Enzyme-Responsive Fluorescent Labeling Strategy for In Vivo Imaging of Gut Bacteria.

Myrosinase (Myr), as a unique ß-thioglucosidase enzyme capable of converting natural and gut bacterial metabolite glucosinolates into bioactive agents, has recently attracted a great deal of attention because of its essential functions in exerting homeostasis dynamics and promoting human health. Such nutraceutical and biomedical significance demands unique and reliable strategies for specific identification of Myr enzymes of gut bacterial origin in living systems, whereas the dearth of methods for bacterial Myr detection and visualization remains a challenging concern. Herein, we present a series of unique molecular probes for specific identification and imaging of Myr-expressing gut bacterial strains. Typically, an artificial glucosinolate with an azide group in aglycone was synthesized and sequentially linked with the probe moieties of versatile channels through simple click conjugation. Upon gut bacterial enzymatic cleavage, the as-prepared probe molecules could be converted into reactive isothiocyanate forms, which can further act as reactive electrophiles for the covalent labeling of gut bacteria, thus realizing their localized fluorescent imaging within a wide range of wavelength channels in live bacterial strains and animal models. Overall, our proposed method presents a novel technology for selective gut bacterial Myr enzyme labeling in vitro and in vivo. We envision that such a rational probe design would serve as a promising solution for chemoprevention assessment, microflora metabolic mechanistic study, and gut bacterium-mediated physiopathological exploration.

CD109 identified in circulating proteomics mitigates postoperative recurrence in chronic rhinosinusitis with nasal polyps by suppressing TGF-ß1-induced epithelial-mesenchymal transition.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a common inflammatory disorder with a high rate of recurrence. This study aimed to explore biomarkers for identifying patients with recurrent CRSwNP (rCRSwNP). METHODS: We recruited two independent cohorts. In the discovery cohort, rCRSwNP patients and non-recurrent CRSwNP (non-rCRSwNP) patients were recruited, and the serum proteomic profile was characterized. The top 5 upregulated and downregulated proteins were confirmed in the validation cohort by ELISA, WB, and qRT-PCR, and their predictive values for postoperative recurrence were assessed. In vitro, human nasal epithelial cells (HNEpCs) were employed to assess the ability of candidate proteins to induce epithelial-mesenchymal transition (EMT). RESULTS: Serum proteomics identified 53 different proteins, including 30 increased and 23 decreased, between the rCRSwNP and non-rCRSwNP groups. ELISA results revealed that serum levels of CD163 and TGF-ß1 were elevated, CD109 and PRDX2 were decreased in the rCRSwNP group compared to the non-rCRSwNP group, and serum CD163, TGF-ß1, and CD109 levels were proved to be associated with the risk of postoperative recurrence. In addition, qRT-PCR and WB revealed that tissue CD163, TGF-ß1, and CD109 expressions in rCRSwNP patients were enhanced compared to those non-rCRSwNP patients. Kaplan-Meier analysis showed that increased CD163 and TGF-ß1 expression and decreased CD109 expression are associated with the risk of recurrence in CRSwNP patients. Receiver operating characteristic curves showed that TGF-ß1 and CD109 had superior diagnostic performances for rCRSwNP. In vitro experiments showed that TGF-ß1 promoted EMT in HNEpCs, and overexpression of CD109 reversed this effect. Functional recovery experiments confirmed that CD109 could attenuate EMT in HNEpCs by inhibiting the TGF-ß1/Smad signaling pathway, attenuating EMT in epithelial cells. CONCLUSION: Our data suggested that TGF-ß1 and CD109 might serve as promising predictors of rCRSwNP. The TGF-ß1/Smad pathway was implicated in fostering EMT in epithelial cells, particularly those exhibiting low expression of CD109. Consequently, the absence of CD109 expression in epithelial cells could be a potential mechanism underlying rCRSwNP.

A universal construction of robust interface between 2D conductive polymer and cellulose for textile supercapacitor.

Conductive polymer (CP) fabric is considered as the ideal electrode for flexible energy storage due to its light weight, good flexibility and high energy storage properties. However, the conventional polymer-coated cellulose fiber synthesized by liquid-phase oxidation polymerization always forms disordered assembly of polymer particles on fiber, which endures poor mechanical stability. Here, we report a two-dimensional (2D) CP based fabric electrode realized by a salt-template assisted vapor-phase polymerization method, which achieves robust coating of 2D CP on various cellulose fibers. Typically, the prepared 2D polypyrrole@cotton electrode displays a high specific capacitance (902.6 mF cm-2) and good cycling stability (86.5% capacitance retention after 12,000 cycles). The capacitance of flexible symmetrical device retains at more than 90% when it is bent to 180° after 1000 bending cycles. This work provides a new strategy for the robust interface between functional materials and cellulose fibers, and has great potential for commercial mass production.

Biosynthesised palladium nanoparticles using Eucommia ulmoides bark aqueous extract and their catalytic activity.

Palladium nanoparticles (PdNPs) are of great importance as catalytic materials. Their synthesis has been widely studied and interest in their properties is growing. Bio-based methods might be a greener option for designing the PdNPs with reduced environmental impacts. This study reports the synthesis of PdNPs by utilising the aqueous extract of medicinally important Eucommia ulmoides (E. Ulmoides) bark which functions as both reducing and capping agent in moderate reaction conditions. Reduction potential of E. Ulmoides bark aqueous extract was about -0.08 V vs. saturated calomel electrode by open-circuit voltage method and the rich polyphenolics was confirmed by cyclic voltammetry, which helps to reduce palladium ions to PdNPs. The characterisation through high-resolution transmission electron microscopic, energy dispersive X-ray spectroscopy and X-ray diffraction infer that the as-synthesised PdNPs were spherical in shape with a face cubic crystal structure. The results from dynamic light scattering suggest the PdNPs have the narrow size distribution with an average size of 12.6 nm. The lower zeta potential (-25.3 mV) and the Fourier transform infrared spectra indicate that the as-synthesised PdNPs keep remarkably stable for a long period due to the capped biomolecules on the nanoparticle surface. This method for synthesis of PdNPs is simple, economic, non-toxic and efficient. The PdNPs show excellent catalytic activity for the electro-catalytic oxidation of hydrazine and the catalytic reducing degradation of p-aminoazobenzene, a model compound of azo-dyes.

ß-Type titanium alloys for spinal fixation surgery with high Young's modulus variability and good mechanical properties.

Along with a high strength, ductility, and work hardening rate, a variable Young's modulus is crucial for materials used as implant rods in spinal fixation surgery. The potential in this context of Ti-(9,8,7)Cr-0.2O (mass%) alloys is reported herein. The microstructural and mechanical properties of the alloys were systematically examined as a function of their chromium content, and the ion release of the optimized alloy was investigated to assess its suitability as an implant material. In terms of the deformation-induced ω-phase transformation required for a variable Young's modulus, the balance between ß-phase stability and athermal ω-phase content is most favorable in the Ti-9Cr-0.2O alloy. In addition, this composition affords a high tensile strength (>1000MPa), elongation at break (∼20%), and work hardening rate to solution-treated (ST) samples. These excellent properties are attributed to the combined effects of deformation-induced ω-phase transformation, deformation twinning, and dislocation gliding. Furthermore, the ST Ti-9Cr-0.2O alloy proves resistant to metal ion release in simulated body fluid. This combination of a good biocompatibility, variable Young's modulus and a high strength, ductility, and work hardening rate is ideal for spinal fixation applications. STATEMENT OF SIGNIFICANCE: Extensive efforts have been devoted over the past decades to developing ß-type titanium alloys with low Young's moduli for biomedical applications. In spinal fixation surgery however, along with excellent mechanical properties, the spinal-support materials should possess high Young's modulus for showing small springback during surgery to facilitate manipulation but low Young's modulus close to bone once implanted to avoid stress shielding. None of currently used metallic biomaterials can satisfy these abovementioned requirements. In the present study, we have developed a novel alloy, Ti-9Cr-0.2O. Remarkably variable Young's modulus and excellent mechanical properties can be achieved in this alloy via phase transformations and complex deformation mechanisms, which makes the Ti-9Cr-0.2O preferred material for spinal fixation surgery.