Xueting Niu,Canying Hu,Shengwei Chen,Jiaying Wen,Xiaoxi Liu,Yanhong Yong,Zhichao Yu,Xingbin Ma,Chengpeng Li,Mohamad Warda,A.M. Abd El-Aty,Ravi Gooneratne,Xianghong Ju
Heat stress (HS) has a negative impact on animal health. A modified chitosan-gentamicin conjugate (CS-GT) was prepared to investigate its potential protective effects and mechanism of action on heat stress-induced intestinal mucosa injury in IPEC-J2 cells and mouse 3D intestinal organs in a mouse model. CS-GT significantly ( P < 0.01) reversed the decline in transmembrane resistance and increased the FITC-dextran permeability of the IPEC-J2 monolayer fusion epithelium caused by heat stress. Heat stress decreased the expression of the tight binding proteins occludin , claudin1, and claudin2. However, pretreatment with CS-GT significantly increased ( P < 0.01) the expression of these tight binding proteins. Mechanistically, CS-GT inhibited the activation of the TLR4/STAT6/MYLK signaling pathway induced by heat stress. Molecular docking showed that CS-GT can bind effectively with TLR4 . In conclusion, CS-GT alleviates heat stress-induced intestinal mucosal damage both in vitro and in vivo . This effect is mediated, at least partly, by the inhibition of the TLR4/STAT6/MYLK signaling pathway and upregulation of tight junction proteins. These findings suggest that CS-GT may have therapeutic potential in the prevention and treatment of heat stress-related intestinal injury.
Shuyun Bi,Yue Yuan,Fengming Zhang,Yuting Wang,Jia Liu,Bin Yang,Daqian Song
Two aminoglycoside antibiotics (AGs), gentamicin (GEN) and tobramycin (TOB), have good antibacterial activity against most pseudomonas aeruginosa and staphylococcus. The molecular structure of these drugs lack chromogenic groups, which brings challenges to their detection. In this project, the detecting methods for GEN and TOB utilizing surface-enhanced Raman spectroscopy (SERS) based on γ -Al 2 O 3 -modified silver nanoparticles (AgNPs) coated with bovine serum albumin (BSA) were established. The enhancement factors (EFs) of GEN and TOB were 2.44 × 10 5 and 2.67 × 10 6 , respectively. The transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and spectrophotometric techniques were used to characterize the substrate and the combination of the substance with drugs. The pH, the addition amounts for the substrate and coagulant, as well as the mixing time were optimized. On the basis of single factor experiments, a more scientific response surface model was established. The concentrations of GEN and TOB showed good linear relationships with their Raman signals in the ranges of 6.67 × 10 −8 – 2.00 × 10 −6 and 6.67 × 10 −9 – 3.00 × 10 −7 mol L −1 respectively. The limits of detection (LODs) were 11.88 and 1.26 nmol L −1 for GEN and TOB, respectively. The methods were used successfully for the samples determination of the two AGs in commercial drugs and meat products.
Herein, we report a facile one-step solvothermal synthesis of nitrogen and sulfur co-doped fluorescent carbon dots (N,S-CDs) using benzoic acid as the carbon source and sulfonamide as the doping agent. The synthesized N,S-CDs exhibit stable photoluminescence with an impressive fluorescence quantum yield of 16.8 %. These N,S-CDs maintain their luminescent properties under various challenging conditions, including high salt concentrations, elevated temperatures, UV radiation exposure, acidic or alkaline environments, long-term storage, and different solvents. Notably, the photoluminescence of N,S-CDs is excitation-wavelength dependent, with emission wavelengths tunable from 470 nm to 585 nm. Furthermore, the N,S-CDs display distinct fluorescent hues in aqueous and ethanolic media, presenting a novel dual-switch anti-counterfeiting ink system. Leveraging the sensitivity of N,S-CDs to gentamicin, we have developed a facile and rapid detection method for this antibiotic, which has been successfully applied to the analysis of authentic milk samples. This research contributes a novel and efficient protocol for the fabrication of high-performance carbon dots, thereby expanding their potential applications in food analysis and anti-counterfeiting technologies.
危险品化学品经营许可证（带存储）