Controlled Deliveryof Cytarabine in Sodium CarboxymethylCellulose/Copper-Doped Prussian Blue Hydrogels for Chemotherapy andChemodynamic Therapy

To improve the therapy of chemotherapy for cancer treatment, hydrogels of sodium carboxymethyl cellulose (CMC)/copper-doped Prussian blue (CDPB) are synthesized for the controlled delivery of cytarabine (Cyt). CMC is connected to 3-aminophenylboronic acid (PBA) and dopamine (DA), respectively, by amidation reactions, and the obtained CMC-PBA and CMC-DA are cross-linked through boronate affinity for the encapsulation of CDPB and Cyt. The resultant CMC/CDPB/Cyt hydrogels can, respectively, respond to pH and H₂O₂, and thus, pH- and H₂O₂-responsive delivery of Cyt from the hydrogels is successfully achieved. More importantly, the overexpressed H₂O₂ in cancer cells can be converted to hydroxyl radicals (^•OH) by the CDPB in the hydrogels through Fenton-like reactions, and the generated ^•OH can participate in the chemodynamic therapy (CDT) of cancers. Due to the combination treatment of chemotherapy and CDT, enhanced anticancer effects are obtained by using human acute promyelocytic leukemia (HL-60) cell lines as the model target.