Design of pH-responsive and amphiphilic pullulan-based biological macromolecule for gene delivery.

Nanomedicine, particularly gene delivery, holds immense potential and offers promising therapeutic options. Non-viral systems gained attention due to their binding capacity, stability and scalability. Among these, natural polysaccharides, such as pullulan, are advantageous in terms of sustainability, biocompatibility and potential degradability.

Bioactive Lyocell Fibers with Inherent Antibacterial, Antiviral and Antifungal Properties.

Functional Lyocell fibers gain interest in garments and technical textiles, especially when equipped with inherently bioactive features. In this study, Lyocell fibers are modified with an ion exchange resin and subsequently loaded with copper (Cu) ions. The modified Lyocell process enables high amounts of the resin additive (>10%) through intensive dispersion and subsequently, high uptake of 2.

The European Polysaccharide Network of Excellence (EPNOE) research roadmap 2040: Advanced strategies for exploiting the vast potential of polysaccharides as renewable bioresources.

Polysaccharides are among the most abundant bioresources on earth and consequently need to play a pivotal role when addressing existential scientific challenges like climate change and the shift from fossil-based to sustainable biobased materials. The Research Roadmap 2040 of the European Polysaccharide Network of Excellence (EPNOE) provides an expert's view on how future research and development strategies need to evolve to fully exploit the vast potential of polysaccharides as renewable bioresources. It is addressed to academic researchers, companies, as well as policymakers and covers five strategic areas that are of great importance in the context of polysaccharide related research: (I) Materials & Engineering, (II) Food & Nutrition, (III) Biomedical Applications, (IV) Chemistry, Biology & Physics, and (V) Skills & Education.

Reactive xylan derivatives for azid-/alkyne-click-chemistry approaches - From modular synthesis to gel-formation.

A modular synthesis was developed to obtain reactive xylan derivatives that are accessible for further functionalization and chemical crosslinking by click-chemistry approaches. Xylan phenylcarbonates (XPCs) with degrees of substitution (DS) from 0.62 to 1.

Starch Formates: Synthesis and Modification.

Starch can be efficiently converted into the corresponding formates homogeneously using -formyl imidazole obtained by the reaction of 1,1'-carbonyldiimidazole and formic acid in dimethyl sulfoxide as a solvent. Starch formates are soluble in polar aprotic solvents, not susceptible against hydrolysis, and not meltable. Thermoplastics could be generated by conversion of starch formates with long-chain fatty acids exemplified by the conversion with lauroyl chloride in -dimethylacetamide, leading to mixed starch laurate formates.

Advanced characterization of regioselectively substituted methylcellulose model compounds by DNP enhanced solid-state NMR spectroscopy.

Dynamic Nuclear Polarization MAS NMR is introduced to characterize model methylcellulose ether compounds at natural isotopic abundance. In particular an approach is provided to determine the position of the methyl ether group within the repeating unit. Specifically, natural abundance C-C correlation experiments are used to characterize model 3-O-methylcellulose and 2,3-O-dimethylcellulose, and identify changes in chemical shifts with respect to native cellulose.

Sulfoethylation of polysaccharides-A comparative study.

The heterogeneous sulfoethylation of cellulose, xylan, α-1,3-glucan, glucomannan, pullulan, curdlan, galactoglucomannan, and agarose was studied using sodium vinylsulfonate (NaVS) as reagent in presence of sodium hydroxide and iso-propanol (i-PrOH) as slurry medium. The influence of the concentration of polymer, water, and NaOH (solid or aqueous solution) on the degree of substitution (DS) was investigated. The sulfoethylation rendered the polysaccharides studied water-soluble.

Recent Progress on Cellulose-Based Ionic Compounds for Biomaterials.

Glycans play important roles in all major kingdoms of organisms, such as archea, bacteria, fungi, plants, and animals. Cellulose, the most abundant polysaccharide on the Earth, plays a predominant role for mechanical stability in plants, and finds a plethora of applications by humans. Beyond traditional use, biomedical application of cellulose becomes feasible with advances of soluble cellulose derivatives with diverse functional moieties along the backbone and modified nanocellulose with versatile functional groups on the surface due to the native features of cellulose as both cellulose chains and supramolecular ordered domains as extractable nanocellulose.

Nanoparticles Based on Hydrophobic Polysaccharide Derivatives-Formation Principles, Characterization Techniques, and Biomedical Applications.

Polysaccharide (PS) nanoparticles (NP) are fascinating materials that combine huge application potential with the unique beneficial features of natural biopolymers. Different types of PS-NP can be distinguished depending on the basic preparation principles (top-down vs bottom-up vs coating of nanomaterials) and the material from which they are obtained (native PS vs chemically modified PS derivatives vs nanocomposites). This review provides a comprehensive overview of an approach towards PS-NP that has gained rapidly increasing interest within the last decade; the nanoself-assembling of hydrophobic PS derivatives.

Modular synthesis of non-charged and ionic xylan carbamate derivatives from xylan carbonates.

Novel non-charged and ionic xylan carbamate (XC) derivatives were synthesized in a modular approach from xylan phenyl carbonates (XPC) as reactive intermediates. XPC with varying degrees of substitution (DS) from 0.5 to 1.

Synthesis of xylan carbonates - An approach towards reactive polysaccharide derivatives showing self-assembling into nanoparticles.

Xylan phenyl carbonate (XPC) derivatives were prepared and characterized comprehensively. By conversion of xylan with phenyl chloroformate either in dipolar aprotic solvents with LiCl or in an ionic liquid, XPC with degrees of substitution (DS) of up to 2.0, i.

Recent Advances in Solvents for the Dissolution, Shaping and Derivatization of Cellulose: Quaternary Ammonium Electrolytes and their Solutions in Water and Molecular Solvents.

There is a sustained interest in developing solvents for physically dissolving cellulose, i.e., without covalent bond formation.

Chitosan-Cellulose Multifunctional Hydrogel Beads: Design, Characterization and Evaluation of Cytocompatibility with Breast Adenocarcinoma and Osteoblast Cells.

Cytocompatible polysaccharide-based functional scaffolds are potential extracellular matrix candidates for soft and hard tissue engineering. This paper describes a facile approach to design cytocompatible, non-toxic, and multifunctional chitosan-cellulose based hydrogel beads utilising polysaccharide dissolution in sodium hydroxide-urea-water solvent system and coagulation under three different acidic conditions, namely 2 M acetic acid, 2 M hydrochloric acid, and 2 M sulfuric acid. The effect of coagulating medium on the final chemical composition of the hydrogel beads is investigated by spectroscopic techniques (ATR-FTIR, Raman, NMR), and elemental analysis.

Preparation of sodium cellulose sulfate oligomers by free-radical depolymerization.

Sodium cellulose sulfates with various degree of substitution (DS) and degree of polymerization (DP) were synthesized by homogeneous sulfation of cellulose with different DP by using SO/pyridine (Py) complex in N,N-dimethylacetamide/lithium chloride (DMA/LiCl). Sodium cellulose sulfate (SCS) samples obtained were free-radically depolymerized with hydrogen peroxide and copper (II) acetate at a controlled pH value of 7.5-8.

Homogeneous tosylation of agarose as an approach toward novel functional polysaccharide materials.

The homogeneous tosylation of agarose was studied with respect to the effects of reaction parameters, such as reaction medium, time, and molar ratio, on the reaction course, the degree of substitution (DS) with tosyl/chloro deoxy groups, and the molecular structure. Tosyl agaroses (TOSA) with DS tosyl ≤ 1 .81 could be obtained in completely homogeneous reactions by using N,N-dimethylacetamide (DMA)/LiCl or 1,3-dimethyl-2-imidazolidinone (DMI) as solvents.

Studies on the tosylation of cellulose in mixtures of ionic liquids and a co-solvent.

The tosylation of cellulose in ionic liquids (ILs) was studied. Due to the beneficial effect of different co-solvents, the reaction could be performed at 25°C without the need of heating (in order to reduce viscosity) or cooling (in order to prevent side reactions). The effects of reaction parameters, such as time, molar ratio, and type of base, on the degree of substitution (DS) with tosyl- and chloro-deoxy groups as well as on the molecular weight were evaluated.

Investigation of the spinnability of cellulose/alkaline ferric tartrate solutions.

Dynamic rheology, UV/VIS spectrometry with temperature programming cuvette and reaction calorimetry were conducted on cellulose pulp/FeTNa (NaOH solution containing ferric tartaric acid complex) solutions to investigate their thermostability and spinnability. Color of cellulose/FeTNa solutions changed above 90°C due to the decomposition of the complex. Thermal activity of cellulose/FeTNa solution started above 130°C induced by water vapor evolution and complex decomposition.

Semi-synthetic polysaccharide sulfates as anticoagulant coatings for PET, 1--cellulose sulfate.

In the present study, blood-compatible PET surfaces were prepared by coating with anticoagulant cellulose sulfates that were synthesized homogeneously in ionic liquids. The adsorption behavior of polysaccharides on PET films was investigated using QCM-D. It was demonstrated that pre-coating with different amino-group-containing polysaccharides improves the affinity toward cellulose sulfate.

Polyelectrolyte synthesis and in situ complex formation in ionic liquids.

For the first time, polyelectrolyte complex (PEC) capsules were prepared from a water insoluble polyanion, namely cellulose sulfates (CSs) with a degree of substitution (DS) below 0.2 in ionic liquids (IL). Capsules prepared via interaction with the polycation poly(dimethyldiallyammonium chloride) were free of residual IL and possessed an outer shell and a hollow inner core that made them ideal containers for enzyme mediated reactions.

Ammonium-based cellulose solvents suitable for homogeneous etherification.

New ammonium-based cellulose solvents with triethylmethylammonium- and tributylmethylammonium cations and carboxylate anions were synthesized and investigated as potential solvents for cellulose. Triethylmethylammonium formate was found to dissolve cellulose. Small amounts of formic acid may be used to adjust the melting point of the organic salt and can increase the dissolution velocity of cellulose.

Spectral assignments and anisotropy data of cellulose I(alpha): 13C-NMR chemical shift data of cellulose I(alpha) determined by INADEQUATE and RAI techniques applied to uniformly 13C-labeled bacterial celluloses of different Gluconacetobacter xylinus strains.

Solid-state (13)C-NMR spectroscopy was used to characterize native cellulose pellicles from two strains of Gluconacetobacter xylinus (ATCC 53582, ATCC 23769), which had been statically cultivated in Hestrin-Schramm (HS) medium containing fully (13)C-labeled beta-D-glucose-U-(13)C(6) as the sole source of carbon. For both samples, the (13)C-NMR chemical shifts were completely assigned for each (13)C-labeled site of cellulose I(alpha) with the aid of 2D refocused INADEQUATE NMR. To determine the principal chemical shift tensor components, a pulse sequence based on the recoupling of anisotropy information (RAI) was applied at 10 kHz MAS.

Water-soluble 3-O-(2-methoxyethyl)cellulose: synthesis and characterization.

The synthesis of novel 3-O-(2-methoxyethyl)cellulose via 2,6-di-O-thexyldimethylsilyl ethers was successfully carried out. Treatments of 3-O-(2-methoxyethyl)-2,6-di-O-thexyldimethylsilylcellulose with tetrabutylammonium fluoride trihydrate led to a complete removal of the protecting groups. Structure characterization carried out by means of 1D and 2D NMR spectroscopy proves a high regioselectivity.

New solvents for cellulose: dimethyl sulfoxide/ammonium fluorides.

New solvents based on DMSO in combination with alkylammonium fluorides, in particular TBAF . 3H(2)O and BTMAF . H(2)O, were established as media for homogeneous functionalization of cellulose.

Tailored cellulose esters: synthesis and structure determination.

A broad variety of cellulose esters with complex and sensitive (against hydrolysis and light) structures was synthesized homogeneously in N,N-dimethylacetamide (DMAc)/LiCl and in the new solvent dimethyl sulfoxide (DMSO)/tetrabutylammonium fluoride (TBAF) via in situ activation of the carboxylic acids with N,N'-carbonyldiimidazole (CDI). New esters of chiral (-)-menthyloxyacetic acid, of unsaturated 3-(2-furyl)-acrylcarboxylic- and furane-2-carboxylic acid, acids with crownether moieties (4'-carboxybenzo-18-crown-6), and with carboxymethyl-beta-cyclodextrin were accessible in a one-pot reaction. Because of the mild conditions and the efficiency of the reaction via imidazolides, very pure and highly functionalized cellulose derivatives were obtained up to a degree of substitution of 2.