A series of five CMC hydrogels (entries 1–5) were prepared from CMC with PEGDE. A typical procedure to prepare the CMC hydrogel was performed as follows: 5.0g of CMC (23mmol for monomeric unit) was completely dissolved in 100 mL of 1.5 mol L−1 aqueous NaOH solution, and 0.50 g of PEGDE (1.1 mmol) was subsequently added to the solution with stirring at 300 rpm using a Teflon impeller at 25 ◦ C. After 10 min, the crosslinking reaction was performed at 60 ◦ C with stirring at 300 rpm for 3 h. The reaction mixture was washed twice with a solution of 1:1 (v/v) deionized water and ethanol, and the resultant reaction mixture was dialyzed