Chitosan-Stabilized Oil-in-Water Nanoemulsions

Chitosan is a natural polysaccharide and emulsifier that can ensure a significant emulsion stability at suitable pH, ionic strength, composition, concentration, or thermal processing. The evaluation of the electrokinetic properties is a key factor in investigation of the stability of the nanoemulsions with a view to their potential applications in bionanotechnology. Consequently, the precise control over the physicochemical characteristics of chitosan (degree of acetylation, DA and molecular weight, Mw) can provide a high stability and specific biological properties of the developed functional structures. The chapter is focused on the interpretation of the electrokinetic response from nanoemulsion stabilized by adsorption of chitosan (as a polyelectrolyte or uncharged polymer) by using appropriate theoretical approaches.

Hyperbaric Oxygen Combined with Alginate Oligosaccharide Delay D-gal-induced Liver, Kidney and Spleen Senescence in Mice by Attenuating Oxidative Stress

Objectives Hyperbaric oxygen treatment (HBOT) is an adjuvant therapy progressively applied in the treatment of clinical diseases, and alginate oligosaccharide (AOS) is a natural polysaccharide with excellent antioxidant property. In this study, the effects of HBOT combined with AOS on the senescence on liver, kidney and spleen were investigated in a D-galactose (D-gal) -induced senescent mice model. Results The findings indicated that HBOT combined with AOS could delay D-gal-induced aging of liver, kidney and spleen in mice. Specifically, HBOT combined with AOS improved the daily behavior and organ indices of mice. Biochemical and morphological analyses of all tissues indicated that HBOT combined with AOS markedly decreased the unusual elevation of ALT, AST and CREA induced by D-gal, alleviated pathological injury, and significantly enhanced the capacity of antioxidant defense system of mice, including increaing T-SOD, CAT AND GSH-Px activities and decreasing MDA content . In addition, Western Blot results indicated that HBOT combined with AOS also inhibited the overexpression of aging-related proteins p53 and p16. Conclusions To some extent, these findings suggest that HBOT combined with AOS has significant anti-senescence potential in D-gal-induced senescent mice, and the underlying factors may be correlated with the enhancement of antioxidant defense capacity.

Advanced Strategies for 3D Bioprinting of Tissue and Organs Analogs Using Alginate Hydrogel Bioinks

Alginate is a natural polysaccharide that typically originates from various species of algae. Due to its low cost, good biocompatibility, and rapid ionic gelation, the alginate hydrogel has become a good option of bioink source for 3D bioprinting. However, the lack of cell adhesive moieties, erratic biodegradability, and poor printability are the critical limitations of alginate hydrogel bioink. This review discusses the pivotal properties of alginate hydrogel as a bioink for 3D bioprinting technologies. Afterward, a variety of advanced material formulations and biofabrication strategies that have recently been developed to overcome the drawbacks of alginate hydrogel bioink will be focused on. In addition, the applications of these advanced solutions for 3D bioprinting of tissue/organ mimicries such as regenerative implants and in vitro tissue models using alginate-based bioink will be systematically summarized.

Natural Gums as Oleogelators

The natural gums used as high molecular weight oleogelators are mainly polysaccharides that deliver a broad spectrum of possible utilization methods when structuring liquid fats to solid forms. The review discusses a natural gums’ structuring and gelling behavior to capture the oil droplets and form the water/oil gelling emulsions basing on their structural conformation, internal charge, and polymeric characteristics. The specific parameters and characteristics of natural gums based oleogels are also discussed. In the future, oleogels may eliminate saturated and trans fats from food products and allow the production of low-fat products, thus reducing the environmental damage caused by the excessive use of palm oil. The increasing knowledge of molecular interaction in polysaccharide chains of natural gums allows to apply more sustainable and wiser strategies towards product formulation. Innovative solutions for using oleogels based on natural polysaccharide biopolymers let incorporate them into the food matrix and replace fats completely or create blends containing the source of fats and the addition of the oleogel. The profound insight into molecular characteristics of natural gums in the function of being oleogelators is presented.

Fabrication of Environmental-Friendly Magnetite Nanoparticle Surface Coatings for the Efficient Collection of Oil Spill

Over the past few decades, there has been an increased trend for the use of natural compounds and their derivatives as alternatives to traditional chemicals and is due to their renewability, green character, and wide availability. This work aims to convert sodium alginate (S.ALG), a natural polysaccharide, into amides through its conversion to alginic acid (H.ALG). The formed H.ALG was esterified using methanol, followed by a reaction with octadecylamine (OA) and dodecylamine (DA) to produce corresponding amides, OA-ALG, and DA-ALG, respectively. The synthesized OA-ALG and DA-ALG were used as capping agents to further form hydrophobic magnetite nanoparticles (MNPs), OA-MNPs and DA-MNPs, respectively. The chemical structures, morphology, hydrophobicity, and magnetic properties of OA-MNPs and DA-MNPs were investigated using different instrumental techniques. Furthermore, the efficacy of as-synthesized MNPs as oil spill collectors were also evaluated using different ratios of MNPs:crude oil. From the analysis of results, the OA-MNPs and DA-MNPs exhibited high efficiency in the collection of oil spill even at low ratios of MNPs:crude oil.

Combination of sodium alginate and nitric oxide reduces browning and retains the quality of fresh-cut peach during cold storage

Fresh-cut peaches are susceptible to browning when exposed to air. Reducing the browning is important to maintain the quality of the fresh-cut peaches. Nitric oxide (NO) as the signal factor can improve the antioxidant capacity of organisms; sodium alginate (SA) is a natural polysaccharide with good antibacterial and film-forming properties. The study aimed to investigate the antioxidant and anti-browning activities of combined application of sodium alginate and nitric oxide on peaches slices preservation. The activities of some browning-related enzymes and antioxidant enzymes and the content of reactive oxygen species (ROS) and some browning-related components in fresh-cut peaches were determined. Results showed that combined treatment of 1% SA + 10 μmol L−1 NO slowed down the decrease in firmness, L*, and SSC, restrained the increase in browning degree and the activities of polyphenol oxidase, phenylalanine ammonia-lyase, peroxidase, and lipoxygenase. At the same time, it reduced the accumulation of O2•–, ·OH, H2O2, malondialdehyde, and total phenolic, and increased the activities of catalase and superoxide dismutase in peach slices. Overall, it was concluded that treatment with 1% SA + 10 μmol L−1 NO maintained quality and extended storage life of fresh-cut peaches.

Recent Progress in Chemical Modification of the Natural Polysaccharide Guar Gum

: Guar gum (GG) is a natural heteropolysaccharide. Due to its non-toxic, eco-friendly, and biodegradable nature, GG has found wide applications in many areas, in particular food, paper, textile, petroleum, and pharmaceutical industries. Therefore, GG is often called “Black Gold” as well. Due to the presence of hydroxyl groups, GG can be modified by various methods. The physical and biological properties of GG can be modulated by chemical modifications. In this manuscript, various methods for the chemical modifications of GG have been discussed according to the type of modifications. Mechanistic insights have also been provided whenever possible. In addition, potential applications of new GG derivatives have also been briefly mentioned.