RESUMEN
Superbug infections and transmission have become major challenges in the contemporary medical field. The development of novel antibacterial strategies to efficiently treat bacterial infections and conquer the problem of antimicrobial resistance (AMR) is extremely important. In this paper, a bimetallic CuCo-doped nitrogen-carbon nanozyme-functionalized hydrogel (CuCo/NC-HG) has been successfully constructed. It exhibits photoresponsive-enhanced enzymatic effects under near-infrared (NIR) irradiation (808 nm) with strong peroxidase (POD)-like and oxidase (OXD)-like activities. Upon NIR irradiation, CuCo/NC-HG possesses photodynamic activity for producing singlet oxygen(1O2), and it also has a high photothermal conversion effect, which not only facilitates the elimination of bacteria but also improves the efficiency of reactive oxygen species (ROS) production and accelerates the consumption of GSH. CuCo/NC-HG shows a lower hemolytic rate and better cytocompatibility than CuCo/NC and possesses a positive charge and macroporous skeleton for restricting negatively charged bacteria in the range of ROS destruction, strengthening the antibacterial efficiency. Comparatively, CuCo/NC and CuCo/NC-HG have stronger bactericidal ability against methicillin-resistant Staphylococcus aureus (MRSA) and ampicillin-resistant Escherichia coli (AmprE. coli) through destroying the cell membranes with a negligible occurrence of AMR. More importantly, CuCo/NC-HG plus NIR irradiation can exhibit satisfactory bactericidal performance in the absence of H2O2, avoiding the toxicity from high-concentration H2O2. In vivo evaluation has been conducted using a mouse wound infection model and histological analyses, and the results show that CuCo/NC-HG upon NIR irradiation can efficiently suppress bacterial infections and promote wound healing, without causing inflammation and tissue adhesions.
Asunto(s)
Infecciones Bacterianas , Staphylococcus aureus Resistente a Meticilina , Animales , Hidrogeles/farmacología , Escherichia coli , Peróxido de Hidrógeno , Especies Reactivas de Oxígeno , Fototerapia , Infecciones Bacterianas/tratamiento farmacológico , Antibacterianos/farmacología , Carbono , Modelos Animales de Enfermedad , NitrógenoRESUMEN
In this work, positively charged N-carbazoleacetic acid decorated CuxO nanoparticles (CuxO-CAA NPs) as novel biocompatible nanozymes have been successfully prepared through a one-step hydrothermal method. CuxO-CAA can serve as a self-cascading platform through effective GSH-OXD-like and POD-like activities, and the former can induce continuous generation of H2O2 through the catalytic oxidation of overexpressed GSH in the bacterial infection microenvironment, which in turn acts as a substrate for the latter to yield ËOH via Fenton-like reaction, without introducing exogenous H2O2. Upon NIR irradiation, CuxO-CAA NPs possess a high photothermal conversion effect, which can further improve the enzymatic activity for increasing the production rate of H2O2 and ËOH. Besides, the photodynamic performance of CuxO-CAA NPs can produce 1O2. The generated ROS and hyperthermia have synergetic effects on bacterial mortality. More importantly, CuxO-CAA NPs are more stable and biosafe than Cu2O, and can generate electrostatic adsorption with negatively charged bacterial cell membranes and accelerate bacterial death. Antibacterial results demonstrate that CuxO-CAA NPs are lethal against methicillin-resistant Staphylococcus aureus (MRSA) and ampicillin-resistant Escherichia coli (AREC) through destroying the bacterial membrane and disrupting the bacterial biofilm formation. MRSA-infected animal wound models show that CuxO-CAA NPs can efficiently promote wound healing without causing toxicity to the organism.
Asunto(s)
Infecciones Bacterianas , Staphylococcus aureus Resistente a Meticilina , Nanopartículas , Animales , Peróxido de Hidrógeno , Fototerapia , Nanopartículas/química , Infecciones Bacterianas/tratamiento farmacológico , Escherichia coli , Antibacterianos/químicaRESUMEN
In this work, we successfully constructed Mn-coordinated nitrogen-carbon nanoparticles (Mn-N-C NPs) exhibiting multienzyme-like activities. In a bacterial infectious microenvironment, the POD-like and OXD-like activities of Mn-N-C NPs could synergistically trigger the generation of ROS (ËOH and O2Ë-), causing oxidative damage to the bacterial cell membrane for killing bacteria. Alternatively, in neutral or weak alkaline normal tissues, the excessive O2Ë- could be converted into O2 and H2O2via the SOD-like ability of Mn-N-C NPs, and subsequently their CAT-like activity catalyzed excess H2O2 into H2O and O2 for protecting normal cells through the antioxidant defense. Mn-N-C NPs also possessed a good NIR-photothermal performance, which could enhance their POD-like and OXD-like activities. Furthermore, Mn-N-C NPs could facilitate the GSH oxidation process and disrupt the intrinsic balance in the bacterial protection microenvironment with the assistance of H2O2, which is beneficial for rapid bacterial death. Undoubtedly, the Mn-N-C NPs + H2O2 system showed the highest antibacterial activity when irradiated with an 808 nm laser, destroying the bacterial membrane and causing the efflux of proteins. Moreover, the Mn-N-C NPs + H2O2 system was immune to the development of bacterial resistance and could efficiently disrupt the formation of a bacterial biofilm with negligible cytotoxicity and low hemolysis ratio. Finally, Mn-N-C NPs exhibited an excellent antibacterial performance in vivo and could accelerate wound healing without cellular inflammation production. Therefore, due to their significant therapeutic effects, Mn-N-C NPs show great potential in fighting antibiotic-resistant bacteria.
Asunto(s)
Infecciones Bacterianas , Nanopartículas , Humanos , Peróxido de Hidrógeno , Antioxidantes , Infecciones Bacterianas/tratamiento farmacológico , Antibacterianos/farmacología , Antibacterianos/uso terapéuticoRESUMEN
In this work, novel cuprous oxide-demethyleneberberine (Cu2O-DMB) nanomaterials are successfully synthesized for photoresponsive-enhanced enzymatic synergistic antibacterial therapy under near-infrared (NIR) irradiation (808 nm). Cu2O-DMB has a spherical morphology with a smaller nanosize and positive ζ potential, can trap bacteria through electrostatic interactions resulting in a targeting function. Cu2O-DMB nanospheres show both oxidase-like and peroxidase-like activities, and serve as a self-cascade platform, which can deplete high concentrations of GSH to produce O2Ë- and H2O2, then H2O2 is transformed into ËOH, without introducing exogenous H2O2. At the same time, Cu2O-DMB nanospheres become photoresponsive, producing 1O2 and having an efficient photothermal conversion effect upon NIR irradiation. The proposed mechanism is that the generated ROS (O2Ë-, ËOH and 1O2) and hyperthermia can have synergetic effects for killing bacteria. Moreover, hyperthermia is not only beneficial for destroying bacteria, but also effectively enhances the efficiency of ËOH production and accelerates GSH oxidation. Upon NIR irradiation, Cu2O-DMB nanospheres exhibit excellent antibacterial ability against methicillin-resistant Staphylococcus aureus (MRSA) and ampicillin-resistant Escherichia coli (AREC) with low cytotoxicity and bare bacterial resistance, destroy the bacterial membrane causing an efflux of proteins and disrupt the bacterial biofilm formation. Animal experiments show that the Cu2O-DMB + NIR group can efficiently treat MRSA infection and promote wound healing. These results suggest that Cu2O-DMB nanospheres are effective materials for combating bacterial infections highly efficiently and to aid the development of photoresponsive enzymatic synergistic antibacterial therapy.