The increase in the number of resistant bacteria caused by the abuse of antibiotics and the emergence of biofilms significantly reduce the effectiveness of antibiotics. Bacterial infections are detrimental to our life and health. To reduce the abuse of antibiotics and treat biofilm-related bacterial infections, a biomimetic nano-antibacterial system, RBCM-NW-G namely, that controls the release of antibiotics through near infrared was prepared. The hollow porous structure and the high surface activity of nanoworms are used to realize antibiotic loading, and then, biomimetics are applied with red blood cell membranes (RBCM). RBCM-NW-G, which retains the performance of RBCM, shows enhanced permeability and retention effects. Fluorescence imaging in mice showed the effective accumulation of RBCM-NW-G at the site of infection. In addition, the biomimetic nanoparticles showed a longer blood circulation time and good biocompatibility. Anti-biofilm test results showed damage to biofilms due to a photothermal effect and a highly efficient antibacterial performance under the synergy of the photothermal effect, silver iron, and antibiotics. Finally, by constructing a mouse infection model, the great potential of RBCM-NW-G in the treatment of in vivo infections was confirmed.

BACKGROUND Different types of nitrogen‐containing wastewater have been treated with dewatered alum sludge (DAS) or neutralized used acid (NUA) or with a combined DAS–NUA biofilter. The connections between the spatiotemporal structures of ammonia‐oxidizing bacteria (AOB) and nitrite‐oxidizing bacteria (NOB) and the nitrogen removal performance of DAS–NUA biofilter have not been fully clarified. To address this issue, AOB and NOB genetic characteristics response to nitrogen conversions in a laboratory‐scale DAS–NUA biofilter were investigated. RESULTS The spatiotemporal distribution of the AOB in DAS was heterogeneous in the bioreactor. The trends observed in its structure were a function of depth along the flowpaths and time. However, AOB in NUA and NOB in both substrates were time and space independent. The spatial and temporal behavior of nitrifying bacteria mainly depended on the pH, followed by dissolved oxygen. The Shannon indexes of AOB and NOB and the relative abundances of Nitrosomonas and Nitrobacter had significantly negative relationships with NH+4–N and total nitrogen concentrations in effluents. CONCLUSIONS The Shannon indexes of AOB and NOB and the relative abundances of Nitrosomonas and Nitrobacter were the key indicators of nitrogen removal and have implications for effective nitrogen attenuation strategies. © 2018 Society of Chemical Industry

Achieving rapid hemostasis in complex and deep wounds with secluded hemorrhagic sites is still a challenge because of the difficulty in delivering hemostats to these sites. In this study, a Janus particle, SEC-Fe@CaT with dual-driven forces, bubble-driving, and magnetic field– (MF–) mediated driving, was prepared via in situ loading of Fe3O4 on a sunflower sporopollenin exine capsule (SEC), and followed by growth of flower-shaped CaCO3 clusters. The bubble-driving forces enabled SEC-Fe@CaT to self-diffuse in the blood to eliminate agglomeration, and the MF-mediated driving force facilitated the SEC-Fe@CaT countercurrent against blood to access deep bleeding sites in the wounds. During the movement in blood flow, the meteor hammer-like SEC from SEC-Fe@CaT can puncture red blood cells (RBCs) to release procoagulants, thus promoting activation of platelet and rapid hemostasis. Animal tests suggested that SEC-Fe@CaT stopped bleeding in as short as 30 and 45 s in femoral artery and liver hemorrhage models, respectively. In contrast, the similar commercial product Celox™ required approximately 70 s to stop the bleeding in both bleeding modes. This study demonstrates a new hemostat platform for rapid hemostasis in deep and complex wounds. It was the first attempt integrating geometric structure of sunflower pollen with dual-driven movement in hemostasis.