Polysaccharides

Xylans, polysaccharides abundantly derived from agricultural byproducts, have shown potential pharmacological properties, making them a subject of increasing research interest. This study aimed to expand the understanding of xylans’ pharmacological properties and relate them to their composition. A method combining ultrasound and alkaline media for xylan extraction from corn cobs (ERX) was used, resulting in a significant increase in final yield compared to other methodologies. The physicochemical characterization of ERX was carried out, and its antioxidant, cytotoxic, anticoagulant, and immunomodulatory properties were evaluated. ERX demonstrated significant antioxidant activity with metal-chelating properties and induced apoptosis in HeLa tumor cells (p < 0.0001). It also reduced nitric oxide (NO) production by activated macrophages and extended the blood coagulation time, as assessed by the APTT assay (p < 0.0001). Further fractionation of ERX using various organic solvents resulted in multiple xylan subfractions. Among them, the ethanol-derived subfraction E1.4 exhibited remarkable pharmacological activities, including metal-chelation, cytotoxicity against HeLa cells via apoptosis, reduced NO production (p < 0.0001), and prolonged coagulation times (p < 0.0001). E1.4 is heteroxylan with a molecular weight of approximately 100 kDa. These findings suggest that corn cobs could be a promising source of pharmacologically significant molecules, particularly the heteroxylan E1.4. Future studies should focus on the structural characterization of this xylan to understand the relationship between structure and biological activity and explore the therapeutic potential of E1.4 in vivo models. Full article

The printing and dyeing industries generate wastewater containing toxic, hard-to-degrade organic dyes like methylene blue (MB). Recent research focuses on biodegradable, renewable materials such as cellulose-based absorbents to address this issue. This study investigates bacterial cellulose (BC) functionalized with citric acid as a sustainable adsorbent for MB removal. BC, a by-product of kombucha fermentation, is functionalized with citric acid, and its adsorption capacity is analyzed. BC production reaches 3.65 ± 0.16 g L⁻¹ by day 12. Using 0.05 g of functionalized BC (FBC) at pH 7, a maximum adsorption capacity of 13.22 ± 1.27 mg g⁻¹ is achieved for MB at 600 mg L⁻¹ over 60 min. The adsorption mechanism is complex, with both pseudo-first- and pseudo-second-order models fitting well at 20 °C, 40 °C, and 70 °C. The carboxyl groups of citric acid bind to the hydroxyl groups of cellulose fibers via esterification, altering the material’s charge, reactivity, thermal, and crystallinity properties. This functionalization enhances BC’s adsorption capacity, making it a promising material for bioremediation in circular systems. Full article

Pullulan is a natural polysaccharide used in many health products, including dry powders for oral and pulmonary administration. In these cases, the control of the shape and dimensions of particles is crucial for obtaining the desired functionality. Different from other polysaccharides, pullulan cannot be easily shaped without chemical modifications or adjuvants’ addition. This work aims to systematically investigate the impact of the solvent composition and polymer concentration on the possibility of tuning the pullulan particle shape by spray drying. The results revealed that the microparticle-to-fiber transition can be induced using a hydro-alcoholic solution since ethanol increased the relaxation time and reduced the evaporation rate. Furthermore, a high Péclet number during drying favors the formation of wrinkled surfaces at all feed compositions. Overall, these data evidenced the possibility of tuning the spray-dried product morphology without any processing aids, paving the way for new applications of pullulan, especially in the pharmaceutical field. Full article

The nasal cavity has become a focal point for drug delivery research. Beyond its use in treating local diseases, the nasal route is appealing due its ability to deliver systemically potent drugs with low oral bioavailability. Recent interest in nasal vaccination has driven significant pre-clinical and clinical advancements. Further R&D holds promise for expanding nasal medications, offering innovative healthcare solutions. This review explores strategies using polysaccharides to enhance nasal delivery of hydrophilic drugs, peptides, proteins, genes, and other active compounds that typically struggle to permeate the nasal epithelium. Polysaccharides are attractive excipients due to their potential to enhance nasal absorption, regulate drug release, and extend residence time in the nasal cavity through bioadhesive properties. Studies on their mechanisms affecting drug absorption, potential toxicities, and applications will also be reviewed considering the particularities of nasal epithelium anatomy and physiology. Most products with these excipients are in pre-clinical and clinical evaluation, but PecFent, a pectin-based formulation, is approved for nasal administration of opioids for breakthrough cancer pain, offering faster pain relief and a better benefit–risk ratio due to pectin. Other polysaccharides like chitosan, cyclodextrins, hyaluronic acid, and alginate have shown potential in enhancing nasal drug absorption. This approach also holds promise for enhancing drug transport from the nasal cavity to the CNS (nose-to-brain), potentially advancing treatments for neurodegenerative diseases. Full article

Polysaccharides offer a perfect option as raw materials for the development of a new generation of sustainable batteries and supercapacitors. This is due to their abundance and inherent structural characteristics. Polysaccharides can be chemically functionalized and engineered, offering a wide range of possibilities as electrode materials (as precursors of porous nanocarbons), binders and separators. Their hierarchical morphology also enables their exploitation as aerogel and hydrogel structures for quasi-solid and solid polymer electrolytes with high conductivity and wide voltage stability windows. In this review, we discuss how different polysaccharides, such as lignocellulosic biomass, starch, chitosan, natural gums, sugars and marine polysaccharides, can be applied in different components of energy storage systems (ESSs). An overview of the recent research work adhering to each functionality of different polysaccharides in various storage systems is provided. Full article

The search for developing materials of natural origin has become imperative due to the resistance shown by phytopathogenic microorganisms to traditional antimicrobial agents. Natural polymers such as chitosan offer a new alternative to fungal infections because, in most cases, these polymers are biocompatible, nontoxic, and natural. This study aimed to synthesize nanochitosan using ultrasonication and evaluate its antifungal activity on Colletotrichum chrysophillum and Colletotrichum musae. Nanochitosan of 302.4 ± 92.3 nm and a zeta potential of +35.9 ± 2.3 Mv, amorphous in shape, and a rough surface, was obtained. Nanochitosan reduced the radial growth 21%, for C. chrysophillum while C. musae showed a maximum inhibition of 26% at a concentration of 1.5 mg mL⁻¹ of nanochitosan. C. musae was the species most affected, with a 38% increase in hyphal diameter to 12 h. Also, nanochitosan affected the integrity of the fungi cell walls, plasma membrane, and generated low oxidative stress level. Our findings indicate that nanochitosan induces notable changes in the intracellular structures of the tested phytopathogens. Nevertheless, additional investigations are required to clarify the mechanisms underlying adaptability or resistance in fungal strains that exhibit reduced sensitivity to this biopolymer. Full article

There are limited studies in the literature on the surface characterization of modified graphene and graphene oxide and the impact of these modified adsorbents on adsorption performance. In addition, the amine group essentially has a promising affinity for carbon dioxide (CO₂). Therefore, chitosan was used in this study to be grafted onto graphene and graphene oxide respectively. This study examines the effects of graphene, graphene oxide, and chitosan-modified graphene oxide thin films on the removal of carbon dioxide (CO₂). Thin films of graphene, graphene oxide, and their chitosan-modified counterparts were prepared via the methods of precipitation and grafting. The differences in the chemical structure, surface properties, and surface morphology of the films were evaluated, and their effect on the adsorption performance of CO₂ is discussed herein. The micrographs from a scanning electron microscope (SEM) show that the surface of graphene oxide appeared to be more porous than graphene, and the amount of grafted chitosan on graphene oxide is higher than that on graphene. An analysis of atomic force microscope (AFM) finds that the surface of chitosan-modified graphene oxide is rougher than that of chitosan-modified graphene. The results of energy-dispersive X-ray spectroscopy (EDS) spectra reveal that the composition of oxygen in graphene oxide is greater than that in graphene and confirm that the oxygen and nitrogen contents of chitosan-modified adsorbents are greater than those of the pristine materials. An analysis of Fourier-transform infrared spectroscopy (FTIR) shows that most of the oxygen-containing groups are reacted or covered by amide or amine groups due to modification with chitosan. The adsorption isotherms for CO₂ adsorbed by the prepared graphene and graphene oxide presented as type I, indicating great adsorption performance under low pressure. The appropriate amount of chitosan for modifying graphene oxide could be found based on the change in surface area. Although the breakthrough times and the thicknesses of the mass transfer regions for graphene oxide modified with 0.9% and 1.2% chitosan were similar, the modification of graphene oxide with 0.9% chitosan was appropriate in this study due to a significant decrease in surface area with 1.2% chitosan dosage. The adsorption uptake difference between chitosan-modified graphene oxide and graphene was greater than that without modification with chitosan due to more chitosan grafted on graphene oxide. The Toth adsorption isotherm model was used to fit the adsorption uptake, and the average deviation was about 1.36%. Full article

Nowadays, agricultural biomass is one the most valuable sources of natural polysaccharides. In addition to primary agricultural goods, agricultural waste is abundant, diverse, and renewable and can also be utilized as raw material for the production of polysaccharides and their derivatives. The extraction and purification of agri-waste-derived polysaccharides involves multiple processes that can vary depending on the type of raw material and the specific polysaccharides targeted. This study proposes a particular pathway from corn waste to hemicellulosic polysaccharides, which involves alkaline treatment and several physicochemical separation/purification phases using precipitation and ion exchange resins (Purolite A400, Purolite A100+, Purolite C100H). The ion exchange separation stage was optimized to retain most of the acid-soluble lignin derivatives from the extraction liquors. The process parameters considered for optimization included the solid (resin) liquid (black liquor pH 4.5) ratio, contact time, and temperature. These ranged from 0.05 to 0.15 g·mL⁻¹, 30 to 180 min, and 20 to 50 °C, respectively. The chemical composition of the separated hemicelluloses varied from 44.43 to 75.28% for xylan, 2.43 to 3.93% for glucan, 1.86 to 2.44% for galactan and 8.93 to 12.68% for arabinan. The total carbohydrate content increased from 57.65 to 96.3%. Full article

Dyes abundance in industrial wastewater exerts adverse effects on the environment and human health; adsorption represents a promising remediation strategy. Chitosan-based composites are interesting materials for dye adsorption. In this work, methyl orange (MO) adsorption using chitosan (CH) and chitosan–graphene oxide (CH-GO) aerogels produced by supercritical gel drying, performed at 200 bar/35 °C, was assessed by studying the effect of driving force (25–100 ppm) and adsorbent dosage (1–8 g/L). It was highlighted that the difference in the performance between the two adsorbents was non-negligible only at high concentrations: processing a 100 ppm MO solution, q_eq is 59 mg/g and 28 mg/g for CH-GO and CH, respectively. Starting from a 10 ppm MO solution, using a dosage of 8 g/L, it was possible to achieve adsorption efficiency of about 85%, meaning that small amounts of nanostructured devices can result in good process outcomes. Freundlich isotherm reliably describes the system behavior (R² = 0.99). The multi-linear IPD kinetic model confirms that in the case of nanostructured porous devices, there are different mass transfer phenomena that control molecule diffusion through the system. The research proposed in this work aims to explore, as a first assessment, the potential of nanostructured devices for adsorption purposes. Full article

Xanthan gum (XG) is a well-known anionic polysaccharide that finds broad application in the food and petroleum industries because of its ability to enhance solution viscosity at low concentrations and moderate temperatures. The aim of this work was to use the solvation probe coumarin 153 (C153) to characterize changes in the xanthan gum (XG) solution microstructure as a function of XG concentration and temperature from the perspective of a dissolved solute molecule. We established the utility of C153 fluorescence to track solution changes for XG concentrations that span the transition region from a dilute to a semi-dilute solution, defined by the xanthan gum overlap concentration, C*~0.02 g/dL. The temperature was varied from 293 to 353 K to probe solution conditions wherein XG has been reported to undergo a structural change from helix to random coil conformation, the details of which are still under debate. While C153 fluorescence does not elucidate direct structural information, the emission response is a simple means by which changes in aqueous XG solution can be identified. C153 spectroscopy is observed to correlate with XG conformational changes, as reported in the literature. Full article

Large quantities of seeds are generated and discarded during agro-industrial mango processing. However, mango seeds still contain valuable components such as starch, which has applications in various industries. This study aimed to obtain and characterize starches from the seeds of five mango cultivars (Ataulfo, Manililla, Piña, Tapana, and Tommy Atkins). The isolated starches were evaluated for their physicochemical, morphological, structural, thermal, and rheological characteristics. The starches showed creamy white colorations, and their granules had spherical and oval shapes. This starch source contains a high percentage of apparent amylose, greatly influencing its thermal, rheological, and functional properties. Structural and molecular studies showed that all starches presented an A-type X-ray diffraction pattern, impacting their water absorption and viscosity. The transition temperatures were relatively high, which could be influenced by the length of the amylopectin chains and their intermediate components, the apparent amylose content, and other components such as lipids and anomalous amylopectin. The starches evaluated behaved as pseudoplastic materials, while oscillatory tests revealed that the pastes formed with mango starches are more elastic than viscous. In conclusion, research on the seed starch properties of different mango cultivars provides interesting results for their potential application in foods. It could contribute to the value-added processing of mango seeds as a potential starch source. Full article

Bacterial cellulose (BC) is a versatile biopolymer with significant potential across biomedical, food, and industrial applications. To remove bacterial contaminants, such as protein and DNA, BC pellicles undergo purification, which traditionally relies on harsh alkali treatments, such as sodium hydroxide or strong surfactants, which present environmental concerns. In response, this study evaluates the efficacy of various non-conventional surfactants—both non-biodegradable and biodegradable—as alternatives for BC purification. Among the surfactants tested, sodium cocoyl isethionate (SCI), a mild anionic and biodegradable surfactant, emerged as particularly effective, achieving an 80.7% reduction in protein content and a 65.19% reduction in double-stranded DNA (dsDNA) content relative to untreated samples. However, these advantages were not without additional challenges, such as the appearance of residual surfactants. Given SCI’s promising performance and biodegradability, it was further examined in two-step treatment protocols; additionally, sodium dodecyl sulfate (SDS) was also examined as a more traditional anionic surfactant as well as NaOH. For the two-step treatment protocol, BC pellicles were treated with one reagent for 3 h, followed by a second reagent for an additional 3 h. Notably, by using NaOH as the final step in the two-step treatment protocol, residual surfactant was not detected in the FTIR analysis. Overall, this work demonstrates that SCI, in addition to subsequent NaOH treatment, can be used as a surfactant-based approach for BC purification, representing a potential environmentally friendly alternative to traditional surfactant-based approaches for BC purification. Full article

Polyelectrolyte complexes (PECs) have gained increasing attention in recent decades due to their importance in various applications, such as water treatment and paper processing. These complexes are formed by mixtures of polycations (n+) and polyanions (n−), known as polyelectrolytes (PEs). In this study, a series of PECs were prepared with different molar charge ratios (n−/n+) using biopolymers such as chitosan (lch) and pectin (p) at pH 5, in addition to the synthetic polymer poly(ethylene alt maleic acid) (PEMA) at the same pH. Two types of chitosan—low molecular weight chitosan (lch) and high molecular weight chitosan (hch)—were used as polycations, and these were mixed with two types of pectin with either a high esterification degree (hp) or a low esterification degree (lp), as well as PEMA as polyanions. These components interacted via electrostatic forces to form the following PEC combinations: (lch&lp), (lch&hp), (hch&hp), and (lch&PEMA). The charge density, turbidity, and particle size of the formed PECs were examined to evaluate the influence of molecular weight and mixing speed on the formation process. Full article

Here, super porous carboxymethyl cellulose (CMC) cryogels were synthesized in 10–100% crosslinker and the presence of TA, at varying amounts of TA, e.g., 10 and 25 wt% of CMC under cryogenic conditions (−20 °C) as TA@CMCs. To control the degradation of CMC cryogel networks, the crosslinking ratio of divinyl sulfone (DVS:X) to CMC varied at 10, 25, 50, and 100% moles of the CMC repeating unit. Higher hydrolytic degradation was observed for CMC 10%X cryogels at pH 1.0 with 28.4 ± 1.2% weight loss. On the other hand, the TA-release studies from TA@CMC-based cryogels showed that higher TA releases were observed for both TA@CMC 10% and 25% cryogels at pH 7.4, with 23.6 ± 1.1, and 46.5 ± 2.3 mg/g in 480 min, which are equal to almost 24% and 18% of the TA contents of the corresponding cryogels, respectively. The antioxidant properties of TA@CMC cryogels were examined, and worthy antioxidant properties were observed due to the TA. The alpha-glucosidase enzyme inhibition ability of the prepared cryogels was examined at different concentrations by grinding cryogels, and it was determined that TA@CMC 25% cryogel at 3 mg/mL concentration inhibited 70.4 + 1.3% of the enzyme. All bare CMC-based cryogels were found to be non-hemolytic with a less than 1% hemolysis ratio and also effective on the blood coagulation mechanism with blood-clotting index (BCI) values between 62.1 and 81.7% at 1 mg/mL concentrations. On the other hand, TA@CMC 25% cryogels exhibited a slight hemolytic profile with a 6.1 ± 0.8% hemolysis ratio and did not affect the blood coagulation mechanism with 97.8 ± 0.4% BCI value. Full article

PLA biocomposites, incorporating 5% wt. of lignocellulosic fibres (LF) from Posidonia oceanica waste with different degrees of cellulose purification, were obtained by melt blending and compression moulding. The LF were obtained after removing part of the non-cellulosic components by subcritical water extraction at 150 and 170 °C and after bleaching the extracted residues with hydrogen peroxide or sodium chlorite. The non-bleached LF provided the composites with a brown colour and opacity, while the bleached LF impacted the optical properties of composites to a lower extent, depending on their whiteness. The LF composition had a noticeable effect on the composites’ mechanical and barrier properties. All LF reduced the water vapour barrier capacity while promoting the oxygen barrier of the films. Bleached LF enhanced the film stiffness and reduced extensibility and resistance to break, whereas non-bleached LF had lower impacts on the tensile parameters. Considering the mechanical and barrier performance of the composites, the fibres obtained at 170 °C and bleached with sodium chlorite exhibited the best behaviour. Nevertheless, if transparency and colour are not limiting for the use of the films, untreated LF allowed for good preservation of the water vapour permeability of PLA films and enhanced the oxygen barrier capacity, with a similar mechanical response as the other non-bleached fractions. Full article

Cellulose nanomaterials have been demonstrated to be excellent barriers against grease, oxygen, and other vapors, but their implementation in packaging materials is challenging because of numerous technical and practical challenges. In this work, the oxygen, air, grease, and heptane barrier performance of copy papers coated with cellulose nanocrystals (CNCs), oxidized cellulose nanofibrils (TOCNs), and carboxymethyl cellulose (CMC) weas examined. The effects of different materials and processing conditions were evaluated for their impacts on the resulting barrier properties. TOCN coatings demonstrated significantly better barrier properties than CNC and CMC coatings due to the long-range networked structure of TOCN suspensions eliciting enhanced film formation at the paper surface. Neat coatings of nanocellulose did not readily result in strong oxygen barriers, but the addition of CMC and/or an additional waterborne water barrier coating was found to result in oxygen barriers suitable for packaging applications (1 cm³/m²·day transmission at low humidity with a 10 g/m² coating). Cast films and thick coatings of CMC were good barriers to oxygen, grease, and air, and its addition to cellulose nanomaterial suspensions aided the coating process and reduced coating defects. In all cases, the incorporation of additional processing aids or coatings was necessary to achieve suitable barrier properties. However, maintaining the strong barrier properties of nanocellulose coatings after creasing remains challenging. Full article

In the quest for sustainable and efficient solutions for modern electronics, flexible electronic devices have garnered global attention due to their potential to revolutionize various technological applications. The manufacturing of these devices poses significant challenges, particularly regarding environmental sustainability and ease of production. A novel method employing direct inkjet printing of silver nanoparticle (npAg) ink onto cellulose nanocrystal (CNC) substrates is presented, offering a promising alternative to conventional methods. This study demonstrates the ability of CNCs to serve as a flexible and biodegradable substrate that does not require complex post-printing treatments to achieve adequate electrical performance. This method was implemented in the fabrication of an electrowetting-on-dielectric (EWOD) device, achieving circuit patterns with high resolutions and reduced resistances. The findings not only validate the use of CNCs in flexible electronic applications but also underscore the potential of advanced printing techniques to develop flexible electronics that are environmentally sustainable and technically feasible. Full article

Immobilized enzyme reactors (IMERs) are critical tools for developing novel oligosaccharides based on the enzymatic catalysis of polysaccharides. In this paper, a novel glucuronan lyase from Peteryoungia rosettiformans was produced, purified, and then immobilized on a CIM^® CDI disk for cleaving glucuronan. The results showed that around 63.6% of glycuronan lyases (800.9 μg) were immobilized on the disk. The V_max values of immobilized glucuronan lyases did not significantly change (56.9 ± 4.7 μM∙min⁻¹), while the K_m values (0.310 ± 0.075 g∙L⁻¹) increased by 2.5 times. It is worth noting that immobilized glucuronan lyases overcame the catalytic inhibition of free enzymes observed under high glucuronan concentrations (0.5–2 g∙L⁻¹). circumscribed central composite design (CCCD) and response surface methodology (RSM) showed that glucuronan concentration, flow rate, and reaction time significantly affected the yield of oligoglucuronans. The degree of polymerization (DP) of degraded glucuronan ranged from DP 2–8 according to the results obtained by high performance anion exchange chromatography coupled with a pulsed amperometric detector (HPAEC-PAD). The IMER retained 50.9% activity after running 2373 column volumes of glucuronan. Finally, this glucuronan lyase reactor was tentatively connected to an immobilized laccase reactor to depolymerize, and gallic acid (GA) was added to glucuronan. Approximately 8.5 mg of GA was added onto 1 g of initial glucuronan, and the GA–oligoglucuronan conjugates showed notable antioxidant activity. Full article

Although diglycidyl ethers of glycols (DEs)—FDA-approved reagents for biomedical applications—were considered unsuitable for the fabrication of chitosan (CH) hydrogels and cryogels, we have recently shown that CH cross-linking with DEs is possible, but its efficiency depends on the nature of the acid used to dissolve chitosan and pH. To elucidate the origin of the low efficiency of chitosan interactions with DEs in acetic acid solutions, we have put forward two hypotheses: (i) DEs are consumed in a side reaction with acetic acid; (ii) DE chain length strongly affects the probability of cross-linking. We then verified them using FT-IR spectroscopy, rheological measurements, and uniaxial compression tests. The formation of esters in acetic acid solutions was confirmed for ethylene glycol diglycidyl ether (EGDE) and poly(ethylene glycol) diglycidyl ether (PEGDE). By the 7th day of gelation at pH 5.5, the G’_HCl/G’_HAc ratio was 5.1 and 1.5 for EGDE and PEGDE, respectively, indicating that the loss of cross-linking efficiency in acetic acid solution was less pronounced for the long-chain cross-linker. Under conditions of cryotropic gelation, only weak cryogels were obtained from acetic acid solutions at a DE:CH molar ratio of 1:1, while stable cryogels were fabricated at a molar ratio of 1:20 from HCl solutions. Full article