On the Relation between the Viscoelastic Properties of Granular Hydrogels and Their Performance as Support Materials in Embedded Bioprinting.

Granular hydrogels, formed by jamming microgels suspension, are promising materials for three-dimensional bioprinting applications. Despite their extensive use as support materials for embedded bioprinting, the influence of the particle's physical properties on the macroscale viscoelasticity on one hand and on the printing performance on the other hand remains unclear. Herein, we investigate the linear and nonlinear rheology of κ-carrageenan granular hydrogel through small- and large-amplitude oscillatory shear measurements.

Comparative analysis of classic network vs. nanogel junction network in konjac glucomannan/kappa carrageenan hybrid hydrogels.

The three-dimensional network architecture of hydrogels significantly influences their mechanical and physical properties; therefore, understanding them is essential for designing optimized hydrogel-based biomaterials. This study presents a comparative analysis of two hybrid hydrogels composed of konjac glucomannan (KGM) and kappa carrageenan (KCAR) with the same stiffness (5.2-5.

Mucus-Mimicking Mucin-Based Hydrogels by Tandem Chemical and Physical Crosslinking.

Mucosal tissues represent a major interface between the body and the external environment and are covered by a highly hydrated mucins gel called mucus. Mucus lubricates, protects and modulates the moisture levels of the tissue and is capitalized in transmucosal drug delivery. Pharmaceutical researchers often use freshly excised animal mucosal membranes to assess mucoadhesion and muco-penetration of pharmaceutical formulations which may struggle with limited accessibility, reproducibility, and ethical questions.

Dual functionality of diacylglycerols in water-in-oil emulsion gel systems.

Distearin (DS) can be used as an emulsifier, due to its surface activity derived from the amphiphilic nature of the molecule, moreover, it can also crystallize and form a 3D crystal network that can induce oil gelation. The current research aimed to examine the ability to combine both emulsifying and oil gelation properties to structure and stabilize water-in-oil emulsion gel system. Different water contents and DS concentrations produce emulsion gels with different textural attributes while incorporating up to 30% of water in a 15% wt.

Isotropic liquid state of cocoa butter.

The complex crystal structure of coca butter (CB) is responsible for the unique melting behavior, surface gloss, and mechanical properties of chocolate. While most studies concentrated on the crystalline state of CB, few studied the isotropic liquid state, which has a major impact on the crystallization process and the characteristics of the resulting crystals. In this study, the molecular organizations of the main CB triacylglycerols (TAGs; 1,3-dipalmitoyl-2-oleoylglycerol, palmitoyl-oleoyl-stearoylglycerol, POS, and 1,3-distearoyl-2-oleoylglycerol) were studied.

Cultured meat platform developed through the structuring of edible microcarrier-derived microtissues with oleogel-based fat substitute.

With the increasing global demand for meat, cultured meat technologies are emerging, offering more sustainable solutions that aim to evade a future shortage of meat. Here, we demonstrate a cultured meat platform composed of edible microcarriers and an oleogel-based fat substitute. Scalable expansion of bovine mesenchymal stem cells on edible chitosan-collagen microcarriers is optimized to generate cellularized microtissues.

The effect of preparation temperature and composition on bigel performance as fat replacers.

Consumer awareness of the deleterious effect of a diet rich in saturated fat pushes the food industry to find new fat alternatives. Bigels, hybrids of hydrogels and oleogels, are an attractive option for formulating oil-based fat mimetics, particularly lamination fats. This research explored the characteristics of a hydrogel-in-oleogel bigel, made of candelilla wax and xanthan gum.

An experimental and theoretical approach to understand the interaction between particles and mucosal tissues.

Nanonization of poorly water-soluble drugs has shown great potential in improving their oral bioavailability by increasing drug dissolution rate and adhesion to the gastrointestinal mucus. However, the fundamental features that govern the particle-mucus interactions have not been investigated in a systematic way before. In this work, we synthesize mucin hydrogels that mimic those of freshly excised porcine mucin.

Print-and-Grow within a Novel Support Material for 3D Bioprinting and Post-Printing Tissue Growth.

3D bioprinting holds great promise for tissue engineering, with extrusion bioprinting in suspended hydrogels becoming the leading bioprinting technique in recent years. In this method, living cells are incorporated within bioinks, extruded layer by layer into a granular support material followed by gelation of the bioink through diverse cross-linking mechanisms. This approach offers high fidelity and precise fabrication of complex structures mimicking living tissue properties.

Structured edible lipid-based particle systems for oral drug-delivery.

Oral administration is the most popular and patient-compliant route for drug delivery, though it raises great challenges due to the involvement of the gastro-intestine (GI) system and the drug bioavailability. Drug bioavailability is directly related to its ability to dissolve, transport and/or absorb through the physiological environment. A great number of drugs are characterized with low water solubility due to their hydrophobic nature, thus limiting their oral bioavailability and clinical use.

The Effect of the HLB Value of Sucrose Ester on Physiochemical Properties of Bigel Systems.

The current research explored the effect of different sucrose esters (SEs), with different hydrophilic-lipophilic balance (HLB) values, on bigel structure and properties. Bigels consisting of a water phase with glycerol and gelatin and an oil phase with glycerol mono-stearate, lecithin, and SEs with different HLB values were prepared. Rheological and thermal analyses revealed similar gelation-melting transitions governed by glycerol-monostearate crystallization (at ≈55 °C) for all bigel samples.

Controlling lipid intestinal digestibility using various oil structuring mechanisms.

This research demonstrates the ability to direct the rate and extent of lipid hydrolysis of oleogels using a combination of different structuring agents. Combinations of ethyl cellulose (EC) (20 cP and 45 cP) and commercial mixture of mono and di-glycerides (E471), at different ratios, were examined. The results suggest that the combination of E471 and EC significantly affects both gel physical properties and intestinal lipolysis.

Comparison of Thermal and High-Pressure Gelation of Potato Protein Isolates.

Potato protein isolate (PPI), a commercial by-product of the starch industry, is a promising novel protein for food applications with limited information regarding its techno-functionality. This research focused on the formation of both thermal and high-pressure gels at acidic and neutral pH levels. Our results reveal that physical gels are formed after 30 min by heat at pH 7 and pH 3, while pressure (300-500 MPa) allows the formation of physical gels only at pH 3, and only when the system crosses 30 °C by adiabatic heating during pressurization.

The role of hydrogen bonds in TAG derivative-based oleogel structure and properties.

Glycerol monosterate (GMS) and stearic acid (SA) share a similar carbon chain structure while SA has a carboxyl head group and GMS has two free hydroxyl groups. The current research focuses on the relationship between GMS and SA chemical structure, nano and mesoscale crystal structure, and the oleogel macroscopic characteristics. Molecular analysis revealed the formation of different types of hydrogen bonds, which disappear upon temperature increase at different temperatures.

Shear thinning pectin hydrogels physically cross-linked with chitosan nanogels.

The development of a polymer-nanogel hydrogel based on a pair of polysaccharides is reported for the first time. This new hydrogel exhibits self-healing properties due to physical interactions between soluble pectin chains and chitosan nanogels. The nanogels act as crosslinking agents between pectin chains, leading to the formation of thermos-responsive hydrogel.

Tuning the mechanical properties of alginate-peptide hydrogels.

Alginate, a polysaccharide that gels in the presence of divalent ions, has been used in the field of regenerative medicine to facilitate cell growth in impaired tissues by providing an artificial bio-surrounding similar to the natural extra cellular matrix (ECM). Here, we present a systematic investigation of the effect of three arginine-glycine-aspartic acid (RGD)-containing peptides, G6KRGDY, A6KRGDY and V6KRGDY, on the physical properties of alginate-peptide hydrogels. Rheology measurements showed that the storage modulus of the alginate-A6KRGDY and alginate-V6KRGDY gels is an order of magnitude higher than that of the alginate-G6KRGDY gel.

Ethylcellulose oleogels for lipophilic bioactive delivery - effect of oleogelation on in vitro bioaccessibility and stability of beta-carotene.

The in vitro lipolysis and β-carotene (BC) transfer from oil to aqueous phase of canola oil ethylcellulose (EC) oleogels were measured using a static monocompartmental model simulating oral, gastric, and duodenal digestive stages. The effects of EC oleogelation on gel in vitro digestibility were examined, using un-structured canola oil as a control. The physicochemical properties of oleogels containing BC were also measured.

Influencing the crystallization behavior of binary mixtures of stearyl alcohol and stearic acid (SOSA) using ethylcellulose.

In the present study we have characterized the influence of the polymer gelator ethylcellulose (EC) on the crystallization behavior of mixtures of stearyl alcohol and stearic acid (SOSA). The presence of EC led to a more abrupt thermo-reversible crystallization process and an increase in the onset of crystallization temperature from 22.7±0.

Modulating the gel properties of soy glycinin by crosslinking with tyrosinase.

The gelation progression and gel properties of enzymatically crosslinked soy glycinin were evaluated in comparison to non-crosslinked glycinin. Glycinin was initially crosslinked using tyrosinase from Bacillus megaterium (TyrBm) and was later used to form gel upon heating. Gelation was evaluated by small deformation rheological measurements and revealed a significant increase in storage modulus (G') obtained in the crosslinked gel.

Physical and structural characteristics of acrylated poly(ethylene glycol)-alginate conjugates.

Transmucosal delivery of therapeutic agents is a non-invasive approach that utilizes human entry paths such as the nasal, buccal, rectal and vaginal routes. Mucoadhesive polymers have the ability to adhere to the mucus layer covering those surfaces and by that promote drug release, targeting and absorption. We have recently demonstrated that acrylated polymers display enhanced mucoadhesive properties due to their ability to covalently attach to mucus type glycoproteins.

Alginate-PEGAc: a new mucoadhesive polymer.

We have synthesized a novel mucoadhesive polymer, alginate-polyethylenglycol acrylate (alginate-PEGAc), in which an alginate backbone carries acrylated polyethylenglycol. This polymer combines the strength, simplicity and gelation ability of alginate with the mucoadhesion properties arising from the characteristics and acrylate functionality of PEG. The strong bonding to the mucus results from a combination of PEG's ability to interpenetrate the mucus surface and a Michael-type addition reaction between an acrylate end group on a polymer and the sulfide end group of the mucin-type glycoprotein.

Novel mucoadhesive system based on sulfhydryl-acrylate interactions.

We propose a novel cross-linked mucoadhesive system that can interact covalently with mucin type glycoprotein, thus providing both strong bonding to mucosa as well as ability to function as a sustained release matrix. The strong bonding results from Michael type addition reaction between an acrylate end group on a polymer and the sulfide end group of the mucin type glycoprotein. A proof of concept is provided using a polyehtylene glycol hydrogel formed in situ from polyehtylene glycol di-acrylate (PEG-DA) macromers.

Mucoadhesion: a review of characterization techniques.

Importance Of The Field: Mucoadhesive drug delivery vehicles attract much attention owing to benefits such as extended residence time of the drug at the site of application, a relatively rapid uptake of a drug into the systemic circulation, and enhanced bioavailability of therapeutic agents. Mucoadhesion, defined as the ability to adhere to the mucus gel layer covering organs that are exposed to the outer surface of the body yet are not covered with skin, such as the mouth and the respiratory tract, is a key element in the design of these drug delivery systems.

Areas Covered In This Review: This review focuses on the numerous experimental methods that have been proposed over the years for mucoadhesion characterization.