搜索结果：Carbohydrate polymers

Multidrug resistance (MDR) remains a formidable challenge in cancer therapy, often rendering conventional chemotherapeutics ineffective. Recent advances in carbohydrate polymer-based stimuli-responsive nanocarriers have opened new avenues for overcoming MDR while achieving targeted drug delivery. This narrative review highlights the unique properties of carbohydrate polymers, such as biocompatibility, biodegradability, and functional versatility, that make them ideal candidates for designing smart nanocarriers. We discuss molecular engineering strategies to develop stimuli-responsive systems capable of releasing drugs in response to tumor-specific cues like pH gradients, enzymatic activity, or external triggers such as light or temperature. A special emphasis is placed on the mechanisms by which these nanocarriers can overcome MDR, including inhibition of efflux pumps, modulation of the tumor microenvironment, and co-delivery of chemotherapeutics with gene therapies or immunomodulators. Applications in preclinical cancer models are reviewed to showcase their translational potential. This article provides a comprehensive overview of the current state-of-the-art while identifying critical knowledge gaps and emerging trends in carbohydrate polymer-based drug delivery systems for cancer therapy. By focusing on MDR and precision targeting strategies, this review offers a unique perspective that distinguishes it from existing literature.

Despite ongoing debate about the "amyloid hypothesis", the imbalance between the production and clearance of β-amyloid (Aβ) peptides in the brain remains one of the most compelling explanations for the progression of Alzheimer's disease. Current strategies therefore focus on discovering clinically relevant therapeutic agents that target Aβ peptides and amyloid structures. Because of their unique and attractive properties - biocompatibility, non-immunogenicity, non-toxicity, and ease of functionalization and production - the use of glycopolymers as amyloid inhibitors has generated interest in therapeutic research for Alzheimer's disease. This review provides a comprehensive and critical overview of the literature on glycopolymers in the treatment of Alzheimer's disease. It begins with a description of the disease's neuropathological mechanisms and the formulations approved by the FDA or currently in clinical trials. The second part discusses the use of glycopolymers as amyloid inhibitors, which prevent the formation of neurotoxic soluble oligomers and subsequent plaques observed in Alzheimer's disease. This is achieved by binding to monomers, blocking self-aggregation, and interrupting toxic interactions, offering a therapeutic strategy to halt disease progression. Finally, the main conclusions and perspectives on the use of glycopolymers as amyloid inhibitors are presented.

Biomolecular diffusion models can now predict proteins and heterogeneous complexes, but glycans remain difficult because their branched topology, conformational flexibility, and strict stereochemical rules must be captured simultaneously. We developed SweetFold, a glycan-aware adaptation of Boltz-1x for the structure prediction of free glycans, glycoproteins, and protein-glycan complexes. SweetFold represents glycans as pseudo-polymers rather than generic ligands, preserving monosaccharide identity, anomeric state, glycosidic connectivity, and atom-level stereochemistry. We pair this representation with glycan-specific architecture, stereochemical supervision, and a sugar-centric training curriculum. Across monosaccharide, oligosaccharide, lectin, and glycoprotein benchmarks, SweetFold improves structural metrics relative to baseline all-atom diffusion models while retaining protein-only benchmark performance. These results show that chemically localized representation and supervision can extend biomolecular diffusion models to carbohydrate chemistry.

Lignin-carbohydrate complex (LCC) is a critical yet understudied determinant of corn bran (CB) recalcitrance, so clarifying its structural features is essential for CB efficient utilization. Herein, Björkman LCCs, isolated from destarched CB (CB-BjLCC) and autohydrolysis residues (residue-BjLCCs), were comprehensively characterized to elucidate pretreatment-induced structural variations and the consequent impact on enzymatic hydrolysis. CB-BjLCC differed from typical herbaceous LCCs by exhibiting a glucan-rich composition (58% of total carbohydrates), lignin dominated by H and G units, and phenyl glycoside (PhGlc) linkages as the predominant LC linkage type (42.67/100Ar). Particularly, the polysaccharide in CB-BjLCC is dominated by mixed-linkage β-1,3/1,4-glucan, accompanied by lower amounts of xyloglucan and cellulose, and associated with highly substituted glucuronoarabinoxylan (GAX). Autohydrolysis shifted the dominant polysaccharide in residue-BjLCCs toward GAX, while both the branching degree of GAX and the abundance of LC linkages decreased with extended pretreatment time. Notably, PhGlc linkages declined sharply by 69-88%, and this reduction in structural complexity thus enhanced monosaccharide yields from autohydrolysis residues and residue-BjLCCs. These findings provide new insights into CB recalcitrance, highlighting the heterogeneous glucan-rich LCC and significant changes in LCC composition and structure depending on pretreatment intensity.

The development of sustainable adsorbents for noble-metal recovery is essential for circular resource utilization. Here, a nitrogen-rich carbohydrate adsorbent was prepared by upcycling pineapple-stem starch via oxidation to dialdehyde starch, followed by crosslinking with pyridine-2,6-dicarbohydrazide (PCH) to form an acylhydrazone ligand network (DAS-PCH). FTIR, solid-state NMR, CHNS, and TGA confirmed successful oxidation and network formation with improved thermal stability. Nitrogen content increased with PCH loading across the series. Among the series, DAS-PCH5 delivered strong noble-metal uptake, reaching capacities of 194 mg g-1 for Pd(II) and > 250 mg g-1 for Au(III) under the tested conditions. Notably, a real-sample demonstration using an acidic gold-leaf leachate afforded quantitative Au, corresponding to an adsorption capacity of 631.51 mg g-1. Kinetic studies revealed rapid Au(III) uptake (equilibrium within 30 min), whereas Pd(II) adsorption was slower. Adsorption was strongly pH dependent and favored acidic media. XPS, PXRD, and TEM analyses are consistent with ligand-assisted adsorption and partial reduction followed by immobilization of the adsorbed noble-metal species, with Au(III) undergoing more extensive reduction to Au(0) nanoparticles than Pd(II). The adsorbent showed high selectivity for Au and Pd and retained excellent performance over repeated adsorption-desorption cycles. Overall, biomass-derived starch offers a sustainable platform for high-performance noble-metal recovery.

While nanocellulose-containing materials show remarkable oil-absorption capabilities for oil-spill cleanup, their biomedical translation remains unexplored. Residual silicone oil (SilOil) following eye surgery represents a significant concern in clinical ophthalmology, as emulsified droplets can lead to serious ophthalmic complications. Here, we demonstrate the first successful biomedical application of a carbohydrate-polymer composite material as an intraoperative SilOil-absorbent tool with a clinically viable form in eye surgery. The engineered microfibers (MFs) were fabricated via wet-reaction spinning of TEMPO-oxidized cellulose nanofibrils (TOCN) and polyvinyl alcohol (PVA), followed by dual crosslinking, freeze-drying, and hydrophobic modification. The resulting composite cryogel MFs exhibited high porosity (up to 86%), exceptional SilOil absorption capacity (more than 12 g per gram (g g-1)), mechanical robustness (70 MPa compressive modulus), and excellent cytocompatibility. The precisely controlled cylindrical morphology enables seamless integration with microcannula systems, permitting both minimally invasive delivery and complete retrieval. Crucially, the composite cryogel MFs achieved superior SilOil removal efficiency compared to the conventional technique in an ex vivo porcine eye model. This work pioneers the transformative application of a structured carbohydrate-polymer composite cryogel as a retrievable intraoperative surgical tool for the management of post-surgery SilOil retention and advances the utilization of carbohydrate-polymer composite porous materials in precision surgery.

The development of bio-based adhesives has emerged as a viable strategy to reduce fossil-derived resin consumption in wood and wood-based panel applications. This review provides a polymer-focused assessment of adhesive systems derived from proteins, carbohydrates, lignin, and tannins, emphasizing molecular architecture, crosslinking chemistry, interfacial interactions, and structure-property relationships. Adhesive performance is primarily dictated by functional group density, crosslinking efficiency, and network topology. Protein-based adhesives rely on hydrogen bonding and covalent crosslinking with lignocellulosic substrates but require structural modification to improve hydrothermal stability. Carbohydrate-based systems, including starch and cellulose derivatives, offer reactive hydroxyl functionalities that enable oxidation, esterification, and etherification pathways for enhanced network formation. Lignin and tannins, characterized by phenolic and aromatic structures, facilitate condensation reactions and enable partial substitution of phenol in thermosetting resins, supporting low-formaldehyde or formaldehyde-free formulations. Hybrid polymer networks, particularly protein-carbohydrate and lignin-modified systems, demonstrate improved crosslink density, reduced hydrophilicity, and enhanced mechanical performance. Life cycle analyses indicate that increasing biogenic carbon content and minimizing fossil-based cross-linkers can lower global warming potential (GWP) and volatile organic compound (VOC) emissions. Overall, a structure-property-sustainability framework is proposed to guide molecular design and performance optimization of next-generation bio-based wood adhesives.

Aeromonas species are important opportunistic pathogens in freshwater aquaculture, including Polish fish farms, where outbreak-associated isolates have been assigned to local provisional serogroups. Among these, PGO1 is frequently detected, but the structural and genetic diversity of the corresponding O-specific polysaccharides remains poorly understood. Here, we characterized Aeromonas sobria strain K221, a PGO1 isolate recovered from common carp during an outbreak of motile Aeromonas infection/septicaemia. The O-specific polysaccharide (OPS), isolated from LPS, was analysed by chemical methods and 1H/13C NMR spectroscopy, and its O-repeating unit was identified as a linear pentasaccharide containing β-GlcpNAc, 2-O-acetylated α-Rhap, and α-Abep residues. Bioinformatic analysis of the O-antigen gene cluster (OGC) revealed gene content consistent with the OPS structure and supported functional assignment of the biosynthesis locus, including a putative α-1,3-CDP-abequosyltransferase. Both the OPS and its OGC differed from those of other recently characterized PGO1 strains, indicating that K221 represents a distinct variant within this serogroup. The occurrence of 2-substituted abequose, not previously reported in Aeromonas O-polysaccharides or as a 2-substituted residue in bacterial O-polysaccharides, highlights an unusual structure-biosynthesis relationship. These findings reveal greater structural and genetic diversity within the Aeromonas PGO1 serogroup than previously recognized and expand current knowledge of bacterial O-specific carbohydrate polymers.

Glycosaminoglycan (GAG)-binding lectins represent a rare class of carbohydrate-binding proteins with the ability to recognize and organize linear polysaccharide chains. Here, we describe XN-IL, a novel calcium-dependent lectin from the Gram-negative bacterium Xenorhabdus nematophila, which exhibits an unusual specificity for glycosaminoglycans. X. nematophila is an entomopathogenic bacterium and a symbiont of insect-parasitic Steinernema nematodes. Glycan array screening, analytical ultracentrifugation, and differential scanning fluorimetry revealed that XN-IL selectively binds hyaluronan and low-sulfated heparan sulfate, while showing negligible affinity for monosaccharides and galactosylated glycans. GAG binding is mediated exclusively by calcium ions, enabling the reversible crosslinking and precipitation of hyaluronan polymers. Crystal structures of the apo and ligand-bound forms reveal a conserved LecA-like fold with a widened, calcium-dependent binding pocket that accommodates extended GAG chains without major conformational rearrangements. XN-IL is the first member of the LecA family with defined GAG specificity and the first lectin identified in the genus Xenorhabdus. Its divergence from galactophilic LecA homologues reflects an evolutionary adaptation towards calcium-driven recognition and reversible assembly of linear polysaccharides. These findings expand the functional diversity of the LecA family and introduce XN-IL as a new tool for probing and manipulating GAG-based polymer systems.

Protein-rich polysaccharides are increasingly recognized as multifunctional biopolymers with significant biomedical potential. In this study, a protein-polysaccharide complex (JrPRP) was isolated for the first time from the root bark of Juglans regia L. and comprehensively characterized. JrPRP was obtained with a yield of 4.7% (w/w) and exhibited an acidic composition enriched in uronic acid-related components, together with minor neutral sugars. Spectroscopic analyses (FTIR and UV-Vis) confirmed the coexistence of carbohydrate and protein domains, while chromatographic profiling (TLC and HPLC) indicated a heterogeneous monosaccharide composition. Scanning electron microscopy revealed a porous and irregular microstructure, consistent with a structured biopolymeric network exhibiting pronounced anionic character. Functionally, JrPRP demonstrated notable antioxidant activity, with IC50 values of 405 ± 1.8 µg/mL (DPPH), 225 ± 3.5 µg/mL (ABTS), and 229 ± 1.7 µg/mL (metal chelation), along with strong ferric-reducing capacity. The complex exhibited antibacterial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus (MIC: 2-9 mg/mL), as well as potent antibiofilm activity, inhibiting up to 94% of Escherichia coli biofilm formation. Biocompatibility assays indicated low hemolytic activity, supporting its favorable safety profile. In addition, JrPRP showed moderate anticoagulant effects and strong anti-inflammatory activity, reaching 98% inhibition of protein denaturation, comparable to or exceeding diclofenac under similar conditions. These findings identify J. regia root bark as a promising and previously underexplored source of structurally distinctive uronic acid-containing protein-rich polysaccharides and provide new insights into the relationship between their compositional features and multifunctional biological activities.

Characterizing the extracellular mechanisms plants use to adapt to water immersion could provide avenues for crop improvement in the face of periodic flooding. One such mechanism is hypoxia-induced aerenchyma formation. The formation of lysigenous aerenchyma occurs through programmed cell death (PCD) that may require the chemical modification of select polysaccharides in root cell walls. Currently, the precise mechanism of cell wall structural modification is not fully defined. To better characterize this mechanism, we investigated whether a relationship exists between modification of cell wall xyloglucans through removal of fucosyl functional groups and the formation of root aerenchyma in agriculturally relevant Fabaceae species. Characterization was conducted through the immunolabeling of specific xyloglucan epitopes within root cell walls during a 48-hour flooding time series. Immunolabeling results suggest progressive alterations in the accessibility or abundance of fucosylated and non-fucosylated xyloglucan epitopes in cell walls bordering developing aerenchyma cavities during PCD. Additionally, we performed an enzymatic pretreatment to remove select cell wall polymers prior to immunolabeling for xyloglucan, xylan and crystalline cellulose. These pretreatments demonstrate potential in vitro epitope masking constraints in root cell walls near developing aerenchyma. Our findings suggest that chemical modification to xyloglucans occurs in tandem with modification of select cell wall pectin epitopes. Our results elucidate previously uncharacterized cell wall carbohydrate remodeling during PCD leading to aerenchyma formation among legume species.

Capsular polysaccharides (CPS) of the human gut microbiota are structurally diverse surface glycopolymers whose monosaccharide composition, linkage patterns, charge properties, and strain-specific modifications directly encode multifaceted biological functions. This review systematically examines the CPS structural landscape across major gut commensals, including Bacteroides spp., Lacticaseibacillus spp., Bifidobacterium spp., Enterococcus spp., and members of the Enterobacteriaceae family. We integrate recent findings to show how CPS architecture governs three interconnected functional domains: environmental fitness (resistance to gastric acid, bile salts, antibiotics, and phage predation), immune modulation (engagement of TLR2, Dectin-1, DC-SIGN, Siglecs, and MHC-II pathways to orchestrate regulatory T- and B-cell responses, macrophage polarization, and epithelial barrier maintenance), and ecological integration (cross-feeding and carbon reservoir functions). We identify critical knowledge gaps-most notably, the lack of high-resolution structure-activity relationships that link three-dimensional CPS conformations to specific immunological outcomes, compounded by a persistent Bacteroides-centric bias and underexplored ecological functions. Emerging tools, including cryo-electron microscopy, solid-state nuclear magnetic resonance, glycan arrays, and machine learning, offer unprecedented potential to advance the nascent field of CPS structure-activity relationships. We propose that a deeper understanding of CPS structural features, once achieved, may eventually inform the rational design of precision interventions that harness host-microbe mutualism for therapeutic benefit.

Polysaccharide-based adhesives hold promise for wet tissue repair, yet their application is often limited by weak interfacial bonding and insufficient cohesive strength in hydrated environments. Here, we report a root-inspired multilevel wet bioadhesive enabled by helical-cavity-preserving starch engineering for corneal repair. Potato starch was sequentially succinylated and methacrylated under aqueous conditions to obtain methacrylate succinate diesterified starch (StaCMA), which retained the ability to form helical-cavity structures while introducing photocrosslinkable groups. When integrated with methacrylated gelatin, StaCMA formed a transparent hydrogel network that mimicked root-like anchoring through tissue-interpenetrating covalent fixation, branched-chain stress dissipation and helical-cavity-mediated polymer confinement. The optimized adhesive exhibited strong wet adhesion on human cornea, achieving a shear adhesion strength of 166 kPa and a burst pressure of 1286 mmHg, while maintaining visible-light transmittance above 90%. Iodine displacement, FTIR, NOESY, helix-denaturation controls and molecular dynamics simulations supported that starch helical cavities confined GelMA segments and promoted molecular association, thereby reinforcing both adhesion and cohesion. In ex vivo and rabbit corneal injury models, the adhesive enabled sutureless sealing of linear and irregular penetrating wounds and supported organized corneal regeneration with reduced fibrotic remodeling. This study establishes helical-cavity-preserving starch as an active carbohydrate-polymer motif for root-inspired wet bioadhesive design.

Carbohydrate-aromatics interactions are well known in Nature and are also exploited in food and pharmaceutical industry for encapsulating low molecular weight drugs or flavors into polysaccharide carriers. Despite that, the non-covalent entrapment of small molecules containing aromatic moieties into the 3D-structure of a polysaccharide is typically overlooked in the context of the structural characterization of derivatized polysaccharides, that is often limited to the measurement of only 1H NMR spectra. This study demonstrates that it can be misleading in some cases. We report some examples of products - obtained by grafting polysaccharides with small molecules containing aromatic moieties and displaying fully satisfying 1H NMR spectra - that were demonstrated to be instead poorly or even not derivatized at all by 2D-NMR analysis. Although these results do not question any polysaccharide grafting with aromatic functionalities reported so far in literature, they strongly support the necessity of a structural characterization based not merely on 1H NMR spectra for a robust demonstration of a successful polysaccharide derivatization.

Polysaccharides may influence surface properties and stability development in multicomponent protein-based nanosystems, but their functional contribution during particle assembly remains insufficiently understood. In this study, zein/soy protein isolate/inulin ternary nanoparticles were constructed using a pH-ultrasound-shifting strategy. The effects of different treatments on particle formation, surface characteristics, stability, and redispersibility were systematically investigated. Compared with ultrasonication alone and pH shifting alone, the combined treatment markedly improved particle formation, yielding ZSI-P-U nanoparticles with a particle size of 134.90 nm, a polydispersity index of 0.202, and an absolute zeta potential of 22.33 mV, together with improved physical, ionic, storage, and freeze-drying redispersibility. FTIR, XRD, circular dichroism, intrinsic fluorescence, and surface analyses suggested that pH-ultrasound-shifting promoted molecular rearrangement and modified the surface characteristics of the ternary nanoparticles, leading to a more homogeneous amorphous assembly. Notably, the incorporation of commercial oligofructose-type inulin was associated with reduced surface hydrophobicity, improved wettability, and enhanced resistance to aggregation and separation. These results suggest that the stability and redispersibility of multicomponent protein-carbohydrate nanoparticles depend not only on particle size reduction but also on treatment-induced surface-property regulation during assembly, providing useful insights for the rational design of stable plant protein-based composite nanoparticles with improved reconstitution performance.

Rosmarinic acid (RosA) demonstrates significant pharmacological properties. However, its oral administration is considerably hindered by inadequate solubility, instability within the gastrointestinal tract, and low intestinal permeability. Chitosan (CS), a functional cationic polysaccharide, presents distinct advantages as an oral delivery vehicle owing to its mucoadhesive, permeation-enhancing, and protective characteristics. This review encompasses recent advancements (2020-2026) in CS-based nanoformulation strategies aimed at enhancing the oral bioavailability of RosA, comprising polyelectrolyte complexes, ionic gelation nanoparticles (NPs), CS-coated lipid and polymeric NPs, self-assembled and chemically modified CS systems, oral film and strip-integrated CS nanoformulations and hybrid CS-based nanosystems. Critical discussions are presented on mechanistic aspects regarding stabilization of CS-RosA interactions, improvement in solubilization and dispersion, prolonged gastrointestinal residence time, enhanced paracellular transport and modulation of intestinal metabolism and efflux processes. Key formulation parameters influencing performance such as molecular weight (MW), degree of deacetylation (DD), and surface charge are compared across delivery platforms. Finally, translational considerations including scalability, safety, and readiness for nutraceutical and pharmaceutical applications are highlighted. CS-based nanoformulations represent a versatile carbohydrate polymer platform for advancing the oral delivery and industrial translation of RosA.

Cyclodextrins (CDs) are structurally defined cyclic oligosaccharides with a hydrophobic cavity, hydrophilic hydroxyl rims, and versatile chemical modifiability. These features make CDs useful building blocks for inclusion nanoparticles, amphiphilic assemblies, nanosponges, CD-MOFs, coated hybrids, and nanocomposites. However, many CD-based nanomaterial studies and reviews remain organized by material type or application field, making it difficult to determine when CD is functionally necessary and which structural descriptor controls performance. This review reframes CD-based nanomaterials through a structure-assembly-interface-function logic. We summarize key molecular descriptors, including CD type, cavity size, hydroxyl distribution, substitution pattern and degree, crosslinking density, host-guest affinity, and surface presentation, and link them to assembly behavior, functional interfaces, and application-driven performance. Particular emphasis is placed on evidence standards for CD-specific structure-performance claims, including non-CD controls, cavity-accessibility tests, binding analysis, competitive guest displacement, structure-variant comparisons, and application-relevant validation. This framework aims to distinguish genuine CD-guided design from conventional formulation effects and support more rational carbohydrate nanomaterial engineering.