High Entropy 2D Layered Double Hydroxide Nanosheet Toward Cascaded Nanozyme-Initiated Chemodynamic and Immune Synergistic Therapy

High-entropy nanomaterials (HEMs) are a hot topic in the fields of energy and catalysis. However, in terms of promising biomedical applications, potential therapeutic studies involving HEMs are unprecedented. Herein, we demonstrated high entropy two-dimensional layered double hydroxide (<b>HE-LDH</b>) nanoplatforms with versatile physicochemical advantages that reprogram the tumor microenvironment (TME) and provide antitumor treatment via cascaded nanoenzyme-initiated chemodynamic and immune synergistic therapy. In response to the TME, the multifunctional <b>HE-LDHs</b> sequentially release metal ions, such as Co²⁺, Fe³⁺, and Cu²⁺, exhibiting exquisite superoxide dismutase (SOD), peroxidase (POD), and glutathione peroxidase (GPX) activities. The multiple enzymatic activities convert specific tumor metabolites into a continuous supply of cytotoxic reactive oxygen species (ROS) to relieve hypoxia under a TME. Thus, <b>HE-LDHs</b> facilitate robust nanozyme-initiated chemodynamic therapy (NCDT), achieving high therapeutic efficacy without obvious side effects. In addition, the release of Zn²⁺ from the <b>HE-LDH</b> matrix triggers the cyclic GMP-AMP synthase/stimulator of interferon gene (cGAS/STING) signaling pathway, boosting the innate immunotherapeutic efficacy. The intratumoral applications of the nanocomposite in tumor-bearing mice models indicate that <b>HE-LDH</b>-mediated NCDT and immune synergistic therapy effectively upregulated the expression of relevant antitumor cytokines and induced cytotoxic T lymphocyte infiltration, showing superior efficacy in inhibiting tumor growth. Therefore, this work opens a new research direction toward synchronized NCDT and immunotherapy of tumors using HEMs for advanced healthcare.