Non-Covalent Interactions in Polysaccharide Systems

Effects of Different Non-Ionic Polysaccharides on the Heat-Induced Gelling Properties of Curdlan

Curdlan's application is constrained by high gelation concentration, poor water solubility, and incompatibility with other polysaccharides. To address these limitations, this study investigated the effects of different concentrations (0.05-0.3%) of non-ionic polysaccharides (pullulan (PL), locust bean gum (LBG), guar gum (GG), and konjac gum (KGM)) on the heat-induced gelling properties of curdlan. PL with no branch showed 0.3% enhanced gel hardness. LBG with a small amount of galactose residue and KGM with an acetyl group had similar effects on hardness, while GG with a large amount of galactose residue slightly weakened the mixed gel. The rheological results showed that PL had little effect on curdlan, and LBG and KGM had a positive effect on curdlan unfolding, but 0.3% GG was significantly antagonistic to curdlan. The above results implied that non-ionic polysaccharides without side chains interacted weakly with the curdlan and hardly changed the properties of curdlan. Curdlan unfolding and stable suspension were favored if the structure contained galactose or acetyl side chains that interacted with curdlan through hydrogen bonding. These results suggested an effective way to modify curdlan by strengthening the interaction of curdlan with others and weakening the hydrogen bonding of curdlan to broaden its application in food colloids.

Enhancing volumetric muscle loss (VML) recovery in a rat model using super durable hydrogels derived from bacteria

Bacteria can be programmed to deliver natural materials with defined biological and mechanical properties for controlling cell growth and differentiation. Here, we present an elastic, resilient and bioactive polysaccharide derived from the extracellular matrix of Pantoea sp. BCCS 001. Specifically, it was methacrylated to generate a new photo crosslinkable hydrogel that we coined Pantoan Methacrylate or put simply PAMA. We have used it for the first time as a tissue engineering hydrogel to treat VML injuries in rats. The crosslinked PAMA hydrogel was super elastic with a recovery nearing 100 %, while mimicking the mechanical stiffness of native muscle. After inclusion of thiolated gelatin via a Michaelis reaction with acrylate groups on PAMA we could also guide muscle progenitor cells into fused and aligned tubes - something reminiscent of mature muscle cells. These results were complemented by sarcomeric alpha-actinin immunostaining studies. Importantly, the implanted hydrogels exhibited almost 2-fold more muscle formation and 50 % less fibrous tissue formation compared to untreated rat groups. In vivo inflammation and toxicity assays likewise gave rise to positive results confirming the biocompatibility of this new biomaterial system. Overall, our results demonstrate that programmable polysaccharides derived from bacteria can be used to further advance the field of tissue engineering. In greater detail, they could in the foreseeable future be used in practical therapies against VML.

Strong gelation capacity of a pectin-like polysaccharide in the presence of K+ ion

In the present study, a pectin-like apple polysaccharide (AP) obtained by metal precipitation technique was demonstrated to show strong gelling capacity in the presence of K+ ion upon cooling. Increasing amount of K+ addition monotonically promoted the gelation of AP, as characterized by the increased gelation temperature (Tgel), gel melting temperature (Tmelt) and the gel strength. Compared with K+ ion, Na+ was unable to induce AP gelation even at high ionic concentrations, but other monovalent cations (Rb+, Cs+) can induce the gelation as in the case of K+ addition. At room temperature, the minimum cationic concentration as required to induce AP gelation followed the order of K+ ≈ Cr+ (8 mM) > Rb+ (3.5 mM), indicating that cationic radius (Na+ < K+ < Rb+ < Cs+) played a dominant role in inducing AP gelation, but other factors may also be involved. Finally, the gelation behavior of AP in the presence of K+ was explained as the suppressed intermolecular electrostatic repulsion between AP chains due to the strong electrostatic shielding effect of K+, which led to the formation of a gel network mediated by intermolecular hydrogen bonding. This reported gelation property may allow AP to find application as a new gelling polysaccharide.

Distinctions in structure, rheology, antioxidation, and α-glucosidase inhibitory activity of β-glucans from different species

To investigate the distinctions between β-glucans from different species, Lentinula edodes β-glucan (LG), yeast β-glucan (YG), and oat β-glucan (OG) were extracted with hot water and determined as β-d-glucopyranose form by HPLC and FT-IR analysis. The molecular weight (Mw) of LG, YG, and OG was 670 kDa, 341 kDa, and 66 kDa, respectively. Scanning electron microscopy exhibited different micro surfaces of three β-glucans and the relative crystallinity of YG was the highest (29.8 %), followed by that of LG (23.2 %) and OG (20.3 %) determined by X-ray diffraction. Congo red analysis and atomic force microscopy showed that LG and YG have triple helical structures. The apparent viscosity, storage modulus (G'), and loss modulus (G") of β-glucans were increased with the increase of Mw. DPPH·, ABTS+·, HO·, and reducing power assays showed that β-glucans from different species exhibited different antioxidant activities, and the DPPH· scavenging rate of 2 mg/mL LG reached >80 % higher than that of YG and OG. The α-glucosidase inhibitory activity of OG was better than YG and LG. In summary, β-glucans from different species have different structures, physicochemical properties, and physiological functions, which provides theoretical evidence for the precise processing and utilization of β-glucan.

Copper-zinc/chitosan complex hydrogels: Rheological, degradation and biological properties

Polymer hydrogels crosslinked by therapeutic metal ions have attracted increased interest in recent years due to their unique and versatile properties. Chitosan hydrogels are widely investigated for various biomedical applications such as tissue engineering and drug delivery. Copper and zinc ions are considered as therapeutic metal ions, that have important roles in bone regeneration. The aim of this study was to investigate the physicochemical and biological properties of bimetallic-chitosan complex hydrogels with different cupric and zinc ions content. Scanning electron microscopy (SEM) revealed changes in the morphology from the microstructure with larger, tubular pores for aerogels with higher Zn content, to the sheets-like structure with long pores for samples with higher Cu content. FTIR analysis indicated the formation of bimetallic-chitosan aerogels. The obtained X-ray diffraction patterns showed a broadening of chitosan's characteristic diffraction maximum, while characterization of physical properties showed decreased swelling ability and increased shear modulus with higher Cu content. ICP-MS results showed a negligible amount of copper and zinc ions released under physiological conditions during 24 h indicating a strong physical crosslink between metal ions and chitosan chains. Furthermore, accelerated in vitro degradation showed that hydrogels maintained good stability during four weeks of lysozyme activity. The MTT assay indicated that the cytotoxicity of Cu2+-Zn2+/chitosan complexes could be adjusted by the amount of cupric ions. All results imply that Cu2+ and Zn2+ ions act as physical crosslinkers of the polymer network. Also, results are in agreement with the prediction of density functional theory (DFT) which indicated stronger chitosan-Cu tetrahedral aqua complex interactions in comparison to the chitosan-[Zn(H2O)4]2+ interactions.

Polysaccharide-based antibacterial coating technologies

To tackle antimicrobial resistance, a global threat identified by the United Nations, is a common cause of healthcare-associated infections (HAI) and is responsible for significant costs on healthcare systems, a substantial amount of research has been devoted to developing polysaccharide-based strategies that prevent bacterial attachment and biofilm formation on surfaces. Polysaccharides are essential building blocks for life and an abundant renewable resource that have attracted much attention due to their intrinsic remarkable biological potential antibacterial activities. If converted into efficient antibacterial coatings that could be applied to a broad range of surfaces and applications, polysaccharide-based coatings could have a significant potential global impact. However, the ultimate success of polysaccharide-based antibacterial materials will be determined by their potential for use in manufacturing processes that are scalable, versatile, and affordable. Therefore, in this review we focus on recent advances in polysaccharide-based antibacterial coatings from the perspective of fabrication methods. We first provide an overview of strategies for designing polysaccharide-based antimicrobial formulations and methods to assess the antibacterial properties of coatings. Recent advances on manufacturing polysaccharide-based coatings using some of the most common polysaccharides and fabrication methods are then detailed, followed by a critical comparative overview of associated challenges and opportunities for future developments. STATEMENT OF SIGNIFICANCE: Our review presents a timely perspective by being the first review in the field to focus on advances on polysaccharide-based antibacterial coatings from the perspective of fabrication methods along with an overview of strategies for designing polysaccharide-based antimicrobial formulations, methods to assess the antibacterial properties of coatings as well as a critical comparative overview of associated challenges and opportunities for future developments. Meanwhile this work is specifically targeted at an audience focused on featuring critical information and guidelines for developing polysaccharide-based coatings. Including such a complementary work in the journal could lead to further developments on polysaccharide antibacterial applications.

Macrophage-Targeted Berberine-Loaded β-Glucan Nanoparticles Enhance the Treatment of Ulcerative Colitis

Aim

This study focuses on constructing of an anti-inflammatory drug delivery system by encapsulation of berberine in the β-glucan nanoparticles and evaluates its effect on treating ulcerative colitis.

Methods

β-Glucan and the anti-inflammatory drug berberine (BER) are self-assembled into nanoparticles to construct a drug delivery system (GLC/BER). The interaction between the drug and the carrier was characterized by circular dichroism, ultraviolet-visible spectroscopy, and dynamic light scattering. The anti-inflammatory effect of the GLC/BER was evaluated through a lipopolysaccharide (LPS)-induced RAW264.7 macrophage inflammation model and a sodium sulfate (DSS)-induced C57BL/6 mouse ulcerative colitis model.

Results

The GLC/BER nanoparticles have a particle size of 80-120 nm and a high encapsulation efficiency of 37.8±4.21%. In the LPS-induced RAW264.7 macrophage inflammation model, GLC/BER significantly promoted the uptake of BER by RAW264.7 cells. RT-PCR and ELISA assay showed that it could significantly inhibit the inflammatory factors including IL-1β, IL-6 and COX-2. Furthermore, GLC/BER shows inhibiting effect on the secretion of pro-inflammatory factors such as IL-1β and IL-6, down-regulating the production of nitrite oxide; in animal studies, GLC/BER was found to exert a relieving effect on mice colitis.

Conclusion

The study found that GLC/BER has an anti-inflammatory effect in vitro and in vivo, and the GLC carrier improves the potency and bioavailability of BER, providing a new type of nanomedicine for the treatment of colitis.

Polysaccharide nanoparticles for oral controlled drug delivery: the role of drug-polymer and interpolymer interactions

Introduction: The oral route still represents the most popular way of administering drugs; nowadays oral administration faces new challenges, in particular with regards to the delivery of APIs that are poorly absorbed and sensitive to degradation such as macromolecules and biotechnological drugs. Nanoparticles are promising tools for the efficient delivery of these drugs to the gastrointestinal tract. Areas covered:Approaches and techniques for the formulation of drugs, with particular focus on the preparation of polysaccharide nanoparticles obtained by non-covalent interactions. Expert opinion:Polysaccharide-based nanoparticulate systems offer the opportunity to address some of the issues posed by biotechnological drugs, as well as by small molecules, with problems of stability/intestinal absorption, by exploiting the capability of the polymer to establish non-covalent bonds with functional groups in the chemical structure of the API. This area of research will continue to grow, provided that these drug delivery technologies will efficaciously be translated into systems that can be manufactured on a large scale under GMP conditions. Industrial scale-up represents the biggest obstacle to overcome in view of the transformation of very promising results obtained on lab scale into medicinal products. To do that, an effort toward the simplification of the process and technologies is necessary.

Interaction Between Chitosan and Mucin: Fundamentals and Applications

The term chitosan (CS) refers to a family of aminopolysaccharides derived from chitin. Among other properties, CS is nontoxic, mucoadhesive and can be used for load and transport drugs. Given these and other physicochemical and biological properties, CS is an optimal biopolymer for the development of transmucosal drug delivery systems, as well as for the treatment of pathologies related to mucosal dysfunctions. Mucins are glycoprotein macromolecules that are the major components of mucus overlaying epithelia. CS interacts with mucin and adsorbs on and changes the rheology of mucus. However, CS and mucins denote families of polymers/macromolecules with highly variable chemical structure, properties, and behavior. To date, their interactions at the molecular level have not been completely unraveled. Also, the properties of complexes composed of CS and mucin vary as a function of the sources and preparation of the polymers. As a consequence, the mucoadhesion and drug delivery properties of such complexes vary as well. The breadth of this review is on the molecular interactions between CS and mucin. In particular, in vitro and ex vivo characterization methods to investigate both the interactions at play during the formation of CS-mucin complexes, and the advances on the use of CS for transmucosal drug delivery are addressed.

C-H/π and C-H-O Interactions in Concert: A Study of the Anisole-Methane Complex using Resonant Ionization and Velocity Mapped Ion Imaging

Noncovalent forces such as hydrogen bonding, halogen bonding, π-π stacking, and C-H/π and C-H/O interactions hold the key to such chemical processes as protein folding, molecular self-assembly, and drug-substrate interactions. Invaluable insight into the nature and strength of these forces continues to come from the study of isolated molecular clusters. In this work, we report on a study of the isolated anisole-methane complex, where both C-H/π and C-H/O interactions are possible, using a combination of theory and experiments that include mass-selected two-color resonant two-photon ionization spectroscopy, two-color appearance potential (2CAP) measurements, and velocity mapped ion imaging (VMI). Using 2CAP and VMI, we derive the binding energies of the complex in ground, excited, and cation radical states. The experimental values from the two methods are in excellent agreement, and they are compared with selected theoretical values calculated using density functional theory and ab initio methods. The optimized ground-state cluster geometry, which is consistent with the experimental observations, shows methane sitting above the ring, interacting with anisole via both C-H/π and C-H/O interactions, and this dual mode of interaction is reflected in a larger ground-state binding energy as compared with the prototypical benzene-methane system.

Cellular hydrogels based on pH-responsive chitosan-hydroxyapatite system

The development of bioactive injectable system as cell carrier with minimal impact on viability of encapsulated cells represents a great challenge. In the present work, we propose a new pH-responsive chitosan-hydroxyapatite-based hydrogel with sodium bicarbonate (NaHCO₃) as the gelling agent. The in situ synthesis of hydroxyapatite phase has resulted in stable composite suspension and final homogeneous hydrogel. The application of sodium bicarbonate has allowed non-cytotoxic fast gelation of chitosan-hydroxyapatite within 4min, and without excess of sodium ions concentration. Rheological properties of crosslinked hydrogel have demonstrated possible behaviour as 'strong physical hydrogel'. The live dead staining has confirmed good viability and dispersion, as well as proliferation of encapsulated cells by the culture time. Presented preliminary results show good potential of chitosan-hydroxyapatite/NaHCO₃ as a cell carrier, whose impact on the cell differentiation need to be confirmed by encapsulation of other cell phenotypes.

Stiff chains inhibit and flexible chains promote protein adsorption to polyelectrolyte multilayers

We tested the hypothesis that the level of protein adsorption onto polyelectrolyte multilayers (PEMs) is influenced by the chain stiffness of the polymers forming the multilayer. The implication being that by altering the chain stiffness, PEMs can be formed that promote or inhibit protein adsorption. Protein adsorption to PEMs consisting of flexible and semi-flexible polyelectrolytes was investigated. The flexible polyelectrolytes were poly(sodium 4-styrene sulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDDA) and the semi-flexible polyelectrolytes were sulfated chitosan (SC) and cationic guar gum (CGG). Polyelectrolytes were used in pairs to produce four types of polyelectrolyte multilayer films. Moreover, each of these films could be terminated with either of the polyelectrolytes resulting in protein adsorption being studied on 8 systems. Protein adsorption was investigated by optical reflectometry and quartz crystal microbalance with dissipation using bovine serum albumin as the test protein. We found that when a pair of semi-flexible polyelectrolytes was used very little protein adsorption took place, irrespective of which polyelectrolyte was used to terminate the film. When the film was formed by flexible polyelectrolytes, significant protein adsorption took place and the degree of adsorption depended strongly on which polyelectrolyte was used to terminate the film. We explain these observations by considering the conformation of the polyelectrolyte in the outermost region of the film and relate this to the flexibility of the polyelectrolyte chains employed to produce the polyelectrolyte multilayer.

Carbon nanotubes induced gelation of unmodified hyaluronic acid

This work reports an experimental study of the kinetics and mechanisms of gelation of carbon nanotubes (CNTs)-hyaluronic acid (HA) mixtures. These materials are of great interest as functional biogels for future medical applications and tissue engineering. We show that CNTs can induce the gelation of noncovalently modified HA in water. This gelation is associated with a dynamical arrest of a liquid crystal phase separation, as shown by small-angle light scattering and polarized optical microscopy. This phenomenon is reminiscent of arrested phase separations in other colloidal systems in the presence of attractive interactions. The gelation time is found to strongly vary with the concentrations of both HA and CNTs. Near-infrared photoluminescence reveals that the CNTs remain individualized both in fluid and in gel states. It is concluded that the attractive forces interplay are likely weak depletion interactions and not strong van der Waals interactions which could promote CNT rebundling, as observed in other biopolymer-CNT mixtures. The present results clarify the remarkable efficiency of CNT at inducing the gelation of HA, by considering that CNTs easily phase separate as liquid crystals because of their giant aspect ratio.

Supramolecular assembled nanogel made of mannan

The supramolecular assembly of amphiphilic mannan, synthesized by the Michael addition of hydrophobic 1-hexadecanethiol to vinyl methacrylated mannan, originates in aqueous medium the formation of a nanogel, stabilized by hydrophobic interactions among alkyl chains. The critical aggregation concentration, calculated by fluorescence spectroscopy ranged between 0.002 and 0.01 mg/mL, depending on the polymer degree of substitution. The cryo-field emission scanning electron microscopy showed spherical macromolecular micelles with diameters between 100 and 500 nm. The dynamic light scattering analysis revealed a polydisperse colloidal system, with mean hydrodynamic diameter between 50 and 140 nm, depending on the polymer degree of substitution. The nanogel is negatively charged, stable over a 6 months storage period, and stable at pH 3-8, salt or urea solutions. Bovine serum albumin and curcumin were spontaneously incorporated in the nanogel, being stabilized by the hydrophobic domains, opening the possibility for future applications as potential delivery systems for therapeutic molecules. In vitro assays were carried out to characterize the biocompatibility of the nanogel. A toxic effect of mannan-C(16) was observed, specific to mouse macrophage-like cell line J774, not affecting mouse embryo fibroblast cell line 3T3 viability.

Self-Assembled Hydrogel Nanoparticles for Drug Delivery Applications

Hydrogel nanoparticles—also referred to as polymeric nanogels or macromolecular micelles—are emerging as promising drug carriers for therapeutic applications. These nanostructures hold versatility and properties suitable for the delivery of bioactive molecules, namely of biopharmaceuticals. This article reviews the latest developments in the use of self-assembled polymeric nanogels for drug delivery applications, including small molecular weight drugs, proteins, peptides, oligosaccharides, vaccines and nucleic acids. The materials and techniques used in the development of self-assembling nanogels are also described.

Preparation, characterization and applications of low-molecular-weight alginate-oligochitosan nanocapsules

The development of drug-delivering nanoparticles from natural materials for various biomedical applications is an area of great promise. However, the contradictory data on their uncontrollable diameter, unstable structure and toxic effects, highlight the need to study their preparation, characterization and cytotoxic effects in cells. In this work, nanocapsules are made from a type of W/O microemulsion system with low-molecular-weight alginate (LMWALG) and oligochitosan (OCS). The particles possess excellent biocompatibility and good biodegradability. The size of capsules is controlled and optimized by carefully adjusting the molecular weight and concentration of LMWALG and OCS. We found, from orthogonal experiments, the encapsulation time leading to a uniform size distribution with an average diameter of 136 nm. Furthermore, we found that molecular weights of LMWALG and OCS significantly influence the stability and size of capsules. The optimized nanocapsules are further used to study the drug release of BSA. Results show that the efficiency of encapsulation approximately reaches 88.4% and the concentration of BSA in phosphate-buffered solution (PBS, pH = 7.4) is well maintained at a level of 35 to 40% from 12 h to 48 h, due to the stable and slow degradation of the nanocapusules. The biocompatibility of LMWALG/OCS nanocapsules is cross-examined by cytotoxicity experiments and acute systemic toxicological tests, and they were found to enhance the survival rate of the cells from 80.30 to 95.39% in 7 days. The synthesized nanocapsules exhibit high biocompatibility, non-toxicity, biodegradation, and uniform size, providing a new potential candidate for drug releases in clinic experiments.

Structural behavior of highly concentrated hyaluronan

When investigated under high concentration conditions, hyaluronan (HA) solutions in physiological saline are shown to generate stable superstructures. An abrupt change in the rheological properties observed on increasing the temperature suggests the breaking of certain cooperative bonds. The thermal disruption of the HA superstructure is accompanied by a sharp transition from a long- to a restricted-connectivity water structuring, which is interpreted as a concurrent transition from a stable to a temporary polymer network. The intermolecular associations are considered to be originated by hydrophobic interactions between the nonpolar groups of the polymer backbones.

Force Spectroscopy of Hyaluronan by Atomic Force Microscopy: From Hydrogen-Bonded Networks toward Single-Chain Behavior

The conformational behavior of hyaluronan (HA) polysaccharide chains in aqueous NaCl solution was characterized directly at the single-molecule level. This communication reports on one of the first single-chain atomic force microscopy (AFM) experiments performed at variable temperatures, investigating the influence of the temperature on the stability of the HA single-chain conformation. Through AFM single-molecule force spectroscopy, the temperature destabilization of a local structure was proven. This structure involved a hydrogen-bonded network along the polymeric chain, with hydrogen bonds between the polar groups of HA and possibly water, and a change from a nonrandom coil to a random coil behavior was observed when increasing the temperature from 29 +/- 1 to 46 +/- 1 degrees C. As a result of the applied force, this superstructure was found to break progressively at room temperature. The use of a hydrogen-bonding breaker solvent demonstrated the hydrogen-bonded water-bridged nature of the network structure of HA single chains in aqueous NaCl solution.

Relationship between swelling and the electrohydrodynamic properties of functionalized carboxymethyldextran macromolecules

The electrostatic, hydrodynamic, and swelling properties of a well-defined, functionalized carboxymethyldextran (CMD) polysaccharide are investigated in aqueous NaNO3 solution over a broad ionic strength range. The impact of the polycarboxylate charge and molar mass of the CMD macromolecules on their electrohydrodynamic features is thoroughly examined by combined protolytic titration, dynamic light scattering, and electrokinetic analyses. Electrophoretic mobility data obtained for sufficiently high electrolyte concentrations reveal a typical soft particle behavior. Upon decrease of the ionic strength, mobilities strongly increase in magnitude while significant electrostatic swelling takes place, as reflected in a decrease in the diffusion coefficients. CMD entities undergo conformational transitions from compact random coil at large ionic strengths to swollen coil and possibly a wormlike structure at lower NaNO3 concentrations. The magnitude of the variations in size and mobility with electrolyte concentration strongly depends on the overall charge of the CMD entity as well as on its molar mass. These factors control the stiffness of the constituent polymer chains and thus the degree of macromolecular permeability ("softness"). Using the soft-diffuse interface formalism previously developed for the electrohydrodynamics of charged permeable macromolecules, a quantitative analysis of the electrophoretic mobility data is presented. The measured values of the diffusion coefficient and space charge density Gamma degrees, as evaluated independently from the modeling of potentiometric titration curves, are taken into account in a self-consistent manner. It is found that large CMD entities of low charge densities are the most permeable to flow penetration with a limited heterogeneous electrostatic stiffening of the chains, whereas small CMD entities of larger Gamma degrees significantly expand upon lowering the ionic strength, giving rise to a strong anisotropy for the spatial distribution of polymer chain density.

Self-assembled nanogels of cholesteryl-modified polysaccharides: effect of the polysaccharide structure on their association characteristics in the dilute and semidilute regimes

The assembly of cholesteryl derivatives of the highly branched polysaccharide mannan Mw = (5.2 x 104 g/mol) in dilute aqueous solution was investigated by 1H nuclear magnetic resonance (NMR) spectroscopy, size-exclusion chromatography coupled with multiangle laser scattering (SEC-MALLS), dynamic light scattering (DLS), atomic force microscopy (AFM), fluorescence quenching, and fluorescence depolarization measurements. In the dilute regime, cholesteryl-bearing mannans (CHM) containing approximately 1 cholesteryl group per 100 mannopyranose units formed nanogels with a hydrodynamic radius (RH) of approximately 20 nm containing approximately 8 macromolecules held together via hydrophobic nanodomains consisting of approximately 9 cholesteryl groups. Their density Phih ( approximately 0.02) was significantly lower than the density ( approximately 0.16) of nanogels formed by a cholesteryl derivative of the linear polysaccharide pullulan (CHP) of identical molar mass and level of cholesteryl substitution. In the semidilute regime, CHM nanogels formed a macrogel network for concentrations higher than 12.5% w/w, whereas CHP nanogels underwent macrogelation only above a threshold concentration of 8.0% w/w, as revealed by oscillatory and steady-shear viscosity measurements. The differences in the solution properties of CHM and CHP reflect differences in their assembly on the molecular level, in particular, the size and number of hydrophobic nanodomains and the hydration level. They are attributed to differences in the mobility of the cholesteryl groups which, itself, can be traced to the fact that in CHM the cholesteryl groups are predominantly linked to short oligomannopyranose branches, whereas in CHP they are linked to the polymer main chain. Our study provides a novel means to nanoengineer polysaccharide nanogels which may find unique biotechnological applications.