CA4 and central nervous system cancer: In the case of the human glioma U87 cell line, the DTX-loaded nanospheres engineered from the CA4-βCD heterodimer 2, which combine small size and fast drug release, were significantly more efficacious than the other three nanoformulations assayed, whereas the rat glioblastoma cell line C6 was instead more sensitive to the higher size and slow DTX releasing nanocapsules assembled from 1.