Living Cell-Metal Cyborg Microalgae for Treating MRSA Infection.

Abstract

Metal-ion-based antibacterial agents are promising against antibiotic-resistant bacteria like MRSA, but their reactive oxygen species (ROS)-dependent bactericidal activity is greatly hampered by the infection-related hypoxic microenvironments. Here, we green-synthesized silver nanoparticles (AgNPs) on the surface of biocompatible microalgae <i>Chlorella vulgaris</i> (CV) to develop a live cell-metal hybrid system. These living cyborg AgNP@CV microalgae not only provide sustained oxygen generation to alleviate hypoxia under illumination due to their photosynthetic capability, but also synergistically enhance Ag ion-mediated ROS production to kill MRSA. Moreover, AgNP@CV promotes angiogenesis of endothelial cells via the VEGF-VEGFR2-PI3K-Akt signaling pathway, facilitating tissue regeneration. In a clinically relevant MRSA-infected wound model, a single dose of AgNP@CV achieves efficient bacterial elimination and wound healing, significantly surpassing Ag-containing hydrogel dressing. In addition, this approach is universal and cost-effective for producing many other metal-NP@CV systems with strong antibacterial ability, such as CuNP@CV and ZnNP@CV. These cyborg microalgae provide a sustainable and translatable strategy for treating resistant bacterial infections through self-oxygenation and synergistic metal ion therapy.