Therapeutic Uses of Phycocolloids
Leonel Pereira in Therapeutic and Nutritional Uses of Algae, 2018
Phycocolloids (the collective term used for colloids extracted from seaweeds) are used in global food industries as natural additives and have a number of different European codes: E400 (alginic acid), E401 (sodium alginate), E402 (potassium alginate), E403 (ammonium alginate), E404 (calcium alginate), E405 (propylene glycol alginate), E406 (agar), E407 (carrageenan), and E407a (semi-refined carrageenan or “processed Eucheuma seaweed”) (Pereira et al. 2013). Agar, alginates, and carrageenans are the colloids with the highest economic and commercial significance, since these polysaccharides exhibit high molecular weights, high viscosity, and excellent gelling, stabilizing, and emulsifying properties. All polysaccharides are water soluble and can be extracted with hot water or alkaline solutions (Minghou 1990).
Alginate and Hydrogel Applications for Wound Dressing
Se-Kwon Kim in Marine Biochemistry, 2023
Dutra et al. (2020) successfully made transparent, soft, flexible, and mechanically resistant film wound dressings. It used 2% papain as the active agent to speed up the healing process. The films were cast using polyvinyl alcohol: calcium alginate mixes with increasing polysaccharide contents (10%, 20%, and 30% v/v). Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry analyses were used to determine the thermal properties of the hydrogel. Tensile strength, elasticity modulus, and breakpoint elongation were measured. The effect of calcium alginate concentration on film properties such as weather resistance, swelling capacity, and mechanical properties has been studied. The stability of the papain in the films was indirectly tested using direct contact hemolysis and validated by blood agar diffusion. The XTT (tetrazolium salt XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) technique was used to assess cytotoxicity. The mixtures were miscible in the polymer concentrations tested. Increased calcium alginate content improves the weatherability and swelling properties of wound dressing films. During swelling testing, the mechanical resistance decreased without the films breaking. The films’ hemolytic activity was mostly maintained throughout the study, indicating that papain was stable in the formulations. The films were non-toxic when tested on cells. The results show that PVA and calcium polymers blend can produce an interactive and bioactive wound dressing containing papain.
A Strategy for Regeneration of Three-Dimensional (3D) Microtissues in Microcapsules: Aerosol Atomization Technique
Naznin Sultana, Sanchita Bandyopadhyay-Ghosh, Chin Fhong Soon in Tissue Engineering Strategies for Organ Regeneration, 2020
Aerosol atomization technique is an efficient technique to microencapsulate cells in calcium alginate leading to the growth of microtissues within 16 days. The encapsulated cells have the ability to proliferate, self-assemble and grow into microtissues in the microcapsules of calcium alginate. The size of the microtissues within the range of a few hundreds of micrometres is controllable by varying the extrusion rate of the syringe pump and air flow rate. In this technique, the drop distance is a factor to determine if spherical microcapsules can be produced. Degradation of calcium alginate membrane using alginate lyase confirmed the formation of 3D microtissues model. In addition to the live and dead cell staining, the microtissues re-seeding experiment is a simple test to examine the viability and basic cell functionality of the microtissues.
Oil-entrapped ranitidine HCl beads heal peptic ulcers via local and systemic mechanisms
Published in Drug Development and Industrial Pharmacy, 2019
Sayed Ismail, Mona El-Mahdy, Noura Hassan Abd Ellah, Dina Adel Abdelmalek
In this study, it was focused on oil-entrapped alginate beads as an approach to gastroretentive delivery. The idea of incorporating oil within the alginate matrix is to impart buoyancy by providing a density less than that of the gastric fluid (1.003 g/cm3). Several types of oils were used such as liquid paraffin and sunflower oil [14,17]. Here, site-specific delivery for RHCl was achieved using floating beads, which were prepared using liquid paraffin as a floating aid and sodium alginate (NaAlg) chosen as main polymer. Alginate is a natural polysaccharide, composed of β-d-mannuronic acid monomers, regions of ∞-l-guluronic acid residues [18]. Sodium alginate undergoes gelation by Ca2+ forming calcium alginate due to an ionic interaction between carboxylic acid content of alginate and Ca2+. Sodium alginate is known for its biodegradability, mild gelling properties, and pH-dependent gelation [19].
Encapsulation of Lactobacillus plantarum ATCC 8014 and Pediococcus acidilactici ATCC 8042 in a freeze-dried alginate-gum arabic system and its in vitro testing under gastrointestinal conditions
Published in Journal of Microencapsulation, 2019
I. Sandoval-Mosqueda, A. Llorente-Bousquets, J. F. Montiel-Sosa, L. Corona, Z. Guadarrama-Álvarez
As for what elasticity concerns, no difference was observed (p < 0.05) despite the increase of gum arabic concentration. This elasticity was high (0.99–1.00), which means that the samples return to their original shape after the force acting on them has been removed. The elasticity reference values are between 0 and 1, for that matter, when a sample has a high elasticity, it seems to show a gummy texture, whereas, when the elasticity values are low, the type is brittle. Similar outcomes were reported by Pillay and Fassihi (1999), where calcium alginate (1.5%) and calcium pectinate (1.5%) reticulated pellets were made for the administration of specific drugs in the gastrointestinal tract. Calcium alginate pellets showed viscoelastic consistency in the TPA test, while calcium pectinate pellets displayed higher weakness during compression. This is due to pectin´s ability to preserve its structure during the gelation process. Moreover, calcium alginate demonstrated a cross-linking mechanism higher than its structure, which is related to the presence of calcium ions.
Stability enhancement of mulberry-extracted anthocyanin using alginate/chitosan microencapsulation for food supplement application
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Sorada Kanokpanont, Rungnapha Yamdech, Pornanong Aramwit
The alginate/chitosan beads were fabricated by spray drying and external gelation using two different protocols, as summarized in Table 2 [19]. The first protocol produced the alginate/chitosan beads by spraying alginate solution (1.5% w/v) into 0.1 M CaCl2 solution containing different concentrations of chitosan (0.05, 0.10, 0.15, and 0.20% w/v) under continuous stirring for 30 min. The second protocols used 2 steps to produce alginate/chitosan beads. The alginate solution (1.5% w/v) was sprayed into 0.1 M CaCl2 solution to form calcium alginate beads. Then, the calcium alginate beads were transferred to chitosan solution at different concentrations (0.05, 0.10, 0.15, and 0.20% w/v) and incubated under continuous stirring for 30 min. The beads obtained from both protocols were washed repeatedly with deionized water and freeze-dried. The freeze-dried beads (100 mg) were loaded with mulberry-extracted solution containing anthocyanin (40 ml) using physical absorption technique. The alginate/chitosan beads encapsulating mulberry-extracted anthocyanin were freeze-dried again and stored under vacuum for further characterization. The scheme of alginate/chitosan beads prepared from different protocols was shown in Figure 1.
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