Preparation of polysaccharide-coated gelatin sponge

The gelatin sponges were cut into pieces (0.8 cm × 0.8 cm × 0.8 cm) under sterile condition. The polysaccharides were dissolved in PBS to obtain a 0.125% solution. Subsequently, 40 μl of SCS, PSS, CCS, HACC, and Hep was dropped onto the gelatin sponges in sterile condition and stayed for a while to be totally absorbed. The equal volume of PBS was added onto the sponge as blank group. The polysaccharide-coated gelatin sponges were lyophilized and stored at −20°C. The release kinetics of SCS from gelatin sponge was detected as previously reported (40).