To see the other types of publications on this topic, follow the link: Alginates.
Journal articles on the topic 'Alginates'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Alginates.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Rizfa, Mila Safitri, Ervia Yudiati, and Diah Permata Wijayanti. "Improving The Antioxidant Activity of Sodium Alginate from Sargassum sp. by Thermal Heating and Chemical Methods." Jurnal Kelautan Tropis 23, no. 3 (November 14, 2020): 284–90. http://dx.doi.org/10.14710/jkt.v23i3.8946.
Full textAbstract:
The relationship between molecular structure and bioactivity was evaluated for sodium alginates obtained under different degradation treatment (raw alginates, heat-treated, and chemical-treated) from Sargassum sp. This study was conducted to identify the antioxidant activities of the degraded sodium alginate from Sargassum sp. compared to raw extract. Raw alginate as the control treatment was dried overnight at 60 °C, while heat-treated was heated raw alginate at 140oC in a laboratory oven (4.5 hours). Two chemical-treated were applied. Raw alginate added hydrogen peroxide and raw alginat with hydrogen peroxide plus ascorbic acid. This treatments were replicated three times. All the parameters were evaluated spectrophotometrically. The spectroscopy results from the degradation methods showed a new absorbance spectra pattern. The FT-IR spectrum revealed that treatment affects the structure of the alginates. Heat treated and chemical treated sodium alginates showed non significantly different on DPPH radical scavenging activity. Meanwhile, the combination of alginate and hydrogen peroxide treatment was at the lowest scavenging ability. Therefore, alginate oligosaccharides (AOS) produced by heating or adding chemical reagents could be considered as a stronger antioxidant than raw alginate, which may be applied in the industry and biomedical
2
Ochbaum, Guy, Maya Davidovich-Pinhas, and Ronit Bitton. "Tuning the mechanical properties of alginate–peptide hydrogels." Soft Matter 14, no. 21 (2018): 4364–73. http://dx.doi.org/10.1039/c8sm00059j.
Full textAbstract:
Covalent bonding peptides to alginates is routinely used to tailor alginate's biofunctionality. Here, we investigate the possibility of tuning the mechanical properties of alginate–peptide gels by altering the sequence of the covalently bound peptide.
3
Abourehab, Mohammad A. S., Rahul R. Rajendran, Anshul Singh, Sheersha Pramanik, Prachi Shrivastav, Mohammad Javed Ansari, Ravi Manne, Larissa Souza Amaral, and A. Deepak. "Alginate as a Promising Biopolymer in Drug Delivery and Wound Healing: A Review of the State-of-the-Art." International Journal of Molecular Sciences 23, no. 16 (August 12, 2022): 9035. http://dx.doi.org/10.3390/ijms23169035.
Full textAbstract:
Biopolymeric nanoparticulate systems hold favorable carrier properties for active delivery. The enhancement in the research interest in alginate formulations in biomedical and pharmaceutical research, owing to its biodegradable, biocompatible, and bioadhesive characteristics, reiterates its future use as an efficient drug delivery matrix. Alginates, obtained from natural sources, are the colloidal polysaccharide group, which are water-soluble, non-toxic, and non-irritant. These are linear copolymeric blocks of α-(1→4)-linked l-guluronic acid (G) and β-(1→4)-linked d-mannuronic acid (M) residues. Owing to the monosaccharide sequencing and the enzymatically governed reactions, alginates are well-known as an essential bio-polymer group for multifarious biomedical implementations. Additionally, alginate’s bio-adhesive property makes it significant in the pharmaceutical industry. Alginate has shown immense potential in wound healing and drug delivery applications to date because its gel-forming ability maintains the structural resemblance to the extracellular matrices in tissues and can be altered to perform numerous crucial functions. The initial section of this review will deliver a perception of the extraction source and alginate’s remarkable properties. Furthermore, we have aspired to discuss the current literature on alginate utilization as a biopolymeric carrier for drug delivery through numerous administration routes. Finally, the latest investigations on alginate composite utilization in wound healing are addressed.
4
Adamiak, Katarzyna, and Alina Sionkowska. "State of Innovation in Alginate-Based Materials." Marine Drugs 21, no. 6 (June 8, 2023): 353. http://dx.doi.org/10.3390/md21060353.
Full textAbstract:
This review article presents past and current alginate-based materials in each application, showing the widest range of alginate’s usage and development in the past and in recent years. The first segment emphasizes the unique characteristics of alginates and their origin. The second segment sets alginates according to their application based on their features and limitations. Alginate is a polysaccharide and generally occurs as water-soluble sodium alginate. It constitutes hydrophilic and anionic polysaccharides originally extracted from natural brown algae and bacteria. Due to its promising properties, such as gelling, moisture retention, and film-forming, it can be used in environmental protection, cosmetics, medicine, tissue engineering, and the food industry. The comparison of publications with alginate-based products in the field of environmental protection, medicine, food, and cosmetics in scientific articles showed that the greatest number was assigned to the environmental field (30,767) and medicine (24,279), whereas fewer publications were available in cosmetic (5692) and food industries (24,334). Data are provided from the Google Scholar database (including abstract, title, and keywords), accessed in May 2023. In this review, various materials based on alginate are described, showing detailed information on modified composites and their possible usage. Alginate’s application in water remediation and its significant value are highlighted. In this study, existing knowledge is compared, and this paper concludes with its future prospects.
5
T., Jayanthy, and Vayyala P. Reddy. "Efficacy of an alginate versus proton pump inhibitor in the symptomatic relief of gastroesophageal reflux symptoms in pregnant women." International Journal of Reproduction, Contraception, Obstetrics and Gynecology 12, no. 6 (May 26, 2023): 1616–21. http://dx.doi.org/10.18203/2320-1770.ijrcog20231524.
Full textAbstract:
Background: Gastroesophageal reflux disease (GERD) is frequently seen during pregnancy with prevalence of 80%. Proton pump inhibitors (PPI) are the most effective drugs used in the treatment of reflux symptoms. Alginates are natural polysaccharide polymer which builds a non-systemic barrier against acid and food reflux in the oesophagus. Aims and objectives were to compare the efficacy of alginate versus PPIs in pregnant women, and to determine the time to onset of decrease in the pain intensity of alginate to PPIs. Methods: This is a prospective randomised study conducted in pregnant women with symptoms of heartburn comparing the efficacy of alginates to PPIs in Kempegowda Institute of Medical Sciences. After subjects have signed the consent, two sachets of 10 ml liquid preparation alginate were given to the alginate group while 40 mg intravenous pantoprazole to the PPI group. Results: Among 40 patients studied, 20 were given alginates and 20 were given PPIs. 7 presented in the 1st trimester and 33 in 2nd trimester. Onset of action is faster with alginates when compared to PPIs, it was 30 min to 1 hour in patients taking alginates and 6-12 hours in patients taking PPIs, duration of action was longer for PPIs than alginates, with alginates it’s observed that it attains 24-hour symptom free interval in shorter time when compared to PPIs. Conclusions: ¬Alginates to be used for rapid symptom relief in patients with acute symptoms as an induction agent, PPIs to be used for longer duration of action as maintenance.
6
Jeoh, Tina, Dana E. Wong, Scott A. Strobel, Kevin Hudnall, Nadia R. Pereira, Kyle A. Williams, Benjamin M. Arbaugh, Julia C. Cunniffe, and Herbert B. Scher. "How alginate properties influence in situ internal gelation in crosslinked alginate microcapsules (CLAMs) formed by spray drying." PLOS ONE 16, no. 2 (February 25, 2021): e0247171. http://dx.doi.org/10.1371/journal.pone.0247171.
Full textAbstract:
Alginates gel rapidly under ambient conditions and have widely documented potential to form protective matrices for sensitive bioactive cargo. Most commonly, alginate gelation occurs via calcium mediated electrostatic crosslinks between the linear polyuronic acid polymers. A recent breakthrough to form crosslinked alginate microcapsules (CLAMs) by in situ gelation during spray drying (“CLAMs process”) has demonstrated applications in protection and controlled delivery of bioactives in food, cosmetics, and agriculture. The extent of crosslinking of alginates in CLAMs impacts the effectiveness of its barrier properties. For example, higher crosslinking extents can improve oxidative stability and limit diffusion of the encapsulated cargo. Crosslinking in CLAMs can be controlled by varying the calcium to alginate ratio; however, the choice of alginates used in the process also influences the ultimate extent of crosslinking. To understand how to select alginates to target crosslinking in CLAMs, we examined the roles of alginate molecular properties. A surprise finding was the formation of alginic acid gelling in the CLAMs that is a consequence of simultaneous and rapid pH reduction and moisture removal that occurs during spray drying. Thus, spray dried CLAMs gelation is due to calcium crosslinking and alginic acid formation, and unlike external gelation methods, is insensitive to the molecular composition of the alginates. The ‘extent of gelation’ of spray dried CLAMs is influenced by the molecular weights of the alginates at saturating calcium concentrations. Alginate viscosity correlates with molecular weight; thus, viscosity is a convenient criterion for selecting commercial alginates to target gelation extent in CLAMs.
7
Rosiak, Piotr, Ilona Latanska, Paulina Paul, Witold Sujka, and Beata Kolesinska. "Modification of Alginates to Modulate Their Physic-Chemical Properties and Obtain Biomaterials with Different Functional Properties." Molecules 26, no. 23 (November 30, 2021): 7264. http://dx.doi.org/10.3390/molecules26237264.
Full textAbstract:
Modified alginates have a wide range of applications, including in the manufacture of dressings and scaffolds used for regenerative medicine, in systems for selective drug delivery, and as hydrogel materials. This literature review discusses the methods used to modify alginates and obtain materials with new or improved functional properties. It discusses the diverse biological and functional activity of alginates. It presents methods of modification that utilize both natural and synthetic peptides, and describes their influence on the biological properties of the alginates. The success of functionalization depends on the reaction conditions being sufficient to guarantee the desired transformations and provide modified alginates with new desirable properties, but mild enough to prevent degradation of the alginates. This review is a literature description of efficient methods of alginate functionalization using biologically active ligands. Particular attention was paid to methods of alginate functionalization with peptides, because the combination of the properties of alginates and peptides leads to the obtaining of conjugates with properties resulting from both components as well as a completely new, different functionality.
8
Colin, Camille, Emma Akpo, Aurélie Perrin, David Cornu, and Julien Cambedouzou. "Encapsulation in Alginates Hydrogels and Controlled Release: An Overview." Molecules 29, no. 11 (May 26, 2024): 2515. http://dx.doi.org/10.3390/molecules29112515.
Full textAbstract:
This review aims to gather the current state of the art on the encapsulation methods using alginate as the main polymeric material in order to produce hydrogels ranging from the microscopic to macroscopic sizes. The use of alginates as an encapsulation material is of growing interest, as it is fully bio-based, bio-compatible and bio-degradable. The field of application of alginate encapsulation is also extremely broad, and there is no doubt it will become even broader in the near future considering the societal demand for sustainable materials in technological applications. In this review, alginate’s main properties and gelification mechanisms, as well as some factors influencing this mechanism, such as the nature of the reticulation cations, are first investigated. Then, the capacity of alginate gels to release matter in a controlled way, from small molecules to micrometric compounds, is reported and discussed. The existing techniques used to produce alginates beads, from the laboratory scale to the industrial one, are further described, with a consideration of the pros and cons with each techniques. Finally, two examples of applications of alginate materials are highlighted as representative case studies.
9
Soukaina, Bouissil, EL Alaoui-Talibi Zainab, Pierre Guillaume, Rchid Halima, Michaud Philippe, El Modafar Cherkaoui, and Delattre Cédric. "Radical Depolymerization of Alginate Extracted from Moroccan Brown Seaweed Bifurcaria bifurcata." Applied Sciences 10, no. 12 (June 17, 2020): 4166. http://dx.doi.org/10.3390/app10124166.
Full textAbstract:
The degradation of alginate extracted from Moroccan Bifurcaria bifurcata has not been fully established to date. In this work, we report the extraction and the characterization of alginate (ASBB) from the brown algae B. bifurcata, as well as the production of oligo-alginates (OGABs) by using a green chemistry process. The depolymerization of ASBB was carried out by controlled radical hydrolysis through our green chemistry process using a hydrogen peroxide (H2O2) catalyst. The molecular weight (Mw) and degree of polymerization (DP) distribution of oligo-alginates (OGABs) obtained were then characterized by HPLC size exclusion chromatography (SEC) and high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Structural characterization revealed that after 6 h of depolymerization of ASBB, we obtained OGABs with Mw ≤ 5.5 kDa and 2 ≤ DP ≤ 24. These results highlight the effectiveness of the controlled radical hydrolysis of alginate to produce good yields of alginate fractions with controlled Mw with a known polymerization degree (DP) and without altering properties of oligo-alginates. Bifurcaria bifurcata can be a potential source of alginate and oligo-alginates given its abundance on the northwest Atlantic coast. The production and characterization of oligo-alginates promote their exploitation in the cosmetic, pharmaceutic, and agriculture fields.
10
Kıvılcımdan Moral, Ç., Ö. Doğan, and F. D. Sanin. "Use of laboratory-grown bacterial alginate in copper removal." Water Science and Technology 65, no. 11 (June 1, 2012): 2003–9. http://dx.doi.org/10.2166/wst.2012.101.
Full textAbstract:
Industrial production leads to toxic heavy metal pollution in water bodies. Copper is one of the examples that requires removal from effluents before being discharged. It is difficult and sometimes very expensive to remove toxic heavy metals by conventional treatment techniques. This study aims to remove copper by the use of bacterial alginate as a non-conventional technique. Bacterial alginates (natural polymers composed of mannuronic and guluronic acid monomers) were synthesized by Azotobacter vinelandii ATCC® 9046 in a laboratory fermentor under controlled environmental conditions. The alginates produced, with a range of different characteristics in terms of monomer distribution and viscosity, were investigated for maximum copper uptake capacities. The average copper uptake capacities of alginates produced were found to be about 1.90 mmol/L Cu2+/g alginate. Although the GG-block amount of alginates was varied from 12 to 87% and culture broth viscosities were changed within the range of 1.47 and 14 cP, neither the block distribution nor viscosities of alginate samples considerably affected the copper uptake of alginates.
11
Fischer, Melissa, Florian Gebhard, Timo Hammer, Christian Zurek, Guido Meurer, Christoph Marquardt, and Dirk Hoefer. "Microbial alginate dressings show improved binding capacity for pathophysiological factors in chronic wounds compared to commercial alginate dressings of marine origin." Journal of Biomaterials Applications 31, no. 9 (March 29, 2017): 1267–76. http://dx.doi.org/10.1177/0885328217702173.
Full textAbstract:
Marine alginates are well established in wound management. Compared with different modern wound dressings, marine alginates cannot prove superior effects on wound healing. Alginates from bacteria have never been studied for medical applications so far, although the microbial polymer raises expectations for improved binding of wound factors because of its unique O-acetylation. Due to its possible positive effects on wound healing, alginates from bacteria might be a superior future medical product for clinical use. To prove the binding capacity of microbial alginates to pathophysiological factors in chronic wounds, we processed microbial alginate fibres, produced from fermentation of the soil bacterium Azotobacter vinelandii ATCC 9046, into needle web dressings and compared them with commercial dressings made of marine alginate. Four dressings were assessed: Marine alginate dressings containing either ionic silver or zinc/manganese/calcium, and microbial alginate dressings with and without nanosilver. All dressings were tested in an in vitro approach for influence on chronic wound parameters such as elastase, matrix metalloproteases-2, tumour necrosis factor-α, interleukin-8, and free radical formation. Despite the alginate origin or addition of antimicrobials, all dressings were able to reduce the concentration of the proinflammatory cytokines TNF-α and IL-8. However, microbial alginate was found to bind considerable larger amounts of elastase and matrix metalloproteases-2 in contrast to the marine alginate dressings. The incorporation of zinc, silver or nanosilver into alginate fibres did not improve their binding capacity for proteases or cytokines. The addition of nanosilver slightly enhanced the antioxidant capacity of microbial alginate dressings, whereas the marine alginate dressing containing zinc/manganese/calcium was unable to inhibit the formation of free radicals. The enhanced binding affinity by microbial alginate of Azotobacter vinelandii to pathophysiological factors may be interesting to support optimal conditions for wound healing.
12
Tøndervik, Anne, Olav A. Aarstad, Randi Aune, Susan Maleki, Philip D. Rye, Arne Dessen, Gudmund Skjåk-Bræk, and Håvard Sletta. "Exploiting Mannuronan C-5 Epimerases in Commercial Alginate Production." Marine Drugs 18, no. 11 (November 18, 2020): 565. http://dx.doi.org/10.3390/md18110565.
Full textAbstract:
Alginates are one of the major polysaccharide constituents of marine brown algae in commercial manufacturing. However, the content and composition of alginates differ according to the distinct parts of these macroalgae and have a direct impact on the concentration of guluronate and subsequent commercial value of the final product. The Azotobacter vinelandii mannuronan C-5 epimerases AlgE1 and AlgE4 were used to determine their potential value in tailoring the production of high guluronate low-molecular-weight alginates from two sources of high mannuronic acid alginates, the naturally occurring harvested brown algae (Ascophyllum nodosum, Durvillea potatorum, Laminaria hyperborea and Lessonia nigrescens) and a pure mannuronic acid alginate derived from fermented production of the mutant strain of Pseudomonas fluorescens NCIMB 10,525. The mannuronan C-5 epimerases used in this study increased the content of guluronate from 32% up to 81% in both the harvested seaweed and bacterial fermented alginate sources. The guluronate-rich alginate oligomers subsequently derived from these two different sources showed structural identity as determined by proton nuclear magnetic resonance (1H NMR), high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and size-exclusion chromatography with online multi-angle static laser light scattering (SEC-MALS). Functional identity was determined by minimum inhibitory concentration (MIC) assays with selected bacteria and antibiotics using the previously documented low-molecular-weight guluronate enriched alginate OligoG CF-5/20 as a comparator. The alginates produced using either source showed similar antibiotic potentiation effects to the drug candidate OligoG CF-5/20 currently in development as a mucolytic and anti-biofilm agent. These findings clearly illustrate the value of using epimerases to provide an alternative production route for novel low-molecular-weight alginates.
13
Szekalska, Marta, Agata Puciłowska, Emilia Szymańska, Patrycja Ciosek, and Katarzyna Winnicka. "Alginate: Current Use and Future Perspectives in Pharmaceutical and Biomedical Applications." International Journal of Polymer Science 2016 (2016): 1–17. http://dx.doi.org/10.1155/2016/7697031.
Full textAbstract:
Over the last decades, alginates, natural multifunctional polymers, have increasingly drawn attention as attractive compounds in the biomedical and pharmaceutical fields due to their unique physicochemical properties and versatile biological activities. The focus of the paper is to describe biological and pharmacological activity of alginates and to discuss the present use and future possibilities of alginates as a tool in drug formulation. The recent technological advancements with using alginates, issues related to alginates suitability as matrix for three-dimensional tissue cultures, adjuvants of antibiotics, and antiviral agents in cell transplantation in diabetes or neurodegenerative diseases treatment, and an update on the antimicrobial and antiviral therapy of the alginate based drugs are also highlighted.
14
Garanin, Roman, and Igor Lykov. "Biosorption of zinc and copper ions by immobilized yeast under aerobic and anaerobic conditions." E3S Web of Conferences 548 (2024): 02004. http://dx.doi.org/10.1051/e3sconf/202454802004.
Full textAbstract:
Studies have been conducted to evaluate the efficiency of biosorption of zinc and copper ions by brewing yeast Saccharomyces cerevisiae immobilized on alginates. The studies were carried out under aerobic and anaerobic conditions using calcium, calcium, magnesium, and aluminum alginates. Under aerobic conditions, when live yeast was immobilized in calcium alginate, the concentration of zinc ions in an aqueous solution decreased within 2 hours by 99.76%, and copper ions by 91.7%. Biosorbents based on a mixture of calcium and magnesium alginates work less effectively (reducing the concentration of zinc ions by 99.3%, and copper ions by 75.8%). Under anaerobic conditions, a biosorbent based on calcium alginate decreased its efficiency in the presence of zinc ions by 0.8%, and that based on aluminum alginate - by 5.4%. In the presence of copper ions, the biosorption efficiency under anaerobic conditions decreased by 2.1%–9.9%, depending on the alginate. This work demonstrates the potential of the brewing yeast Saccharomyces cerevisiae as a calcium alginate-based biosorbent.
15
Kaidi, Soukaina, Fouad Bentiss, Charafeddine Jama, Khaoula Khaya, Zahira Belattmania, Abdeltif Reani, and Brahim Sabour. "Isolation and Structural Characterization of Alginates from the Kelp Species Laminaria ochroleuca and Saccorhiza polyschides from the Atlantic Coast of Morocco." Colloids and Interfaces 6, no. 4 (September 27, 2022): 51. http://dx.doi.org/10.3390/colloids6040051.
Full textAbstract:
Alginates are linear unbranched polysaccharides produced by brown seaweeds. The gel properties of this phycocolloid are mainly linked to the monomer composition, sequential structure and molecular weight of the polymeric chain. Nevertheless, these structural parameters are also dependent on the age and tissue of the thalli used. In this work, the kelp species Laminaria ochroleuca and Saccorhiza polyschides harvested from the Moroccan coast were analyzed for their alginates content and composition in different thalli parts (blade and stipe). Spectroscopic characterization (1H NMR and FT-IR), viscosity, and molecular weight of the extracted alginates were investigated. The obtained results showed that the alginate contents ranged from 20.19 ± 2 to 49.8 ± 2.4% dw. FT-IR spectroscopy exhibited similar spectra between the alginates extracted from both species and the commercial alginate. The 1H-NMR results revealed interesting variations in block composition between species, and less disparity with regard to the tissue type (M/G values ranging from 0.89 to 2.14). High mannuronate content was found in all alginates except for those extracted from the blade of L. ochroleuca. The homopolymeric fractions FMM are remarkably high compared to the FGG and heteropolymeric fractions (FGM/FMG) in S. polyschides. However, for L. ochroleuca, the heteropolymeric fractions are quite abundant, accounting for more than 34% of the polymer diads. The alginates extracted from both species indicated low values for the intrinsic viscosity. Based on the yield and the structural properties of their alginates, this study suggests that both L. ochroleuca and S.polyschides could be considered potential alginophytes to be incorporated into the industry of alginates. It also proposes an optimization of the yield, using the different thalli parts in the extraction (blade and stipe). The chemical structure and viscosity of their alginates may contribute to expanding their applications, especially in biotechnology and medical fields.
16
Kulašević, Lazar N. "Alginate: Applications in the modern world." Chemia Naissensis 1, no. 1 (2018): 187–97. http://dx.doi.org/10.46793/chemn1.1.187k.
Full textAbstract:
Alginate is a natural polysaccharide extracted from the cell walls of brown algae. Thanks to its biocompatibility, biodegradability, nontoxicity, and low cost, this biopolymer is widely applicable across various fields of biomedical science and bioengineering. Alginates are used as a gelling agent in food industry. Alginate hydrogels are an appealing scaffold material because of their resemblance with natural tissues. Consequently, alginates are widely used in tissue engineering and alginate gel beads as transport vehicles in drug delivery systems. Nonetheless, alginate hydrogels are used in nanotechnology to build artificial capillary blood vessels.
17
Beata Łabowska, Magdalena, Izabela Michalak, and Jerzy Detyna. "Methods of extraction, physicochemical properties of alginates and their applications in biomedical field – a review." Open Chemistry 17, no. 1 (October 29, 2019): 738–62. http://dx.doi.org/10.1515/chem-2019-0077.
Full textAbstract:
AbstractIn this paper, the current state-of-art of extraction of alginates and the determination of their physico-chemical properties as well as their overall applications focussing on biomedical purposes has been presented. The quality and quantity of the alginate obtained with a variable yield prepared from brown seaweeds as a result of many factors, such as type of algae, extraction methods, chemical modification and others. Alginates are mainly extracted by using conventional alkaline extraction. However, novel extraction techniques such as microwave and ultrasound assisted extractions have gained a lot of interest. The extraction parameters (e.g., temperature and time of extraction) have critical impact on the alginate physiochemical and mechanical properties and thus, their potential applications. By controlling a chemical process makes it possible get various forms of alginates, such as fibres, films, hydrogels or foams. It is important to characterise the obtained alginates in order to their proper applications. This article presents several techniques used for the analysis of alginate properties. These natural polysaccharides are widely used in the commercial production, as a food ingredient, in the pharmaceutical industry due to their antibacterial, anticancer and probiotic properties. Their gelling characteristic and absorbable properties enable using alginates as a wound management material. Moreover, they are also biocompatible, non-toxic and biodegradable, therefore adequate in other biomedical applications.
18
Belattmania, Zahira, Soukaina Kaidi, Samir El Atouani, Chaimaa Katif, Fouad Bentiss, Charafeddine Jama, Abdeltif Reani, Brahim Sabour, and Vitor Vasconcelos. "Isolation and FTIR-ATR and 1H NMR Characterization of Alginates from the Main Alginophyte Species of the Atlantic Coast of Morocco." Molecules 25, no. 18 (September 22, 2020): 4335. http://dx.doi.org/10.3390/molecules25184335.
Full textAbstract:
Alginates are widely used as gelling agents in textile print pastes, medical industries, impression material in dentistry, and anticoagulant material in toothpaste. In the present study, the content and spectroscopic characterization (1H NMR and FT-IR) of the sodium alginates were investigated in the eight brown seaweeds Sargassum muticum, Fucus vesiculosus f. volubilis, Carpodesmia tamariscifolia, Bifurcaria bifurcata, Laminaria ochroleuca, Cystoseira humilis, Saccorhiza polyschides, and Fucus guiryi harvested from the NW Atlantic coast of Morocco. The results proved that the most studied algae depicted alginate yields higher than 18% dry weight. The FT-IR analysis showed that the spectra of the extracted alginates exhibited significant similarities to the commercial alginate from Sigma-Aldrich. The 1H NMR spectroscopy indicated that the extracted alginates have a high content of β-d-mannuronic (M) than α-l-guluronic acid (G) with M/G ratio values ranging from 1.04 to 4.41. The homopolymeric fractions FMM are remarkably high compared to the FGG and heteropolymeric fractions (FGM = FMG) especially for F. guiryi, C humilis, C. tamariscifolia, L. ochroleuca, and S. polyschides. Nevertheless, the heteropolymeric fractions (FGM/FMG) are quite abundant in the alginates of S. muticum, F. vesiculosus f. volubilis, and B. bifurcata accounting for more than 52% of the polymer diads. Based on these results, the investigated algal species (except Fucus guiryi and Bifurcaria bifurcata) could be regarded as potential sources of alginates for industrial uses.
19
Aguanza, Ma Aezel, Roberta Lauzon, and Ivy Emnace. "Improving the Extraction Process of Sodium Alginate from Samu (Sargassum piluliferum) using the PlackettBurman Design." Science and Humanities Journal 12, no. 1 (December 1, 2018): 54–65. http://dx.doi.org/10.47773/shj.1998.111.4.
Full textAbstract:
Alginates, which are mainly produced from kelp, improve and stabilize the texture of foods. Thus, they are important in the food and beverage industry. Brown seaweeds such as Sargassum piluliferum are abundant in the Philippines and could be potential sources of alginates. The PlackettBurman screening was used as a tool to evaluate the importance of seven selected variables (formaldehyde solution, extractant ratio, Na2CO3 concentration, HCl concentration, extraction temperature, bleaching, and precipitant), which influence the extraction process of sodium alginates. The main factors that affected the extraction of sodium alginates were extraction ratio, Na CO concentration, and bleaching. Extraction ratio and 2 3 Na CO significantly affected the production of sodium alginate by lowering 2 3 the level of extractant concentration and obtaining a positive effect in terms of its yield. Bleaching with NaOCl did not significantly affect the yield. However, it had a positive effect on the purity of the alginate which is an essential physico-chemical parameter that reflects the proportion of the target compound. These factors could be further optimized to extract high yield and good quality sodium alginate from Sargassum piluliferum.
20
Song, Yun Ha, Hee Chul Woo, and Jaekyoung Lee. "Eco-Friendly Depolymerization of Alginates by H2O2 and High-Frequency Ultrasonication." Clean Technologies 5, no. 4 (December 6, 2023): 1402–14. http://dx.doi.org/10.3390/cleantechnol5040069.
Full textAbstract:
Marine biomass has attracted attention as an environmentally sustainable energy source that can replace petroleum-based resources. Alginates, the main natural polysaccharides extracted from seaweeds, are used in various fields, such as food, pharmaceuticals, and chemical raw materials. Because the versatile applications of alginates depend on their physicochemical properties, which are controlled by their molecular weights, proper alginate depolymerization should be established. Previous approaches have limitations such as long reaction times and environmental issues. In this study, we report eco-friendly alginate depolymerization using hydrogen peroxide (H2O2)-induced oxidative decomposition and high-frequency ultrasonication. In oxidative decomposition, the depolymerization tendency depends on both the temperature and the use of iron oxide catalysts that can promote the Fenton reaction. Ultrasonication is effective in promoting selective depolymerization and ring-opening reactions. Oligo-alginates obtained through the precise molecular weight regulation of alginate offer potential applications in medical devices and platform chemicals.
21
De Oliveira, Marciana Castanha, Thais Maira Borges, Flaviana Alves Dias, Paula Vanessa Pedron Oltramari-Navarro, Marcelo Lupion Poletic, and Thais Maria Freire Fernandes. "Dimensional Stability of Alginates Molds Tridimentionally Scanned." Journal of Health Sciences 20, no. 2 (July 27, 2018): 78. http://dx.doi.org/10.17921/2447-8938.2018v20n2p78-82.
Full textAbstract:
AbstractAlginate is among the most used materials in dentistry to create teeth negative printing and reproduction. The goal of this study was to compare dimensional changes of alginate scanned impression materials. Thirty impressions of a standard typodont were performed using three types of alginate (Hydrogum 5; Jeltrate Plus and Avagel). The impressions were scanned by the scanner 3Shape R700T and scans were performed immediately after molding. The analysis of digita models were performed at OrthoAnalyzer ™ 3D software. Measurements were carried out in relation to the transverse dimension (intercanine, interpremolares and intermolar). Method error was evaluated through the Intraclass Correlation Coefficient (ICC) and Bland-Altman. One-way ANOVA, Dunnet Post-test were used to compare the different groups in relation to Typodont (gold standard) for the different outcome variables. The data were tabulated in Statistical Package for Social Sciences version 20.0 and Minitab 17.0 softwares to compare groups. The significance level was 5%. The posterior transverse variables (D1PM, D2PM and DM) presented a statistically significant difference regarding the gold standard (Typodont) for the plaster models performed after the Avagel molding. In the digital models performed just after molding, only in DM, the Avagel material group presented values statistically higher than the control group. The alginates Hydrogum 5 and Jeltrate Plus presented dimensions closer to the gold standard.Keywords: Dental Impression Materials. Dental Models. Imaging, Three-Dimensional.ResumoO alginato está entre os materiais de moldagem mais utilizados na Odontologia para criar impressão e reprodução negativa dos dentes. O objetivo desse trabalho foi comparar alterações transversais de três marcas comerciais de alginato (Hydrogum, Jeltrate e Avagel) em moldes de alginatos. Trinta moldes de um Typodont padrão foram realizados, utilizando três tipos de alginato (Hydrogum 5; Jeltrate Plus e Avagel). Os moldes foram escaneados por meio do scanner 3Shape R700T e os escaneamentos realizados logo após a moldagem e logo após a obtenção dos modelos de gesso. As análises dos modelos digitais foram realizadas no software OrthoAnalyzer™ 3D. Foram realizadas mensurações em relação à discrepância transversal (inter-caninos, inter primeiro pré-molar, inter-segundo pré-molar e inter-molares). O erro do método foi avaliado por meio do Coeficiente de Correlação Intraclasse (CCI) e Bland-Altman. Utilizou-se Análise de Variância (one-way ANOVA, Pós-teste Dunnet) para comparação dos diferentes grupos em relação ao typodont (padrão-ouro) para as diferentes variáveis de desfecho. A análise estatística foi realizada nos programas Statistical Package for Social Sciences versão 20.0 e no programa Minitab 17.0 para comparação dos grupos. O nível de significância foi de 5%. As variáveis transversais posteriores (D1PM; D2PM e DM) apresentaram diferença estatisticamente significante em relação ao padrão-ouro (manequim) para os modelos de gesso realizados após a moldagem com Avagel. Nos modelos digitais realizados logo após a moldagem, apenas na DM, o grupo do material Avagel apresentou valores estatisticamente maiores do que o grupo controle. Os alginatos Hydrogum 5 e Jeltrate Plus apresentaram dimensões mais próximas do padrão-ouro.Palavras-chave: Materiais para Moldagem Odontológica. Modelos Dentários. Imagem Tridimensional.
22
Zhu, Yuanjia, Charles J. Stark, Sarah Madira, Sidarth Ethiraj, Akshay Venkatesh, Shreya Anilkumar, Jinsuh Jung, et al. "Three-Dimensional Bioprinting with Alginate by Freeform Reversible Embedding of Suspended Hydrogels with Tunable Physical Properties and Cell Proliferation." Bioengineering 9, no. 12 (December 15, 2022): 807. http://dx.doi.org/10.3390/bioengineering9120807.
Full textAbstract:
Extrusion-based three-dimensional (3D) bioprinting is an emerging technology that allows for rapid bio-fabrication of scaffolds with live cells. Alginate is a soft biomaterial that has been studied extensively as a bio-ink to support cell growth in 3D constructs. However, native alginate is a bio-inert material that requires modifications to allow for cell adhesion and cell growth. Cells grown in modified alginates with the RGD (arginine-glycine-aspartate) motif, a naturally existing tripeptide sequence that is crucial to cell adhesion and proliferation, demonstrate enhanced cell adhesion, spreading, and differentiation. Recently, the bioprinting technique using freeform reversible embedding of suspended hydrogels (FRESH) has revolutionized 3D bioprinting, enabling the use of soft bio-inks that would otherwise collapse in air. However, the printability of RGD-modified alginates using the FRESH technique has not been evaluated. The associated physical properties and bioactivity of 3D bio-printed alginates after RGD modification remains unclear. In this study, we characterized the physical properties, printability, and cellular proliferation of native and RGD-modified alginate after extrusion-based 3D bioprinting in FRESH. We demonstrated tunable physical properties of native and RGD-modified alginates after FRESH 3D bioprinting. Sodium alginate with RGD modification, especially at a high concentration, was associated with greatly improved cell viability and integrin clustering, which further enhanced cell proliferation.
23
Putri, Arlina Prima, Francesco Picchioni, Sri Harjanto, and Mochamad Chalid. "Alginate Modification and Lectin-Conjugation Approach to Synthesize the Mucoadhesive Matrix." Applied Sciences 11, no. 24 (December 13, 2021): 11818. http://dx.doi.org/10.3390/app112411818.
Full textAbstract:
Alginates are natural anionic polyelectrolytes investigated in various biomedical applications, such as drug delivery, tissue engineering, and 3D bioprinting. Functionalization of alginates is one possible way to provide a broad range of requirements for those applications. A range of techniques, including esterification, amidation, acetylation, phosphorylation, sulfation, graft copolymerization, and oxidation and reduction, have been implemented for this purpose. The rationale behind these investigations is often the combination of such modified alginates with different molecules. Particularly promising are lectin conjugate macromolecules for lectin-mediated drug delivery, which enhance the bioavailability of active ingredients on a specific site. Most interesting for such application are alginate derivatives, because these macromolecules are more resistant to acidic and enzymatic degradation. This review will report recent progress in alginate modification and conjugation, focusing on alginate-lectin conjugation, which is proposed as a matrix for mucoadhesive drug delivery and provides a new perspective for future studies with these conjugation methods.
24
Pasaribu, Adam Sojuangon, Sri Sedjati, and Rini Pramesti. "Analisis Kualitas Alginat Rumput Laut (Padina sp.) Menggunakan Metode Ekstraksi Jalur Kalsium." Journal of Marine Research 9, no. 1 (February 20, 2020): 75–80. http://dx.doi.org/10.14710/jmr.v9i1.25502.
Full textAbstract:
ABSTRAK: Padina sp. merupakan spesies rumput laut cokelat (Phaeophyta) penghasil alginat, namun kualitas alginat yang dihasilkan tergolong rendah dibandingkan alginofit lainnya. Metode ekstraksi jalur kalsium diduga dapat meningkatkan kualitas alginat sehingga penelitian ini perlu dilakukan. Tujuan penelitian ini untuk mengkaji apakah ekstraksi jalur kalsium dapat meningkatkan mutu alginat yang dihasilkan dari rumput laut Padina. Ekstraksi dilakukan dengan metode jalur kalsium konvensional dan jalur kalsium MAE (Microvawe Assisted Extraction). Metode penelitian yang digunakan adalah eksperimental laboratoris dengan 1 perlakuan (kosentrasi CaCl2) dan 3 taraf konsentrasi yaitu 0,5 M 1,0 M dan 1,5 M. Parameter kualitas yang dianalisis meliputi rendemen, kadar air, Kadar abu, viskositas, pH dan FTIR. Hasil uji two way ANOVA menunjukan terdapat signifikansi rendemen dengan nilai 0,007. Metode jalur kalsium MAE dengan konsentrasi 1,0 M CaCl2 menghasilkan kualitas terbaik dengan nilai rendemen (26,83%), kadar air (10,67%), kadar abu (21,83%), viskositas (11,42 cPs) dan pH (6,77). Hasil analisis FTIR menunjukan ke-2 metode ekstraksi menghasilkan natrium alginat dengan adanya sidik jari guluronat dan manuronat pada bilangan gelombang 930-890 cm-1 dan 870-820 cm-1. ABSTRACT: Padina sp. is a species of brown seaweed (Phaephyta) producing alginates, but the quality of alginates produced is relatively low compared to other alginophytes. The calcium pathway extraction method is thought to improve the quality of alginates thus the reason of the research. This research aims to examine whether the calcium pathway extraction improves the quality of alginates produced from Padina. Seaweed extraction was carried out using conventional calcium pathways and MAE (Microwave Assisted Extraction) calcium pathways. The research method used was laboratory experimental with 1 treatment (CaCl2 concentration) and 3 concentration levels : 0.5 M, 1.0 M, 1.5 M. Quality parameters analyzed includes yield, moisture content, ash contetnt, viscosity, pH and FTIR. The two way ANOVA test results showed that there was a significance of yield value of 0.007. The MAE calcium pathway method with a concentration of 1.0 M CaCl2 produces the best quality with a yield value (26.83%), water content (10.67%), ash content (21.83%), viscosity (11.42 cPs) and pH (6.77). FTIR analysis results show that the two extraction methods produces sodium alginate in the presence of guluronate and manuronic fingerprints at wave numbers 930-890 cm-1 and 870-820 cm-1.
25
Muhamad Rahim, Nur Syairah, Norlaily Ahmad, and Dzaraini Kamarun. "Preparation and Characterization of Chitosan/Alginate Polyelectrolyte Complex Prepared by Using Calcium Tripolyphosphate Ionic Gelator." Materials Science Forum 857 (May 2016): 447–51. http://dx.doi.org/10.4028/www.scientific.net/msf.857.447.
Full textAbstract:
The formation of polyelectrolyte complexes (PECs) between chitosan and alginate has been widely investigated for many pharmaceutical and biomedical uses. Ionotropic gelation resulted from the crosslinking of polyelectrolytes (PEs) in the presence of ionic crosslinkers to form hydrogels. The most widely used ionic crosslinker for chitosan is sodium tripolyphosphate (NaTPP); and Ca2+ ions for alginates. The use of these cross-linkers to prepare PECs of chitosan and alginates resulted in hydrogels of similar moieties: chitosan-chitosan and alginate-alginate rather than the sought for hybrid chitosan-alginate PECs. Calcium tripolyphosphate (CaTPP) is a single molecule ionic gelator of chitosan and alginate that have the capability of producing the true hybrid compound of chitosan/alginate polyelectrolyte complex. This paper reported the synthesis of calcium tripolyphosphate and the preparation of a hybrid chitosan/alginate PECs using this newly identified ionic gelator. The newly-synthesized ionic gelator was characterized using ICP-OES; the PECs thereof prepared were characterized using TGA and SEM. The degradation temperature of the prepared PECs is higher than the degradation temperatures of the individual chitosan and alginates. SEM image of the prepared PECs showed rougher surfaces compared to the images of the individual chitosan and alginate compound. Both TGA and SEM revealed the possibility of the newly prepared material to be of the PECs sought for.
26
Rashedy, Sarah H., Mohamed S. M. Abd El Hafez, Mahmoud A. Dar, João Cotas, and Leonel Pereira. "Evaluation and Characterization of Alginate Extracted from Brown Seaweed Collected in the Red Sea." Applied Sciences 11, no. 14 (July 7, 2021): 6290. http://dx.doi.org/10.3390/app11146290.
Full textAbstract:
Alginates are one of the most important compounds of brown seaweeds. These compounds are employed in the food area, because of their important rheological properties, such as viscosity, gelling, and stabilizing features and as dietary fiber source. In this study, five species of dominant brown seaweeds were collected in the Red Sea (Padina boergesenii, Turbinaria triquetra, Hormophysa cuneiformis, Dictyota ciliolata, and Sargassum aquifolium) so as to characterize the alginate yield and its properties. The analysis demonstrated differences in the alginate yield among the seaweeds. The highest yield of alginate was recorded in the species T. triquetra (22.2 ± 0.56% DW), while the lowest content was observed in H. cuneiformis (13.3 ± 0.52% DW). The viscosity from the alginates varied greatly between the species, whereas the pH varied slightly. The alginate exhibited a moisture content between 6.4 and 13.1%, the ash content ranged between 12.3 and 20% DW, the protein reached values from 0.57 to 1.47% DW, and the lipid concentration varied from 0.3 to 3.5% DW. Thus, the phytochemical analysis demonstrated that the extracted alginates can be safely applied in the food industry. Furthermore, the alginate yield reveals the potential application of these seaweeds as a nutraceutical raw source, which can be exploited by the food industry.
27
Irvin, Randall T., and Howard Ceri. "Immunochemical examination of the Pseudomonas aeruginosa glycocalyx: a monoclonal antibody which recognizes L-guluronic acid residues of alginic acid." Canadian Journal of Microbiology 31, no. 3 (March 1, 1985): 268–75. http://dx.doi.org/10.1139/m85-050.
Full textAbstract:
Mice immunized with Formalin-fixed mucoid Pseudomonas aeruginosa cells developed an immune response directed, in part, towards the P. aeruginosa glycocalyx. The polyclonal mouse sera produced good immunofluorescent staining of the P. aeruginosa glycocalyx and cell surface. A library of 250 hybridoma cell lines which produced monoclonal antibodies directed against P. aeruginosa was established. Twelve clones (4.8%) produced antibody which reacted with alginate in an enzyme-linked immunosorbent assay (ELISA). Clone Ps 53 was chosen for further study, cloned, and an ascites tumor established. Clone Ps 53 was chosen for further study because the antibody produced demonstrated a specificity similar to that of a recently isolated heparin – rat-lung lectin which recognizes alginates of the Homma nontypable P. aeruginosa strains. The Ps 53 clone produced an immunoglobulin M which reacted with P. aeruginosa alginate and produced good immunofluorescent staining of the P. aeruginosa glycocalyx. The Ps 53 monoclonal antibody has an apparent specificity for L-guluronic residues in ELISA. Competitive binding studies with various alginates and monosaccharides suggest that the C6 carboxyl group of uronic acids are recognized by the antibody and that the antigen-binding site is fairly large and may recognize a particular sequence or epitope of alginic acid which is rich in L-guluronic acid. The Ps 53 monoclonal antibody did not react uniformily with all P. aeruginosa alginates but did react with all of the alginates of the Homma nontypable strains tested, suggesting that acetylation or various modifications found in P. aeruginosa alginates may interfere with antibody binding and define specific epitopes. The Ps 53 antibody also reacted with purified outer membrane, indicating that some alginate or L-guluronic acid is intimately associated with outer membrane.
28
Aitouguinane, Meriem, Zainab El Alaoui-Talibi, Halima Rchid, Imen Fendri, Slim Abdelkafi, Mohamed Didi Ould El-Hadj, Zakaria Boual, et al. "Elicitor Activity of Low-Molecular-Weight Alginates Obtained by Oxidative Degradation of Alginates Extracted from Sargassum muticum and Cystoseira myriophylloides." Marine Drugs 21, no. 5 (May 16, 2023): 301. http://dx.doi.org/10.3390/md21050301.
Full textAbstract:
Alginates extracted from two Moroccan brown seaweeds and their derivatives were investigated for their ability to induce phenolic metabolism in the roots and leaves of tomato seedlings. Sodium alginates (ALSM and ALCM) were extracted from the brown seaweeds Sargassum muticum and Cystoseira myriophylloides, respectively. Low-molecular-weight alginates (OASM and OACM) were obtained after radical hydrolysis of the native alginates. Elicitation was carried out by foliar spraying 20 mL of aqueous solutions (1 g/L) on 45-day-old tomato seedlings. Elicitor capacities were evaluated by monitoring phenylalanine ammonia-lyase (PAL) activity, polyphenols, and lignin production in the roots and leaves after 0, 12, 24, 48, and 72 h of treatment. The molecular weights (Mw) of the different fractions were 202 kDa for ALSM, 76 kDa for ALCM, 19 kDa for OACM, and 3 kDa for OASM. FTIR analysis revealed that the structures of OACM and OASM did not change after oxidative degradation of the native alginates. These molecules showed their differential capacity to induce natural defenses in tomato seedlings by increasing PAL activity and through the accumulation of polyphenol and lignin content in the leaves and roots. The oxidative alginates (OASM and OACM) exhibited an effective induction of the key enzyme of phenolic metabolism (PAL) compared to the alginate polymers (ALSM and ALCM). These results suggest that low-molecular-weight alginates may be good candidates for stimulating the natural defenses of plants.
29
Ursini, Ornella, Roberta Angelini, Silvia Franco, and Barbara Cortese. "Understanding the metal free alginate gelation process." RSC Advances 11, no. 55 (2021): 34449–55. http://dx.doi.org/10.1039/d1ra06599h.
Full textAbstract:
Alginate gelling by ionic cross-linking using multivalent ions has been known and exploited for several decades. We focus on the possibility to obtain alginate hydrogels without using metal cation in order to obtain metal-free alginates hydrogels.
30
Ding, Liang, Xinxia Cui, Rui Jiang, Keya Zhou, Yalei Wen, Chenfeng Wang, Zhilian Yue, Shigang Shen, and Xuefeng Pan. "Design, Synthesis and Characterization of a Novel Type of Thermo-Responsible Phospholipid Microcapsule–Alginate Composite Hydrogel for Drug Delivery." Molecules 25, no. 3 (February 6, 2020): 694. http://dx.doi.org/10.3390/molecules25030694.
Full textAbstract:
Liposomes are extensively used in drug delivery, while alginates are widely used in tissue engineering. However, liposomes are usually thermally unstable and drug-leaking when in liquids, while the drug carriers made of alginates show low loading capacities when used for drug delivery. Herein, we developed a type of thermo-responsible liposome–alginate composite hydrogel (TSPMAH) by grafting thermo-responsive liposomes onto alginates by using Ca2+ mediated bonding between the phosphatidic serine (PS) in the liposome membrane and the alginate. The temperature-sensitivity of the liposomes was actualized by using phospholipids comprising dipalmitoylphosphatidylcholine (DPPC) and PS and the liposomes were prepared by a thin-film dispersion method. The TSPMAH was then successfully prepared by bridge-linking the microcapsules onto the alginate hydrogel via PS-Ca2+-Carboxyl-alginate interaction. Characterizations of the TSPMAH were carried out using scanning electron microscopy, transform infrared spectroscopy, and laser scanning confocal microscopy, respectively. Their rheological property was also characterized by using a rheometer. Cytotoxicity evaluations of the TSPMAH showed that the composite hydrogel was biocompatible, safe, and non-toxic. Further, loading and thermos-inducible release of model drugs encapsulated by the TSPMAH as a drug carrier system was also studied by making protamine–siRNA complex-carrying TSPMAH drug carriers. Our results indicated that the TSPMAH described herein has great potentials to be further developed into an intelligent drug delivery system.
31
Bennacef, Chanez, Stéphane Desobry, Jordane Jasniewski, Sébastien Leclerc, Laurent Probst, and Sylvie Desobry-Banon. "Influence of Alginate Properties and Calcium Chloride Concentration on Alginate Bead Reticulation and Size: A Phenomenological Approach." Polymers 15, no. 20 (October 20, 2023): 4163. http://dx.doi.org/10.3390/polym15204163.
Full textAbstract:
Two types of alginates, AlgLF and AlgP, were used in this study to produce alginate beads by electro-vibratory extrusion. AlgLF and AlgP exhibited different Mannuronate/Guluronate (M/G) ratios and molecular weights as measured by NMR and SEC-MALS. The calcium chloride concentration was found to have the greatest effect on bead size. Higher concentrations resulted in smaller beads. AlgLF with a higher molecular weight and a lower proportion of G blocks showed smaller beads. For both alginates, the bead size was also influenced by the flow rate and vibration frequency. Alginate solution aging showed a minimal effect. Alginate reticulation was modeled using a mathematical equation. The study provides insights for the optimization of alginate-based materials in different applications by shedding light on the main factors influencing bead size. The importance of the molecular weight, M/G ratio and calcium ion concentration in the gelling process is highlighted, providing opportunities for the tailoring of alginate materials through a phenomenological model.
32
Kwiatkowska-Marks, Sylwia, Justyna Miłek, and Marek Wójcik. "The effect of pH on the sorption of copper ions by alginates." Polish Journal of Chemical Technology 10, no. 1 (January 1, 2008): 28–30. http://dx.doi.org/10.2478/v10026-008-0007-5.
Full textAbstract:
The effect of pH on the sorption of copper ions by alginates The effect of pH on copper ions sorption by alginates has been investigated. The granules of the sorbent obtained from sodium alginate (type DMF, manufactured by KELCO) have been applied. By using a new method of gelation a biosorbent containing from 11.3 to 20.3% mas. of alginate has been produced. Investigations have been carried out at a constant temperature of 25°C and the pH values ranging from 3 to 5. The obtained experimental results have been described by the Langmuir equation. It has been found that with the increasing pH of the solution the maximum biosorbent sorption capacity increased.
33
Walker, Mike, and Jennifer Hurlow. "A tale of two alginates." Journal of Wound Care 30, Sup2 (February 1, 2021): S29—S36. http://dx.doi.org/10.12968/jowc.2021.30.sup2.s29.
Full textAbstract:
Background: All fibrous wound dressings are considered to have the same action and value to the support of wound healing. Although clear distinction has been accepted between cotton gauze and calcium alginates, there is still no formally recognised distinction between calcium alginates and the more rapidly gelling fibre dressings. Method: Scientific and clinical evaluations were used to differentiate two different fibrous wound care products. One is derived from polymer extraction of algae (alginate dressings); the other has been manufactured from a uniquely patented carboxymethylation process that produces 100% carboxymethyl cellulose (CMC)-based dressings. Structural differences between these dressings were evaluated with respect to three important areas of wound care management: optimal wound moisture control; the ability to reduce risk of complication by locking away harmful components (e.g. bacteria); and reducing the overall cost of wound care by promoting more efficient use of nursing time. Results: Clear differentiation was illustrated through both scientific and clinical evaluations. Conclusion: This study supports the potential advantages of using a technically advanced fibrous wound dressing over the traditional fibrous alginate wound care product.
34
Salgado, Leonardo Tavares, Rodrigo Tomazetto, Leonardo Paes Cinelli, Marcos Farina, and Gilberto Menezes Amado Filho. "The influence of brown algae alginates on phenolic compounds capability of ultraviolet radiation absorption in vitro." Brazilian Journal of Oceanography 55, no. 2 (June 2007): 145–54. http://dx.doi.org/10.1590/s1679-87592007000200007.
Full textAbstract:
Brown algae phenolic compounds (PC) are secondary metabolites that participate in many biological processes, such as ultraviolet radiation (UV) protection, polyspermy blocking and trace metals bounding. Recently, PC has also been studied due to possible interactions with cell wall polysaccharides. However, there are few evidences of these interactions and their influence in physiological processes. The interactions between PC from the brown alga Padina gymnospora and alginates and the influence of these interactions on the UV absorption properties of PC were investigated in this work. Chromatography and spectrophotometry techniques were used to isolate, characterize and determine UV absorption capacity of studied compounds. Even after the P. gymnospora polysaccharide extraction and isolating methods, the PC was maintained linked to the alginate. The interaction of alginates with PC did not cause modifications on absorbance pattern of electromagnetic spectrum (UV-VIS-IR). The UV absorbance capability of PC linked to alginate was maintained for a longer period of time if compared with the purified PC. The obtained results reveal the strong linkage between PC and alginates and that these linkages preserve the UV absorption capability of PC along time.
35
Oppelt, Marie, and Christos G. Aneziris. "Analysis and Evaluation of Different Influencing Factors in Processing of Hollow and Full Beads by Alginate Gelation Based on Zirconia and TRIP Steel." Materials Science Forum 825-826 (July 2015): 158–66. http://dx.doi.org/10.4028/www.scientific.net/msf.825-826.158.
Full textAbstract:
A novel and innovative process for full as well as hollow metal-matrix composite bead fabrication using gel-casting process by alginate gelation is investigated. In particular the influence of four different alginates and various solidifying agents have been investigated regarding the formation and stability of full and hollow beads. The suspension contained a metastable austenitic steel powder (16Cr7Mn3Ni) and zirconia particles as well as different alginates and was added dropwise into water containing different solidifying agents for forming beads. With the aid of sodium and potassium alginate dropped in solution with CaCl2, full metal beads have been obtained. Hollow beads have been produced using potassium alginate and Ca (OH)2 as solidifying agent and show a hollow space fraction of 65%. At lower strains (up to 15 %), all zirconia reinforced full steel beads obtain higher specific energy absorption (SEA) in comparison to pure steel beads.
36
Dalheim, Marianne Ø., Line Aa Omtvedt, Isabel M. Bjørge, Anita Akbarzadeh, João F. Mano, Finn L. Aachmann, and Berit L. Strand. "Mechanical Properties of Ca-Saturated Hydrogels with Functionalized Alginate." Gels 5, no. 2 (April 19, 2019): 23. http://dx.doi.org/10.3390/gels5020023.
Full textAbstract:
In this work, the mechanical properties and stability of alginate hydrogels containing functionalized alginates (peptide and β-cyclodextrin) were studied. There is an increasing interest in the modification of alginates to add functions such as cell attachment and increased solubility of hydrophobic drugs, for better performance in tissue engineering and drug release, respectively. Functionalization was achieved in this study via periodate oxidation followed by reductive amination, previously shown to give a high and controllable degree of substitution. Young’s modulus and the stress at rupture of the hydrogels were in general lowered when exchanging native alginate with the modified alginate. Still, the gel strength could be adjusted by the fraction of modified alginate in the mixed hydrogels as well as the degree of oxidation. No notable difference in deformation at rupture was observed while syneresis was influenced by the degree of oxidation and possibly by the nature and amount of the grafted molecules. The mixed hydrogels were less stable than hydrogels with only native alginate, and modified alginate was released from the hydrogels. Furthermore, the hydrogels in general rather disintegrated than swelled upon saline treatments.
37
Racmayani, Novia, and Amir Husni. "Effect of Different Formulations on Characteristic of Biobased Alginate Edible Films as Biodegradable Packaging." E3S Web of Conferences 147 (2020): 03003. http://dx.doi.org/10.1051/e3sconf/202014703003.
Full textAbstract:
Edible film can be used for food packaging. The main raw materials for edible film were alginates and plasticizers including glycerol and olive oil. This study aims to determine the characteristics of edible film composed of alginate, glycerol and olive oil. The study was carried out through the manufacture of edible films composed of alginates with various concentrations (2, 3, 4, 5 and 6%, w / v), 10% glycerol and 0.01% olive oil. Characteristics of edible film was observed including thickness, tensile strength, water vapor transmission rate, solubility and elongation. The results showed that the products met the edible film standard of the Japanese Industrial Standard. Concentration of alginate used had significant effect on thickness, tensile strength, solubility and elongation of the edible film. The films with 6% concentration of alginate showed optimum results with thickness 0,227 ± 0,008 mm, tensile strength 3,097 ± 0,384 MPa, elongation 86,682 ± 5,090 %, solubility 8,690 ± 2,892 % and water vapor transmission rate 45,477 ± 6,262 g/m2/24 h.
38
Hernández-Gallegos, Minerva Aurora, Javier Solorza-Feria, Maribel Cornejo-Mazón, José Rodolfo Velázquez-Martínez, María Eva Rodríguez-Huezo, Gustavo F. Gutiérrez-López, and Humberto Hernández-Sánchez. "Protective Effect of Alginate Microcapsules with Different Rheological Behavior on Lactiplantibacillus plantarum 299v." Gels 9, no. 9 (August 24, 2023): 682. http://dx.doi.org/10.3390/gels9090682.
Full textAbstract:
Alginate encapsulation is a well-known technique used to protect microorganisms from adverse conditions. However, it is also known that the viscosity of the alginate is dependent on its composition and degree of polymerization and that thermal treatments, such as pasteurization and sterilization, can affect the structure of the polymer and decrease its protection efficiency. The goal of this study was to evaluate the protective effect of encapsulation, using alginates of different viscosities treated at different temperatures, on Lactiplantibacillus plantarum 299v under in vitro gastrointestinal conditions and cold storage at 4 °C and −15 °C, respectively. Steady- and dynamic-shear rheological tests were used to characterize the polymers. Thermal treatments profoundly affected the rheological characteristics of alginates with high and low viscosity. However, the solutions and gels of the low-viscosity alginate were more affected at a temperature of 117 °C. The capsules elaborated with high-viscosity alginate solution and pasteurized at 63 °C for 30 min provided better protection to the cells of L. plantarum 299v under simulated gastrointestinal and cold storage conditions.
39
Prasad. B, Venkata Nagendra, and Latha D. "Investigating the Synergistic Antibacterial Activity of Epiphytic Bacterial Polyketides and Biopolymer Alginates from Marine Microalgae." Journal of University of Shanghai for Science and Technology 23, no. 10 (October 4, 2021): 115–35. http://dx.doi.org/10.51201/jusst/21/09704.
Full textAbstract:
The objective was framed to analyse the synergistic antibacterial activity and woundhealing ability of the developed polyketide-alginate polymers. Alginates were extracted from a brown seaweed Padina tetrastromatica and used as a synergistic compound along with bacterial polyketides. Polyketides and alginate polymer combinations were used against test bacteria to determine the synergistic antibacterial activity. A novel wound-healing film was developed using polyketide and alginates with synergistic concentrations and its degradability and wound-healing ability was investigated. The findings in the present research showed most significantly that, Staphylococcus aureus showed complete synergy with the mean MIC value of 0.03 μg/ml and with best FIC value of 0.24 (p<0.5). Degradation of developed films revealed that more moisture leads to more release of antibacterial alginate content at the wound site and hence more degradation. This was evident from the FESEM analysis. In vitro wound-healing assay revealed that the developed polyketide-alginate polymers exhibited cell migration and proliferation after 24th hour of incubation at 370C indicating the wound-healing abilities. Hence, it can be concluded that the biochemical compounds present in the developed polyketide-alginate polymers are considered highly significant in treating any types of wounds.
40
Nagpal, Ajay, Ranjith Madhavan, Navia George, Niharika R. Thummala, and SV Ravi. "Self-disinfecting Alginate vs Conventional Alginate: Effect on Surface Hardness of Gypsum Cast—An in vitro Study." Journal of Contemporary Dental Practice 18, no. 11 (2017): 1061–64. http://dx.doi.org/10.5005/jp-journals-10024-2176.
Full textAbstract:
ABSTRACT Introduction For the construction of any dental prosthesis, accurate impressions are necessary. Hence, we undertook the present study to evaluate and compare the surface hardness of gypsum casts poured from impressions made using conventional alginate and self-disinfecting alginate. Materials and methods A total of 30 impressions of stainless steel die were made, out of which 15 impressions were made with conventional alginate and 15 were made with selfdisinfecting alginate and poured using Type III dental stone. Thirty stone specimens were subjected for hardness testing. Data were analyzed using independent samples t-test to compare the mean surface hardness. Results Difference in surface hardness was statistically insignificant (p > 0.05). Conclusion Surface hardness of gypsum casts poured using impressions made from self-disinfecting alginate and conventional alginates were comparable. Clinical significance Self-disinfecting alginates may be employed in clinical practice as safe and effective materials to overcome the infection control issues without compromising on the properties of the material. How to cite this article Madhavan R, George N, Thummala NR, Ravi SV, Nagpal A. Self-disinfecting Alginate vs Conventional Alginate: Effect on Surface Hardness of Gypsum Cast—An in vitro Study. J Contemp Dent Pract 2017;18(11):1061-1064.
41
Thomas, S. "Alginates." Journal of Wound Care 1, no. 1 (May 2, 1992): 29–32. http://dx.doi.org/10.12968/jowc.1992.1.1.29.
Full text
42
Gacesa, Peter. "Alginates." Carbohydrate Polymers 8, no. 3 (January 1988): 161–82. http://dx.doi.org/10.1016/0144-8617(88)90001-x.
Full text
43
Penfold, Rafael Da Rocha Santos, William Cunha Brandt, Milton Edson Miranda, and Rafael Pino Vitti. "Evaluation of dimensional stability and details reproduction of alginate molds storage in different times and temperature." Brazilian Dental Science 21, no. 1 (March 28, 2018): 37. http://dx.doi.org/10.14295/bds.2018.v21i1.1501.
Full textAbstract:
<p><strong>Objective:</strong> The aim of this study was to evaluate dimensional stability and detail reproduction in alginate molds stored at different times and temperatures. <strong>Material and </strong><strong>Methods:</strong> Three different commercially available alginates (Cavex Color Change, Jeltrate Plus and Hydrogum 5) were tested at four different times (0 - control, 1, 3 and 5 days) and two temperatures (25ºC and 37ºC) (n=5). The alginates were handled following the manufacturer's instructions. The impression procedures occurred in an environment with controlled room temperature (25ºC) and relative humidity (50±5%). A metallic model (ISO 1563:1990) was used to perform the impressions. The tray containing alginate remained on the metallic model under constant pressure (2 kgf) until the alginate gelation process. The molds were stored (different times and temperatures) and analyzed in stereomicroscope at 30x magnification and 0.5 μm accuracy (Olympus Measuring Microscope STM). The molds and the metallic model measurements were compared, and the data were statistically analyzed by Kolmogorov-Smirnov and three-way ANOVA tests, and the means were compared by Tukey test (5%). <strong>Results:</strong> The results showed no double interactions (p>0.05) and the different alginates presented statistically similar values of dimensional stability (p=0.102). However, 25ºC (temperature) and control group (time) showed the highest values of dimensional stability (p<0.05). Jeltrate Plus was the only material that presented inaccuracy in details reproduction. <strong>Conclusion</strong>: It is recommended that, for tested alginates, the stone casts should be poured immediately, even though the molds are dimensionally stable up to 5 days when stored at 25ºC.</p><p><strong> </strong></p><p><strong>Keywords</strong></p><p>Dental impression materials; Dimensional measurement accuracy; Shrinkage.<strong></strong></p>
44
Moral, Çiğdem Kıvılcımdan, Özdemir Doğan, and Faika Dilek Sanin. "Comparison of chemical fractionation method and 1H-NMR spectroscopy in measuring the monomer block distribution of algal alginates." Journal of Polymer Engineering 33, no. 3 (May 1, 2013): 239–46. http://dx.doi.org/10.1515/polyeng-2012-0066.
Full textAbstract:
Abstract Alginates are composed of β-D-mannuronic acid (M) and α-L-guluronic acid (G). In this study, block distributions of alginate samples were measured by a chemical fractionation method and 1H-NMR spectroscopy, to compare the usefulness of the two methods. Block distribution results obtained from the two methods were found to be statistically different from each other; the chemical fractionation method gave consistently lower estimates for the amount of homopolymeric blocks. The repeatability of the results was also lower in the chemical fractionation method. By contrast, 1H-NMR spectroscopy was found to be a reproducible and a faster method for determining the distribution of monomeric blocks in alginates.
45
Pérez Villalba, Luis Darío, Diana Carolina Freire Villena, and Juliana Nicol Almachi Chancusig. "Do the alginates show true instructions for setting time?" Interamerican Journal of Health Sciences 4 (July 22, 2024): 85. http://dx.doi.org/10.59471/ijhsc202485.
Full textAbstract:
Objective: Check the correspondence of the setting time predisposed in the indications for use of the alginates IQ green and Max Print. Materials and methods: A patient was selected so that the operator can test the two types of alginates (Max Print and IQ green) in the upper jaw at the time of making an impression, thus testing whether the indications regarding setting time are correct with a minimum of error in obtaining them. Results: The models obtained presented many statistically insignificant changes with respect to the instructions indicated in each alginate, however, the evaluation was also oriented towards the result of the impression. Conclusion: It can be distinguished that each alginate shows good results at the time of obtaining the impression and although each one has its own indications, it is shown that the setting time meets the objective of the two selected brands.
46
Dewi, Maula Yasinta, and Amir Husni. "Characterization of Biobased Alginate/Glycerol/ Sunflower Oil as Biodegradable Packaging." E3S Web of Conferences 147 (2020): 03004. http://dx.doi.org/10.1051/e3sconf/202014703004.
Full textAbstract:
The most used packaging material was plastic, but can cause environmental problems because it was not easily degraded. Therefore, it was necessary to look for alternative packaging materials that are easily biodegraded including edible film. The main raw materials for edible films were alginates and plasticizers including glycerol and sunflower oil. The objective of this study was to determine the characteristics of edible film composed of alginate, glycerol and sunflower oil. The study was carried out through the manufacture of edible films composed of various alginates concentrations (2, 3, 4, 5 and 6%), 10% glycerol and 0.01% sunflower oil. The characteristics tested included thickness, tensile strength, elongation, solubility, and rate of water vapor transmission. The results showed that all treatments met the edible film standard of the Japanese Industrial Standard. The various alginate concentrations used did not significantly influence the water vapor transmission rate and tensile strength but significantly affected the elongation, solubility and thickness of the edible film.
47
Barros, Joyce Lima de, Layla Thais Gomes de Souza, Luana Amaral Cerqueira, and Eduardo Fernandes Marques. "Dimensional Stability Analysis of Different Types of Alginate." International Journal of Advanced Engineering Research and Science 9, no. 11 (2022): 388–91. http://dx.doi.org/10.22161/ijaers.911.47.
Full textAbstract:
Irreversible hydrocolloids, or simply alginates, are the most used molding materials in different areas of dentistry, due to their ease of handling, low cost and good reproducibility. The present work aims to analyze the dimensional stability of different types of alginates at different time intervals. It is applied research, in which its approach was qualitative-quantitative, of an exploratory nature. Three different brands of alginate were used, where a standard dummy was molded and the leakage happened immediately: G1 (n: 10) Hydrogun, G2 (n: 10) Jet Plus and G3 (n: 10) Ava gel. With the digital caliper, the distances were measured and compared with the standard model, the data obtained were tabulated, analyzed using parametric tests and the areas of each model were added. As a result, the area of the standard model was similar in both groups. It is possible to conclude that the type of alginate did not interfere with the distortion of the standard model.
48
Lee, Jin W., and F. Day. "The separation of alginate biosynthesis and acetylation in Pseudomonas syringae." Canadian Journal of Microbiology 44, no. 4 (April 1, 1998): 394–98. http://dx.doi.org/10.1139/w98-008.
Full textAbstract:
Seaweed alginate was acetylated by resting cells of Pseudomonas syringae subsp. phaseolicola ATCC 19304. Physiological studies on this strain and its UV-induced mutants showed no correlation between bacterial alginate biosynthesis and acetylation. Specific yields of alginate and degree of acetylation in these polymers varied with strain and culture medium. This was indirect evidence that alginate biosynthesis is separate from polysaccharide acetylation. It indicated that the enzyme system involved in alginate biosynthesis was not directly linked to alginate acetylation and explained why microbial acetylation of seaweed alginates was possible.Key words: resting cell, Pseudomonas syringae, acetylation, bacterial alginate, seaweed alginate.
49
Hisano, Tomohiro, Minoru Nishimura, Yoshimasa Yonemoto, Shiro Abe, Tetsuo Yamashita, Kenji Sakaguchi, Akira Kimura, and Kousaku Murata. "Bacterial alginate lyase highly active on acetylated alginates." Journal of Fermentation and Bioengineering 75, no. 5 (January 1993): 332–35. http://dx.doi.org/10.1016/0922-338x(93)90129-v.
Full text
50
Bertolo, Marcus Vinicius Loureiro, Lucas de Oliveira Tomaselli, Rafael Pino Vitti, Gabriel Abuna, William Cunha Brandt, and Mário Alexandre Coelho Sinhoreti. "Accuracy of partially edentulous arch impressions obtained from different alginates and storage times." Brazilian Journal of Oral Sciences 15, no. 4 (September 20, 2017): 252. http://dx.doi.org/10.20396/bjos.v15i4.8650031.
Full textAbstract:
This study aimed to assess the dimensional accuracy of five commercial alginates verified in stone casts. Methods: Each alginate impression (Cavex ColorChange, Cavex Holland BV; Jeltrate Plus, Dentsply; Hydrogum, Zhermack; Kromopan 100, Lascod; Ezact Kromm, Vigodent) was performed on partially edentulous standard stainless steel mandibular arch cast with reference points on teeth 33, 43, 37 and 47. On the stainless steel cast, the anteroposterior (33-37 and 43-47) and transverse (33-43 and 37-47) distances were measured in a stereomicroscope at 30x magnification and 0.5 μm accuracy. The distances between these points were measured three times, obtaining an average, which was analyzed statistically and compared with the distances obtained from the stone casts. For each alginate the casts were poured gypsum (n = 5) immediately and after a period of 1, 2, 3 and 5 days of the impression procedure. Results: The dimensional accuracy values of stone and stainless steel casts were analyzed statistically by two-way ANOVA and Tukey's test (α=0.05). The results showed significant differences between the alginates; however, no differences in dimensional accuracy were found among the different storage times of alginate impression. Conclusions: It can be concluded that the alginate impressions can be stored for up to 5 days.