BDNF and neuroblastoma: Cellular uptake of PAMAM 5.5-AF488 (no BDNF), PAMAM 5.5-AF488-BDNF, PAMAM 5.5-AF488-BDNF-PEG, PAMAM 6-AF488 (no BDNF), PAMAM6-AF488-BDNF-, PAMAM 6-AF488-BDNF-PEG in differentiated human neuroblastoma cell line SH-SY5Y treated with 6-OHDA was examined through spectrofluorimetry with a fixed concentration of BDNF (0.1 mg L−1).