Remedying a multidrug-resistant (MDR) bacteria wound infection is a major challenge due to the inability of conventional antibiotics to treat such infections against MDR bacteria. Thus, developing wound dressings for wound care, particularly against MDR bacteria, is in huge demand. Here, we present a strategy in designing wound dressings: we use a small molecule (6-aminopenicillanic acid, APA)-coated gold nanoparticles (AuNPs) to inhibit MDR bacteria. We dope the AuNPs into electrospun fibers of poly(ε-caprolactone) (PCL)/gelatin to yield materials that guard against wound infection by MDR bacteria. We systematically evaluate the bactericidal activity of the AuNPs and wound-healing capability via the electrospun scaffold. APA-modified AuNPs (Au_APA) exhibit remarkable antibacterial activity even when confronted with MDR bacteria. Meanwhile, Au_APA has outstanding biocompatibility. Moreover, an in vivo bacteria-infected wound-healing experiment indicates that it has a striking ability to remedy a MDR bacteria wound infection. This wound scaffold can assist the wound care for bacterial infections.

Widespread multidrug resistance caused by the abuse of antibiotics calls for novel strategies and materials. Gold nanoclusters (AuNCs) are scarcely explored for combating multidrug-resistant (MDR) bacteria in vivo. We herein synthesized a novel class of AuNCs, namely quaternary ammonium (QA) capped AuNCs (QA-AuNCs) as potent antibiotics selectively targeting MDR Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE), in vivo. QA-AuNCs kill bacteria through a combined physicochemical mechanism, and show excellent therapeutic effects in both a skin infection model and a bacteremia model induced by MRSA. In addition, owing to their intense fluorescence, QA-AuNCs can be used for the discrimination of live/dead bacteria and bacteria counting, suggesting their potential for clinical theranostics.

No abstract

Multidrug‐resistant (MDR) bacteria pose serious threats to public health as there is currently a lack of effective and biocompatible drugs to kill MDR bacteria. Here, a bifunctional aggregation‐induced emission luminogen (AIEgen), triphenylethylene‐naphthalimide triazole (TriPE‐NT), is reported, which is capable of both staining and killing Gram‐positive (G+) and Gram‐negative (G−) bacteria. The intrinsic fluorescence generating ability of the TriPE unit enables TriPE‐NT to monitor the drug–bacteria interactions, meanwhile, the NT unit renders TriPE‐NT the antibacterial activity. Furthermore, TriPE‐NT can generate reactive oxygen species (ROS) under light irradiation and drastically enhance its antibacterial efficacy by photodynamic therapy against wild bacteria and clinical isolated MDR bacteria with a very low toxicity to mammalian cells. Moreover, the efficiency of TriPE‐NT staining on bacteria closely correlates with its antibacterial efficacy. As an example of application, TriPE‐NT is utilized in curing Escherichia coli‐ (E. coli), MDR E. coli‐, Staphylococcus epidermidis‐ (S. epidermidis), and MDR S. epidermidis‐ infected wounds on rats with high efficacy and high safety. Thus, TriPE‐NT can be used not only as a powerful antibiotic agent for treating MDR bacteria‐infected diseases but also as a potential fluorescent agent for monitoring the bacterial infections and further exploring the related antibacterial mechanism.