In addition, imatinib-loaded coated nanoparticles increased, even more, the cytotoxicity effect when compared with the free drug (5.5- and 5.6-fold higher in U251MG and C6 cells), demonstrating the importance of inhibiting P-gp for improving the efficacy of imatinib in glioma treatment [81]. Here, PGP is linked to central nervous system cancer.