however,it may be noted that Liang et al. found that the rate of in vitro degradation of PGS sheets crosslinked at 125 ◦C for 2 or 7 days were 0.6–0.9 or 0.2–0.6 mm/month, respectively, in the culture medium, which is in the range of in vivo degradation rates (0.2–1.5 mm/month) of PGS