An oxidative polymerized carboxymethyl cellulose hydrogel for the combined anti-tumor recurrence

Malignant tumor has always been a complex disease that endangers human health. Traditional treatment methods include surgical resection, chemotherapy, and radiotherapy. However, solid tumors are prone to recur. Herein, we developed a hydrogel-based drug-carrying system to prevent postoperative tumor recurrence. Sodium carboxymethyl cellulose was modified with dopamine via the N-hydroxysuccinimide (NHS) and 1-ethyl-(3-dimethylaminopropyl) carbanyl diimide (EDC)-mediated coupling chemistry. The CMC-DA-MnO2/MnO (CDM) hydrogel was prepared by oxidative cross-linking, using KMnO4 as the oxidizing agent. In the hydrogel, the KMnO4 can not only be used as an oxidant to trigger the polymerization and gelation of CMC-DA but also transformed into MnO2 and MnO to afford the T-2-weighted magnetic resonance imaging (MRI). The fluorescent dye IR808 as a photosensitizer was introduced into the hydrogel system by simply soaking the CDM hydrogel in the IR808 solution. Under the 808 nm laser irradiation, IR808 and PDA endowed the hydrogel with tumor photodynamic therapy (PDT) and photothermal therapy (PTT) capacities, respectively. With the proven hemo- and cyto-compatibilities, the CDM hydrogel was successfully used for the PDT and PTT prevention of postoperative tumor recurrence.