Theoretical Model of Enzymatic Degradation of Polylactide

A continuousdistribution theory was applied to the kinetics of the enzymatic degradation of polylactide(PLA) for the modelling of enzymatic degradation of PLA by proteinase K. The enzymatic degradation of PLA is a threestep process: adsorption of enzyme on PLA substrate; formation of activated transition complex between PLA and enzyme; specific chain scission of the polymer. These integral and differential equations were converted into ordinary differential equations by moment operation. Calculated time courses of the mass concentration of the specific product were in good agreement with experiments. The model parameters (k′,kE) were found to depend on the concentration of enzyme, flow rate, pH and the temperature.