In vitro model for the degradation of alkylcyanoacrylate nanoparticles.

A photometric assay was developed to study the surface erosion of polymeric nanoparticles. The hydrolytic degradation of polyalkylcyanoacrylate particles was studied in different environments (NaOH, buffer, cell culture medium and serum). The influence of particle modification on the degradation rate was assessed. Particularly, the effect of polymer coating for particle targeting and fluorescence labelling was investigated. From the absorption data, a t50% and t100% can be calculated for fast degrading particles and obtained by an extrapolation in case of a slow degradation process. The degradation rate was found to decrease with increasing alkyl chain length from methyl-, ethyl-, isobutyl- to isohexylcyanoacrylate particles. Polymer coating and fluorescent labelling had little effect on the rate of degradation.