Synthesis, characterization and biological safety of O-carboxymethyl chitosan used to treat Sarcoma 180 tumor

► 340 kDa CM-chitosan is prepared and characterized. ► CM-chitosan is safe to normal cell and tumor cells. ► CM-chitosan slightly inhibits the growth of sarcoma 180 and enhances body immunity. ► CM-chitosan is safe in tumor therapy as biomedical material.