pH-Sensitive nanogels based on the electrostatic self-assembly of radionuclide 131I labeled albumin and carboxymethyl cellulose for synergistic combined chemo-radioisotope therapy of cancer

Development of biocompatible and biodegradable nanocarriers with multiple functionalities has attracted great interest in recent years. In this study, a hybrid hydrogel nanoparticle (nanogel) platform based on the self-assembly of carboxymethyl cellulose (CMC) and bovine serum albumin (BSA) is presented for the first time. It was facile to realize the efficient co-delivery of radionuclide I-131 and chemotherapeutic drugs such as camptothecin (CPT) to achieve the combined chemo-radioisotope therapy of cancer. Notably, a nanogel was prepared by a simple and green electrostatic interaction approach, instead of chemical reaction, showing typical spherical shape with average size about 120 nm, high drug loading capacity, robust stability and low hemolysis. Interestingly, such nanogels exhibited pH-dependent drug release profile, leading to significant reduction of damage to normal tissues. Furthermore, the as-prepared nanogels could effectively promote intracellular uptake, prolong blood circulation time and enhance accumulation in the tumor tissues. As a result, an excellent therapeutic effect was achieved both in vitro and in vivo through combined chemo-radioisotope therapy. Collectively, this study presents the preparation of a novel green nanocarrier by a reliable and simple approach, and offers an effective strategy for the combination of chemotherapy and radiotherapy.