Disclosed herein is a process for sterilizing implantable biomaterials comprising contacting said cross-linked collagen-based biomaterial with a sterilization solution comprising between 3% and 6% v/v propylene oxide and incubating said biomaterial between 30°C and 55°C for greater than 48 hours； with the proviso that the sterilization solution does not include alcohol. Also disclosed is the storage of the biomaterial in the propylene oxide solution wherein the propylene oxide is converted to propylene glycol.
