Bacteria-derived hydrogen sulfide (H 2 S) often contributes to the emergence of antibiotic-recalcitrant bacteria, especially persister (a sub-population of dormant bacteria), thus causing the treatment failure of Catheter-associated urinary tract infection (CAUTI). Here, an H 2 S harvester nanosystem to prevent the generation of persister bacteria and disrupt the dense biofilm matrix by the self-adaptive ability of shape-morphing is prepared. The nanosystem possesses a core-shell structure that is composed of liquid metal nanoparticle (LM NP), AgNPs, and immobilized urease. The nanosystem decomposes urea contained in urine to generate ammonia for eliminating bacteria-derived H 2 S. Depending on the oxidative layer of liquid metal, the nanosystem also constitutes a long-lasting reservoir for temporarily storing bacteria-derived H 2 S, when urease transiently overloads or in the absence of urine in a catheter. Depriving H 2 S can prevent the emergence of persistent bacteria, enhancing the bacteria-killing efficiency of Ga 3+ and Ag + ions. Even when the biofilm has formed, the urine flow provides heat to trigger shape morphing of the LM NP, tearing the biofilm matrix. Collectively, this strategy can turn trash (urea) into treasure (H 2 S scavengers and biofilm rippers), and provides a new direction for the antibacterial materials application in the medical field.
Fei Wang,Siwei Li,Xing Wang,Qisen Yang,Jinyou Duan,Yu Yang,Haibo Mu
The progression of severe skin injury healing can be easily impeded by bacterial infections and the resultant overproduction of reactive oxygen species (ROS) within the wound microenvironment. In this study, we developed a multifunctional antibacterial hydrogel by integrating gallium ion-tannic acid and polydopamine particles into gellan gum via a facile heat-cooling process. By harnessing the synergistic effects of polydopamine for short-term photothermal therapy and gallium ion for long-term chemotherapy, the hydrogel obtained shows outstanding antibacterial activities. Sustained release of gallium ion and tannic acid ensures a prolonged sterilization along with ROS-scavenging benefits. Moreover, this hydrogel demonstrates superior cytocompatibility, hemostatic properties, as well as capabilities including promoting cell migration, and adsorption to bacterial cells and toxin. The therapeutic efficacy of the hydrogel was validated using a mouse model of MRSA-induced cutaneous infections. Overall, this work introduces a straightforward yet highly efficient multifunctional hydrogel platform that combines synergetic antibacterial actions, ROS scavenging, and hemostasis to enhance the healing of bacteria-associated wounds.
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