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The misuse of antibiotics has led to the emergence of multidrug-resistant bacteria. There is an urgent need to explore methods to effectively kill bacteria without relying on antibiotics. In this paper, a vanadium carbide-based (V2CTx-Au) nanostructures was successfully synthesized by electrostatic self-assembly for the direct detection and killing of bacteria. The nanostructures could be directly used for label-free surface-enhanced Raman spectroscopy detection of bacteria without tedious processing. Photothermal detection demonstrated that the temperature of the V2CTx-Au nanostructures can increase above 50 °C within just 200 s, and the photothermal conversion efficiency of the material is 37.82%. Reactive oxygen species detection experiments showed that the V2CTx-Au nanostructures can produce the O2·– and 1O2. Combined with SEM images of the bacteria, the results showed that V2CTx-Au nanostructures produced photothermal therapy antibacterial effects under 808 nm laser irradiation and exhibited photodynamic therapy synergistic antibacterial properties. The survival rates of Escherichia coli (E. coli) and extended-spectrum β-lactamase Escherichia coli (ESBL- E. coli) were 6.88 and 1.58%, respectively. In addition, cytotoxicity experiments and hemolytic tests showed that the prepared V2CTx-Au nanostructures exhibited good biocompatibility. This study provides a feasible route for the label-free and rapid detection of bacteria and rapid sterilization without antibiotics, which can help solve the problem of bacterial infection, especially drug-resistant bacteria. [ABSTRACT FROM AUTHOR]

The proliferation of drug-resistant bacteria and infections such as methicillin-resistant Staphylococcus aureus (MRSA) pose a serious challenge to global healthcare. Photothermal therapy (PTT) is becoming a highly effective antimicrobial method. Compared with near infrared I (NIR-I), near infrared II (NIR-II) has deeper penetration depth, less light scattering and higher maximum permissible exposure (MPE). The selection of a photothermal agent (PTA) and laser parameters is important. Three kinds of MXenes, Nb2C, Ti3C2 and V2C, were prepared in this paper, and the extinction coefficient and photothermal conversion efficiency (PCE) of NIR-I and NIR-II were compared. The extinction coefficient of Ti3C2 (26.23 L g−1 cm−1) at 808 nm was greater than those of Nb2C (24.38 L g−1 cm−1) and V2C (19.43 L g−1 cm−1). However, V2C had a higher temperature than Nb2C at 808 nm due to its high PCE (49.26%). Nb2C had a higher extinction coefficient (24.99 L g−1 cm−1) and PCE (45.55%) at 1064 nm, resulting in the highest temperature change. High extinction coefficient and high PCE are the two important factors for an excellent PTA. To reduce laser power used in the treatment, NIR-II laser and a gelation strategy for MXenes were used. The prepared Nb2C/Gel could be rapidly heated to 62 °C at a laser power of 0.112 W (lower than MPE), and the sterilization rate for MRSA was 92.48%. A NIH-3T3 cell activity study showed that the prepared Nb2C had good biocompatibility. Nb2C/Gel has excellent antibacterial properties and it is expected that a rapid, efficient and safe biological antimicrobial strategy against bacterial infections can be established using Nb2C/Gel, especially for drug-resistant bacterial infections. [ABSTRACT FROM AUTHOR]

Dysregulation of hepcidin-iron axis is presumed to account for abnormal iron status in patients with chronic liver disease (CLD). Our aim is to determine the effect of specific etiologies of CLD and of cirrhosis on serum hepcidin levels. PubMed, Embase, Web of Science were searched for studies comparing serum hepcidin levels in patients with CLD to that in controls using enzyme-linked immunosorbent assay. The study was conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Guidelines. Statistical analysis was carried out with STATA using random effects model to calculate the mean difference (MD) between two groups. Hepcidin levels were significantly lower in subjects with hepatitis C virus (16 studies) [MD −1.6 (95 % CI: −2.66 to −0.54), p<0.01] and alcoholic liver disease (3 studies) [MD −0.84 (95 % CI: −1.6 to −0.07), p=0.03] than controls. Serum hepcidin was significantly higher in subjects with non-alcoholic fatty liver disease (12 studies) [MD 0.62 (95 % CI: 0.21 to 1.03), p<0.01], but did not differ in subjects with hepatitis B and controls (eight studies) [MD −0.65 (95 % CI: −1.47 to 0.16), p=0.12]. Hepcidin levels were significantly lower in patients with cirrhosis of any etiology (four studies) [MD −1.02 (CI: −1.59 to −0.45), p<0.01] vs. controls (CI: confidence interval). Serum hepcidin levels are altered in common forms of CLD albeit not in a consistent direction. Additional study is needed to determine how changes in hepcidin levels are related to dysregulation of iron metabolism in CLD. [ABSTRACT FROM AUTHOR]

Bacterial infections have become a serious global health problem due to the misuse of antibiotics which causes the emergence of antibiotic-resistant strains. Photothermal therapy (PTT) has been widely studied in recent years as a method to combat the development of bacterial resistance. However, PPT may cause damage to the human body due to excessive laser power. Therefore, it is important and urgent to develop a multifunctional platform that can sensitively detect bacteria and effectively inhibit or kill bacteria at low laser power. Herein, a novel multifunctional paper substrate of Ti 3 C 2 T x -AuNP was successfully synthesized by a self-assembly and freeze-drying method for bacterial detection and photothermal sterilization at low laser power. The typical Gram-negative Escherichia coli ( E. coli ) and the Gram-positive Methicillin-resistant Staphylococcus aureus (MRSA) were used as models to perform label-free, rapid and sensitive detection of bacteria based on the surface-enhanced Raman spectroscopy (SERS) method with detection limits as low as 10 5 CFU mL -1 and 5 × 10 5 CFU mL -1 , respectively, demonstrating the paper substrate's ability to detect bacteria with sensitivity and accuracy. The paper substrate of Ti 3 C 2 T x -AuNP exhibits significant antibacterial effects when irradiated with 808 nm light at a low laser power of only 300 mW cm -2 and a short irradiation time of 5 minutes, and the germicidal rates for E. coli and MRSA were 99.94% and 92.71%, respectively. At the same time, the paper substrate of Ti 3 C 2 T x -AuNP also produces a variety of reactive oxygen species under 808 nm laser irradiation, resulting in photodynamic therapy (PDT). Accordingly, this paper substrate of Ti 3 C 2 T x -AuNP can not only sensitively detect bacteria, but also has photothermal and photodynamic sterilization, providing a promising countermeasure for the clinical treatment of diseases caused by multidrug-resistant bacteria., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)