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Multifunctional photothermal nanomaterials offer notable opportunities for antimicrobial therapy due to their excellent antibacterial activities without leading to drug resistance. Herein, we report a facile one-step strategy for fabricating anisotropic corn-like α-Fe2O3/AgAu/polydopamine (PDA) nanospindles with photothermally enhanced antibacterial performance. The AgAu bimetallic nanocrystals sandwiched between the α-Fe2O3 core and the PDA shell are achieved by simultaneous reduction from AgNO3 and HAuCl4 during the oxidative polymerization of dopamine and galvanic replacement reaction between the obtained Ag nanocrystals and Au precursor. The inner nanostructure and atom ratio of AgAu bimetallic nanocrystals can be modulated by varying the experimental parameter, thus further controlling the photothermal activities. In comparison to α-Fe2O3/Au/PDA, Fe2O3/Ag1.7Au0.8/PDA (50 μg/mL) has a better photothermal conversion effect (60.69%). Moreover, the α-Fe2O3/Ag1.7Au0.8/PDA nanospindle exhibits moderate antibacterial activity, which may be derived from Ag+ release. Under application of near-infrared light irradiation, the corn-like α-Fe2O3/Ag1.7Au0.8/PDA nanospindles (50 μg/mL) exhibit a photothermally enhanced sterilization effect against both Escherichia coli and Staphylococcus aureus (99.99%). This "Ag+ release–photothermal" coupling sterilization method provides a simple synergistic antimicrobial therapy strategy, which possesses great promise for future nanomedicine against bacteria in water treatment. [ABSTRACT FROM AUTHOR]

Due to the abuse of antibiotics, the sensitivity of patients to antibiotics is gradually reduced. This work develops a Fe3O4@SiO2@Au/PDA nanochain which shows an interesting magnetic-field-induced improvement of its photothermal antibacterial property. First, SiO2 was wrapped on Fe3O4 nanospheres assembled in a chain to form a Fe3O4@SiO2 nanocomposite with a chain-like nanostructure. Then, the magnetic Fe3O4@SiO2@Au/PDA nanochains were prepared using in situ redox-oxidization polymerization. Under the irradiation of an 808 nm NIR laser, the temperature rise of the Fe3O4@SiO2@Au/PDA nanochain dispersion was obvious, indicating that they possessed a good photothermal effect. Originating from the Fe3O4, the Fe3O4@SiO2@Au/PDA nanochain showed a typical soft magnetic behavior. Both the NIR and magnetic field affected the antimicrobial performance of the Fe3O4@SiO2@Au/PDA nanochains. Escherichia coli and Staphylococcus aureus were used as models to verify the antibacterial properties. The experimental results showed that the Fe3O4@SiO2@Au/PDA nanochains exhibited good antibacterial properties under photothermal conditions. After applying a magnetic field, the bactericidal effect was further significantly enhanced. The above results show that the material has a broad application prospect in inhibiting the growth of bacteria. [ABSTRACT FROM AUTHOR]

Infectious diseases associated with drug-resistant bacteria increasingly threaten public health. Effective antibacterial nanoplatforms are of special importance for treating bacterial infections. In this work, a novel magnetic Fe3O4–Au–PDA hybrid microcapsule with both photothermal (PTT) and photodynamic (PDT) anti-bacterial functions was developed. First, the Fe3O4@Au/PDA core/shell microspheres with hollow nature were obtained by a simple in situ redox–oxidize polymerization method. Then, they were etched in acid to improve the hollow interior and porous shell. Finally, the tetracarboxyzinc phthalocyanine (ZnPc) was used as the photosensitizer to be loaded into the above Fe3O4–Au–PDA hybrid microcapsule. Owing to the dual-mode photothermal Au–PDA hybrid shell and the ZnPc photosensitizer, the final Fe3O4–Au–PDA/ZnPc hybrid microcapsule serves as a wonderful photothermal/photodynamic (PTT/PDT) synergistic therapy agent. The experimental results show that the Fe3O4–Au–PDA/ZnPc microcapsule possesses excellent photothermal sterilization effect (808 nm laser irradiation) against Escherichia coli, and the experimental results further demonstrate good photodynamic behavior under Xenon lamp irradiation. The product exhibits much higher antibacterial performance by combining the PTT/PDT treatment, which demonstrates that this work provides a novel dual-mode phototheranostic nano-agent for an effective treatment of bacterial infections. [ABSTRACT FROM AUTHOR]

BACKGROUND: Protecting the intestinal mucosa from being destroyed helps reduce the inflammation caused by acute pancreatitis (AP). In this study, whether okra pectin (OP) could attenuate the inflammation of AP through protecting the intestinal barrier was investigated. RESULTS: OP was obtained from crude okra pectin (COP) through the purification by DEAE cellulose 52 column. Supplementation with OP or COP in advance reduced the severity of AP, as revealed by lower serum amylase and lipase levels, abated pancreatic edema, attenuated myeloperoxidase activity and pancreas histology. OP or COP inhibited the production of pancreatic proinflammatory cytokines, including tumor necrosis factor‐α and interleukin‐6. In addition, the upregulation of AP‐related proteins including ZO‐1, occludin, the antibacterial peptide‐defensin‐1 (DEFB1) and cathelicidin‐related antimicrobial peptide (CRAMP), as well as the histological examination of colon injuries, demonstrated that OP or COP provision could effectively maintain intestinal barrier function. Ultimately, dietary OP or COP supplementation could inhibit AP‐induced intestinal inflammation. For the above, the effect of OP was better than COP. CONCLUSION: Dietary OP supplementation could be considered as a preventive method that effectively interferes with intestinal damage and attenuates inflammatory responses trigged by AP. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

A rapid and robust preparation method of six isoflavones from ethanol aqueous extract of Iris tectorum Maxim (I. tectorum) was established by using macroporous resin column chromatography and preparative high-performance liquid chromatography (Prep-HPLC). After separation by AB-8 resins, total flavonoids content increased from 10.60% in the crude extract to 54.20% with a recovery yield of 75.12%. Subsequently, the extracts were purified by Prep-HPLC, and the purities were more than 82.2% after assessment by analytical HPLC and characterization by mass spectrometry. The established method is expected to be used for preparing available quantities of pure isoflavones from I. tectorum. [ABSTRACT FROM AUTHOR]

Ginkgolide B is in great demand worldwide on account of its extensive and excellent pharmacological effects, however, it is difficult to separate and purify ginkgolide B. In this study, ginkgolide B molecularly imprinted polymers were prepared by combining software simulation and molecular imprinting technique, and its characterization and adsorption performed evaluation were performed to understand the adsorption behavior of the polymers. The adsorption equilibrium concentration of molecularly imprinted polymers was 0.70 mg/mL, and the adsorption equilibrium time was 4 h. Meanwhile, the adsorption isotherm of the polymers for ginkgolide B fitted well with the Langmuir model, and the adsorption kinetics was in line with the pseudo‐second‐order kinetics. In contrast, the adsorption capacity of molecularly imprinted polymers on ginkgolide B was higher than that of non‐molecular imprinted polymers, with better selectivity and better adsorption after repeated use for six times. The application experiments showed that molecular imprinted polymers have a good adsorption effect in low purity samples. Therefore, the polymers reported herein can be expected to apply in the adsorption and separation of ginkgolide B samples. [ABSTRACT FROM AUTHOR]