Liquid Metal Dealloying Enables on-Demand Drug Release and Combined Antibacterial Therapy

Deformable materials permit spatiotemporally precise on-demand drug delivery via responsive morphological or structural changes, yet limited deformation mechanisms hinder their advancement. Herein, we present a photothermal-triggered deformable system engineered through liquid metal (LM) dealloying, enabling controlled multi-drug release and combined antibacterial therapy. This system features eutectic gallium-indium (EGaIn) nanoparticles (NPs) encapsulated within a polydopamine (PDA) coating, which confers stability and drug-loading capacity to the LMNPs. Additionally, this PDA coating amplifies the photothermal response, critically facilitating the dealloying and structural reconfiguration of EGaIn LMNPs under near-infrared (NIR) irradiation. The separation of In and Ga generates an In-rich core and a gallium oxide shell aggregate, inducing expansion of LMNPs that ruptures the PDA coating to trigger payload release. The results demonstrate that photosensitizer (IR820) and antibiotics levofloxacin (Lev) loaded in this system achieve on-demand release via this photothermal-triggered dealloying process. This approach achieved 6.7-log (99.99998%) reductions in Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) burdens in vitro, and a ∼5.6-log (99.999%) decrease in bacterial load in an E. coli-infected superficial wound model, via combined photothermal, photodynamic, and chemotherapeutic effects. This work pioneers the integration of LM dealloying dynamics with controlled drug release, offering a transformative strategy for precision and multimodal therapy.