A radical emulsion polymerization of alkylcyanoacrylates (ACA) has been investigated to produce core-shell nanoparticles coated with polysaccharides. It was initiated by dextran on which a radical was created by reaction with cerium(IV) ions in an aqueous acidic medium. The redox radical polymerization developed in this study occurred much faster at pH 1 than the spontaneous anionic polymerization of ACA. It was applied to several ACA and has led to the formation of very stable suspensions of nanoparticles. The mean diameter of the nanoparticles depended on the monomer. Different analysis showed that the polymer forming the nanoparticles was an amphiphilic dextran based copolymer of poly(alkyleyanoacrylate). This copolymer exhibited surfactant properties. The size, morphology, and potential of the nanoparticles have been determined as well as the mobility of the polysaccharide chains at the nanoparticle surface, which was investigated by electron paramagnetic resonance.