across the blood-brain barrier (BBB). Chemically functionalized carbon nanotubes (f-CNT) constitute a novel class of nanomaterials with attractive physical, chemical and electronic properties. The key advantage of f-CNTs is the extremely high surface area to size ratio allowing a high degree of chemical functionalization making them invaluable tools for designing drug delivery systems to the brain. One of the most interesting characteristics of f-CNTs is their ability to translocate across plasma membranes and enter the cells either passively by direct translocation across membranes or actively via endocytosis. Herein, we confirmed the ability of f-CNTs to cross the BBB and reach the brain in in vitro using a co-culture model of PBEC and primary rat astrocytes and in vivo after intravenous injection. Thanks to their unique optical properties, the uptake of f-CNT in brain was confirmed using state-of-the-art spectroscopic imaging techniques such as multi-photon luminescence imaging, fluorescence lifetime microscopy and Raman spectroscopy. Conjugation with angiopep-2 (ANG), a small peptide targeting the LRP1 receptor overexpressed in the BBB and glioma cells, further enhanced brain parenchyma accumulation in healthy brains. Higher uptake in glioma than brain parenchyma was also observed in glioma-bearing mice after intravenous administration. The inherent brain accumulation ability of f-CNTs coupled with improved brain-targeting by ANG favours the future clinical applications of f-CNTs-ANG to deliver active therapeutics for brain glioma therapy.