Biomimetic Synthesis of Nanomachine Inspired from Neutrophil Extracellular Traps for Multimodal Antibacterial Application

Bacterial infections, especially drug-resistant bacterial infections, are causing increasing harm in clinical practice, and there is an urgent need to develop effective antimicrobial materials. Biomimetic DNA nanomachines have attracted much attention due to their flexible design, precise control, and high biocompatibility, but their use for bacterial inhibition has not been reported. Neutrophil extracellular traps (NETs), a network structure released by neutrophils with good bactericidal function, can be used as a superior biomimetic object for the construction of functional bacterial inhibition materials. In this study, Y-shaped DNA was polymerized using magnesium ions to develop reticulated DNA structures, which were used as templates to synthesize copper nanoclusters, leading to the construction of compositionally well-defined and simple reticulated DNA nanomachines. The nanomachine had a three-dimensional, reticular structure similar to that of NETs and especially had excellent antibacterial activity. More importantly, the NETs-imitated nanomachine had a multimodal bacterial inhibition mechanism. The nanomachine could target and localize around the bacteria and eliminate the biofilm, and then the DNA network structure effectively trapped and aggregated the bacteria and caused damage to the bacterial morphology and membrane structure; at the same time, the reticulated DNA nanomachine could also damage the bacterial membrane, causing the degradation and leakage of the proteins and the cellular contents and breakage of the DNA structure, ultimately causing irreversible inhibition of the bacteria. Importantly, the developed nanomachines with high biocompatibility could be used as antimicrobial biomaterials for the efficient treatment and healing of skin wounds infected with bacteria. This study develops a biomimetic DNA nanomachine that can be an excellent antibacterial biomaterial, which expands the application of DNA nanomachine in bacteriostatic and therapeutic fields; it is also an improved biomimetic NETs biomaterial, which brings distinctive design sources for biomimetic materials.