Hydrolysis of poly (n-butylcyanoacrylate) nanoparticles using esterase

Poly (n-butyl cyanoacrylate) nanoparticles were produced by a dispersion polymerisation process carried out in water at a pH 3 and employing a polymeric stabilising agent, dextran. The degradation of the nanoparticles was studied in Ringer's solution at pH 7 and 37 °C. The influence of esterase, a proteolytic enzyme on the stability of PBCA nanoparticles was also assessed. The degradation of the nanoparticles followed a biphasic mechanism where an initial burst of butanol was produced, followed by a more gradual release, as a result of the ester side chain hydrolysis. A particle size reduction during the degradation process indicated that the PBCA nanoparticles degraded mainly by surface erosion. The analytical techniques employed to characterise the degradation of were gas chromatography (GC), gel permeation chromatography (GPC), laser light scattering, Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The degradation rate of the polymer was found to be dependent on both the enzyme concentration and degradation time. The analyses suggested that polyacrylic acid was the polymer formed as a result of the hydrolytic degradation process.