International Journal of Biological Macromolecules最新文献

To improve chitosan hemostasis, carboxylated sisal fiber and kaolin were introduced to obtain carboxylated sisal fiber/chitosan/kaolin (SF/CS/K) composite sponges (the weight ratio of 3: 3:4, 4:4:2, 5:5:0) by freeze-drying method. The results showed that the ionic cross-linking of the carboxylated sisal fiber with chitosan and kaolin-loading endowed the composite sponges with not only oriented groove porous structure, high mechanical strength, porosity, water absorption and compress recovery, but also suitable biodegradation, good cytocompatibility, hemocompatibility, protein adsorption, antibacterial activity. Especially, compared with commercial gelatin hemostatic sponges, the composite sponge of SF/CS/K displayed the better coagulation ability and hemostatic effect, and animal experiments further demonstrated that the bleeding amount and hemostatic time of SF/CS/K were greatly reduced in rat hemostatic models of tail amputation, femoral vein trauma and liver injury, owing to the synergistic hemostatic effect of chitosan, kaolin and sisal fiber, as well as the groove porous structure, which endowed them with strong adhesion for red blood cells. Conclusively, SF/CS/K₂ composite sponge had the best hemostatic effect because of the most appropriate component ratio, which is a novel promising natural hemostatic sponge for effective and rapid hemostasis in deep massive bleeding sites.

Human serum albumin (HSA), a crucial plasma protein, plays a significant role in drug interactions within the bloodstream, bearing considerable clinical relevance. Bortezomib (BTZ) is a potent anti-cancer drug for multiple myeloma (MM) and mantle cell lymphoma (MC). The mechanism of BTZ transfer in the blood remains undetermined. This study aims to investigate the binding of BTZ to HSA using the techniques of differential scanning calorimetry (DSC), circular dichroism (CD), fluorescence spectroscopy, and computational methods such as molecular docking and molecular dynamics simulations. This study presents the thermal dissection of domain I (D_I) of HSA by subjecting it to a temperature elevation of 79.2 °C (2 °C above T_m of D_I) using DSC, which provides new information on the thermal behavior of HSA domains. Furthermore, the deconvolution analysis of the HSA thermogram in the absence and presence of BTZ revealed that the drug binding site is located in D_I and impacts D_II. The interaction between BTZ and HSA with a binding affinity (K_b) of 7.744±0.2 ×10⁵ M^-1 influences protein dynamics and reduces HSA's thermal stability by almost 1 °C. This study is crucial for predicting the pharmacokinetics and pharmacodynamics of BTZ, aiding in developing safer and more effective treatments for MM and MC.

An efficient strategy for passive delivery of doxorubicin (DOX) to the breast (MDA-MB-231) and lung (A-549) cancer cells is presented and compared with MCF-10A normal breast cells. Two versions of a peptide structure (linear and cyclic) have been designed and assessed. The molecular dynamic simulations in Material Studio2017 exhibited a higher adsorption capacity for L² (cyclic version) compared with the adsorption capacity of L¹ (linear version) on the PG surface by electrostatic interactions between guanidine of arginine and -OH of PG. The prepared final product based on iron oxide nanoparticles and MIL-101(Fe) (formulated as DOX@Fe₃O₄/MIL-101-(C,L)C[RW]₃) is characterized and the drug content has been estimated. The release profiles revealed an ultra-fast stimulus-sensitive model in acidic media, which corroborates a pH-triggered release. The in vitro assessments disclosed that aggregation of nanocargo around the cancer cells and resulted toxicity are more than the neat DOX in the same dosage as DOX@Fe₃O₄/MIL-101-CC[RW]₃. The obtained distinguished features lie in ability to utilize a biocompatible nanocargo structure to release an appropriate dose of DOX in a controlled manner in the cancer cell environment. Moreover, the functionalization of MIL-101 using cyclic and linear peptides and their comparison is one of the important features of this project.

This study investigated the immunoregulatory activity of exopolysaccharides (EPS) produced by Lacticaseibacillus rhamnosus ZFM216 in immunosuppressed mice induced by cyclophosphamide (CTX). The results showed that EPS treatment effectively improved the body weight, immune organ index and splenic lymphocyte proliferation. EPS also mitigated the damage of immune organs, restored intestinal morphology, and regulated the levels of serum hemolysin and cytokines (e.g. TNF-α, INF-γ and IL-10). EPS promoted the release of NO, TNF-α, IL-1β, and IL-6 in RAW 264.7 cells, however, such effect was inhibited in the presence of inhibitors of TLR4 and MAPKs signaling pathways-related proteins, confirming that EPS achieved the immunomodulation by activating these two signaling pathways. Additionally, EPS, as a prebiotic, effectively improved the diversity of microbial communities, regulated the relative abundance of dominant microbial communities, restored CTX-induced gut microbiota dysbiosis, and promoted the production of short chain fatty acids (SCFAs) in the gut of mice. Thus, immunoregulatory effect of EPS could be attributed to its good ability to modulate the gut microbiota. EPS produced by L. rhamnosus ZFM216 has promising application as an ingredient of functional foods due to its potent probiotic effect.

Current approaches to managing diabetic oral ulcers are often inadequate in medical settings due to risks of bacterial contamination, oxidative harm, and hindered blood vessel growth during recovery. Here, we have developed a hydrogel (OQC2) consisting of oxidized dextran, quaternized chitosan, and melanin nanoparticles sourced from cuttlefish ink to effectively treat wounds from diabetic oral ulcers. Initially, by administering a straightforward local injection, a protection barrier forms over the mucosal injury, promptly stopping bleeding and neutralizing inflammatory agents. The OQC2 excels in innate antibacterial activity and can effectively remove reactive oxygen species, aiding in bacterial eradication and managing oxidative states, thereby hastening the wound's transition from inflammation to tissue growth. Moreover, the OQC2 features a three-dimensional structure made up of elements sourced from natural materials, potentially making it an excellent resource for providing structural and nutritional support to cells. This support encourages cell attachment, movement, and growth, as well as further blood vessel formation in the process of mucosal remodeling. Both in vitro and in vivo trials indicate that the OQC2 significantly speeds up the repair of mucosal wounds, presenting a viable option for treating diabetic oral ulcers.

Dandelion polysaccharides contribute to a variety of biological activities. This study evaluated the effect of different extraction temperatures (4 °C and 80 °C) on the structural characteristics and antioxidant activity of dandelion leaf polysaccharides (DLP). The findings demonstrated that the extraction efficiency improved at the higher temperature, while molecular weight exist a trend of degradation with increasing extraction temperature. Ion chromatography (IC) analysis indicated that the polysaccharides DLP4 and DLP80 were structurally complex heteropolysaccharides mainly composed of galactose, arabinose, glucose and mannose, with galactose and arabinose dominating. FT-IR and methylation analysis revealed that DLP4 and DLP80 had similar chemical structures and branches. DLP4 contained a higher amount of 6-Galactose. Microstructure analysis showed that heat treatment caused conformational changes in DLP4 and DLP80. Both had excellent free radical scavenging ability including DPPH·, ABTS^·+, OH· and reducing power. The Reactive Oxygen Species assay indicated that the protective effect of DLP4 against H₂O₂-induced oxidative damage in vitro was stronger than that of DLP80. Superoxide dismutase (SOD) and malondialdehyde (MDA) measurements also confirmed that the antioxidant effect of DLP4 was more prominent. Overall, low temperature extracted DLP can be used as an antioxidant in the areas of food, medicine and biomaterials.

The effects of dynamic high-pressure microfluidization (DHPM) on the structural, emulsifying properties, in vitro digestion and antioxidant activity of whey protein isolate (WPI) were investigated. The results demonstrated that WPI treated with 100 MPa DHPM exhibited superior emulsification performance. This can be attributed to the conformational changes induced by 100 MPa DHPM in WPI, leading to a transformation from disordered structures to ordered structures and an increased exposure of fluorophore such as tryptophan residues and hydrophobic groups, reduced aggregation state and particle size of WPI. These factors facilitated the migration of WPI towards the oil-water interface, resulting in the formation of a robust and compact adsorption layer which reduces interfacial tension and enhances emulsification stability. Furthermore, it was observed that while DHPM did not significantly affect the digestibility of WPI, it did enhance exposure to antioxidant amino acids in the digestive products thereby enhanced their antioxidant properties. In summary, structural modification induced by DHPM treatment enhanced both emulsification and antioxidant properties of WPI. These findings highlight the significant potential of DHPM treatment for enhancing the quality of meat products with an emulsion-type structure.

Bauhinia forficata is a medicinal plant known as cow's paw, used for many purposes. Although there are studies that aimed to elucidate compounds from the plant leaves, there is no information about its polysaccharides. This study intended to obtain a polysaccharide rich fraction from its leaves, structurally characterize the water-soluble polysaccharides, as well as evaluate their effect on THP-1 cells. From the aqueous extract, followed by purification processes, a polysaccharide fraction (TCAS) was obtained, constituted mainly of arabinose and galactose. Bidimensional NMR (¹³C/¹H, HSQC) and methylation analyses identified type I and type II arabinogalactans, arabinan and starch as the major polysaccharides of the fraction. TCA-S was then submitted to starch removal process and renamed as TCASα. TCASα (2 to 500 μg/mL) was not cytotoxic to THP-1-cells and exhibited an immunostimulatory effect by increasing the secretion of nitric oxide and both pro-inflammatory cytokine IL-1β and anti-inflammatory cytokine IL-10. Immunomodulatory effect on IL-6 secretion was observed when macrophages were treated with TCA-Sα at 500 μg/mL. Additionally, the ratio between the concentrations of pro and anti-inflammatory cytokines produced by LPS-treated cells was higher than that produced by LPS plus TCA-Sα treated ones, suggesting that the polysaccharide fraction could modulate the LPS inflammation effects.

Photocatalytic oxidation emerges as an eco-friendly approach for chemically degrading water-borne organic pollutants. Establishing a more sustainable process for synthesizing photocatalyst membranes with higher efficiency and reusability is crucial for advancing safe water remediation solutions. In this study, we present a novel photocatalytic membrane incorporating bacterial cellulose (BC), a naturally occurring biopolymer with an intricate fibrous network, and graphitic carbon nitride (g-C₃N₄), a visible light-responsive non-metal photocatalyst. The composite membrane is augmented with a coating of polydopamine (PDA), an amorphous polymeric layer derived from dopamine to enhance light absorption and reduce photoexcited charge recombination. The BC/g-C₃N₄/PDA membrane demonstrates a substantial improvement in methylene blue removal efficiency, up to 95.39 % within 150 min of irradiation. Moreover, the PDA-modified membrane exhibits noteworthy recyclability, retaining significant photodegradation ability for up to three cycles. This method offers an accessible and scalable approach to fabricating a highly effective photocatalyst composite membrane suitable for industrial applications.