Polysaccharides

Heparin, a widely used polysaccharidic anticoagulant of animal origin, is associated with risks of contamination and adverse effects, notably bleeding and thrombocytopenia. These limitations have prompted interest in alternative sulfated polysaccharides with anticoagulant properties and improved safety profiles. This study explored the anticoagulant potential of two marine bacterial exopolysaccharides (EPS), infernan and diabolican. It assessed whether chemical modifications (depolymerization, oversulfation) could enhance their anticoagulant properties compared to unfractionated and low molecular weight heparins. Native EPS were depolymerized to generate different molecular weights and then chemically oversulfated to increase negative charge density. Anticoagulant activities were evaluated using clotting and thrombin generation assays (TGA). Molecular docking was performed to model interactions with antithrombin and heparin cofactor II. Only highly sulfated derivatives significantly prolonged activated partial thromboplastin time while showing negligible effect on thrombin time and anti-factor Xa activity. They present different structures, and their binding to antithrombin is not achieved via the classic pentasaccharide motif. In TGA, these derivatives inhibited thrombin formation at higher doses than heparin but induced a marked delay in clot generation. Docking analyses supported their ability to bind serpins, albeit with lower specificity than heparin. Their limited anti-Xa activity and non-animal origin position them as promising anticoagulant candidates. Full article

This review explores the eco-friendly synthesis of metallic nanoparticles derived from polysaccharides obtained from agricultural and food industry waste. Initially, it outlines the problem of agri-food waste, highlighting its abundance and the potential to extract valuable polysaccharides such as cellulose, hemicellulose, lignin, and pectin. The focus is on green synthesis methods that use these polysaccharides to produce metallic nanoparticles, emphasizing the environmental benefits compared to conventional methods. The article reviews the physicochemical properties of key polysaccharides and details their extraction processes from various agricultural waste. The synthesis of diverse types of metallic nanoparticles, including monometallic (e.g., gold, silver, and platinum), bimetallic (e.g., gold–silver and gold–zinc), and oxide nanoparticles (e.g., zinc oxide and iron oxide), is extensively covered. Additionally, mechanisms of nanoparticle synthesis, such as nucleation, growth, stabilization, and capping, are examined, alongside examples from existing research. The article highlights the applications of these nanoparticles in diverse fields, including food safety, healthcare, agriculture, and environmental protection. It concludes by underscoring the potential of green synthesis to reduce waste and promote sustainable industrial practices and calls for further research to optimize these methods. Full article

Anthracnose is a disease caused by phytopathogenic fungi such as Colletotrichum siamense that attacks plants and fruits causing great postharvest losses. Different alternatives for the control of this fungus have been studied. In the present study, we evaluated the in vitro antifungal activity of the methanolic extracts of Baccharis glutinosa (ExB) and Jacquinia macrocarpa (ExJ) individually, as well as in combination with chitosan (CS), along with their toxicity in different models. Using the radial growth technique, it was observed that the mycelial development of C. siamense was altered and reduced during exposure to the different treatments evaluated during the first hours of incubation, indicating a fungistatic effect. While the cell viability, by colorimetric assay using the XTT salt, showed alteration since the chitosan reduced proliferation by 50%, while the plant extracts and their mixtures with chitosan reduced approximately 40% indicating cell damage, which was confirmed by fluorescence microscopy. In addition, toxicity tests demonstrated that the J. macrocarpa extract significantly affected the germination percentage of Lactuca sativa seeds, whereas radicle length was reduced in all treatments except for chitosan. The larval survival test for Artemia salina with the extracts indicated their potential toxicity by causing up to 60% mortality. The results indicate that ExB and ExJ mixed with CS are a good option for controlling C. siamense; however, at the concentrations used, they exhibit a toxic effect on the evaluated models. Full article

Due to its gelling and thickening properties, sweet potato starch (Ipomoea batatas L.) could be a promising ingredient to improve characteristics such as the viscosity and consistency of foods like dressings. The objective of this study was to use sweet potato starch by adding it to salad dressing-type emulsion formulations. Sweet potato starch was characterized (microscopic appearance, granule size, and thermal properties). Four formulations (F1–F4) were developed incorporating different amounts of sweet potato starch (2 and 4%), and were characterized by particle size, emulsion stability, rheology, and sensory analysis. The starch granules were oval shaped, with a size range of 10–33 μm, and a temperature and enthalpy gelatinization (ΔH) of 69.08 °C and 10.72 J/g, respectively. The formulations were evaluated for 30 days, the particle size had a range of 2.18–13.88 μm, the emulsion stability was 98.89–100%, all formulations presented a creaming index at 0%, and the coalescence rate obtained values between −2.33 × 10⁻⁸ and 7 × 10⁻⁸Kc (s⁻¹) showing a significant difference. The consistency coefficient (K) was obtained, 2.477–35.207 Pa·sⁿ, and there was no significant difference between F1 and F2 with respect to a commercial dressing. In the sensory analysis, F2 presented greater acceptance. The values obtained suggest that sweet potato starch could be used in this type of food, showing similarities to the commercial brand. Full article

Starch films were obtained by solvent casting and thermoprocessing using glycerol as a plasticiser from a new starch source: tiger nut waste from horchata production. The tiger nut starch (TNS) films showed a barrier capacity to water vapour and gases in the typical range of other starch films, such as corn starch (CS) films, with a high barrier capacity to oxygen. The tensile properties of the films were affected by the processing method, exhibiting higher stiffness and resistance to break and lower stretchability than the more common CS films. Thermoprocessed TNS films were less water soluble than CS films, and their solubility was higher than that of cast TNS films. However, all films exhibited similar swelling power. Thermal stability was also similar for all TNS and CS films, showing the typical thermal degradation pattern of starch–glycerol films. Therefore, TNS obtained from horchata production waste can be used to obtain thermoplastic starch films for packaging applications, with characteristics comparable to the most common corn starch films. Full article

Localized treatment has emerged as an excellent alternative to minimize the side effects associated with the systemic dispersion of therapeutic agents, which can damage healthy tissues. Injectable hydrogels offer a promising solution because they can encapsulate and release therapeutic agents in a controlled manner. In this context, this study focuses on the development and characterization of an injectable hydrogel based on carboxymethyl chitosan (CMCh) and oxidized agarose (OA), in which chemical crosslinking through imine bond formation avoids the use of external crosslinking agents. Several polymer ratios were evaluated to obtain hydrogels (OA:CMCh), and stable gels were formed at physiological temperatures in all cases. The hydrogels were injectable through a 21 G needle with forces below 30 N, formed porous structures, and exhibited a self-healing capacity after 48 h. Additionally, the hydrogels displayed compressive strengths ranging from 26 to 71 kPa and elastic moduli similar to those of human tissues (6–20 kPa). Swelling percentages of up to 3090% were achieved owing to the high hydrophilicity of CMCh and OA, and strong chemical crosslinking maintained the gel stability for two weeks with low mass loss rates (<21%). Furthermore, polymer ratio variation and storage at 4 °C were observed to affect the hydrogel characteristics, allowing for property modulation according to the application needs. These results indicate that the proposed polymeric combination enables the formation of hydrogels with the potential for localized drug delivery. Full article

Membrane processes are extensively employed in a range of industrial and food applications. Due to growing environmental concerns and the introduction of regulatory measures, it is imperative to develop innovative membrane materials that can effectively replace petrochemical-based polymers, in line with the principles of a circular economy. The focus of this review is the use of polysaccharides for obtaining films/membranes for food and industrial applications using selected case studies. Besides the polysaccharides extracted from biomass, the valorization of agrifood residues and the use of plants adapted to arid lands (i.e., cactus) to produce polysaccharide films for food packaging is addressed. Moreover, microbial polysaccharides produced using renewable resources present a significant alternative to commercial hydrophilic membranes for gases and ethanol dehydration. To meet industry requirements, the mechanical and barrier properties of the films can be improved by the inclusion of inert impermeable fillers and/or the chemical modification of the polysaccharides. The adsorption of proteins, dyes, and pharmaceutical compounds using a cellulose-based polymer is discussed. Despite their unique characteristics, polysaccharide production costs are still higher than most synthetic polymers. This is a challenge that can be overcome by scaling up the production and by valorizing agro-industrial wastes and by-products to make the application of polysaccharide membranes/films in the food and industry sectors more widespread. Full article

Long-term solutions for cartilage repair after injury are currently being investigated, with most research aiming to exploit the regenerative and chondrogenic differentiation potential of stem-cell-based spheroids. The incorporation of the bioactive polymer CTL, a lactose-modified chitosan, into spheroids is a strategy to improve cell viability and accelerate type II collagen gene expression. In this work, the role of CTL in influencing the dynamics of spheroid formation and its interplay with cell membrane adhesion molecules (integrins and cadherins) and cytoskeletal components is elucidated. The results indicate that CTL is actively involved in the reorganization of cells into spheroids. An analysis of the effects of physical form of CTL (rehydrated polymer coating or polymer solution) in stimulating peculiar biological responses indicates that CTL matrix in spheroids facilitates an early phase of chondrogenic differentiation. Once the CTL matrix is included in spheroids, there is an increase in COL2A1 gene expression and matrix deposition, regardless of the initial physical form of CTL. Overall, these results contribute to a better understanding of the dynamics of spheroid formation in the presence of the polymer and on its bioactive role in mesenchymal stem cell spheroids. Full article

Starch is one of the leading nutritional carbohydrates in the human diet; its characteristics, such as digestion rate, depend on molecular structure, and in particular, the molecular composition, type and length of amylopectin chains, which are known to present a parabolic behavior with respect to digestion rate. Amylopectin with a higher density of small branches (Chains A) and those abundant in long chains (B2/B3) often present a marked resistance to digestion and could be a challenge in bread production since both fermentation and digestion could be further modulated in the presence of hydrocolloids or gluten. The objective of this work was to analyze different mixtures of starches (rice, potato, and corn) with hydrocolloids (guar and xanthan gum) and vital gluten to understand the relationship between chain length and molecular characteristics with respect to speed of digestion and glycemic index, and their incorporation into a bread loaf at 50 and 100% wheat flour substitution. A Plackett–Burman design was used to design the mixtures. Mixtures were characterized in terms of amylose/amylopectin content, fast, slow, and resistant (SDS, RS) starch digestion fractions, in vitro glycemic index, molecular weight (Mw), radius of gyration (Rz) of amylopectin, chain length distribution, and textural analysis. In the bread, a tendency to increase the SDS was observed when the mixtures included rice or potato, which can be related to the relationship between Mw and size and the prevalence of B2 and B3 chains. The Rz and RS content were related to average chain size and amylose content. The use of vital gluten was a determinant in achieving volume and textural characteristics in the final products and significantly affected the proportions of SDS and RS. By combining the molecular characteristics of starch with hydrocolloids, we can obtain food ingredients for specific applications, such as gluten-free products. Full article

In this work, κ-carrageenan (κ-C) and polyethylene oxide (PEO) were utilized to synthesize polymeric films (κ-C-PEO). A 2^k experimental design was employed to optimize the synthesis of κ-C-PEO systems by considering the content of κ-carrageenan, PEO, and glycerin and their influence on the mechanical features of the resultant films. The κ-C-PEO systems were robustly characterized by FTIR spectroscopy, thermogravimetric analyses, and scanning electron microscopy (SEM). Magnesium oxide nanoparticles (MgO-NPs) were utilized to load κ-C-PEO films as an efficient approach to enhance their biological performance. The activity of κ-C-PEO films was studied against Gram-negative bacteria through the Kirby–Bauer assay. Artemia salina nauplii were cultured to assess the possible toxicity of κ-C-PEO films. The results demonstrated that κ-C-PEO films were elongated with the heterogeneous distribution of MgO-NPs. The tensile strength, thickness, and swelling capacity of κ-C-PEO films were 129 kPa, 0.19 mm, and 52.01%, respectively. TGA and DTA analyses revealed that κ-C-PEO films are thermally stable structures presenting significant mass loss patterns at >200 °C. Treatment with κ-C-PEO films did not inhibit the growth of Escherichia coli nor Pseudomonas aeruginosa. Against A. salina nauplii, κ-C-PEO films did not decrease the survival rate nor compromise the morphology of the tested in vivo model. The retrieved data from this study expand the knowledge about integrating inorganic nanomaterials with polysaccharide-based structures and their possible application in treating chronic wounds. Even though this work provides innovative insights into the optimal design of bioactive structures, further approaches are required to improve the biological performance of the synthesized κ-C-PEO films. Full article

In this study, cellulose nanocrystals (CNCs) were successfully isolated through the acid hydrolysis of freeze-dried and oven-dried bacterial nanocellulose (BNC) recovered from the floating pellicle generated during Kombucha tea production. The influence of the BNC drying method and its concentration on the yield and main characteristics of the CNCs obtained were studied. Additionally, selected CNC suspensions at various pH levels were subjected to freeze-drying and oven-drying, followed by an assessment of their dispersibility in water after undergoing different mechanical treatments. Results demonstrate the potential of utilizing byproducts from the expanding Kombucha industry as an alternative cellulose source for CNC production. Furthermore, the drying method applied to the BNC and its initial concentration in the hydrolysis medium were found to significantly impact the properties of the resulting CNCs, which exhibited diverse size distributions and Z-potential values. Finally, the redispersion studies highlighted the beneficial effect of drying CNCs from neutral and alkaline dispersions, as well as the requirement of ultrasound treatments to achieve the proper dispersion of dehydrated CNC powders. Full article

The multifactorial modification of the structure and properties of alginate matrix was conducted using partially acetylated cellulose nanocrystals. Fourier-transform infrared spectroscopy and thermogravimetric analysis indicated the absence of chemical interactions between the polymer matrix and the filler. The surface texture was examined using optical microscopy and scanning electron microscopy, along with a reconstruction of its 3D model. With an increase in the content of nanoparticles in the composite, the following was revealed. Firstly, the roughness and density of the arrangement of surface elements increased, while their size decreased. Secondly, at pH values < 7, the puncture resistance increased, whereas the swelling coefficient of the films decreased. In Hanks solutions, the low solubility of the films was established, as well as a higher swelling coefficient at pH > 7. Thirdly, the contribution of donor centers to the free surface energy, cytocompatibility of composite films, and adhesion of fibroblasts to the surface increased. The hematological tests of the composites showed a procoagulant effect. Summarizing the data, we propose a model that explains the influence of nanocrystals and their concentration on the formation of the observed composites’ structure and their physicochemical and biological properties. The main driving forces of structurization are the factor of the excluded volume and interactions in a heterogeneous colloidal system. Full article

Adsorption has been found to be highly effective for removing heavy metals from polluted industrial wastewater. Adsorbents of biological origin, such as negatively charged polysaccharides, e.g., alginate and carrageenan, have attracted a lot of attention recently. In this study, these three polysaccharides were used to adsorb different heavy metal ions from aqueous solutions. The results showed that the sorption yields of various lanthanides with the kappa and iota carrageenan were similar, though the sorption yields of the iota beads were higher. Also, the iota and the kappa beads had higher sorption yields for Ru³⁺ and Rh³⁺ than they did for the lanthanides. In general, the presence of light metal ions in the solution affected the sorption yields of the heavy metal ions, depending on the type and concentration of the light metal ions. All three polysaccharides were also capable of adsorbing mixtures of lanthanides and heavy metal ions. In binary solutions that contained both lanthanide ions (Ce³⁺ or Eu³⁺) and transition heavy metal ions (Ru³⁺ or Rh³⁺), differences in sorption yields were observed, with all polysaccharides exhibiting higher selectivity for Ru³⁺ and Rh³⁺. Finally, FTIR, SEM/EDS, and TGA analyses confirmed that all metal ions were adsorbed onto both types of carrageenan. Full article

Lollipop sticks were developed with fully biobased materials made of different plantain by-products, using extrusion processing followed by hot compression molding. The thermoplastic matrix was constituted of flour and starch from plantain bunch pulp and plantain peel cake. At the same time, two types of reinforcement were used, one of them being yarn from the lignocellulosic fibers of the pseudostem sheaths to constitute the BC1 lollipop stick and the other directly from the plantain pseudostem treated sheath to establish the BC2 lollipop stick. The biobased lollipop sticks were characterized in the migration test, finding a higher structural stability in lipophilic foods, with chocolate chosen as a confection to undergo physicochemical, structural, mechanical, and dynamic–mechanical characterization when interacting with the two biobased lollipop sticks until post-consumption was reached. The BC2 lollipop stick was characterized by maintaining higher stability in maximum tensile strength (12.62 to 11.76 MPa), higher flexural strength (19.07 to 10.11 MPa), storage modulus (4.97 to 1.65 GPa at 30 °C), and Tan delta (66.90 to 52.64 °C). Full article

Starch was plasticized with epoxidized soybean oil (ESO) modified by reaction with cinnamic acid (CA), and films were prepared using solvent casting from water/ethanol solutions. They exhibited good hydrophobicity, reduced water sensitivity, and showed the same transparency as glycerol-plasticized counterparts, but with less flexibility. Interestingly, modified ESO enhanced gelatinization and hindered retrogradation of the biopolymer. ESO was reacted with CA without the use of catalysts to obtain a β-hydroxyester; in order to optimize the synthesis process, different reaction conditions were explored, varying the stoichiometry and the heating cycles. Products were fully characterized by Fourier transform infrared (FTIR) spectroscopy, ¹H and ¹³C nuclear magnetic resonance (NMR), and the different reactions following the opening of the oxirane ring were discussed. The properties of the novel starch-based films prepared with modified ESO highlight their use in food packaging, disposable devices, and agricultural mulching films. Full article

This work investigates the effects of gamma irradiation (0.1–10 kGy) on four Italian wheat matrices, such as durum, conventional soft, integrated soft, and biological soft wheat, by coupling Raman, FTIR-ATR and EPR spectroscopies to provide complementary insights into the structural, conformational, and radical-based transformations occurring in starch, the primary polysaccharide in wheat. As a general trend, gamma irradiation up to 10 kGy does not induce drastic degradation or depolymerization of wheat components. However, deeper investigations reveal that wheat composition is crucial in modulating the effects of gamma irradiation on structural and conformational rearrangements of starch units. Raman and FTIR-ATR spectroscopy analyses showed an increase in random coil fractions, with the most significant changes observed in durum wheat, plausibly attributed to its higher protein content. EPR analyses confirmed a dose-dependent increase in free radicals, with different recombination kinetics between wheat types influenced by their intrinsic composition and molecular organization. The proposed spectroscopic approaches allow for rapid and non-destructive analyses of molecular structure, chemical composition, and free radical content in irradiated wheat matrices with minimal sample preparation. These approaches can be extended in the development of screening methods for a wide range of polysaccharides in a variety of crops. Full article

ABC transporters are a large family of proteins that mediate the export or import of a variety of molecules, including capsular polysaccharides. The capsules are an important virulence factor that protect bacteria from host immune system attacks, antibiotics, and physicochemical changes in their environment. In some Gram-negative pathogenic bacteria, ABC transporter-dependent systems facilitate the export of capsular polysaccharides. These transport systems are composed of three parts: the ABC transporter and the polysaccharide co-polymerase protein in the inner membrane and the outer membrane polysaccharide export protein in the outer membrane. The glycolipid anchor of the capsular polysaccharide binds to a pocket between the two subunits of the ABC transporter transmembrane domain. The three parts of the ABC transporter-dependent system form a tunnel, through which the capsular polysaccharide is exported using energy from ATP hydrolysis. Knowledge of the ABC transporter-dependent system and its function is incomplete, requiring further research to better understand the processes of capsular polysaccharide export. This may also allow, in the future, to develop new molecules that inhibit capsular polysaccharide export, which would help the host immune system fight Gram-negative pathogenic bacteria coated with capsular polysaccharides. This review presents the latest findings on ABC transporter-dependent systems that export capsular polysaccharides in Gram-negative pathogenic bacteria. Full article

Polysaccharide-based materials are a highly promising bioresource in the realm of biomaterial technologies due to their unique properties and versatility. Cellulose gels leverage the renewability, biocompatibility, and biodegradability of cellulose, a glucose polymer, making them ideal for various applications. This review examines various types of cellulose gels, a well-known polysaccharide used in agriculture, including natural (such as non-wood and bacterial cellulose gels), regenerated cellulose gels, and gels derived from cellulose derivatives. The properties of these cellulose gels, advanced technologies used in their potential fabrication, and their utilization techniques are comprehensively summarized based on a comprehensive systematic literature review to provide an in-depth understanding of the research theme, identify research gaps, and highlight future research directions. The review also explores the various applications of cellulose gels in agriculture, from fundamental research to practical implementations. Cellulose gels are versatile materials that can be used for soil conditioning, controlled release of fertilizers, water retention, and other important purposes. This exploration aims to provide a comprehensive understanding of the current state of cellulose gels in agriculture, bridging the gap between fundamental advances and their real-world applications. Full article

Aloe Vera (Aloe barbadensis Miller), a historically revered medicinal plant, has garnered great scientific attention due to its polysaccharide-rich bioactive compounds with significant therapeutic potential. This review examines the role of Aloe Vera polysaccharides as therapeutic agents in biomedical applications, highlighting their benefits as well as the risks. Traditionally recognized for its anti-inflammatory and antimicrobial effects, which are very important in wound healing, the Aloe Vera relies on its polysaccharides, which confer immunomodulatory, antioxidant, and tissue-regenerative properties. These compounds have shown promise in various applications, including skin repair, tissue engineering scaffolds, and antiviral therapies, with their delivery being facilitated via gels, thin films, or oral formulations. This review explores also their mechanisms of action and applications in modern medicine, including in the development of topical gels, dietary supplements, and innovative delivery systems such as thin films and scaffolds. Despite the promising benefits, the review addresses the possible side effects too, including allergic reactions, gastrointestinal disorders, and drug interactions, emphasizing the importance of understanding these risks for their safe clinical use. Assessing both the advantages and challenges of Aloe Vera polysaccharide medical use, this review contributes to the ongoing dialog regarding the integration of natural products into therapeutic practices, ultimately supporting informed decisions regarding their clinical application. Full article