International Journal of Biological Macromolecules最新文献

Diabetic foot ulcer (DFU) is a complication associated with diabetes characterised by high morbidity, disability, and mortality, involving chronic inflammation and infiltration of multiple immune cells. We aimed to identify the critical genes in nonhealing DFUs using single-cell RNA sequencing, transcriptomic analysis and machine learning. The GSE165816, GSE134431, and GSE143735 datasets were downloaded from the GEO database. We processed and screened the datasets, and identified the cell subsets. Each cell subtype was annotated, and the predominant cell types contributing to the disease were analysed. Key genes were identified using the LASSO regression algorithm, followed by verification of model accuracy and stability. We investigated the molecular mechanisms and changes in signalling pathways associated with this disease using immunoinfiltration analysis, GSEA, and GSVA. Through scRNA-seq analysis, we identified 12 distinct cell clusters and determined that the basalKera cell type was important in disease development. A high accuracy and stability prediction model was constructed incorporating five key genes (TXN, PHLDA2, RPLP1, MT1G, and SDC4). Among these five genes, SDC4 has the strongest correlation and plays an important role in the development of DFU. Our study identified SDC4 significantly associated with nonhealing DFU development, potentially serving as new prevention and treatment strategies for DFU.

Recently, research on the plant-based oleogels, has gained significant attention as a promising approach for oil formulation. In this research, emulsion-templated technique utilizing millet prolamin (MP) as oleogelator was employed for crafting edible oleogels from various vegetable oils of varying degree of unsaturation. The focus of the study was to examine the formation process, structural characteristics, rheological properties, and lipid digestion of these oleogels. The results indicated that MP-based oleogels exhibited uniform morphology and low oil loss. The construction of the oleogel network could be attributed to hydrogen bonding between oleogelator molecules, hydrophobic interactions among the oleogelator molecules and between the oleogelator and oil, as well as van der Waals forces between the oil molecules themselves. Increasing MP concentration formed a denser oleogel network, and exhibited greater elastic moduli (G') and viscous moduli (G''). Additionally, 8 % MP oleogel prepared from flaxseed oil with high linolenic acid showed low oil loss, high hardness and efficient release of free fatty acids. These results indicated the potential of MP as an oleogelator in creating oleogels, and it is promising for fabricating trans-free and low-saturated oleogel-based products.

The catalytic activity and stability of proteases are essential for their application in the detergent industry. To enhance the catalytic properties of BAPB92, homologous sequence comparison combined with rational design was employed. Six mutants were generated: BAPB92 (A188P), BAPB92 (V262I), BAPB92 (Q239R), BAPB92 (A188P/V262I), BAPB92 (Q239R/V262I), and BAPB92 (Q239R/A188P). Remarkably, the mutant BAPB92 (A188P/V262I) exhibited the most significant improvement, exhibiting a 4.30-fold increase in k_cat/K_m compared to the wild type, and a 0.75-fold enhancement in thermal stability at 60 °C. The enzymatic activity of BAPB92 (A188P/V262I) reached 6511.81 U/mg, which is 2.95 times higher than that of the wild type BAPB92. Furthermore, the optimal reaction temperature of this mutant increased from 50 °C to 60 °C. The BAPB92 (A188P/V262I) mutant also showed a marked improvement in detergent stability. In sodium tripolyphosphate liquid detergent, its washing efficacy was 17.84 % higher than that of the wild type, and in methyl glycine diacetate liquid detergent, the improvement was 18.51 %. These findings suggest that BAPB92 (A188P/V262I) holds significant potential as a detergent protease in the washing industry. Structural analysis and molecular dynamics simulations further confirmed the enhanced stability of this mutant compared to the wild type. This study provides valuable theoretical insights for the application of the serine protease BAPB92 in detergent formulations.

Oral administration of homogalacturonan (HG) has shown significant potential in anti-colitis activity, yet the therapeutic efficacy of naturally sourced HG still requires enhancement. Herein, HG from the fruits of Ficus pumila L. was modified by chemical methods and the intervention effect of modified HG with different degrees of methyl-esterification (DM) and acetylation (DA) on dextran sulfate sodium-induced colitis in mice was explored. Our results indicated that low-DM HG (DM3 and DM25) primarily mitigated colitis by reducing inflammation (TNF-α, IL-1β, IL-17, and IL-6), while high-DM HG (DM54 and DM94) primarily repaired the intestinal barrier. These effects may be attributed to the differential regulation of gut microbiota by HG with varying DM, such as Lachnospiraceae_NK4A136_group, Lactobacillus, Mucispirillum, Escherichia-Shigella, Bifidobacterium, and Bacteroides. Increased DA reduced the solubility of HG, showing limited anti-inflammatory response but unique advantages in intestinal barrier repair and microbiome regulation (Bifidobacterium, Candidatus_Saccharimonas, Lachnospiraceae_NK4A136_group, Mucispirillum, and Escherichia-Shigella). Furthermore, various structural parameters and substitution degrees showed no significant impact on HG's regulation of oxidative stress reactions. This study emphasized the importance of substituent effect in determining HG's functional role, providing a robust foundation for the design and development of functional polysaccharides for the prevention of intestinal inflammation and other related conditions.

Widely used polysaccharide-based films in ophthalmic drug delivery have major limitations of inadequate mechanical strength, poor electrical conductivity, and insufficient ocular drug permeability. Moxifloxacin (MFX) biocomposite film of adequate mechanoelectrical properties was developed for sustained ophthalmic drug delivery. Nanocellulose (NC) incorporated (2.5, 5.0, 7.5, and 10.0 %) PVA-tamarind gum-based moxifloxacin composite was prepared using solvent casting method. The addition of NC improved the mechanical properties of the film, demonstrating its ability to strengthen the structure. Stress relaxation (SR) of the film has been augmented (64.67±7.55 to 73.15±0.34 %) due to increased content of NC (0 to 10 %) respectively. Film containing 5 % NC showed the critical edge of tensile strength (11.9±0.39 MPa), and also the threshold limit of electrical conductivity (4.5*10⁷ Ω). The same film exhibited continued drug release as well as erosion-controlled sustained ocular permeation (pH 7.4) and revealed the highest antibacterial activity (ZOI of disc diffusion, cm) with Pseudomonas aeruginosa (4.63±0.15) and Staphylococcus aureus (4.30±0.26) of MFX (≈224 μg). Notably, incorporating NC produced non-irritating and safe for corneal delivery as confirmed by the Draize model test. Our findings suggested that the NC-containing PVA-tamarind gum-based composite film holds a promising approach for sustained ophthalmic delivery of MFX.

A microwave-assisted method was used to extract the polysaccharide from Bulbophyllumkwangtumgense Schltr, and the optimum extraction conditions were determined by orthogonal experiments. The purified polysaccharide component BKP-1 had an obvious polysaccharide characteristic structure on the infrared spectrum and was mainly composed of xylose and glucuronic acid at a ratio of 0.568:0.432. Its molecular weight distribution (polydispersity index was 0.58) was uniform with 1.92× 10⁶ Da. The main structural skeleton of BKP-1 was →4)-β-D-Xylp-(1 → [4)-β-D-Xylp-(1]₄ → 4)-α-D-GlcAp-(1 → [4)-α-D-GlcAp-(1]₂→. BKP-1 could clear certain free radicals, among which the hydroxyl free radical scavenging ability was the best, with a clearance rate of 61.46 %. Furthermore, BKP-1 significantly modulated the secretion of both pro-inflammatory and anti-inflammatory cytokines at a concentration of 125 μg/mL. Notably, the mechanism BKP-1 exhibiting inhibitory effects were related to regulating of the NF-κB signaling pathway.

Aronia Melanocarpa (Michx.) Elliott fruit has been extensively used in the food and medicinal fields. This study aimed to analyze the physicochemical properties of a polysaccharide fraction (AMP2) isolated from this fruit for the first time and investigated its immune regulatory mechanism. The physicochemical properties of AMP2 were determined using high-performance gel permeation chromatography, PMP derivatization-high performance liquid chromatography, Ultraviolet spectroscopy, and infrared spectroscopy. The metagenomic technology was applied to investigate the regulatory effects and mechanisms of AMP2 on the gut microbiota of immunosuppressed mice. The results showed that molecular weight of AMP2 was 83,444 Da, which was mainly composed of D-arabinose, D-xylose, D-mannose, D-rhamnose and d-glucose, and both β-type and α-type glycosidic bonds contained in its structure. AMP2 changed the composition of gut microbiota by increasing the number of beneficial and probiotic bacteria, thereby regulated the intestinal mucosal immune system of host. AMP2 improved intestinal immune system response and antimicrobial capacity through positive regulation of the NOD-like receptor signaling pathway and neutrophil extracellular trap formation. The results demonstrate the potential of AMP2 in immune regulation, providing a new perspective for its subsequent development and contributing to the development and application of related health foods.

Heavy metal (HM) contamination poses significant threat to agricultural productivity. This study identified and characterized Os09g29690 (OsELP), a rice expansin-like protein. We demonstrated OsELP localizes to the cell wall and is upregulated under various abiotic stresses. Sequence analysis revealed a potential metal-binding CXXXC motif in its conserved domain. Heterologous expression of OsELP in yeast mutants (Δacr3 and Δycf1) enhanced metal tolerance under arsenate [As(V)], arsenite [As(III)], and cadmium [Cd] stress. Yeast cells expressing OsELP accumulated higher amounts of As and Cd, suggesting a potential metal-binding mechanism. This was confirmed through site-directed mutagenesis on the conserved cysteine and serine residues within OsELP. Mutants lacking cysteine residues (mutCS) reduced tolerance to As(III) and Cd but enhanced tolerance to As(V), indicating a role of cysteine in As(III) and Cd binding. Conversely, mutants lacking serine residues (mutSA) reduced tolerance to As(V), suggesting serine's involvement in As(V) binding. These findings reveal the roles of cysteine and serine residues in mediating HM tolerance and binding, confirming OsELP as a key player in HM detoxification through cell wall localization and chelation. This study provides novel insights into the molecular mechanisms of HM tolerance in plants, with potential applications in developing crops with enhanced resistance to HM toxicity.

We have developed an innovative peripheral nerve tissue repair approach by designing biomimetic microparticles loaded with cannabidiol (CBD) using horseradish peroxidase-mediated crosslinking within a microfluidic device. This method utilizes a water-in-oil emulsion system where a mixture of phenol-substituted hyaluronic acid (HAPh), CBD, and laccase is channeled into oil flow, forming hydrogel microparticles. The physical properties, such as their swelling rate, mechanical strength, and the sustained release of CBD, emphasize their potential in tissue engineering and drug delivery applications. Cellular proliferation studies within the microparticles demonstrate their cytocompatibility, making them suitable for developing microtissues. The microparticles also served as a controlled release mechanism for CBD-targeted delivery to the injured locations, showcasing the effectiveness and ability to aid in the regeneration of the sciatic nerve tissue. In vivo, histopathological analysis of treated sciatic nerve injuries showed enhanced axonal restoring and remyelination with HAPh microparticles containing CBD in contrast to control groups. Furthermore, microparticles enhanced various functional aspects of locomotor activities, such as functional sciatic index (SFI) values, response to heat stimulation, and muscle mass retention. In conclusion, results indicate that these composite biomimetic microparticles with CBD effectively promote nerve structural restoration and increase the reconstruction process in a sciatic nerve injury model.

Carboxymethyl cellulose (CMC) hydrogels are commonly used for heavy metal removal due to their abundant hydroxyl and carboxyl groups. However, pristine CMC hydrogels always suffer from low gel strength and limited adsorption properties in large-scale applications. In this study, to improve the gel strength and heavy metal ions removal capacity, fish gelatin and bamboo shoot particle (BSP) were introduced to CMC hydrogels, respectively. The formation of the composite hydrogel with enhanced gel strength was primarily driven by hydrogen bonding, which exhibited an increase strain resistance with a critical strain value up to 214.68 %. As expected, the composite hydrogel can effectively remove Cd²⁺, Hg²⁺, and Pb²⁺ from aqueous solutions simultaneously. The physical adsorption process of heavy metals by the composite hydrogel was well described by the pseudo-second-order kinetic model, while the Langmuir model indicated maximum adsorption capacities of 147.7 mg/g for Cd²⁺, 88.62 mg/g for Hg²⁺, and 163.89 mg/g for Pb²⁺. Notably, the composite hydrogel exhibited enhanced recyclability, maintaining its efficacy for up to at least five cycles. This study underscores the potential of using naturally occurring biodegradable materials for the removal of heavy metals, and paved ways for heavy metal removal at industrial levels.