In vitro release behavior of 5-FU from PECE hydrogel (25wt%). Error bars represent the standard deviation (n = 3). 5-FU could be released from PECE hydrogel in a sustained period. The initial drug loading amount had great effect on 5-FU release profile. With lower initial drug loading amount (black square), 5-FU released faster and reached higher cumulative release rate compared to higher initial drug loading hydrogel (black circle).