Degree Of Branching Research Articles

Customizable Glycopolymers as Adjuvants for Cancer Immunotherapy: From Branching Degree Optimization to Cell Surface Engineering.

Engineering dendritic cell (DC) maturation is paramount for robust T-cell responses and immunological memory, critical for cancer immunotherapy. This work unveils a novel strategy using precisely controlled branching in synthetic glycopolymers to optimize DC activation. Using the distinct copolymerization kinetics of 2-(methacrylamido) glucopyranose (MAG) and diethylene glycol dimethacrylate (DEGDMA) in a RAFT polymerization, unique glycopolymers with varying branching degrees are created. These strategically produced gradient branched glycopolymers with sugar moieties on the outer chain potently promote DC maturation. Strikingly, low-branched glycopolymers demonstrate superior activity, both in pure form and when engineered on tumor cell surfaces. Quartz crystal microbalance and theoretical simulations elucidate the crucial role of branching in modulating glycopolymer-DC receptor interactions. Low-branched gradient glycopolymers have shown a notable advantage and are promising adjuvants in DC-based cancer immunotherapy.

Maltogenic amylase and glucosyltransferase synergistically control the chain structure of rice starch and their effects on rheological properties and functional characteristics of rice milk

Maltogenic amylase (MA) and glucosyltransferase (TG) were used synergistically for the development of rice milk products with low glycemic index (GI), and its storage properties and nutritional functions were evaluated. The structural results showed that MA and TG treatment could effectively reduce the molecular weight of rice starch and increases its overall branching degree, which further affected the storage and nutritional properties of rice milk products. Compared with gelatinized rice milk and rice milk treated with MA or TG, MTRM (treated with MA and TG) had lower paste viscosity, stable storage modulus, and stronger ability to bind water during storage period, indicating that the dual-enzyme treatment significantly improved the retrogradation properties of rice milk and the anti-retrogradation rate reached 76.12%. In vitro studies showed that dual-enzyme treatment significantly increased the resistant starch content of rice milk to 39.46%, thereby reducing its predicted glycemic index to 53.85, improving its antioxidant properties and contributing to the proliferation of short-chain fatty acids produced bacteria. Notably, MTRM significantly elevated butyrate content which showed a better prebiotic effect. This research provides new approaches for the preparation of low-GI rice-based beverages.

Mechanism of maltogenic α-amylase modification on barley granular starches spanning the full range of amylose

Amylopectin (AP)-only (APBS), normal (NBS), and amylose (AM) only (AOBS) barley starches were selected here to investigate catalysis pattern of maltogenic α-amylase (MA) on hydrolyzing AP and AM granular starches. MA shortened starch side chains with degree of polymerization (DP) 11–30. MA-treated APBS exhibited porous granular structures and dramatically increased degree of branching (DB, 17–20 %), and reduced ordered degrees, suggesting high hydrolysis and transglycosylation activities of MA. MA-treated NBS showed less pronounced porous structures and slightly increased DB (2–4 %), indicating high hydrolysis but low transglycosylation activities. AOBS displayed minimal changes in DB (0.2–0.3 %) and starch structures, implying low hydrolysis and transglycosylation activities. Therefore, MA preferred to attack the AP molecules with abundant glucan substrates with DP 11–30, while AM restricted MA activity likely by creating ineffective binding sites and undergoing rapid reorganization. These findings deepened the understanding of the mechanisms of MA in modifying granular starches with varying AM content.

Tearing properties, crystallization behavior, microstructure, and morphology of LLDPE with different short branched chain distributions

Abstract The length and distribution of comonomers with short-chain branching (SCB) have a significant influence on the crystallization behavior and crystal structure of polymers, as well as the mechanical properties of the material. This study investigates the crystallization behavior and properties of linear low-density polyethylene (LLDPE) samples with similar density, molecular weight, and branching degree but varying SCB distributions. The results show that LLDPE with butene as the comonomer has a stronger ability to suppress crystallization compared to LLDPE with hexene as the comonomer due to its more uniform SCB distribution. Additionally, among LLDPEs with comonomers of octene, hexene, and butene, the LLDPE with the most uniform SCB distribution exhibits the weakest crystallization ability. Small-angle X-ray scattering (SAXS) and scanning electron microscopy (SEM) results indicate that LLDPE with more uniform distribution of SCB has smaller long-period and more regular lamellar structure. Therefore, LLDPE with more uniform SCB distribution exhibits weaker inhibition ability towards crystallization, leading to less agglomerated phases and weaker phase separation, resulting in higher tear strength.

The Degree of Branching of Serum IgG N-glycans as a Marker of Advanced Endometriosis.

Endometriosis is a gynecological disease for which the diagnostics are difficult and often invasive; therefore, non-invasive diagnostic methods using sensitive and specific parameters present in easily available body fluid such as blood serum are needed for the detection of this disease. Our study aimed to answer the question of whether there are any differences between women with advanced endometriosis (AE), patients with gynecological diseases other than endometriosis (NE), and healthy women (control) in terms of the number of antennas of N-glycans from serum IgG. The degree of branching of IgG N-glycans was determined by a modified lectin ELISA with biotinylated lectin Con A (Canavalia ensiformis agglutinin) recognizing α-linked mannose, specifically reacting with biantennary N-glycans. The PHA-L/Con A ratio was calculated from the obtained N-glycan reactivities with Con A and PHA-L (Phaseolus vulgaris leucoagglutinin, specific to tri- and/or tetra-antennary N-linked glycans). The expression of Con A-reactive biantennary N-glycans in serum IgG was significantly lower in the control group than in the NE group (p = 0.045). The values of the PHA-L/Con A ratio were significantly higher in the NE group than in the AE and control groups (p = 0.019 and p = 0.022, respectively). The PHA-L/Con A ratio could be taken into account as a parameter helpful in the non-invasive diagnosis of advanced endometriosis, thus differentiating this disease from other gynecological diseases with an inflammatory background.

Synthesis and validation of clickable multimeric mannose ligands for dendritic cell targeting

The efficacy of therapeutics can be enhanced with their off-target effects being minimized through targeted delivery. In vaccination and cancer immunotherapy, targeting dendritic cells (DCs) and macrophages (Mφs) is crucial for the activation of the immune system. To this end, we have developed a set of carbohydrate-based ligands targeting C-type lectins (CTLs) present on the surface of DCs for receptor-mediated uptake. Branched structures functionalized with up to four mannose units were synthesized through CuI-catalysed click chemistry, and the products were further functionalized with the DBCO group to facilitate their conjugation with cargos of interest via Cu-free click chemistry. Thus, the ligands were conjugated with fluorescein azide, and the fluorescent conjugates were assessed for their internalization in CTL expressing immature DCs. The results showed that high-mannose branched structures were efficiently internalized through the endocytic pathway, with a positive qualitative correlation between branching degree of sugar-based ligands and internalization. As evidence for payload delivery, conjugating with a mannotriose ligand quantitatively increased the uptake of a fluorescently labeled oligonucleotide by immature DCs. Our work supports the use of click chemistry to synthesize and conjugate promising ligands for efficient delivery of nucleic acid-based drugs.

Synthesis of perylene‐PEO hyperdispersants for aqueous graphene dispersion

AbstractGraphene, with excellent thermal conductivity, electrical and corrosion shielding performance has great application potential in the fields of heat dissipation coating, conductive agent and anticorrosion composite coatings. However, due to its large specific surface area, resulting strong aggregation behavior limits its application. Herein, the hyperdispersants with perylene anchoring groups are synthesized through the amidation coupling reaction between diacid anhydride and polyetheramine. The branching degree and length of hydrophilic chains on hyperdispersant are revealed to be the very important factors to affect the dispersion stability of aqueous graphene dispersion. The hyperdispersant with a single hydrophilic chain and the molecular weight 2000 of polyetheramine has the excellent dispersal activity discovered by Rheology, particle size distribution and Raman measurements. The possible mechanism is the strongest anchoring effect of perylene on graphene surface and thus achieving in best effective spatial exclusion stabilization effect of hydrophilic chains.

Metabolomic analysis reveals the potential of fucosylated chondroitin sulfate from sea cucumber in modulating metabolic homeostasis

In this study, we prepared four derivatives of fucosylated chondroitin sulfate (FCS): full-length FCS (flFCS) from Holothuria leucospilota, low molecular weight FCS (lmFCS) derived from flFCS, and their de-branched counterparts, de-branched flFCS (d-flFCS) and de-branched lmFCS (d-lmFCS) via controlled acid treatment. Following structural verification using various analytical techniques, we applied targeted metabolomics to examine the impact of FCS on nutritional efficacy and its structure-activity relationship. Analysis of 225 plasma and feces samples from 75 mice revealed a positive correlation between metabolomic shifts and increased weight gain, underscoring FCS’s potential to enhance nutrient absorption and promote growth. The observed linear relationship between the levels of short-chain fatty acids in plasma and feces suggests that FCS may facilitate catabolic activities in the gastrointestinal tract. The comparative study of different FCS derivatives on mouse growth and metabolic homeostasis regulation led to the conclusion that FCS exhibits greater biological activity with a higher degree of branching and larger molecular weight.

Upcycling of polyethylene waste to biodegradable adhesive and coating via Baeyer-Villiger reaction: A new view on oxidation-fracture mechanism and structure-function relationship

Non-biodegradable polyethylene waste accumulates in large quantities in the environment posing a serious threat to the survival of creatures. Meanwhile, polyethylene suffers from inherent polarity limitations that curtails its application scope. Oxidation is an efficient approach of upcycling waste polyethylene through introduction of hydrophilic functional groups (such as –COOH, –OH), yet often at the expense of their original hydrophobicity. Herein, the hydrophobic ester groups, were introduced via Baeyer-Villiger oxidation to ingeniously balance the contradiction among hydrophobicity, interfacial forces and sustainability of polyethylene oxidation products. A tandem conversion mechanism among the oxidative groups was proposed while the decrease in molecular weight and branching degree was clarified to be a result of β-scissions occurring the branches during the oxidation. Meanwhile, the effect of oxidation degree and molecular weight on interfacial forces was revealed. The excellent hydrophobicity and corrosion resistance of the oxidized polyethylene coating can be attributed to the low content of carboxyl/hydroxyl groups, rich hydrophobic ester groups and the retained long carbon chain structure. Besides, the introduced ester groups and lower molecular weight also provided the oxidation products with potential biodegradability. This work provided a new insight on the Baeyer-Villiger oxidation of polyethylene and the potential for upcycling of polyethylene waste into sustainable materials.

Effects of galactomannans of varied structural features on the functional characteristics and in vitro digestibility of wheat starch

This study explores the effects of four natural galactomannans (GMs) with varying degrees of branching (fenugreek gum, guar gum, tara gum and locust bean gum) on the functional properties and in vitro digestibility of wheat starch (WS). Results from rapid viscosity analysis (RVA) and low-field nuclear magnetic resonance (LF-NMR) analysis revealed that GMs with lower branching degrees were correlated with higher paste viscosity, peak viscosity, and greater water-holding capacity in the WS-GM mixtures. Additionally, these lower branching GMs more effectively inhibited amylose leaching during starch gelatinization, leading to a softer gel texture and increased transparency of the mixtures. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis demonstrated that starch mixtures containing lower branching GMs exhibited reduced relative crystallinity and enthalpy values during aging. Furthermore, the incorporation of lower branching GMs resulted in decreased starch digestibility in vitro, thereby enhanced resistant starch content. These findings highlight the potential of selectively branched GMs to modulate the functional properties and nutritional profile of WS, providing a promising approach for the development of starch-based products with improved health benefits.

Characteristic of fluoroether gum via non-linear rheological approaches

Abstract Large amplitude oscillatory shear (LAOS) tests were conducted on four types of fluoroether elastomer gum, namely VPL-85540, VPL-75545, VPL-65455, and VPL-55540 in order to study their molecular weight, chain structure, and branching degree from the perspective of rubber rheology. For the setting of shear rate in varied LAOS measurements, frequency and angular velocity controlling modes were attempted and compared. Non-linear rheological parameters showed that VPL-65455 possessed significant polymeric branching characteristics. VPL-55540 possessed the lowest molecular weight, and VPL-75545 was detected with higher long-pendant monomer content in its polymer chain. Rheological properties concluded from the analysis of two shear rate controlling modes of LAOS tests exhibited great consistency, which confirmed the reliability of LAOS tests in the characterization of fluoroether gum.

HSMAOA: An enhanced arithmetic optimization algorithm with an adaptive hierarchical structure for its solution analysis and application in optimization problems

The Arithmetic Optimization Algorithm (AOA) has recently gained significant attention as a novel meta-heuristic algorithm. However, it faces challenges such as premature convergence and entrapment in local optima when addressing complex optimization problems. To overcome these limitations, this paper proposes an enhanced AOA, termed the Self-Adaptive Hierarchical Arithmetic Optimization Algorithm (HSMAOA). The proposed method integrates three key strategies: Firstly, a spiral-guided random walk mechanism is introduced to improve global search ability. Secondly, a novel adaptive hierarchy leader and follower mechanism is proposed, which establishes a complete multi-branch tree hierarchy with decreasing branching degrees within the population, thereby increasing information exchange among population individuals to escape local optima. Finally, a differential mutation strategy based on ranked selection is introduced to enhance candidate solution quality. HSMAOA's performance was evaluated on the CEC2022 test suite against some state-of-the-art algorithms. Results, including optimization accuracy analysis, convergence curves, and various statistical tests, demonstrate HSMAOA's superior optimization capability and robustness. In addition, tests on eight engineering structure optimization problems, including the pressure vessel design problem, the multiple disk clutch brake design problem, and the step-cone pulley problem, and so forth, further validate its effectiveness. Thus, HSMAOA shows strong competitiveness in complex optimization tasks and potential for a wide range of applications, and is an advantageous and promising alternative solution for optimization problems.

Effects of Low Field Temperature on the Physicochemical Properties and Fine Structure Stability of High-Quality Rice Starch during the Grain Filling Stage.

The consumption of high-quality rice is increasing. Low temperatures during grain filling may affect the starch synthesis of high-quality rice and thus affect the quality of the rice itself. In this study, two high-quality conventional rice cultivars and two high-quality hybrid rice cultivars were selected and sown at a low temperature and normal temperature in the field. The low temperature during grain filling increased the amylose content, final viscosity, setback, short amylopectin chain ratio, and degree of amylopectin branching in four high-quality rice cultivars; meanwhile, the amylopectin content, gelatinization temperature, proportion of medium-long chain amylopectin, and the short-range order of starch decreased. Compared with the normal temperature, the alterations in the physicochemical and structural qualities of high-quality conventional rice cultivars YZX and NX42 were less significant at lower temperatures. The starch quality of high-quality conventional rice was more stable than hybrid high-quality rice.

Nutrition and health effects of pectin: A systematic scoping review of human intervention studies.

Pectin is composed of a group of complex polysaccharides that are naturally found in various plants and are associated with a range of beneficial health effects. Health outcomes from dietary pectin can vary depending on botanical origin, dietary dose and structure of pectin. The objective of this scoping review is to build a comprehensive overview of the current evidence available on intervention studies conducted in humans and to better understand the possible knowledge gaps in terms of structure-function relationships across the different health-related effects. PubMed and Embase databases were searched using PRISMA-ScR guidelines, yielding 141 references (from the initial 3704), representing 134 intervention studies performed between 1961 and 2022 that met inclusion criteria. Studies were divided into six categories, which included gut health, glycaemic response and appetite, fat metabolism, bioavailability of micronutrients, immune response and other topics. Review of these human intervention studies identified a variety of cohort characteristics and populations (life stage, health status, country), sources/types of pectin (i.e. citrus, sugarbeet, apple, other and non-defined), intervention timeframes (from one single intake to 168 d) and doses (0.1-50 g/d) that were tested for health outcomes in people. Gut health, post-prandial glucose regulation and maintenance of blood cholesterol represented the largest categories of studied outcomes. Further research to strengthen the structure-function relationships for pectin with health properties and associated outcomes is warranted and will benefit from a more precise description of physico-chemical characteristics and molecular compositions, such as degree of esterification, weight, degree of branching, viscosity, gel formation and solubility.

The production and characteristics of glycogen synthesized by various strains of the thermoacidophilic red microalgae Galdieria grown heterotrophically

AbstractRed microalgae from the Cyanidiophyceae, particularly Galdieria sulphuraria and Cyanidioschyzon merolae, are primitive photosynthetic thermoacidophiles that thrive in acidic hot springs and geysers. Unlike most Cyanidiophyceae, Galdieria strains are metabolically flexible as they can switch from photoautotrophic growth in the light to heterotrophic growth in complete darkness. Galdieria sulphuraria is especially noteworthy for its accumulation of various commercially valuable, functional compounds such as glycogen and phycocyanin. Glycogen, a branched fractal-like polysaccharide composed of several thousands of anhydroglucopyranose units, can be added to cosmetic products and sports drinks as a moisturizer or slow-digestible carbohydrate. While the production and structural characteristics of the glycogen of G. sulphuraria 108.79, isolated from Yellowstone National Park, have been previously described, our investigation aimed to explore glycogen production and properties across various Galdieria strains from different locations. Our findings reveal that all examined strains produce substantial amounts of highly branched glycogen when grown heterotrophically on glycerol in the dark. Notably, the structural characteristics of Galdieria glycogen distinguish it from both eukaryotic and prokaryotic glycogen, exhibiting a significantly higher degree of branching, substantially shorter side chains, and a considerable extent of indigestibility. These findings support the hypothesis that this highly branched, small glycogen is a long-term energy store, enabling survival during extended periods of complete darkness.

Investigating the Impact of Moisture Levels on Structural Alterations and Physicochemical Properties of Cassava Flour through Extrusion: A Comprehensive Study.

The extrusion process, a vital technique for starch modification, is notably influenced by the moisture content (MC). This study aimed to elucidate the effect of varying MC levels (18, 22, 26, and 30%) on the structural and physicochemical characteristics of cassava flour during extrusion. Extrusion resulted in the fraction of degree of polymerization 13‒24, degree of branching, and molecular weight increased with increasing MC, with values of above indexes being 32.29%, 1.05%, and 1.21 × 105 g/mol, respectively, at a MC of 18%. This suggested that the degradation of amylopectin and amylose. Additionally, there was an increase in rapidly digestible starch (RDS) and a decrease in slowly digestible starch (SDS) in the extrudates in comparison to the native cassava flour. The extrusion of cassava flour at 18% MC exhibited the highest levels of RDS and SDS, reaching 64.52% and 4.06%, respectively. These findings indicated that low moisture extrusion could be a more effective method for disrupting the structure of cassava starch and enhancing the digestibility of cassava flour, offering valuable insights for the optimized use of cassava extrudates in various applications.

Tailoring highland barley bran arabinoxylans: Insights into composition, structure, and functional properties

Highland barley bran (HBB) stands as an underutilized source of arabinoxylans (AXs), presenting promising prospects for various applications. This study focuses on the isolation of four different AXs (S20, S40, S60, S80) from HBB using alkali extraction and gradient alcohol precipitation. These AXs exhibited diverse purity (56.47%–80.92%), monosaccharide compositions (A/X:0.47–0.96), and molecular weights (Mw) (173.5–498.2 kDa) of different AXs, along with different microstructural variations, amorphous qualities, and thermal stability. Rheological analyses demonstrated their shear-thinning behavior and distinctive gel-forming capacities, with S20 exhibiting superior viscosity and gel-forming ability. Notably, all four AXs demonstrate notable DPPH and ABTS radical scavenging capacities, with S80 demonstrating the highest antioxidant potency. Correlation analyses highlighted connections between molecular weight, branching degree, and rheological and antioxidant properties of AXs. Among different AXs, S20, with its low branching degree (0.47) and high molecular weight (390.4 kDa), exhibited significant viscosity, suggesting its suitability as a natural thickener in food processing. Conversely, S80, characterized by its low molecular weight (173.5 kDa), high branching degree (0.96), and potent antioxidant activity, holds promise as a natural antioxidant in functional foods. This study provides crucial insights for tailoring AX applications, unlocking the potential for the valorization of HBB in diverse scenarios.

Features of water crystallization

Water is mainly composed of ice nanocrystals. The peculiarities of water crystallization can be explained on the basis of its nanostructural structure and nanostructural crystallization. Atmospheric air molecules dissolve well in water and are adsorbed by its nanocrystals. It is shown that the amount of expansion of ice, when water solidifies, is proportional to the concentration of air dissolved in it. The concentration of air dissolved in water decreases significantly with an increase in its temperature. Hot water solidifies faster than cold water because there is less air concentration in hot water. Its bubbles, released on ice crystals, reduce the rate of crystallization of water. A large supercooling of water occurs as a result of the blocking action of adsorbed air, which prevents the unification of ice nanocrystals into crystallization centers. Shaking a bottle of supercooled water leads to desorption of air and accelerated crystallization of water. Air bubbles released on dendritic ice crystals reduce the degree of branching of these crystals. It has been shown that music increases the intensity of removal of gas bubbles and is able to influence the shape of dendritic ice crystals during water crystallization. It has been shown that an increase in the volume of sound and (or) a decrease in its frequency increase the intensity of removal of air bubbles from dendritic ice crystals and increase the branching of these crystals.

Synthesis of Ultralow-Density Polyethylene Elastomers Using Triarylnaphthyl Iminopyridyl Ni(II) Catalysts.

Recently, the chain-walking ethylene polymerization strategy has garnered widespread attention as an efficient and straightforward method for preparing polyolefin elastomers. In this study, a series of 2,4,8-triarylnaphthyl iminopyridyl nickel catalysts were synthesized and used in ethylene polymerization. These catalysts demonstrated moderate catalytic activity (105 g mol-1 h-1), producing high-molecular-weight (up to 145.5 kg/mol) polyethylene materials with high branching degrees (75-95/1000C) and correspondingly low melting points. Detailed analysis using 13C NMR spectroscopy revealed that the polyethylenes primarily featured methyl and long-chain branches. Mechanical testing of the polyethylene samples obtained from catalysts Ni1-Ni3 exhibited moderate stress at break (4.64-6.97 MPa) coupled with a very high strain at break (1650-3752%), indicating their very good ductility. Furthermore, these polyethylenes showcased great elastic recovery abilities, with strain recovery values ranging from 72% to 85%. In contrast, the polyethylene produced by Ni4 displayed notably inferior tensile strength (0.16 MPa) and tensile recovery (43%). To the best of our knowledge, this study represents the inaugural utilization of a nickel iminopyridyl catalyst in the preparation of a polyethylene thermoplastic elastomer.

Structural design of cellulose-hyperbranched double-network for enhanced intramolecular diffusion kinetics of heavy metal ion capture processes

Extracting cellulose from agricultural residues and converting it into environmentally friendly adsorbents to solve the heavy metal contamination problem of groundwater and farmland is an effective strategy to achieve high-value utilization of agricultural residues. Herein, we propose a streamlined crosslinking strategy to fabricate a cellulose-based amphoteric hyperbranched adsorbent (MAHPA) in a controlled manner. The strategy involves synthesizing the amphoteric hyperbranched functional reagent first and then crosslinking it with microcrystalline cellulose (MCC). This approach simplifies the complexity of the multi-component cross-linking system, resulting in a conversion rate of reaction reagents exceeding 99 %. MAHPA, with a three-dimensional hyperbranched structure (degree of branching: 0.77), exhibits a high swelling rate (247.62 %) and high densities of carboxyl (7.05 mmol·g−1) and amino (8.27 mmol·g−1) groups. Moreover, the cellulose-hyperbranched double-network structure of MAHPA greatly enhances the intramolecular diffusion kinetics of heavy metal ions on MAHPA, enabling it to complete the removal of low concentrations of Cr(VI), As(V), Pb(II), and Cd(II) within 20 min. Interestingly, MAHPA demonstrates excellent synchronous capture performance for Cr(VI), As(V), Pb(II), and Cd(II) in groundwater at a velocity of 1.60 × 10−2 m·s−1. Meanwhile, applying MAHPA can realize the safe utilization of Cd-As contaminated soil. This work offers a general strategy for the structural design of cellulose-based hyperbranched adsorbent holding great promise as heavy metal contaminated groundwater and soil remediation field.