An injectable hydrogel CCT@CAD realizes the synergistic treatment of chemotherapy, photothermal therapy and nanozyme therapy for breast cancer

Breast cancer (BC) is a common malignant tumor in women, which seriously affects the health of patients. In this paper, a plasma nano-composite injectable hydrogel CCT@CAD was developed to realize multi-therapy synergistic anti-cancer. In the acidic tumor microenvironment, CCT@CAD released Au-modified cerium dioxide loaded with cisplatin (CAD), and the surface charge of CAD changed from negative to positive based on the pH-responsive charge inversion characteristic, which significantly improved the internalization efficiency and permeability of tumor cells to CAD. The introduction of Au nanoparticles endowed CAD with localized surface plasmon resonance (LSPR) effects. This effect enhanced electron transfer to activate the Ce active site on the surface of cerium dioxide, thus enhancing the activity of nanozyme, which enabled CAD to rapidly produce O₂ and consume glutathione in tumor cells. Meanwhile, Au nanoparticles endowed CAD with excellent photothermal conversion ability, and local hyperthermia could be realized under near infrared laser irradiation. Animal experimental results showed that the tumor inhibition rate was nearly 100% after 14-day treatment of CCT@CAD. The combination of chemotherapy, photothermal therapy and nanozyme therapy proposed in this study provides a new idea for the treatment of BC.