A pH-responsive ultrathin Cu-based nanoplatform for specific photothermal and chemodynamic synergistic therapy

Abstract

Noninvasive tumor therapy requires a new generation of bionanomaterials towards sensitive response to the unique tumor microenvironment to achieve accurate and effective treatment. Herein, we have developed a tumor therapy nanoplatform by immobilizing natural glucose oxidase (GOD) onto Cu-based layered double hydroxide (CuFe-LDH) nanosheets, which for the first time integrates acid-enhanced photothermal therapy (PTT), and pH-responsive and heat-facilitated chemodynamic therapy (CDT) simultaneously. As demonstrated by EXAFS and HRTEM, CuFe-LDH nanosheets possess a considerable number of defects caused by different acid conditions, resulting in a significantly acid-enhanced photothermal conversion efficiency (83.2% at pH 5.4vs.46.0% at pH 7.4). Moreover, GOD/CuFe-LDH nanosheets can convert a cascade of glucose into hydroxyl radicals (˙OH) under tumor acid conditions, which is validated by a high maximum velocity (Vmax= 2.00 × 10−7M) and low Michaelis-Menten constant (KM= 12.01 mM). With the combination of PTT and CDT, the tumor tissuein vivois almost eliminated with low-dose drug injection (1 mg kg−1). Therefore, this novel pH-responsive Cu-based nanoplatform holds great promise in tumor-specific CDT/PTT synergistic therapy.