TF and glioma: Moreover, Medes et al. describe in their in vitro study how ultra-small nanostructure lipid carriers (usNLCs) can be coupled with specific cell-penetrating peptides (CPPs), tumour-targeting peptides (TTPs), stearylamine, or transferrin, to enhance their permeability across the BBB as well as uptake into glioma cells for more targeted drug delivery [73].