2.7.1 Preparation of RHC and RHC/EGF freeze-dried dressing
RHC, EGF and RHC/EGF (1: 1) were lyophilized separately to obtain freeze-dried dressing. In short, the configured RHC and RHC/EGF solutions were subjected to gradient cooling, respectively. Place at 4°C for 1 hour, then at -20℃ for 6 hours, and finally at -80℃ overnight. Next, the frozen RHC, EGF and RHC/EGF were vacuum freeze-dried at -50℃. The freeze-dried dressing was sterilized by Co60 and stored in a sterile dry sealed EP tube for further experiment purpose.