Methylene Blue (MB) has recently showed beneficial effects towards neurological disorders such as Alzheimer’s and Parkinson’s diseases. Intravenous administration of MB could be difficult because of its poor cooperation with patients, thus entrapment in a carrier system could improve compliance. PLGA nanospheres have been proposed as a delivery system for MB, but they suffer from low encapsulation efficiency and rapid release of their cargo. Here, we design nanospheres with high affinity for hydrophilic MB based on PLGA and a non-ionic amphiphilic cyclodextrin (SC6OH) as an additional component. Interaction between MB and SC6OH was firstly investigated by UV-vis spectroscopy and steady-state emission fluorescence in aqueous solution. PLGA/SC6OH nanospheres loaded with MB were prepared by a nanoprecipitation/solvent displacement method and characterized by STEM and FTIR-ATR …