Liquid Metal-Enabled General Nanoarchitectonics of Self-Propelled Nanorobots with Cascaded-Enhanced Antibiofilm Efficacy.

Abstract

Recalcitrant biofilms are firmly attached structures linked to drug-resistant infections and surface destruction. Micro/nanorobots offer a promising antibiofilm strategy, but their effectiveness in complex microstructures is hindered by the lack of robust self-propelled miniaturized systems. Current nanorobot synthesis methods are technically demanding, require specialized equipment, and lack scalability, thereby limiting clinical translation. Herein, we exploit the nanoscale plasticity and reactivity of liquid metal gallium (LM Ga) to develop a general platform that enables the nanoarchitectonics of self-propelled nanorobots with operational simplicity and compositional diversity. Asymmetrically anchored LM Ga acts as an interfacial galvanic replacement reactor for the <i>in situ</i> deposition of diverse catalase-like metals or metal oxides as functional "engines". Using biofilm-metabolized H₂O₂ as an endogenous fuel, these nanorobots initiate a bioresponsive cascade that begins with photothermal-enhanced oxygen generation, which drives self-propulsion and, in turn, alleviates local hypoxia, reactivates biofilm-resident bacteria, and ultimately facilitates the suicidal uptake of the antibacterial Ga³⁺ via iron-mimicking mechanisms. The cascaded-enhanced antibiofilm efficacy was demonstrated <i>in vitro</i> and on dental implants with complex surfaces. These nanorobots achieved complete biofilm removal without compromising the integrity of the implant surface, outperforming traditional titanium curet debridement. This work presents a versatile strategy for nanorobot fabrication and offers a delicate, active approach to combating biofilms in precision medicine.