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The present study aimed to investigate the effect of covalent coupling with the dietary polyphenol rosmarinic acid (RA) on the structure and properties of β-lactoglobulin (β-LG). β-LG-RA complexes were prepared using the free radical and alkaline methods. The structural changes of β-LG after coupling with RA were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV) absorption spectroscopy, fluorescence spectroscopy, and circular dichroism (CD) spectroscopy. The antioxidant activity of β-LG and its complexes with RA was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical cation scavenging methods. Furthermore, their binding capacity to serum-specific immunoglobulin G (IgG) were evaluated using enzyme-linked immunosorbent assay (ELISA). The results revealed that the secondary structure of β-LG transformed from α-helix to β-sheet and random coil after RA covalent conjugation. The protein underwent changes in its secondary and tertiary structures. Additionally, compared to β-LG, the β-LG-RA covalent conjugates showed significantly enhanced antioxidant activity and reduced binding ability with serum specific IgG. In conclusion, covalent coupling with RA led to a significant improvement in the antioxidant activity of β-LG and a significant decrease in its binding capacity to serum-specific IgG by introducing phenolic hydroxyl groups.

Cell migration is an essential physiological process in the life cycle of cells, playing a crucial role in cancer metastasis, neural development, and cellular immune response. However, achieving precise control of cell migration at single‐cell level is challenging due to the intricate and diverse microenvironments of cells. Here, an optical technique is presented that utilizes light‐actuated micronavigators to guide the directional migration of individual cells both in vitro and in vivo. Employing high‐speed scanning optical tweezers, micronavigators near target cells are trapped and rotated at a rotation speed of up to 12 000 rpm, which, to the best of knowledge, represents the fastest rotation of light‐driven micromotors in a biological environment to date. The micronavigators generate a powerful fluid shear force (up to 40 pN) which can guide the migration of immune and nerve cells in a predetermined direction. Furthermore, micronavigators are employed to guide cell migration in various biological systems, including lab‐on‐a‐chip devices and blood vessels within living animals. This technique offers new opportunities for controlling cell migration, enabling precise immune activation, and neuron repair at the single‐cell level. [ABSTRACT FROM AUTHOR]

Aflatoxin B1 (AFB1), a widespread contaminant in food and feeds, poses a threat to the health of animals and humans. Consequently, it is significant to develop a rapid, precise and highly sensitive analytical method for the detection of AFB1. Herein, we developed an immunochromatographic strip (ICS) based on a tetrahedral DNA (TDN) immunoprobe for AFB1 determination in rice bran oil. Three sizes of TDN immunoprobes (AuNP-TDN13bp-mAb, AuNP-TDN17bp-mAb, AuNP-TDN26bp-mAb) were constructed, and the performance of these three immunoprobes, including the effective antibody labeling density and immunoaffinity, was measured and compared with that of the immunoprobe (AuNP-mAb) developed using the physical adsorption method. Subsequently, the optimal TDN immunoprobe, namely AuNP-TDN13bp-mAb, was selected to prepare the immunochromatographic strip (ICS) for the qualitative and quantitative detection of AFB1 in rice bran oil. The visual limits of detection (vLODs) of the ICS based on AuNP-TDN13bp-mAb and AuNP-mAb were 0.2 ng/mL and 2 ng/mL, with scanning quantitative limits (sLOQs) of 0.13 ng/mL and 1.4 ng/mL, respectively. The ICS demonstrated a wide linear range from 0.02 ng/mL to 0.5 ng/mL, with good specificity, accuracy, precision, repeatability, and stability. Moreover, a high consistency was observed between the constructed ICS and ultra-high-performance liquid chromatography (UPLC) in the quantification of AFB1. The results indicated that the introduction of TDN was beneficial for promoting efficient antibody labeling, protecting the bioactivity of immunoprobes, and increasing the sensitivity of detection, which would provide new perspectives for the achievement of the highly sensitive detection of mycotoxins. [ABSTRACT FROM AUTHOR]

Deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON) belong to type B trichothecenes that are widely detected in agricultural products as one of the most common classes of mycotoxins. In the present study, we aimed to characterize the alteration of lipid metabolism in normal human hepatocytes by poisoning with DON and its acetylated derivatives. After verifying the hepatotoxicity of the three toxins, DON, 15-ADON, and 3-ADON, the mRNA expression was determined by transcriptomics, and the results showed that DON and 15-ADON had a significant regulatory effect on the transcriptome, in which glycerophospholipid metabolism pathway and phospholipase D signaling pathways have not been reported in studies of DON and its acetylated derivatives. For further validation, we explored lipid metabolism in depth and found that PC (15:0/16:0), PC (16:1/18:3), PC (18:1/22:6), PC (16:0/16:0), PC (16:0/16:1), PC (16:1/18:1), PC (14:0/18:2), PE (14:0/16:0) and PE (18:1/18:3) were downregulated for all nine lipids. Combined with the transcriptome results, we found that hepatic steatosis induced by the three toxins, DON, 15-ADON and 3-ADON, was associated with altered expression of genes related to lipid oxidation, lipogenesis and lipolysis, and their effects on lipid metabolism in L-02 cells were mainly realized through the PC-PE cycle. [ABSTRACT FROM AUTHOR]

Fuberidazole and pirimicarb are carbamate pesticides for insect control. There is pesticide accumulation through the food chain that may ultimately migrate into the human body through the crayfish. Here a rapid method for simultaneous determination of fuberidazole and pirimicarb in crayfish is reported. The excitation-emission fluorescence matrix was obtained by simple pretreatment of crayfish meat using acetonitrile, and qualitative and quantitative information was separated from overlapping spectra using the self-weighted alternating trilinear decomposition. The detection limits of the pesticides for fuberidazole and pirimicarb were 0.068 mg/kg and 0.160 mg/kg, respectively, and the limits of quantitation were 0.207 mg/kg and 0.485 mg/kg. The average recoveries were 90.79% and 98.77%. The results show that a combination of excitation-emission fluorescence matrix and alternating trilinear decomposition can be used for the determination of fuberidazole and pirimicarb in crayfish with simple pretreatment using acetonitrile. [ABSTRACT FROM AUTHOR]