TF and glioblastoma: In another study, Guo et al. (2013) altered the surface of resveratrol-loaded polyethylene glycol-polylactic acid nanoparticles with transferrin moieties (Tf-NP), which further resulted in increased cytotoxicity, elevated level of intracellular uptake, and apoptosis of human U-87 MG GBM cell lines and C6 rat glioma cells in vitro, as compared to nanoparticles without transferrin and free resveratrol.