Alginate as Promising Natural Polymer for Pharmaceutical, Food, and Biomedical Applications

Alginate microparticles containing silver@hydroxyapatite functionalized calcium carbonate composites

This paper focuses on the preparation and characterization of antibacterial alginate microparticles containing silver@hydroxyapatite functionalized calcium carbonate composites for tissue engineering. Microparticles were prepared by cross-linking a silver@composite sodium alginate dispersion with CaCl2. This method showed a very good silver efficiency loading and the presence of silver chloride nanoparticles was detected. Silver free microparticles, containing hydroxyapatite functionalized calcium carbonates and neat alginate microparticles were prepared as well. All microparticles were characterized for water absorption and for in vitro bioactivity by immersion in simulated body fluid (SBF). Finally, antimicrobial and antibiofilm activities as well as cytotoxicity were evaluated. Microparticles containing silver@composites exhibited good antimicrobial and antibiofilm activities against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans, but exerted a certain cytotoxicity against the tested cell models (fibroblasts and osteoblasts). Microparticles containing hydroxyapatite functionalized calcium carbonates were found to be always less cytotoxic, also in comparison to neat alginate microparticles, proving that the presence of the inorganic matrices exerts a protective effect on microparticle cytotoxicity.

Fabrication of a self-healing hydrogel with antibacterial activity using host-guest interactions between dopamine-modified alginate and β-cyclodextrin dimer

Self-healing hydrogels possess an ability to recover their functionality after experiencing damage by regenerating cross-links. The main challenge in making self-healing hydrogels based on host-guest (HG) interactions is their limited mechanical strength, which can be solved using beta-cyclodextrin dimers (β-CDsD). Here, β-CDsD as a host cross-linker was used to increase the mechanical property of the HG interactions. Alginate with acceptable biocompatibility was modified by dopamine (ALG-DOP) and employed as a guest polymer. Self-healing hydrogel was developed between them, and Ag nanoparticles were added to create an antibacterial activity. Dopamine with appropriate size and suitable adhesiveness established HG interactions with β-CDsD, and cells were able to grow well on hydrogel. This hydrogel showed an impressive self-healing capability <5 min. These hydrogels revealed a respectable porosity from 15 to 55 μm essential for exchanging the substances required for cell growth and cell waste elimination. Biocompatibility was investigated against NIH 3 T3 fibroblasts cells, and the results showed that the cells grew well. The in vitro release of curcumin from the hydrogel was examined in PBS at pH of 7.4. The hydrogel can be a perfect candidate for controlled drug release, and wound-dressing due to self-healing property, antibacterial activity, adhesion, and biocompatibility.

Structural basis for the minimal bifunctional alginate epimerase AlgE3 from Azotobacter chroococcum

Among the epimerases specific to alginate, some of them in Azotobacter genera convert β-d-mannuronic acid to α-l-guluronic acid but also have lyase activity to degrade alginate. The remarkable characteristics of these epimerases make it a promising enzyme for tailoring alginates to meet specific demands. Here, we determined the structure of the bifunctional mannuronan C-5 epimerase AlgE3 from Azotobacter chroococcum (AcAlgE3) in complex with several mannuronic acid oligomers as well as in apo form, which allowed us to elucidate the binding manner of each mannuronic acid oligomer, and the structural plasticity, which is dependent on calcium ions. Moreover, a comprehensive analysis of the lyase activity profiles of AcAlgE3 combined with structural characteristics explained the preference for different chain length oligomers.

The application of encapsulation technology in the food Industry: Classifications, recent Advances, and perspectives

Encapsulation technology has been extensively used to enhance the stability, specificity, and bioavailability of essential food ingredients. Additionally, it plays a vital role in improving product quality and reducing production costs. This study presents a comprehensive classification of encapsulation techniques based on the state of different cores (solid, liquid, and gaseous) and offers a detailed description and analysis of these encapsulation methods. Specifically, it introduces the diverse applications of encapsulation technology in food, encompassing areas such as antioxidant, protein activity, physical stability, controlled release, delivery, antibacterial, and probiotics. The potential impact of encapsulation technology is expected to make encapsulation technology a major process and research hotspot in the food industry. Future research directions include applications of encapsulation for enzymes, microencapsulation of biosensors, and novel technologies such as self-assembly. This study provides a valuable theoretical reference for the in-depth research and wide application of encapsulation technology in the food industry.

Tetramethylpyrazine-loaded liposomes surrounded by hydrogel based on sodium alginate and chitosan as a multifunctional drug delivery System for treatment of atopic dermatitis

Tetramethylpyrazine (TMP) has low bioavailability due to its fast metabolism and short half-life, which is not conducive to transdermal treatment of atopic dermatitis (AD). Therefore, in this study, TMP was encapsulated into liposomes (Lip) by film dispersion method, and then the surface of Lip was modified by sodium alginate (ALG) and chitosan (CS). The tetramethylpyrazine-loaded liposomes in sodium alginate chitosan hydrogel called T-Lip-AC hydrogel. In vitro experiments, we found that T-Lip-AC hydrogel not only had the antibacterial effect of CS, but also enhanced the anti-inflammatory and antioxidant effects of TMP. In addition, T-Lip-AC hydrogel could also provide a moist healing environment for AD dry skin and produce better skin permeability, and can also achieve sustained drug release, which is conducive to the treatment of AD. The lesions induced by 1-chloro-2,4-dinitrobenzene were used as the AD lesions model to test the therapeutic effect of the T-Lip-AC hydrogel on AD in vivo. The studies have showed that T-Lip-AC hydrogel could effectively promote wound healing. Therefore, we have developed a T-Lip-AC hydrogel as multifunctional hydrogel drug delivery system, which could become an effective, safe and novel alternative treatment method for treating AD.

Alginate biopolymeric structures: Versatile carriers for bioactive compounds in functional foods and nutraceutical formulations: A review

Alginate-based biopolymer products have gained attention for protecting and delivering bioactive components in nutraceuticals and functional foods. These naturally abundant anionic, unbranched, and linear copolymers are also produced commercially by microorganisms. Alone or in combination with other copolymers, they efficiently transport bioactive molecules in food and nutraceutical products. This review aims to provide an in-depth understanding of alginate-based products and structures, emphasizing their role in delivering functional molecules in various formulations and delivery systems. These include edible coatings/films, gels/emulsions, beads/droplets, microspheres/particles, and engineered nanostructures where alginates have been used potentially. By exploring these applications, readers gain insights into the benefits of these products. Because, alginate-based biopolymer products have shown promise in delivering bioactive compounds like vitamin C, vitamin D3, curcumin, β-carotene, resveratrol, folic acid, gliadins, caffeic acid, betanin, limonoids, quercetin, several polyphenols and essential oils, etc., which are chief contributors to treating specific/overall nutritional and chronic metabolic disorders. So, this review summarizes the potential of alginate-based structures/products in various forms for delivering a wide range of functional food ingredients and nutraceutical components that offer promising perspectives for future investigations.

Alginate-Based Hydrogels Enriched with Lavender Essential Oil: Evaluation of Physicochemical Properties, Antimicrobial Activity, and In Vivo Biocompatibility

Owing to its antibacterial, anti-inflammatory, and antioxidant activities, in the last few years, lavender essential oil (LVO) has been used in medical applications as a promising approach for treating infected wounds. However, the practical applicability of LVO is limited by its high volatility and storage stability. This study aimed to develop a novel hybrid hydrogel by combining phytic acid (PA)-crosslinked sodium alginate (SA) and poly(itaconic anhydride-co-3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5] undecane (PITAU) and evaluate its potential effectiveness as an antibacterial wound dressing after incorporating LVO. The influence of the mass ratio between SA and PITAU on the properties and stability of hydrogels was investigated. After LVO loading, the effect of oil addition to hydrogels on their functional properties and associated structural changes was studied. FTIR analysis revealed that hydrogen bonding is the primary interaction mechanism between components in the hybrid hydrogels. The morphology was analyzed using SEM, evidencing a porosity dependent on the ratio between SA and PITAU, while LVO droplets were well dispersed in the polymer blend. The release of LVO from the hydrogels was determined using UV-VIS spectroscopy, indicating a sustained release over time, independent of the LVO concentration. In addition, the hybrid hydrogels were tested for their antioxidant properties and antimicrobial activity against Gram-positive and Gram-negative bacteria. Very good antimicrobial activity was obtained in the case of sample SA_PITAU3+LVO10% against S. aureus and C. albicans. Moreover, in vivo tests showed an increased antioxidant effect of the SA_PITAU3+LVO10% hydrogel compared to the oil-free scaffold that may aid in accelerating the healing process of wounds.

Spatially resolved polymer mobilization revisited - Three-dimensional, UltraShort Echo Time (3D UTE) magnetic resonance imaging of sodium alginate matrix tablets

HYPOTHESIS

Three-dimensional 1H UltraShort Echo Time magnetic resonance imaging (1H 3D UTE MRI) of the matrix tablet made of hydrophilic polymer hydrated in heavy water (D2O) will allow investigation of the hydration-induced spatiotemporal evolution of the material originally included in the matrix tablet during manufacturing (i.e., polymer chains and bound water).

EXPERIMENTS

The oblong-shaped sodium alginate matrix tablets were used to verify the hypothesis. The matrix was measured before and during hydration in D2O for up to 2 h using the 1H 3D UTE MRI. Five echo times (first at 20 μs) were used, resulting in five three-dimensional images (one image for each echo time). In chosen cross-sections, two parametric images, i.e., amplitude and T2* relaxation time maps, were calculated using "pixel-by-pixel" mono-exponential fitting.

FINDINGS

The regions of the alginate matrix with T2* shorter than 600 μs were analyzed before (air-dry matrix) and during hydration (parametric, spatiotemporal analysis). During the study, only hydrogen nuclei (protons) pre-existing in the air-dry sample (polymer and bound water) were monitored because the hydration medium (D2O) was not visible. As a result, it was found that morphological changes in regions having T2* shorter than 300 μs were the effect of fast initial water ingress into the core of the matrix and subsequent polymer mobilization (early hydration providing additional 5% w/w hydration medium content relating to air-dry matrix). In particular, evolving layers in T2* maps were detected, and a fracture network was formed shortly after the matrix immersion in D2O. The current study presented a coherent picture of polymer mobilization accompanied by local polymer density decrease. We concluded, that the T2* mapping using 3D UTE MRI can effectively be applied as a polymer mobilization marker.

Protein-modified nanomaterials: emerging trends in skin wound healing

Prolonged inflammation can impede wound healing, which is regulated by several proteins and cytokines, including IL-4, IL-10, IL-13, and TGF-β. Concentration-dependent effects of these molecules at the target site have been investigated by researchers to develop them as wound-healing agents by regulating signaling strength. Nanotechnology has provided a promising approach to achieve tissue-targeted delivery and increased effective concentration by developing protein-functionalized nanoparticles with growth factors (EGF, IGF, FGF, PDGF, TGF-β, TNF-α, and VEGF), antidiabetic wound-healing agents (insulin), and extracellular proteins (keratin, heparin, and silk fibroin). These molecules play critical roles in promoting cell proliferation, migration, ECM production, angiogenesis, and inflammation regulation. Therefore, protein-functionalized nanoparticles have emerged as a potential strategy for improving wound healing in delayed or impaired healing cases. This review summarizes the preparation and applications of these nanoparticles for normal or diabetic wound healing and highlights their potential to enhance wound healing.

Development of a Novel, Ecologically Friendly Generation of pH-Responsive Alginate Nanosensors: Synthesis, Calibration, and Characterisation

Measurement of the intracellular pH is particularly crucial for the detection of numerous diseases, such as carcinomas, that are characterised by a low intracellular pH. Therefore, pH-responsive nanosensors have been developed by many researchers due to their ability to non-invasively detect minor changes in the pH of many biological systems without causing significant biological damage. However, the existing pH-sensitive nanosensors, such as the polyacrylamide, silica, and quantum dots-based nanosensors, require large quantities of organic solvents that could cause detrimental damage to the ecosystem. As a result, this research is aimed at developing a new generation of pH-responsive nanosensors comprising alginate natural polymers and pH-sensitive fluorophores using an organic, solvent-free, and ecologically friendly method. Herein, we successfully synthesised different models of pH-responsive alginate nanoparticles by varying the method of fluorophore conjugation. The synthesised pH nanosensors demonstrated a low MHD with a relatively acceptable PDI when using the lowest concentration of the cross-linker Ca+2 (1.25 mM). All the pH nanosensors showed negative zeta potential values, attributed to the free carboxylate groups surrounding the nanoparticles' surfaces, which support the colloidal stability of the nanosensors. The synthesised models of pH nanosensors displayed a high pH-responsiveness with various correlations between the pH measurements and the nanosensors' fluorescence signal. In summation, pH-responsive alginate nanosensors produced using organic, solvent-free, green technology could be harnessed as potential diagnostics for the intracellular and extracellular pH measurements of various biological systems.

Materials Engineering to Help Pest Control: A Narrative Overview of Biopolymer-Based Entomopathogenic Fungi Formulations

Biopolymer-based formulations show great promise in enhancing the effectiveness of entomopathogenic fungi as bioinsecticides. Chitosan and starch, among other biopolymers, have been utilized to improve spore delivery, persistence, and adherence to target insects. These formulations offer advantages such as target specificity, eco-friendliness, and sustainability. However, challenges related to production costs, stability, and shelf life need to be addressed. Recently, biomimetic lure and kill approaches based on biopolymers offer cost-effective solutions by leveraging natural attractants. Further research is needed to optimize these formulations and overcome challenges. Biopolymer-based formulations have the potential to revolutionize pest control practices, providing environmentally friendly and sustainable solutions for agriculture.

The synthesis and evaluation of thiolated alginate as the barrier to block nutrient absorption on small intestine for body-weight control

Obesity is the most common health concern all over the world. However, till now, there is no promising way to manage obesity or body-weight control. The aim of the study is to develop an edible gel as a health supplement that temporarily attaches to the mucus of the intestines, forming an absorption barrier to block the nutrients. We modify the alginate with the thiol group as thiolated alginate (TA) that may stay on the mucosa layer for a much longer time to reduce nutrient absorption. In this study, the TA is synthesized successfully and proved a good mucosal adhesion to serve as a barrier for nutrient absorption both in vitro and in vivo. The results of in vivo imaging system (IVIS) show that the synthesized TA can be exiled from the gastrointestinal tract within 24 h. The animal study shows that the TA by daily oral administration can effectively reduce body weight and fat deposition. The biosafety is evaluated in vitro at the cellular level, based on ISO-10993, and further checked by animal study. We do believe that the TA could have a greater potential to be developed into a safe health supplement to manage obesity and for body-weight control.

Polysaccharide-Based Edible Films/Coatings for the Preservation of Meat and Fish Products: Emphasis on Incorporation of Lipid-Based Nanosystems Loaded with Bioactive Compounds

The high water and nutritional contents of meat and fish products make them susceptible to spoilage. Thus, one of the most important challenges faced by the meat industry is extending the shelf life of meat and fish products. In recent years, increasing concerns associated with synthetic compounds on health have limited their application in food formulations. Thus, there is a great need for natural bioactive compounds. Direct use of these compounds in the food industry has faced different obstacles due to their hydrophobic nature, high volatility, and sensitivity to processing and environmental conditions. Nanotechnology is a promising method for overcoming these challenges. Thus, this article aims to review the recent knowledge about the effect of biopolymer-based edible films or coatings on the shelf life of meat and fish products. This study begins by discussing the effect of biopolymer (pectin, alginate, and chitosan) based edible films or coatings on the oxidation stability and microbial growth of meat products. This is followed by an overview of the nano-encapsulation systems (nano-emulsions and nanoliposomes) and the effect of edible films or coatings incorporated with nanosystems on the shelf life of meat and fish products.

Silica modified copper-based alginate/chitosan hybrid hydrogel to control soil fumigant release, reduce emission and enhance bioactivity

Soil fumigant has been extensively used for excellent efficacy on soil-borne diseases. However, rapid emission and insufficient effective duration typically limit its application. In this study, hybrid silica/polysaccharide hydrogel was proposed (SIL/Cu/DMDS) by emulsion-gelation method to encapsulate dimethyl disulfide (DMDS). The orthogonal study was used to optimize the preparation parameters for LC and EE of SIL/Cu/DMDS, which was 10.39 % and 71.05 %, respectively. Compared with silica, the time for 90 % of the total emissions was extended by 4.36 times. The hydrogel possessed a longer persistent duration and the degradation half-life of DMDS was 3.47 times greater than that of silica alone. Moreover, the electrostatic interaction between abundant groups of polysaccharide hydrogel bestowed DMDS with pH-triggered release behavior. Additionally, SIL/Cu/DMDS had excellent water holding and water retention capacity. The bioactivity of the hydrogel was 58.1 % higher than that of DMDS TC due to the strong synergistic effect between DMDS and the carriers (chitosan and Cu²⁺), and showed obvious biosafety to cucumber seeds. This study seeks to provide a potential approach to develop hybrid polysaccharide hydrogel to control soil fumigants release, reduce emission and enhance bioactivity in plant protection.

A Critical Review on Classified Excipient Sodium-Alginate-Based Hydrogels: Modification, Characterization, and Application in Soft Tissue Engineering

Alginates are polysaccharides that are produced naturally and can be isolated from brown sea algae and bacteria. Sodium alginate (SA) is utilized extensively in the field of biological soft tissue repair and regeneration owing to its low cost, high biological compatibility, and quick and moderate crosslinking. In addition to their high printability, SA hydrogels have found growing popularity in tissue engineering, particularly due to the advent of 3D bioprinting. There is a developing curiosity in tissue engineering with SA-based composite hydrogels and their potential for further improvement in terms of material modification, the molding process, and their application. This has resulted in numerous productive outcomes. The use of 3D scaffolds for growing cells and tissues in tissue engineering and 3D cell culture is an innovative technique for developing in vitro culture models that mimic the in vivo environment. Especially compared to in vivo models, in vitro models were more ethical and cost-effective, and they stimulate tissue growth. This article discusses the use of sodium alginate (SA) in tissue engineering, focusing on SA modification techniques and providing a comparative examination of the properties of several SA-based hydrogels. This review also covers hydrogel preparation techniques, and a catalogue of patents covering different hydrogel formulations is also discussed. Finally, SA-based hydrogel applications and future research areas concerning SA-based hydrogels in tissue engineering were examined.

A Novel Alginate Film Based on Nanocoating Approach for Enteric-Release Tablets

The objective of this study was to propose a new coating film for biodegradable polymers and environmentally friendly processing. Here, a novel implementation of solid lipid nanoparticles (SLN) into a biodegradable alginate (ALG) film composition created a new gastric-resistant film for an enteric-release tablet. Experiments were performed on a water-soluble substance (thiamine nitrate) to characterize the effects of SLN upon the addition of the ALG coating formulation. The coated tablets or cast films were characterized based on delayed-release properties, surface morphology, moisture resistance, and chemical interactions. The SLN-ALG film displayed gastric-resistant properties (< 10% drug substance dissolved at pH 1.2) and rapid disintegration in the intestinal medium (pH 6.8). Morphological analysis using a microscope and scanning electron microscope confirmed the uniformity and smoothness of the SLN-ALG film, which improved the mechanical properties of the film. Fourier transform infrared spectroscopy and differential scanning calorimetry indicated that SLN contributed to the formation of the film, which maintained free carboxylic groups, making the SLN-ALG film a higher acid resistance, but soluble in pH 6.8 buffer. These promising results suggest a novel nanotechnology-based coating formulation for various enteric-release dosage forms. Because of their biodegradability, the proposed ingredients and processes are safe and environment-friendly.

Sodium alginate-based drug delivery for diabetes management: A review

Diabetes mellitus (DM) is among the biggest global health problems of the 21st century, which is characterised by insufficient insulin secretion and results in the augmentation of blood sugar levels. The current foundation of hyperglycemia therapy is oral antihyperglycemic medications like biguanides, sulphonylureas, α-glucosidase inhibitors, peroxisome proliferator-activated receptor gamma (PPAR-γ) agonists, sodium-glucose co-transporter 2 (SGLT-2) inhibitors, dipeptidyl peptidase-4 (DPP-4) inhibitors and others. Many naturally occurring substances have shown promise in treating hyperglycemia. Inadequate prologitivity of action, restricted bioavailability, site specificity, and dose-related side effects are some problems with currently available anti-diabetic medications. Sodium alginate has shown promise as a drug delivery mechanism, potentially solving issues with current therapies for several substances. This review summarizes the research on the efficacy of drug delivery systems based on alginate for transporting oral hypoglycemic medicines, phytochemicals, and insulin for treating hyperglycemia.

Phytochemical-Based Nanomaterials against Antibiotic-Resistant Bacteria: An Updated Review

Antibiotic-resistant bacteria (ARB) is a growing global health threat, leading to the search for alternative strategies to combat bacterial infections. Phytochemicals, which are naturally occurring compounds found in plants, have shown potential as antimicrobial agents; however, therapy with these agents has certain limitations. The use of nanotechnology combined with antibacterial phytochemicals could help achieve greater antibacterial capacity against ARB by providing improved mechanical, physicochemical, biopharmaceutical, bioavailability, morphological or release properties. This review aims to provide an updated overview of the current state of research on the use of phytochemical-based nanomaterials for the treatment against ARB, with a special focus on polymeric nanofibers and nanoparticles. The review discusses the various types of phytochemicals that have been incorporated into different nanomaterials, the methods used to synthesize these materials, and the results of studies evaluating their antimicrobial activity. The challenges and limitations of using phytochemical-based nanomaterials, as well as future directions for research in this field, are also considered here. Overall, this review highlights the potential of phytochemical-based nanomaterials as a promising strategy for the treatment against ARB, but also stresses the need for further studies to fully understand their mechanisms of action and optimize their use in clinical settings.

Natural Gums in Drug-Loaded Micro- and Nanogels

Gums are polysaccharide compounds obtained from natural sources, such as plants, algae and bacteria. Because of their excellent biocompatibility and biodegradability, as well as their ability to swell and their sensitivity to degradation by the colon microbiome, they are regarded as interesting potential drug carriers. In order to obtain properties differing from the original compounds, blends with other polymers and chemical modifications are usually applied. Gums and gum-derived compounds can be applied in the form of macroscopic hydrogels or can be formulated into particulate systems that can deliver the drugs via different administration routes. In this review, we present and summarize the most recent studies regarding micro- and nanoparticles obtained with the use of gums extensively investigated in pharmaceutical technology, their derivatives and blends with other polymers. This review focuses on the most important aspects of micro- and nanoparticulate systems formulation and their application as drug carriers, as well as the challenges related to these formulations.

Low-field time-domain NMR relaxometry for studying polymer hydration and mobilization in sodium alginate matrix tablets

Sodium alginate is used in various industries, including food, pharmaceutical, and agriculture. Matrix systems, e.g., tablets, and granules, are macro samples with incorporated active substances. During hydration, they are neither equilibrated nor homogenous. Phenomena occurring during hydration of such systems are complex, determine their functional properties and hence require multimodal analysis. Still, there's a lack of comprehensive view. The study aimed to obtain unique characteristics of the sodium alginate matrix during hydration, particularly considering polymer mobilization phenomena using low-field time-domain NMR relaxometry in H₂O and D₂O. An increase in total signal during 4 h of hydration in D₂O of ca. 30 μV resulted from polymer/water mobilization. Modes in T₁-T₂ maps and changes in their amplitudes reflected physicochemical state of the polymer/water system: e.g. air-dry polymer mode (T₁/T₂ ~ 600) and two mobilized polymer/water modes (at T₁/T₂ ~ 40 and T₁/T₂ ~ 20). The study describes the approach to evaluating the hydration of the sodium alginate matrix in terms of the temporal evolution of proton pools: those existing in the matrix before hydration and those entering the matrix from the bulk water. It provides data complementary to spatially resolved methods like MRI and microCT.

3D Bioprinting for Pancreas Engineering/Manufacturing

Diabetes is the most common chronic disease in the world, and it brings a heavy burden to people's health. Against this background, diabetic research, including islet functionalization has become a hot topic in medical institutions all over the world. Especially with the rapid development of microencapsulation and three-dimensional (3D) bioprinting technologies, organ engineering and manufacturing have become the main trends for disease modeling and drug screening. Especially the advanced 3D models of pancreatic islets have shown better physiological functions than monolayer cultures, suggesting their potential in elucidating the behaviors of cells under different growth environments. This review mainly summarizes the latest progress of islet capsules and 3D printed pancreatic organs and introduces the activities of islet cells in the constructs with different encapsulation technologies and polymeric materials, as well as the vascularization and blood glucose control capabilities of these constructs after implantation. The challenges and perspectives of the pancreatic organ engineering/manufacturing technologies have also been demonstrated.

Industry chain and challenges of microalgal food industry-a review

Currently, the whole world is facing hunger due to the increase in the global population and the rising level of food consumption. Unfortunately, the impact of environmental, climate, and political issues on agriculture has resulted in limited global food resources. Thus, it is important to develop new food sources that are environmentally friendly and not subject to climate or space limitations. Microalgae represent a potential source of nutrients and bioactive components for a wide range of high-value products. Advances in cultivation and genetic engineering techniques provide prospective approaches to widen their application for food. However, there are currently problems in the microalgae food industry in terms of assessing nutritional value, selecting processes for microalgae culture, obtaining suitable commercial strains of microalgae, etc. Additionally, the limitations of real data of market opportunities for microalgae make it difficult to assess their actual potential and to develop a better industrial chain. This review addresses the current status of the microalgae food industry, the process of commercializing microalgae food and breeding methods. Current research progress in addressing the limitations of microalgae industrialization and future prospects for developing microalgae food products are discussed.

Carbohydrate Polymer-Based Targeted Pharmaceutical Formulations for Colorectal Cancer: Systematic Review of the Literature

Colon cancer is the third most diagnosed cancer worldwide, followed by lung and breast cancer. Conventional treatment methods are associated with numerous side effects and compliance issues. Thus, colon targeted drug delivery has gained much attention due to its evident advantages. Although many technologies have been explored, the use of pH-sensitive polymers, especially biodegradable polymers, holds exceptional promise. This review aims to collate research articles concerning recent advances in this area. A systematic search using multiple databases (Google Scholar, EMBASE, PubMed, MEDLINE and Scopus) was carried out following the preferred reported items for systematic reviews and meta-analyses (PRISMA) guidelines with an aim to explore the use of pH-sensitive carbohydrate polymers in developing colon targeted pharmaceutical formulations. Following screening and quality assessment for eligibility, 42 studies were included, exploring either single or a combination of carbohydrate polymers to develop targeted formulations for colon cancer therapy. Pectin (11) is the most widely used of these biopolymers, followed by chitosan (09), alginate (09) and guar gum (08). This systematic review has successfully gathered experimental evidence highlighting the importance of employing carbohydrate polymers in developing targeting formulations to manage colon cancer.

Fabrication of a magnetic alginate-silk fibroin hydrogel, containing halloysite nanotubes as a novel nanocomposite for biological and hyperthermia applications

In this study, the main focus was on designing and synthesizing a novel magnetic nanobiocomposite and its application in hyperthermia cancer treatment. Regarding this aim, sodium alginate (SA) hydrogel with CaCl₂ cross-linker formed and modified by silk fibroin (SF) natural polymer and halloysite nanotubes (HNTs), followed by in situ Fe₃O₄ magnetic nanoparticles preparation. No important differences were detected in red blood cells (RBCs) hemolysis, confirming the high blood compatibility of the treated erythrocytes with this nanobiocomposite. Moreover, the synthesized SA hydrogel/SF/HNTs/Fe₃O₄ nanobiocomposite does not demonstrate toxicity toward HEK293T normal cell line after 48 and 72 h. The anticancer property of SA hydrogel/SF/HNTs/Fe₃O₄ nanobiocomposites against breast cancer cell lines was corroborated. The magnetic saturation of the mentioned magnetic nanobiocomposite was 15.96 emu g⁻¹. The specific absorption rate (SAR) was measured to be 22.3 W g⁻¹ by applying an alternating magnetic field (AMF). This novel nanobiocomposite could perform efficiently in the magnetic fluid hyperthermia process, according to the obtained results.

Sensory and Nutraceutical Properties of Infusions Prepared with Grape Pomace and Edible-Coated Dried–Minced Grapes

Grapes and grape/wine byproducts such as non-fermented/semi-fermented or fermented grapes, skins, and seeds are a rich source of polyphenols, known to have nutraceutical properties. Grape byproducts present a great potential for the development of new beverages, such as infusions and tisanes. This work aimed to study the effects of different drying temperatures on the sensory and chemical properties of fermented grape pomace infusions, and to evaluate the same sensory and chemical characteristics on infusions of dried–minced grapes coated with different organic matrices. At the end of the work, it was possible to conclude that the presence of some coating agents results in changes in the sensory characteristics of the infusions, also altering the recorded antioxidant activity. However, all matrices seemed suitable for coating, and none showed negative characteristics in the infusions. Furthermore, of the three infusions (50, 60, and 70 °C), the one prepared with dehydrated grape pomace at 70 °C was the one with the highest pH value, highest °Brix value, and significantly greater concentration of phenolic compounds. In the sensory analysis, the constant presence of a bitter taste and astringent sensation stood out, which are not positive aspects from a sensory point of view. However, the addition of natural flavors—especially honey—made the infusion more sensorially pleasant. Overall, grape pomace dehydrated at 70 °C made it possible to obtain a product with phenolic compounds and antioxidant capacity that is more promising to integrate into human food, particularly via the preparation of infusions. Furthermore, the consumer may, if they so choose, add honey or another agent as a natural flavoring, making the final infusion more pleasant from a sensory point of view.

Chitosan/Alginate Nanoparticles for the Enhanced Oral Antithrombotic Activity of Clam Heparinoid from the Clam Coelomactra antiquata

Chitosan/alginate nanoparticles (DG1-NPs and DG1/Cur-NPs) aiming to enhance the oral antithrombotic activity of clam heparinoid DG1 were prepared by ionotropic pre-gelation. The influence of parameters, such as the concentration of sodium alginate (SA), chitosan (CTS), CaCl2, clam heparinoid DG1, and curcumin (Cur), on the characteristics of the nanoparticles, were investigated. Results indicate that chitosan and alginate can be used as polymer matrices to encapsulate DG1, and nanoparticle characteristics depend on the preparation parameters. Nano-particles should be prepared using 0.6 mg/mL SA, 0.33 mg/mL CaCl2, 0.6 mg/mL CTS, 7.2 mg/mL DG1, and 0.24 mg/mL Cur under vigorous stirring to produce DG1-NPS and DG1/Cur-NPS with small size, high encapsulation efficiency, high loading capacity, and negative zeta potential from approximately −20 to 30 mV. Data from scanning electron microscopy, Fourier-transform infrared spectrometry, and differential scanning calorimetry analyses showed no chemical reaction between DG1, Cur, and the polymers; only physical mixing. Moreover, the drug was loaded in the amorphous phase within the nanoparticle matrix. In the acute pulmonary embolism murine model, DG1-NPs enhanced the oral antithrombotic activity of DG1, but DG1/Cur-NPs did not exhibit higher antithrombotic activity than DG1-NPs. Therefore, the chitosan/alginate nanoparticles enhanced the oral antithrombotic activity of DG1, but curcumin did not further enhance this effect.

Electrospun Structural Hybrids of Acyclovir-Polyacrylonitrile at Acyclovir for Modifying Drug Release

In traditional pharmaceutics, drug–crystalline nanoparticles and drug–polymer composites are frequently explored for their ability to modify drug release profiles. In this study, a novel sort of hybrid with a coating of acyclovir crystalline nanoparticles on acyclovir-polyacrylonitrile composites was fabricated using modified, coaxial electrospinning processes. The developed acyclovir-polyacrylonitrile at the acyclovir nanohybrids was loaded with various amounts of acyclovir, which could be realized simply by adjusting the sheath fluid flow rates. Compared with the electrospun composite nanofibers from a single-fluid blending process, the nanohybrids showed advantages of modifying the acyclovir release profiles in the following aspects: (1) the initial release amount was more accurately and intentionally controlled; (2) the later sustained release was nearer to a zero-order kinetic process; and (3) the release amounts at different stages could be easily allocated by the sheath fluid flow rate. X-ray diffraction results verified that the acyclovir nanoparticles were in a crystalline state, and Fourier-transform infrared spectra verified that the drug acyclovir and the polymer polyacrylonitrile had a good compatibility. The protocols reported here could pave the way for developing new types of functional nanostructures.

Effect of the Amount of Polysorbate 80 and Oregano Essential Oil on the Emulsion Stability and Characterization Properties of Sodium Alginate Microcapsules

Essential oils have a high volatility that leads to evaporation and loss of their pharmacological effect when exposed to the environment. The objectives of the present work were to prepare microcapsules with oregano essential oil by extrusion using sodium alginate as a shell material and non-ionic surfactant polysorbate 80 as an emulsifier to stabilize the emulsion. The present study was aimed to evaluate the physical parameters of microcapsules and to compare the influence of the amount of emulsifier and the essential oil-to-emulsifier ratio on the capsules’ physical parameters and encapsulation efficiency; to our knowledge, the existing research had not yet revealed whether unstable emulsion affects the encapsulation efficiency of oregano essential oil. This study showed that increasing the emulsifier amount in the formulation significantly influenced encapsulation efficiency and particle size. Moreover, increasing the emulsion stability positively influenced the encapsulation efficiency. The emulsion creaming index depended on the emulsifier amount in the formulation: the highest creaming index (%) was obtained with the highest amount of polysorbate 80. However, the essential oil-to-polysorbate 80 ratio and essential oil amount did not affect the hardness of the microcapsules (p > 0.05). In conclusion, the obtained results could be promising information for production of microcapsules. Despite the fact that microencapsulation of essential oils is a promising and extremely attractive application area for the pharmaceutical industry, further basic research needs to be carried out.

Sodium alginate and alginic acid as pharmaceutical excipients for tablet formulation: Structure-function relationship

Alginic acid and its sodium salt are well-accepted pharmaceutical excipients fulfilling several roles in the development of solid oral dosage forms. Although they have attractive advantages as safety, abundance, relatively low cost and biodegradability, these natural polysaccharides possess a high variability that may limit their use as excipients for tablet formulation. Thus, to obtain robust formulations and high-quality drug products with consistent performance a complete understanding of the structure-property relationship becomes necessary as the structure of alginates affects both, technological and biopharmaceutical properties. This review compiles the compaction studies carried out that relate the structure of alginates to their mechanical and dissolution performances. The different analytical methods used to determine the chemical composition, primary structure and molecular weight distribution, major factors affecting the behavior of alginates in direct compression, are also exposed. Finally, different strategies reported to improve the properties of alginic acid as direct compression excipient are discussed.

Electrospun Medicated Nanofibers for Wound Healing: Review

With the increasing demand for wound care and treatment worldwide, traditional dressings have been unable to meet the needs of the existing market due to their limited antibacterial properties and other defects. Electrospinning technology has attracted more and more researchers' attention as a simple and versatile manufacturing method. The electrospun nanofiber membrane has a unique structure and biological function similar to the extracellular matrix (ECM), and is considered an advanced wound dressing. They have significant potential in encapsulating and delivering active substances that promote wound healing. This article first discusses the common types of wound dressing, and then summarizes the development of electrospun fiber preparation technology. Finally, the polymers and common biologically active substances used in electrospinning wound dressings are summarized, and portable electrospinning equipment is also discussed. Additionally, future research needs are put forward.

Preparation and Antimicrobial Properties of Alginate and Serum Albumin/Glutaraldehyde Hydrogels Impregnated with Silver(I) Ions

Calcium alginate (CaALG) hydrogel beads and two sets of composite beads, formed from a combination of calcium alginate/propylene glycol alginate/human serum albumin (CaALG/PGA/HSA) and from calcium alginate with the quaternary ammonium salt, (3-(trimethoxysilyl)propyl)-octadecyldimethylammonium chloride (QA), (CaALG/QA), were prepared. Bovine serum albumin (BSA) was condensed with glutaraldehyde (GLA) to form a BSA/GLA hydrogel. The corresponding Ag+-containing gels of all of the above hydrogels were also formed, and slow leaching of the biocidal transition metal ion from the gels bestowed broad spectrum antimicrobial activity. In the absence of added Ag+, CaALG/QA was the only material to deliver marginal to moderate antibacterial and antifungal effects. The Ag+ impregnated hydrogel systems have the potential to maintain the antimicrobial properties of silver, minimising the risk of toxicity, and act as reservoirs to afford ongoing sterility.

Brown Seaweed Sargassum siliquosum as an Intervention for Diet-Induced Obesity in Male Wistar Rats

The therapeutic potential of Sargassum siliquosum grown in Australian tropical waters was tested in a rat model of metabolic syndrome. Forty-eight male Wistar rats were divided into four groups of 12 rats and each group was fed a different diet for 16 weeks: corn starch diet (C); high-carbohydrate, high-fat diet (H) containing fructose, sucrose, saturated and trans fats; and C or H diets with 5% S. siliquosum mixed into the food from weeks 9 to 16 (CS and HS). Obesity, hypertension, dyslipidaemia, impaired glucose tolerance, fatty liver and left ventricular fibrosis developed in H rats. In HS rats, S. siliquosum decreased body weight (H, 547 ± 14; HS, 490 ± 16 g), fat mass (H, 248 ± 27; HS, 193 ± 19 g), abdominal fat deposition and liver fat vacuole size but did not reverse cardiovascular and liver effects. H rats showed marked changes in gut microbiota compared to C rats, while S. siliquosum supplementation increased gut microbiota belonging to the family Muribaculaceae. This selective increase in gut microbiota likely complements the prebiotic actions of the alginates. Thus, S. siliquosum may be a useful dietary additive to decrease abdominal and liver fat deposition.

Ions-induced gelation of alginate: Mechanisms and applications

Alginate is an important natural biopolymer and has been widely used in the food, biomedical, and chemical industries. Ca²⁺-induced gelation is one of the most important functional properties of alginate. The gelation mechanism is well-known as egg-box model, which has been intensively studied in the last five decades. Alginate also forms gels with many other monovalent, divalent or trivalent cations, and their gelation can possess different mechanisms from that of Ca²⁺-induced gelation. The resulted gels also exhibit different properties that lead to various applications. This study is proposed to summarize the gelation mechanisms of alginate induced by different cations, mainly including H⁺, Ca²⁺, Ba²⁺, Cu²⁺, Sr²⁺, Zn²⁺, Fe²⁺, Mn²⁺, Al³⁺, and Fe³⁺. The mechanism of H⁺-induced gelation of alginate mainly depends on the protonation of carboxyl groups. Divalent ions-induced gelation of alginate show different selection towards G, M, and GM blocks. Trivalent ions can bind to carboxyl groups of uronates with no selection. The properties and applications of these ionotropic alginate gels are also discussed. The knowledge gained in this study would provide useful information for the practical applications of alginate.