Hydrogen peroxide-generating nanomedicine for enhanced chemodynamic therapy

Chemodynamic therapy (CDT) is an emerging endogenous stimulation activated tumor treatment approach that exploiting iron-containing nanomedicine as catalyst to convert hydrogen peroxide (H₂O₂) into toxic hydroxyl radical (OH) through Fenton reaction. Due to the unique characteristics (weak acidity and the high H₂O₂ level) of the tumor microenvironment, CDT has advantages of high selectivity and low side effect. However, as an important substrate of Fenton reaction, the endogenous H₂O₂ in tumor is still insufficient, which may be an important factor limiting the efficacy of CDT. In order to optimize CDT, various H₂O₂-generating nanomedicines that can promote the production of H₂O₂ in tumor have been designed and developed for enhanced CDT. In this review, we summarize recently developed nanomedicines based on catalytic enzymes, nanozymes, drugs, metal peroxides and bacteria. Finally, the challenges and possible development directions for further enhancing CDT are prospected.