Engineering a Non-Antibiotic Biomimetic Nano-Urchin for Broad-Spectrum and Long-Acting Antibacterial Spraying

Abstract

The escalating threat of bacterial infections, especially antibiotic-resistant strains, highlights the need for efficient, long-term, broad-spectrum, and non-antibiotic disinfectants. Here a biomimetic nano-disinfectant, Au@ZnO nano-urchins (Au@ZnO-NUs) is introduced, inspired by sea urchin morphology. One of the nano-urchins consisting of an Au-nanocore (25 ± 5 nm in diameter) surrounded by 16 ± 2 ZnO-nanospears (length: 50 ± 5 nm, diameter: 14 ± 6 nm) is screened out via exhibiting exceptional antibacterial efficacy. Impressively, this Au@ZnO-NU shows over 99.47% effectiveness against 7 typical bacteria including the methicillin-resistant Staphylococcus aureus (MRSA) at low concentration (<8 µg mL⁻¹) with effects lasting at least 30 days. The underlying bacteriostatic mechanism involves multiple pathways, including physical penetration of bacterial walls, ROS over-production, membrane-potential dissipation, ATP-level downregulation, and biofilm deformation obtained from both experiment and transcriptomic-analysis. Moreover, these nano-urchins can be easily applied as a spray-coating on any surface, creating a wash-resist, cicada-wing-like nano-spiky array antibacterial layer. Remarkably, this Au@ZnO-NU exhibits excellent anti-bacterial performance in MRSA-infectedlarge wound (25 mm) healing rat models, which is even better than Vancomycin, approaching the natural healing rate of sterile wounds. This study offers a promising candidate for daily antibacterial applications and advances the biomimetic design of non-antibiotic antibacterial strategies.