Recent advances in calcium peroxide nanomedicines for breast cancer treatment.

As a typical solid tumor, breast cancer is characterized by a tumor microenvironment featuring hypoxia, acidosis, and highly reductive conditions. These factors contribute to treatment resistance (e.g., chemoresistance) through various mechanisms, thereby diminishing therapeutic efficacy. Calcium peroxide (CaO2) can generate multiple bioactive molecules (metal ions, H2O2, O2, and OH-) in acidic or neutral environment, making it a promising biomaterial for cancer therapy. Recently, breast cancer has been extensively targeted using CaO2 nanoparticles in both cellular and murine models. In this review, we first provide a summary of strategies employing CaO2 nanomedicine-based breast cancer therapies, then discuss the obstacles and development directions of CaO2 application in breast cancer therapy.