Enzymatic degradation of radiation crosslinked poly( ε–caprolactone)

Poly( ε–caprolactone) (PCL), crosslinked by gamma rays in a super cooled state, had high thermal stability, better transparency and heat shrink property. Biodegradation of such PCL was carried out using lipase AK enzyme in a phosphate buffer solution having a pH of 7.0. The enzymatic degradation was remarkably affected by reaction temperature. Preferable temperatures for enzymatic degradation were 50°C for uncrosslinked PCL and 55°C for crosslinked. The enzymatic degradation rate of crosslinked PCL is slower than that of the uncrosslinked due to network structure. However, it was confirmed that enzymatic degradation occurs even for high crosslink density of PCL such as 80% of gel content.