Synthesis of a novel poly(MePEG cyanoacrylate-co-alkyl cyanoacrylate) amphiphilic copolymer for nanoparticle technology

In order to develop ''stealth'' injectable PEG-coated poly(alkyl cyanoacrylate) (PACA) nanoparticles, a novel poly(MePEG cyanoacrylate-co-alkyl cyanoacrylate) copolymer has been synthetized in a simple way by condensing MePEG cyanoacetate esters with formaldehyde in the presence of dimethylamine. This approach allowed the covalent linkage of PEG moieties to the cyanoacrylate polymer, thus avoiding the risk of desorption of PEG, as in the case of a PEG coating obtained by simple adsorption onto preformed nanoparticles. In addition, the condensation procedure allowed a better control of the polymerization process than in the case of anionic polymerization of alkyl cyanoacrylates. Finally, we have shown that the hydrophobicity of the copolymer can be perfectly modulated by adjusting the MePEG cyanoacetate/alkyl cyanoacetate ratio. Characterization of the copolymer has been performed by NMR, GPC, and FTIR analysis. Monodispersed nanoparticles were easily prepared by nanoprecipitation of this amphiphilic copolymer.