Dually-functionalized boron nitride nanotubes to target glioblastoma multiforme

Boron nitride nanotubes (BNNT) were functionalized under mild conditions with one of three targeting ligands, folic acid, a nerve growth factor,and an antibody against nerve growth factor, using a difunctional amine,such as glycine, as coupling agent. In addition, non-fouling BNNTs were obtained by a facile and versatile, non-destructive method via controlled surface initiated grafting of polyzwitterions. The BNNTs were loaded with a fluorescent probe for convenient imaging of glioblastoma multiforme cells treated with BNNTs. BNNTs bearing targeting factors on their outer surface demonstrated an increased efficiency of internalization in glioblastoma multiforme cells,compared to non-modified BNNTs. The degree of internalization was affected both by the nature of the ligand/agonist linked to the BNNTs surface and by the presence of serum proteins.The polyzwitterion grafts prevented the spontaneous adsorption of serum proteins on the BNNTs.