An advanced and universal method to high-efficiently deproteinize plant polysaccharides by dual-functional tannic acid-feIII complex

Inflammation assessment and therapeutic monitoring based on highly sensitive and multi-level electrochemical detection of PGE2

Prostaglandin E2 (PGE2), an eicosane, regulates the physiological activity of inflammatory cells and represents a potential therapeutic target for facilitating tissue repair in vivo. In our work, an electrochemical immunosensor employing Ketjen black-Au nanoparticles (KB-Au) and poly tannic acid nanospheres conjugated with anti-PGE2 polyclonal antibody (PTAN-Ab) was designed to ultra-sensitively analyze PGE2 levels secreted by living cells and tissues. Antibody assembly strategies were explored to achieve signal amplification. Moreover, we studied the therapy effects of docosahexaenoic acid (DHA), arachidonic acid (AA), hyaluronic acid (HA), and small molecule 15-hydroxyprostaglandin dehydrogenase inhibitor (SW033291) on inflammation and evaluated the protective functions of HA and SW033291 in a murine model subjected to colitis induced by dextran sulfate sodium (DSS) using the developed sensor. The sensor exhibited a linear range of 10-5-106 fg/mL and a detection limit (LOD) of 10-5 fg/mL. Fetal bovine serum (FBS) samples were used to achieve high recovery of target analytes. This study not only presents an effective strategy for ultra-sensitively monitoring PGE2 but also provides valuable insights into assessing the degree of inflammation and the therapeutic effect of related drugs. Research on human health monitoring and regenerative medicine could greatly benefit from the findings.

Integration of a biocompatible metal-phenolic network and fluorescence microspheres as labels for sensitive and stable detection of carbendazim with a lateral flow immunoassay

High fluorescence intensity microspheres such as aggregation-induced emission fluorescence microspheres (AIEFM) have improved the sensitivity of lateral flow immunoassay (LFIA). The preparation of immune probes in LFIA usually adopts the chemical coupling strategy with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide for antibody coupling, which has the problems of low coupling efficiency, tedious coupling process, and poor repeatability. A biocompatible metal-phenolic network (MPN), which contains large amounts of phenols and galloyl groups, could easily, quickly, and stably couple with antibodies. Herein, we proposed a strategy based on MPN modification on ultrabright AIEFM surface as a novel label for the rapid detection of carbendazim. The limit of detection of AIEFM@MPN-LFIA was 0.019 ng/mL, which was 4.9 times lower than that of AIEFM-LFIA. In spiked samples, the average recoveries of AIEFM@MPN-LFIA ranged from 80% to 118% (coefficient of variation <13.45%). Therefore, AIEFM@MPN was a promising signal label that could improve the detection performance of LFIA.

Physicochemical properties of pectin-Fe(III) gained by HG-type hawthorn with different esterification degree

In this study, the complexation ability of HG-type hawthorn pectin with trivalent iron ions after de-esterification was investigated. The moderate esterification reaction could significantly increase the iron content in HG-type hawthorn pectin. Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) experiments proved that -OH and -COOH in the pectin acted as a bridge connecting Fe3+ leading to the formation of β-FeOOH structure, and the trivalent iron ions were successfully complexed into the HG-type hawthorn pectin. In addition, infrared and ultraviolet spectroscopic scans, particle size, and potentiometric measurements were carried out to demonstrate the complexation coordination mechanism of hawthorn pectin with Fe3+, and there were differences in the complexation effect of HG-type hawthorn pectin with different degrees of esterification. The gelling properties of HG-type hawthorn pectin were subsequently verified by in vitro gastrointestinal tract simulation experiments to aid the smooth passage of ferric ions through the gastric juices and reduce irritation. The success of the experiments demonstrated that HG-type hawthorn pectin is an excellent raw material for metal complexation, and the degree of esterification is one of the important factors affecting its complexation effect, which proves its potential application value as an iron supplement.

Fucoidan MF4 from Fucus vesiculosus inhibits Lewis lung cancer via STING-TBK1-IRF3 pathway

Fucoidan, a sulfated polysaccharide of marine origin found in brown algae and sea cucumbers, has been identified as a neuroprotective compound. In this study, a novel fucoidan MF4 was extracted from Fucus vesiculosus and isolated using Q-Sepharose fast-flow ion-exchange chromatography. The physicochemical properties of MF4 were characterized. MF4 is primarily composed of fucose, xylose, galactose, glucose, and mannose in a molar ratio of 12.3: 4.9: 1.1: 1.0: 1.1, with an average molecular weight of 67.7 kDa. Notably, MF4 demonstrated suppression of LLC tumor growth in vivo. RNA-sequencing analysis revealed that MF4 enhanced the expression of type I interferon-associated downstream genes in macrophages. Furthermore, MF4 increased the levels of phosphorylated TBK1 and IRF3 proteins in vitro. By activating the STING-TBK1-IRF3 signaling pathway, MF4 may enhance the antitumor activity of macrophages. Taken together, MF4 has promising potential as an antitumor and immunomodulatory agent.

Structure-function relationship and biological activity of polysaccharides from mulberry leaves: A review

Mulberry (Latin name "Morus alba L.") is a perennial deciduous tree in the family of Moraceae, widely distributed around the world. In China, mulberry is mainly distributed in the south and the Yangtze River basin. Its leaves can be harvested 3-6 times a year, which has a great resource advantage. Mulberry leaves are regarded as the homology of medicine and food traditional Chinese medicine (TCM). Polysaccharides, as its main active ingredients, have various effects, such as antioxidant, hypoglycemic, hepatoprotective, and immunomodulatory. This review summarizes the research progress in the extraction, purification, structural characterization, and structure-function relationship of polysaccharides from mulberry leaves in the last decade, hoping to provide a reference for the subsequent development and market application of polysaccharides from mulberry leaves.

Hawthorn pectin/soybean isolate protein hydrogel bead as a promising ferrous ion-embedded delivery system

In this study, hydrogel beads [SPI/HP-Fe (II)] were prepared by cross-linking soybean isolate protein (SPI) and hawthorn pectin (HP) with ferrous ions as a backbone, and the effects of ultrasound and Fe2+ concentration on the mechanical properties and the degree of cross-linking of internal molecules were investigated. The results of textural properties and water-holding capacity showed that moderate ultrasonic power and Fe2+ concentration significantly improved the stability and water-holding capacity of the hydrogel beads and enhanced the intermolecular interactions in the system. Scanning electron microscopy (SEM) confirmed that the hydrogel beads with 60% ultrasonic power and 8% Fe2+ concentration had a denser network. X-ray photoelectron spectroscopy (XPS) and atomic absorption experiments demonstrated that ferrous ions were successfully loaded into the hydrogel beads with an encapsulation efficiency of 82.5%. In addition, in vitro, simulated digestion experiments were performed to understand how the encapsulated Fe2+ is released from the hydrogel beads, absorbed, and utilized in the gastrointestinal environment. The success of the experiments demonstrated that the hydrogel beads were able to withstand harsh environments, ensuring the bioactivity of Fe2+ and improving its bioavailability. In conclusion, a novel and efficient ferrous ion delivery system was developed using SPI and HP, demonstrating the potential application of SPI/HP-Fe (II) hydrogel beads as an iron supplement to overcome the inefficiency of intake of conventional iron supplements.

Extraction, purification, structural features, modifications, bioactivities, structure-activity relationships, and applications of polysaccharides from garlic: A review

Garlic is a common vegetable and spice in people's daily diets, in which garlic polysaccharide (GP) is one of the most important active components with a variety of benefits, such as antioxidant, immune-enhancing, anti-inflammatory, liver-protective and bowel-regulating properties. >20 types of GPs, mainly crude polysaccharides, have been identified. However, the exact chemical composition of GPs or the mechanism underlying their pharmacological activity is still not fully understood. The extraction and purification methods of GPs are compared in this review while providing detailed information on their structural features, identification methods, major biological activities, mechanisms of actions, structural modifications, structure-activity relationships as well as potential applications. Finally, the limitations of GP research and future issues that need to be addressed are discussed in this review. GPs are widely recognized as substances with great potential in the pharmaceutical and food industries. Therefore, this review aims to provide a comprehensive summary of the latest research progresses in the field of GPs, together with scientific insights and a theoretical support for the development of GPs in research and industrialization.

A review on extraction, purification, structural characteristics, biological activities, applications of polysaccharides from Hovenia dulcis Thunb. (Guai Zao)

Hovenia dulcis Thunb. (H. dulcis) is a widely distributed plant with a long history of cultivation and consumption. As a common plant, it has economic, edible and medicinal value. H. dulcis polysaccharides are one of their main bioactive ingredients and have many health benefits, such as anti-diabetes, antioxidation, anti-glycosylation, anti-fatigue, immune regulation activities and alcoholic liver disease protection activity. In this paper, the research progress of H. dulcis polysaccharides in extraction, purification, structural characteristics, biological activities, existing and potential applications were reviewed, which could provide new valuable insights for future studies.

Natural needle microstructure-based immunochromatographic assay for sensitively detecting streptomycin in food products

Immunochromatographic assays (ICAs) are famous as the point of care test (POCT) technology against food fraud for antibiotics detection. However, the poor sensitivity, stability and the monoclonal antibodies (mAbs)-depended signals limited their further applications. Here, inspired by the vivid color display and functionalization of natural pigments, we developed natural edible pigment-derived needle microstructure (NNMS) as signal tracers by simple crosslinking of alizarin and formaldehyde, allowing high color rendering ability, significant water dispersibility and antibody enrichment. Particularly, immune-network technology was introduced to achieve the simultaneous promotion of colorimetric signal and sensitivity and avoid visual errors in ICA. As a result, the prepared eco-friendly and sustainable NNMS-ICA showed satisfactory performance (LOD was 0.56 ng mL-1), specificity and probe stability (CV was 1.90 %). Furthermore, the NNMS-ICA was successfully applied in food samples (milk and honey) with total recoveries at 91.00-118.82 %.

Polysaccharides from exudate gums of plants and interactions with the intestinal microbiota: A review of vegetal biopolymers and prediction of their prebiotic potential

Polysaccharides in plant-exuded gums are complex biopolymers consisting of a wide range of structural variability (linkages, monosaccharide composition, substituents, conformation, chain length and branching). The structural features of polysaccharides confer the ability to be exploited in different industrial sectors and applications involving biological systems. Moreover, these characteristics are attributed to a direct relationship in the process of polysaccharide enzymatic degradation by the fermentative action in the gut microbiota, through intrinsic interactions connecting bacterial metabolism and the production of various metabolites that are associated with regulatory effects on the host homeostasis system. Molecular docking analysis between bacterial target proteins and arabinogalactan-type polysaccharide obtained from gum arabic allowed the identification of intermolecular interactions provided bacterial enzymatic mechanism for the degradation of several arabinogalactan monosaccharide chains, as a model for the study and prediction of potential fermentable polysaccharide. This review discusses the main structural characteristics of polysaccharides from exudate gums of plants and their interactions with the intestinal microbiota.

Nature-Derived Hollow Micron-Tubular Signal Tracers Conquering the Size Limitations for Multimodal Immunochromatographic Detection of Antibiotics

Developing signal tracers (STAs) with large size, multifunctionality, and high retention bioaffinity is believed to be a potential solution for achieving high-performance immunochromatographic assays (ICAs). However, the size limitations of STAs on strips are always a challenge because of the serious steric hindrance. Here, based on metal-quinone coordination and further metal etching, hollow micron-tubular STAs formed by natural alizarin and Fe3+ ions (named ALIFe) are produced to break through size limitations, provide more active sites, and achieve three-mode ICAs (ALIFe STAs-ICAs). Thanks to the special tubular morphology, ALIFe can successfully pass through the strip and provide an ideal signal intensity within 7 min at low mAb and probe dosages to achieve stable ICA analysis. Importantly, ALIFe shows excellent antibody enrichment and bioaffinity retention capability. With a proof-of-concept for streptomycin, the ALIFe STAs-ICAs showed the limit of detection (LOD) at 0.39 ng mL-1 for colorimetric mode, 0.32 ng mL-1 for catalytic mode, and 0.016 ng mL-1 for photothermal mode with total recoveries ranging from 80.46 to 121.59% in mike and honey samples. We anticipate that our study will help expand the ideas for the design of high-performance STAs with large size and broaden the practical application of ICA.

Fabrication of polyethyleneimine functionalized magnetite nanoparticles for recyclable recovery of fucoidan from aqueous solution

Fucoidan is a kind of natural water-soluble fucose-rich sulfated polysaccharide with promising applications in the food and pharmaceutical industry. However, the traditional methods for fucoidan recovery from aqueous solution are expensive, time-consuming, and environmentally unfriendly. In this work, polyethyleneimine functionalized magnetite nanoparticles (PEI-MNPs) with well-defined core-shell structures were prepared by a Layer-by-Layer (LbL) approach using sodium tripolyphosphate (STPP) as a cross-linker. The as-prepared PEI-MNPs showed improved adsorption capability towards fucoidan at pH 4-8 due to the high density of cationic groups on the surfaces and the absence of internal pores. It was found that the adsorption process of fucoidan onto PEI-MNPs can reach to equilibrium in 50 min at room temperature. The maximum qe derived from the Langmuir isotherm at room temperature was 169.1 mg per g at a pH of 7. A selective fucoidan capture over a model protein BSA can be realized by adjusting pH (6-8) and salt concentration (0.5-2.5 M). The PEI-MNPs loading with fucoidan can be isolated from the final products by a neodymium magnet and regenerated by 4 M NaCl solution as stripping reagent. Therefore, this novel kind of PEI-MNP could be a promising candidate for highly efficient and recyclable recovery of fucoidan from an aqueous solution.

Dual functional antifouling and bactericidal proteinaceous coating

Coatings with both anti-fouling and bactericidal functions are used in many fields. In this work, lysozyme (Lyso) and poly (2-Methylallyloxyethyl phosphorylcholine) (PMPC) conjugate (Lyso-PMPC) is successfully designed and synthesized for the first time. A new nanofilm (PTL-PMPC) is then obtained by phase transition of lysozyme via the reduction of disulfide bonds in Lyso-PMPC. Benefit from lysozyme amyloid-like aggregates as surface anchors, the nanofilm shows excellent stability, it remains unchanged after treatment under extreme conditions such as ultrasonic and 3 M tape peeling. Due to the presence of zwitterionic polymer (PMPC) brush, the PTL-PMPC film has excellent antifouling properties against cell, bacterium, fungi, proteins, biofluids, phosphatide, polyose, esters, and carbohydrates. Meanwhile, the PTL-PMPC film is colourless and transparent. Further, a new coating (PTL-PMPC/PHMB) is fabricated by hybridizing PTL-PMPC with poly (hexamethylene biguanide) (PHMB). This coating had excellent antibacterial properties, and the antibacterial rate against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) is more than 99.99%. In addition, the coating exhibit good hemocompatibility and low cytotoxicity.

Comprehensive analysis of microbiome, metabolome and transcriptome revealed the mechanisms of Moringa oleifera polysaccharide on preventing ulcerative colitis

This study aimed to investigate the protective effect of Moringa oleifera polysaccharide (MOP) on ulcerative colitis (UC) and explore its mechanism through the combined analysis of microbiome, metabolome and transcriptome. A UC model in mice was established using dextran sulphate sodium. After a 21-day experiment, results showed that MOP could inhibit the weight loss and disease activity index in UC mice. The intervention of MOP decreased the expression of inflammatory cytokines and promoted the secretion of tight junctions. MOP could promote the growth of probiotics such as Lachnospiraceae_NK4A136, Intestinimonas and Bifidobacterium in UC mice. The results of metabolomic and transcriptomic analysis indicated that MOP could regulated the metabolism of polyunsaturated fatty acid and PPAR, TLR and TNF signalling pathways might play important roles in the process. Altogether, MOP could be used as a functional food to prevent UC.

Recent developments in Moringa oleifera Lam. polysaccharides: A review of the relationship between extraction methods, structural characteristics and functional activities

Moringa oleifera Lam. (M. oleifera Lam) is a perennial tropical deciduous tree that belongs to the Moringaceae family. Polysaccharides are one of the major bioactive compounds in M. oleifera Lam and show immunomodulatory, anticancer, antioxidant, intestinal health protection and antidiabetic activities. At present, the structure and functional activities of M. oleifera Lam polysaccharides (MOPs) have been widespread, but the research data are relatively scattered. Moreover, the relationship between the structure and biological activities of MOPs has not been summarized. In this review, the current research on the extraction, purification, structural characteristics and biological activities of polysaccharides from different sources of M. oleifera Lam were summarized, and the structural characteristics of purified polysaccharides were focused on this review. Meanwhile, the biological activities of MOPs were introduced, and some molecular mechanisms were listed. In addition, the relationship between the structure and biological activities of MOPs was discussed. Furthermore, new perspectives and some future research of M. oleifera Lam polysaccharides were proposed in this review.

Hydrogel loading 2D montmorillonite exfoliated by anti-inflammatory Lycium barbarum L. polysaccharides for advanced wound dressing

Designing wound dressing materials with hemocompatibility, suitable mechanical properties, outstanding hemostatic effects and anti-inflammatory activity is of great practical significance for wound management. Herein, a hemostatic hydrogel loaded with Lycium barbarum L. polysaccharide (LBP)-functionalized ultrathin MMT nanosheets (L-MMT NSs) was fabricated for efficient hemostasis and wound healing. Loading the L-MMT NSs into polyvinyl alcohol (PVA), the obtained P-L-MMT hydrogel exhibited a 3D porous structure with good swelling properties, cytocompatibility, hemocompatibility, and anti-inflammatory activity. Importantly, in vivo investigations demonstrated that the P-L-MMT hydrogel exerts outstanding hemostasis activity in the hemorrhaging mouse liver model and reduces tissue damage caused by inflammation to shorten wound healing time. Altogether, the convenient exfoliation and functionalization of bulk MMT using LBPs make this inexpensive and rising nanostructure more attractive in the application of nanomedicine. Moreover, due to the synergy between hemostasis and anti-inflammation, this newly developed multifunctional P-L-MMT hydrogel represents a promising material in biomedical fields.

Gentiana straminea Maxim. polysaccharide decolored via high-throughput graphene-based column and its anti-inflammatory activity

Gentiana straminea Maxim. exhibits various biological activities. However, the purification and functions of polysaccharides in Gentiana straminea Maxim. have never been reported. Herein, by proposing a flexible 3D graphene-based decoloration column (3DD column), Gentiana straminea Maxim. polysaccharide (GMP) was high-throughput obtained and its anti-inflammatory activity was investigated. Benefiting from the large macroporous network of 3D NH₂-graphene oxide hydrogel with selective adsorption towards pigments, the 3DD column exhibits high decoloration ratio (96.41%). In addition, the 3DD column provides superior practical functionality as compared to the traditional approaches, which are time-consuming and need toxic solvents, and exhibiting widespread-application for the purification of polysaccharide from other common plant species. More importantly, the decolored GMP as a natural product has promising anti-inflammatory activity on RAW264.7 cells without negative impact on cell viability. Overall, this work reveals a new functional polysaccharides and provides a flexible approach for polysaccharide decoloration, exhibiting a promising prospect for natural polysaccharides in practical application of pharmaceutical.

Tannin foam immobilized with ferric ions for efficient removal of ciprofloxacin at low concentrations

The presence of ciprofloxacin (CIP) in natural water may cause potential threats to the environment. Adsorption is a convenient and efficient method to remove CIP from aqueous solution. Bayberry tannin (BT), a natural polyphenol, has been utilized in the synthesis of tannin foam (TF) due to its abundant polyphenolic hydroxyls to chelate with metal ions. The obtained TF was subsequently immobilized with Fe³⁺ via a facile chelative adsorption to fabricate functional tannin foam (TF-Fe), which was highly porous, with a porosity of 78.93%. The Fe species in the TF-Fe featured good dispersity, which were active for chelative adsorption of CIP. The adsorption of CIP on the TF-Fe was a pH-dependent process. At the optimized pH of 7.0, the TF-Fe provided the adsorption capacity of 91.8 mg g^-1. When applied in removal of CIP at the low concentration of 2.0 µg mL^-1, a high removal efficiency of 96.60% was still obtained, which was superior to commercial activated carbon (28.78%). The adsorption kinetics were well fitted by the pseudo-second-order rate model while the adsorption isotherms were well described by the Langmuir model. The TF-Fe was capable of recycling, which still maintained a high removal efficiency of 92.25% in the 5th cycle.

Acid-Induced Self-Catalyzing Platform Based on Dextran-Coated Copper Peroxide Nanoaggregates for Biofilm Treatment

Nanoantibacterial agents based on catalytic activity were limited due to the low levels of endogenous H₂O₂ in the microenvironment of bacterial biofilms. However, the additional H₂O₂ will trigger more side effects to healthy surroundings, which is still a great challenge. Herein, we report an acid-induced self-catalyzing platform based on dextran-coated copper peroxide nanoaggregates (DCPNAs) for antibiofilm and local infection therapy applications. The dextran-functionalized DCPNAs were mediated and conveniently purified via a dextran and ethanol precipitation method, which can also cluster nanodots into nanoaggregates and show good penetrability as well as biocompatibility. Bacterial biofilms were inhibited and destroyed by the reactive oxygen species generated from the Fenton reaction between the Cu²⁺ and H₂O₂ released from DCPNAs in an acidic environment, which did not require additional H₂O₂. As expected, the DCPNAs exhibit low cytotoxicity and excellent acid-induced antibacterial and antibiofilm ability. Moreover, the DCPNAs realized great therapeutic outcomes in the application for in vivo wound healing. The overall excellent properties associated with the DCPNAs highlight that they could be considered as a kind of ideal antimicrobial agents for microbial biofilm infection treatment.

An effective, green and mild deproteinization method for polysaccharides of Ruditapes philippinarum by attapulgite-based silk fibroin composite aerogel

A large amount of protein impurity severely restricts the application of polysaccharides of Ruditapes philippinarum (PRP) in food and medicine. Moreover, the traditional Sevag deproteinization method always involves organic reagents. The purpose of this paper was to develop an effective, green and mild deproteinization method from PRP by attapulgite-based silk fibroin composite aerogel (ASA). Firstly, ASA was synthesized and applied to remove protein from PRP. Secondly, the deproteinization parameters were optimized with selectivity coefficient as index as follows: dose of ASA 1% and pH 7.0. Under these conditions, deproteinization ratio (Dr%), polysaccharide recovery ratio (Rr%) and selectivity coefficient (Kc) reached 79.44 ± 1.87%, 95.81 ± 2.95% and 18.95 ± 1.55, respectively. Next, the feasibility of ASA method was evaluated. As a result, ASA method not only achieved higher deproteinization efficiency in less time compared with Sevag method, but also retained structure and antioxidant activity of polysaccharides. ASA was also proven with recycling ability and could be reused more than five times. Furthermore, it was found that protein adsorption on ASA was better fitted by pseudo second-order kinetic and Freundlich model. Taking together, the data implied that ASA method would be promising of deproteinization from PRP suitable for polysaccharides processing.

Rapid quality control of medicine and food dual purpose plant polysaccharides by matrix assisted laser desorption/ionization mass spectrometry

With their multiple biological activities and health benefit effects, polysaccharides from medicine and food dual purpose plants (MFDPPPs) have been extensively applied in many fields, including in medical treatments, stock farming, and cosmetics. However, to date, quality issues of MFDPPPs and technologies for the analysis of polysaccharides have posed challenges to chemists. Reported herein is a rapid and high-throughput quality control method for analyzing MFDPPPs, based on matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). For the analysis of illegally added and doped substances, ferroferric oxide nanoparticles were employed as the MALDI matrix to avoid small molecule interference. Qualitatively, high sensitivity was obtained for both illegal drugs and glucose. Quantitatively, the best linear response (R2 > 0.99) was attained in the concentration range from 0.005 to 1 mg mL-1 for glucose. For the analysis of polysaccharides, 2,5-dihydroxybenzoic acid/N-methylaniline was employed as the MALDI matrix to increase the detection sensitivity and mass range coverage. Furthermore, the established method was successfully applied to the analysis of supplements from Astragalus polysaccharides and Lentinan real samples, showing its potential in quality control for MFDPPPs.

Paeoniae radix alba polysaccharides obtained via optimized extraction treat experimental autoimmune hepatitis effectively

The extraction process of Paeoniae radix alba polysaccharides (PRAP) was optimized as the liquid-solid ratio of 10.65 mL/g, the extraction time of 2.10 h, and the 2 extraction repetitions through a response surface methodology. The chemical profiles of the obtained PRAP were characterized by measuring the contents of total carbohydrates, total phenolics, uronic acid and protein, and by analyzing the FT-IR spectrum and monosaccharide composition. To determine the therapeutic effects of PRAP on experimental autoimmune hepatitis (EAH), we established an EAH mice model. After treated with PRAP, liver and spleen injuries were reduced, and hepatocyte regeneration and liver function were improved. Further study of the mechanism by which PRAP treats EAH showed that PRAP significantly inhibited oxidative stress in the livers of EAH model mice. More importantly, PRAP inhibited immune inflammatory reactions in EAH model mice, including the hepatic infiltration of inflammatory CD4⁺ and CD8⁺ T cells, as well as overexpression of inflammatory cytokines IL-2, IL-6 and IL-10, via inhibition of the NF-κB signaling pathway.

The DNA controllable peroxidase mimetic activity of MoS2 nanosheets for constructing a robust colorimetric biosensor

The low activity of nanozymes, which work as an alternative to natural enzymes, limits their applications in the fabrication of biosensors, drawing increasing attention aimed at improving their catalytic capacity. In this work, the peroxidase-like activity of MoS2 nanosheets (NSs) was dramatically enhanced through DNA modification, and was 4.3-times higher than that of bare MoS2 NSs. Such an enhancement of catalytic activity was mainly ascribed to the increased affinity of the DNA/MoS2 NSs toward the substrate, TMB, further accelerating electron transfer from TMB to H2O2. On the basis of DNA-tuned MoS2 NS nanozyme activity, a colorimetric sensing platform was developed for the facile detection of carcinoembryonic antigen (CEA) in a sensitive manner. Interestingly, a convenient, affordable, and instrument-free portable test kit was fabricated to visually monitor CEA via rooting the aptamer/MoS2 NS system into an agarose hydrogel. Importantly, our work illuminates the feasibility of using DNA to enhance the catalysis of nanozymes and their application potential in the label-free, portable, and visual detection of aptamer-targeted biomolecules.

A sustainable and nondestructive method to high-throughput decolor Lycium barbarum L. polysaccharides by graphene-based nano-decoloration

Lycium barbarum L. polysaccharides (LBPs) with outstanding biological activities are of increasing interest. Traditional purification approaches are time-consuming and often involve toxic solvents that destroy the functionality and structure of polysaccharides. Herein, we report a sustainable and nondestructive strategy for purifying LBPs using graphene-based nano-decoloration. The amination of graphene oxide (GO) enables the resulted aminated reduced GO (NH₂-rGO) with abundant sp²-hybridized carbon domains, displaying high adsorption capacity toward pigments in crude polysaccharides. As such, within 5 min, NH₂-rGO can highly effectively and fast to decolor LBPs, with a high decoloration ratio of 98.72% and a high polysaccharides retention ratio of 95.62%. Importantly, compared with traditional decoloration methods, NH₂-rGO is nondestructive toward LBPs and has good reusability. Moreover, it exhibited widespread-use decoloration performance to decolor several common plant species. Overall, our proposed nano-decoloration approach is a general-purpose, sustainable, and nondestructive method to purify LBPs.

Box-Behnken design-based optimization for deproteinization of crude polysaccharides in Lycium barbarum berry residue using the Sevag method

Deproteinization of crude polysaccharides in the residue from Lycium barbarum berries (LBBs) was conducted using the Sevag method. A Box-Behnken design based on single-factor experiments was employed to optimize the deproteinization technology. The results showed that the deproteinization conditions had significant effects on the extraction yield of polysaccharides and the residual protein content in Lycium barbarum polysaccharides (LBP). The experimental data were fitted to a second-order polynomial equation, using multiple regression analysis with a high coefficient of determination (R²) value. The optimal conditions were as follows: a ratio of raw material to water extract concentrate from the residual LBBs of 0.15 g/mL; a ratio of chloroform to n-butyl alcohol of 2.17 mL/mL; and a ratio of water extract concentrate from residual LBBs to Sevag reagent of 0.50 mL/mL; with a maximum polysaccharide yield of 0.49% and minimum residual protein content of 0.087%. The results were confirmed through validation experiments. GPC analysis indicated that deproteinized LBP molecules became much more homogeneous. X-ray diffraction indicated that the hydrogen bonding of deproteinized LBP was weakened. This optimization of LBP should be a useful method for purification of crude LBP.