Polysaccharides, Volume 6, Issue 1 (March 2025) – 10 articles

Polymer matrices can be reinforced with cellulose fillers in a variety of geometric shapes. Depending on the morphology of the particles, the volume fraction of the composite additive may decrease, while the values of the elastic modulus may increase. Increasing the length while decreasing the width of the cellulose filler is an intriguing path in the development of composite additives and materials based on it. It is difficult to form thin continuous cellulose fibers, but this can be accomplished via the sea-island composite fiber manufacturing process. The creation of cellulose fibrils in polyacrylonitrile (PAN)/cellulose based systems happens during the spinning of the mixed solution. A selective solvent facilitates the isolation of cellulose fibrils. The structure of the isolated microfibers was investigated using X-ray diffraction, IR spectroscopy, SEM, and AFM. The structure of the resulting cellulose microfibers was compared to bacterial cellulose. It has been shown that composite fibers have a superposition pattern, while cellulose fibrils have a structure different from native cellulose and similar to Lyocell fibers (polymorph II). The crystallite sizes and crystallinity of regenerated cellulose were determined. The identified structural parameters for cellulose fibrils provide strength at the level of industrial hydrated cellulose fibers. Full article

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