Pretreated Macrophage‐Membrane‐Coated Gold Nanocages for Precise Drug Delivery for Treatment of Bacterial Infections

: Pathogenic bacterial infections and drug resistance make it urgent to develop new antibacterial agents with targeted delivery. Here, a new targeting delivery nanosystem is designed based on the potential interaction between bacterial recognizing receptors on macrophage membranes and distinct pathogen-associated molecular patterns in bacteria. Interestingly, the expression of recognizing receptors on macrophage membranes increases significantly when cultured with specific bacteria. Therefore, by coating pretreated macrophage membrane onto the surface of a gold-silver nanocage (GSNC), the nanosystem targets bacteria more efficiently. Previously, it has been shown that GSNC alone can serve as an effective antibacterial agent owing to its photothermal effect under near-infrared (NIR) laser irradiation. Furthermore, the nanocage can be utilized as a delivery vehicle for antibacterial drugs since the gold-silver nanocage presents a hollow interior and porous wall structure. With significantly improved bacterial adherence, the Sa-M-GSNC nanosystem, developed within this study, is effectively delivered and retained at the infection site both via local or systemic injections; the system also shows greatly prolonged blood circulation time and excellent biocompatibility. The present work described here is the first to utilize bacterial pretreated macrophage membrane receptors in a nanosystem to achieve specific bacterial-targeted delivery, and provides inspiration for future therapy based on this concept.