Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)The aim of this study was to design a new Drug Delivery System (DDS) based on poly (lactide-co-glycolide) (PLGA) biodegradable nanospheres (NS) coated with Chitosan (CTS), in order to prolong its residence time and to deliver the nanoparticles more specifically to cancer cells. We have tried three methods of incorporation of Chitosan in the nanoparticles, but only one was efficient. The first method is named entanglement of chains, the second method is known as single adsorption and, in the third, we prior linked covalently Chitosan to the polymer and then prepared the nanoparticles. After selected the best method, it was monitored the stability following the temporal variation of diameter, polydispersity and zeta potential of particles prepared using different percentages of CTS and pH values, using a pre-optimised formulation of 5-fluorouracil containing PLGA NS.O TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE FEVEREIRO DE 2015.941983SI851861Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAEPEX-UNICAMPCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)