Leonurus cardiaca L. polysaccharide-stabilized Pd-Au nanozymes for NIR-responsive doxorubicin delivery and combined chemo-chemodynamic-photothermal therapy.

Traditional cancer therapies are limited by severe side effects and therapeutic challenges, while noble metal nanozymes offer promising enzyme-like therapeutic potential but remain constrained by poor aqueous stability. In this work, palladium-gold bimetallic nanoparticles (Pd3Au-LCLP NPs) with peroxidase-like activity were constructed using Leonurus cardiaca L. polysaccharide as both a reducing agent and stabilizing template, and further loaded with doxorubicin (DOX) to form Pd3Au-LCLP NPs-DOX. The resulting nanoplatform exhibited excellent water dispersibility, structural stability, anti-protein adsorption capability, and enhanced photothermal conversion performance. Under 808 nm laser irradiation, Pd3Au-LCLP NPs-DOX achieved a cumulative DOX release of 81% at pH 5.5. In vitro, it showed significant cytotoxicity against A549 and HeLa cells. In vivo, the tumor inhibition rate reached 82.6%. Overall, this combined therapeutic strategy integrating chemodynamic therapy (CDT), photothermal therapy (PTT), and chemotherapy (CT) demonstrated strong synergistic anti-tumor efficacy.