International Journal of Biological Macromolecules最新文献

Plant-derived bioactive components, such as polysaccharides, provide promising alleviating effects on constipation with minimal side-effects compared to pharmacological interventions. This study aimed to explore the therapeutic potential of tea flower polysaccharides (TFP) on constipation and the involved mechanisms. In a loperamide-induced constipation mouse model, TFP administration significantly increased fecal water content from 54.23-57.30 % to 63.70-79.36 %, enhanced intestinal transit rate from 30.80 % to 38.81 %, and reduced gastrointestinal (GI) transit time from 234.4 min to 186.2 min. TFP restored levels of both excitatory and inhibitory hormones related to GI motility. Transcriptomic analysis of colonic epithelial cells revealed that TFP restored expression of 544 genes involved in various pathways, including the NF-κB and JAK-STAT signaling pathways, which are associated with the improvement of constipation. Gut microbiota analysis demonstrated that TFP mitigated dysbiosis by normalizing the Firmicutes/Bacteroidota ratio, inhibiting pathogenic genera (e.g., Helicobacter), and promoting beneficial genera (e.g., Muribaculaceae, Bacteroides, Parabacteroides). The mediating role of gut microbiota in the onset of constipation and its alleviation was confirmed through fecal microbiota transplantation (FMT). Furthermore, TFP and its combination with anti-constipation drugs alleviated constipation-induced hepatorenal damage. This study highlights TFP's potential in treating constipation and underscores the essential role of gut microbiota in its therapeutic effects.

Chitin (CT), one of the most abundant biopolymers, is insoluble in both dilute aqueous solutions and common organic solvents. In traditional hemostatic applications, chitin must be either converted into acid-soluble chitosan by removing acetyl groups or dissolved in an alkaline aqueous solution at -20 °C. However, acetyl groups are more advantageous than amino groups in promoting hemostasis, biocompatibility, biodegradability, and wound healing. A significant challenge remains in retaining acetyl groups while directly preparing a hemostatic agent from chitin without requiring its dissociation. In this study, we have successfully applied oxidized chitin (OCT) as a hemostatic material, which is directly derived from chitin through a TEMPO-mediated selective oxidation of C6 primary hydroxyl groups to carboxyl groups. Due to its significantly higher hydrophilicity compared to chitin, OCT rapidly forms a gel upon contact with blood, efficiently sealing broken blood vessels and facilitating wound healing. Among OCTs with varying carboxylate contents and the commercial chitosan hemostat Celox™, OCT-24 demonstrated not only the best hemostatic performance in some injury models but also excellent biocompatibility and biodegradability, effectively preventing tissue adhesion and promoting wound healing. The selective oxidation offers a straightforward method for developing a highly effective hemostatic material from chitin to address uncontrolled massive bleeding.

The polysaccharide chitosan possesses broad-spectrum antimicrobial properties and has proven effective in controlling various postharvest diseases in fruits. Nevertheless, the fundamental mechanisms underlying its action remain unclear. In this study, the antifungal effects of chitosan with different molecular weights against Fusarium avenaceum, a pathogen causing root rot in Angelica sinensis, were evaluated. Additionally, the potential mechanisms of these effects were explored at the microstructural and transcriptomic levels. Notably, low-molecular-weight chitosan (20 kDa) exhibited superior antifungal activity when compared to high-molecular-weight chitosan (500 kDa and 1000 kDa). The half-maximal inhibitory concentration (IC₅₀) of 20, 500, and 1000 kDa chitosan were 0.2103, 0.2183, and 0.2707 g/L, respectively. Morphological and physiological experiments demonstrated that chitosan can inhibit the growth of F. avenaceum by decreasing spore germination, destroying mycelial morphology and microstructure, and promoting the release of intracellular electrolytes. RNA sequencing revealed considerable changes in the transcriptomic profile of F. avenaceum after chitosan treatment, with 2030 genes being differentially expressed. Subsequent KEGG pathway analysis demonstrated that genes associated with translation, human diseases, and transcription were upregulated in F. avenaceum after chitosan treatment. In contrast, genes associated with carbohydrate and amino acid metabolism, cellular processes, exogenous substance degradation and metabolism, and the metabolism of cofactors and vitamins were downregulated. Collectively, these results indicated that chitosan may influence the growth of F. avenaceum by disrupting protein biosynthesis and key metabolic pathways. These findings highlight the substantial potential of chitosan as an alternative agent for the management of fungal diseases in plants used in Chinese herbal medicine.

This study investigated the binding mechanism of taxifolin (TA), daidzein (DA), and S-equol (SQ) flavonoids with fish sperm double helix DNA (dsDNA) under the simulated physiological pH condition using UV-Vis and photoluminescence spectroscopy, as well as viscometric methods. Binding constants (K_b) for the flavonoids to dsDNA were determined as 1.8 × 10⁴ M^-1 for SQ, 1.6 × 10⁴ M^-1 for DA and 1.7 × 10⁴ M^-1 for TA, indicating moderate affinity. The groove binding mode was confirmed by competitive binding studies with ethidium bromide or rhodamine B, UV-Vis spectrophotometry and viscosity evaluation. Additionally, the compounds showed high cholinesterase (ChE) inhibitory activity, with TA being the most potent, particularly against BChE (IC₅₀ = 2.93 μM) and AChE (IC₅₀ = 6.42 μM). Antioxidant activities were also evaluated using DPPH and ABTS assays, with TA showing the lowest IC₅₀ values. Additionally, molecular docking studies were performed to assess the interactions and binding affinities of all compounds with AChE and BChE enzymes. As a result, the studied compounds were found to prefer minor groove binding. This research analyzed the contribution of the structure-activities of natural flavones in terms of their biological properties, which is important for their future application against diseases.

TiO₂/ZnO/Chitosan coated cotton fabric as a self-cleaning, which has been synthesized by various concentrations of TiO₂: 0.5 g, 1 g, and 2 g through the sol-gel method at pH 9. The self-cleaning test was conducted on TiO₂/ZnO/Chitosan-coated cotton fabric samples by irradiating for 15 h using UVA-UVB lamps with clothing stain dye. TiO₂/ZnO/Chitosan composite's structural properties were analyzed from X-ray diffraction (XRD) spectra, chemical bonding by Fourier Transform Infrared (FTIR), and bandgap by quantitative analysis from UV-visible spectroscopy. The XRD diffraction peaks showed a slight shift to the right, except for the sample with the highest TiO₂ concentration, which showed a more significant shift. FTIR spectra showed the presence of Ti-O-Ti bonds at wavenumbers 500 cm^-1 - 700 cm^-1, which identified the presence of TiO₂, and at wavenumber 3485 cm^-1, which was used for stretching-OH and -NH₂ of chitosan. The band gaps were 5.64 eV, 5.63 eV, and 5.58 eV for TiO₂: 0.5 g, 1 g, and 2 g, respectively. The self-cleaning test showed that the best results were in the TiO2 sample with a concentration of 2 g at pH 9, where the dye successfully disappeared after exposure to UVA-UVB lamps for 15 h of irradiation.

The IPNs hydrogel films based on chitosan (CS), 2-hydroxyethyl methacrylate (HEMA), and 2-hydroxypropyl methacrylate (HPMA) were prepared, and their potential for drug delivery and wound dressing was evaluated. The characterizations of the IPNs were examined through swelling tests, FTIR, DSC, SEM, mechanical properties, and BET analyses. The percent swelling of the CS/p(HEMA)1 and CS/p(HPMA)1 were obtained as 240 % and 110 %, respectively. The release behavior of prepared hydrogel formulations was investigated in two different pH values for DOX and CUR at pH 5.5 and 7.4, respectively, at varying drug concentrations. In vitro, drug release profiles revealed a time-dependent release pattern, with a maximum release observed at 48 h for all formulations. Among the IPNs, CS/p(HEMA)1 formulation containing CS/HEMA in a 1:1 ratio showed the highest drug release rates of 76.0 % for doxorubicin and 75.5 % for curcumin. MTT assays revealed that the IPNs formulations exhibit enhanced interaction with drugs, leading to an improved drug release rate. A marked decrease in cell viability was observed as the concentration of both drugs increased for testing the ATCC-CRL 2451 leukemia cell line in the prepared formulations. These findings highlight the potential of these composite hydrogels as efficient drug delivery systems for wound dressing applications.

Glioblastoma (GBM) is a notoriously aggressive primary brain tumor characterized by elevated recurrence rates and poor overall survival despite multimodal treatment. Local treatment strategies for GBM are safer and more effective alternatives to systemic chemotherapy, directly tackling residual cancer cells in the resection cavity by circumventing the blood-brain barrier. Molecularly imprinted polymers (MIPs) are promising drug delivery systems due to their high-affinity binding cavities that enable tailored release kinetics. This study reports the development of a semi-synthetic polysaccharide MIP-based hydrogel intended for the post-surgical management of GBM. The biodegradable implant, made of calcium-crosslinked alginate-poly(N-isopropylacrylamide) graft copolymer, was designed for the sustained release of ruxolitinib (RUX) in the resection cavity, targeting the Janus kinase/Signal Transducer and Activator of Transcription-3 signaling pathway. The molecularly imprinted hydrogel demonstrated thermo-thickening and shear-thinning behavior, high entrapment efficiency of RUX (84.59 ± 0.73 %), and sustained release over 14 days, underscoring the advantages that molecular imprinting of the alginate matrix provides compared to conventional MIPs. The dose-dependent inhibitory effects of the imprinted hydrogel against U251 and A172 GBM cells were demonstrated by increased apoptosis, reduced confluence, colony formation, and delayed wound healing, whereas the non-imprinted hydrogel was biocompatible. The MIP hydrogel could be a safe and effective GBM treatment.

Lactoferrin protein (LF) is a natural protein with certain emulsifying ability, but is sensitive to be affected by environmental factors and has poor oxidative stability to be used as emulsifier. In this study, the emulsifying ability of LF was significantly improved after conjugation with Rosa roxburghii Tratt fruit polysaccharides (RTFP), and the emulsion stability mechanism of LF-RTFP conjugates (L-R) were elucidated through the utilization of CLSM (confocal laser scanning microscopy), interfacial tension, apparent viscosity, and protein adsorption rate. The emulsion stabilized by L-R showed the smaller particle size (17.17 ± 0.13 μm), which reduced by 51 % compared with that of LF. After conjugation with RTFP, the hydrophobic amino acids that are originally inside the structure of LF would be exposed on the protein surface. In addition, the protein adsorption rate of L-R stabilized emulsion interface was 62.70 ± 0.71 %, 2.4 times higher than that of LF. The optical microscopy and CLSM experiments indicated that the glycosylation with RTFP increased the bridged flocculation and further formed gel network structure in the emulsion stabilized by LF. These findings suggested that the novel emulsifier prepared by the Maillard reaction between LF and RTFP showed potential to stable emulsion.

The aim of the present study was to obtain new metal complexes of citrus pectin with cobalt ions based on potassium polygalacturonate and to prepare a new pharmacological composition (PC) PGKCo: PGNaCo (1:1) with antitumor activity based on potassium cobalt polygalacturonate (PGKCo) and sodium cobalt polygalacturonate (PGNaCo). The study of the effect of PGKCo, PGNaCo and PC on the cell viability of tumor cell lines of different genesis in vitro showed that the obtained compounds are soluble in water and exhibit selective cytotoxic activity against the tumor cell lines of human lung carcinoma A549, breast adenocarcinoma MCF-7 and cervical carcinoma M-HeLa, with no significant toxic effect on normal human cells. The possible mechanism of action of the investigated PC on M-HeLa cancer cells was investigated. The mechanism of action of PC was found to be associated with cell cycle arrest in the G0/G1 phase and the induction of apoptosis through the mitochondrial pathway. The results obtained indicate the potential for the non-toxic compounds (PGKCo, PGNaCo and PC) to be developed as drugs for the complex treatment of oncologic diseases.