Drug-resistance has been a major challenge for the failure of chemotherapy.Nitric oxide (NO) as a P-glycoprotein inhibitor can reverse the resistance to antineoplastics by inhibiting drug efflux[1].Appropriate NO donors with biocompatible carrier in organism can provide constant and stable release of NO.The combination of intravenous injection of chemotherapeutics and paratumor administration of NO donors in hydrogel may demonstrate enhanced antitumor action with less drug-resistance.