2.12. Enzymatic Degradation

For the degradation experiments, the dried polymer films (20 × 50 × 0.1 mm³) were gently shaked in a solution of lipase/0.1 M PBS (pH = 7.4) (50 mg/50 mL) at 37 °C. These films were taken out and refreshed thoroughly with distilled water, and then dried in a vacuum oven at 40 °C until weight balanced (~16 h) every week. The degree of degradation was evaluated by the weight loss calculated as following:

where W₀ is the weight of the dried films before degradation and W_t is the weight of the dried films at degradation time t. A higher weight loss (%) implies better degradability of the films.