Construction of pH-Dependent Nanozymes with Oxygen Vacancies as the High-Efficient Reactive Oxygen Species Scavenger for Oral-Administrated Anti-Inflammatory Therapy.

It is of great significance to eliminate excessive reactive oxygen species (ROS) for treating inflammatory bowel disease (IBD). Herein, for the first time, a novel nanozyme NiCo2 O4 @PVP is constructed via a step-by-step strategy. Noticeably, the existence of oxygen vacancy in the NiCo2 O4 @PVP is helpful for capturing oxygenated compounds, while both redox couples of Co3+ /Co2+ and Ni3+ /Ni2+ will offer richer catalytic sites. As expected, the obtained NiCo2 O4 @PVP exhibits pH-dependent multiple mimic enzymatic activities. Benefiting from the introduction of polyvinylpyrrolidone (PVP), the NiCo2 O4 @PVP possesses good physiological stability and excellent biosafety in stomach and intestines' environment. Meanwhile, the NiCo2 O4 @PVP also presents strong scavenging activities to ROS in vitro, including • O2- , H2 O2 , as well as • OH. Furthermore, a dextran sodium sulfate (DSS)-induced colitis model is established for evaluating the anti-inflammatory activity of NiCo2 O4 @PVP in vivo. Based on the size-mediated and charge-mediated mechanisms, the nanozyme can pass through the digestive tract and target the inflamed site for oral-administrated anti-inflammatory therapy. More interestingly, compared with the model group, the expression levels of inflammatory factors (e.g., Interleukin- 6 (IL-6), Interleukin- 1ß (IL-1ß), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS)) in colon of mice show a significant decrease after nanozyme intervention, thereby inhibiting the development of IBD. In short, current work provides an alternative therapy for patients suffering from IBD.

Newly Constructed NiCo2O4 Derived from ZIF-67 with Dual Mimic Enzyme Properties for Colorimetric Detection of Biomolecules and Metal Ions.

Integration of novel bio-/nanostructures as effective sensing platforms is still of great significance for robust and rapid analysis. Herein, a novel metal-organic framework-derived NiCo2O4 was synthesized via a feasible templating method. Significantly, redox couples of both Ni3+/Ni2+ and Co3+/Co2+ provided richer oxidation-reduction reactions, thereby leading to an enhanced catalytic activity. Furthermore, NiCo2O4 as an enzyme mimic with peroxidase-like activity and oxidase-like activity could oxidize colorless thylbenzidine (TMB) to blue oxTMB in the absence of H2O2. Thus, a sensitive chromogenic sensing platform for detecting Fe2+, thiourea, cysteine (Cys), and epigallocatechin-3-gallate (EGCG) was proposed. The colorimetric detection methods exhibited great features of low limit of detection (LOD) and broad linear range. Owing to the complexation reaction, the chromogenic sensing system of TMB + NiCo2O4 + Cys achieved effective detection of Cu2+ and Mn2+ with the LODs of 0.0022 and 0.0181 mM, respectively. Developed detection methods with wide linear ranges of 0.008-0.1 mM for Cu2+ and 0.08-1 mM for Mn2+ had excellent practical potential. Similarly, the reaction system of TMB + NiCo2O4 + EGCG could achieve the colorimetric detection of Cu2+ and Fe3+. The great chromogenic sensing performance for detecting Cu2+ and Fe3+ with a broad linear range and a low LOD could be also realized.

Tailor-Made Cell-Based Biomimetic Nanoprobes for Fluorescence Imaging Guided Colorectal Cancer Chemo-immunotherapy.

Colorectal cancer has become one of the malignant tumors with a high rate of morbidity and mortality. Therefore, how to effectively treat colorectal cancer is crucial. Although nanodelivery system has been applied to the therapy of colorectal cancer, the majority of existing nanodelivery systems still have drawbacks such as low biocompatibility and poor targeting ability. In this work, tailor-made cell-based biomimetic nanoplatform was prepared to enhance the targeting and therapeutic effect for colorectal cancer chemo-immunotherapy. First, hollow long persistence luminescence nanomaterials were synthesized with superior background-free bioimaging effect and high drug-loading content. After loaded with cisplatin, the nanoplatform was camouflaged with tailor-made erythrocyte and programmed cell death receptor 1 (PD-1) expressed hybrid cell membrane. In vivo animal imaging experiment showed that the nanoplatform camouflaged with hybrid cell membrane not only had excellent immune escapability but also had excellent tumor active targeting ability. In vivo anticancer experiments showed that combined chemotherapy and immunotherapy of the nanoplatform could significantly inhibit tumor growth in tumor-bearing mice. In summary, the tailor-made cell-based membrane camouflage produced excellent immune escapability and cancer active targeting ability, providing a modality for biomimetic nanodelivery systems.

Assessment of migration regularity of phthalates from food packaging materials.

Phthalate acid esters (PAEs) are one of the essential plastic additives which may lead to plenty of harmful effects, including reproductive toxicity, teratogenicity, and carcinogenicity. Increasing attention has been paid to the migration of plasticizer. In this article, the disposable plastic lunch boxes were taken as the research object. The result showed that dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP) have been mainly found, whose content was 1.5 mg/kg and 2.4 mg/kg, respectively. The LOD was 2 ng/g, and LOQ was 6.7 ng/g. We further investigated the migration of PAEs into the simulated liquid at different temperature conditions. Then, the linear fitting performing by first-order kinetic migration model revealed that the lower the polarity of the simulated liquid, the larger the rate constant K 1 and initial release rate V 0. The higher the temperature, the bigger the K 1 and V 0.

A Novel Mediation Strategy of DSS-Induced Colitis in Mice Based on an Iron-Enriched Probiotic and In Vivo Bioluminescence Tracing.

Iron deficiency (ID) caused by blood loss and/or reduced iron absorption is a serious problem influencing health in inflammatory bowel disease (IBD). However, traditional iron supplements may fail to meet no side effect demands for ID of IBD; thus, a new iron supplementation is highly desired to be developed. Herein, for the first time, probiotic Lactobacillus alimentarius NKU556 with an iron-enriching ability was screened from Chinese traditional fermented food then employed to intervene DSS-induced colitis with bioluminescence tracing in mice. As expected, oral administration with NKU556-Fe can remarkably enhance the expression of tight junction proteins and effectively reduce the pro-inflammatory cytokines as well as the oxidative stress on DSS-induced colitis in mice. Meanwhile, in comparison with the FeSO4 group, the intake of NKU556-Fe could suppress the expression of hepcidin derived from the liver and reduce the degradation of FPN1, thereby leading to the increase in the iron absorption of colitis in mice. According to the bioluminescence result, it was believed that the beneficial effects of oral administration with NKU556/NKU556-Fe on DSS-induced colitis in mice were hardly related to its metabolites but associated with its own function. These results concluded that the oral administration of NKU556-Fe could relieve colitis inflammation and increase iron absorption. In summary, current work not only proposed a novel mediation strategy for IBD but also offered some inspirations for future treatment of extraintestinal complications.