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Jamshaid U, Anton N, Elhassan M, Conzatti G, Vandamme TF. Novel Hydrogels Based on the Nano-Emulsion Formulation Process: Development, Rheological Characterization, and Study as a Drug Delivery System. Pharmaceutics 2024; 16:812. [PMID: 38931933 PMCID: PMC11207514 DOI: 10.3390/pharmaceutics16060812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 06/05/2024] [Accepted: 06/08/2024] [Indexed: 06/28/2024] Open
Abstract
In this study, we present a new type of polymer-free hydrogel made only from nonionic surfactants, oil, and water. Such a system is produced by taking advantage of the physicochemical behavior and interactions between nonionic surfactants and oil and water phases, according to a process close to spontaneous emulsification used in the production of nano-emulsions. Contrary to the classical process of emulsion-based gel formulation, we propose a simple one-step approach. Beyond the originality of the concept, these nanoemulgels appear as very promising systems able to encapsulate and deliver various molecules with different solubilities. In the first section, we propose a comprehensive investigation of the gel formation process and its limits through oscillatory rheological characterization, characterization of the sol/gel transitions, and gel strength. The second section is focused on the follow-up of the release of an encapsulated model hydrophilic molecule and on the impact of the rheological gel properties on the release profiles.
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Affiliation(s)
- Usama Jamshaid
- INSERM (French National Institute of Health and Medical Research), UMR 1260, Regenerative Nanomedicine (RNM), FMTS, Université de Strasbourg, F-67000 Strasbourg, France; (U.J.); (M.E.); (G.C.)
- Faculty of Pharmacy, The University of Lahore, Lahore 54590, Pakistan
| | - Nicolas Anton
- INSERM (French National Institute of Health and Medical Research), UMR 1260, Regenerative Nanomedicine (RNM), FMTS, Université de Strasbourg, F-67000 Strasbourg, France; (U.J.); (M.E.); (G.C.)
| | - Mohamed Elhassan
- INSERM (French National Institute of Health and Medical Research), UMR 1260, Regenerative Nanomedicine (RNM), FMTS, Université de Strasbourg, F-67000 Strasbourg, France; (U.J.); (M.E.); (G.C.)
- Department of Pharmaceutics, Faculty of Pharmacy, University of Gezira, Wad Medani 21111, Sudan
| | - Guillaume Conzatti
- INSERM (French National Institute of Health and Medical Research), UMR 1260, Regenerative Nanomedicine (RNM), FMTS, Université de Strasbourg, F-67000 Strasbourg, France; (U.J.); (M.E.); (G.C.)
| | - Thierry F. Vandamme
- INSERM (French National Institute of Health and Medical Research), UMR 1260, Regenerative Nanomedicine (RNM), FMTS, Université de Strasbourg, F-67000 Strasbourg, France; (U.J.); (M.E.); (G.C.)
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Li Y, Wu Y, Zhai H, Qiao C, Zhao G, Xue Z, Xia Y. Effect of the pre-crosslinking of Ba 2+ ions on wet spinning of agar fibers. Int J Biol Macromol 2024; 259:129169. [PMID: 38171435 DOI: 10.1016/j.ijbiomac.2023.129169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/29/2023] [Accepted: 12/29/2023] [Indexed: 01/05/2024]
Abstract
Decreased coagulation bath concentration and difficult recovery are classical issues observed during the wet spinning of fibers. In this paper, a novel method was presented for preparing environment-friendly agar fibers using deionized water as the coagulation and stretch baths. The addition of Ba2+ into the spinning solution increased the crosslinking time and improved the performance of spinning solution. The results showed that the introduction of Ba2+ in the spinning solution increased the viscosity of the spinning solution. Particularly, when the concentration of BaCl2 in the spinning solution was 7 wt%, the viscosity increased to 39.29 Pa·s, which made the molecular chain arrangement of agar more compact and ordered and promoted the gelation transformation of the spinning solution, resulting in an increase in the gel temperature from 0.2 °C (Ba-0/agar) to 5.4 °C (Ba-7/agar). The spinning solution was more conducive to the formation of fibers in deionized water. In addition, the physical and chemical properties of agar fibers were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, tensile testing, and scanning electron microscopy. The results showed that the use of deionized water as the coagulation bath can improve the color of fiber and solve the problem of fiber adhesion, whereas the mechanical strength of agar fibers with pre-cross-linking metal ions was also improved. For example, the breaking strength of Ba-7/agar/DIW was 0.73 cN/dtex while the breaking strength of Ba-0/agar/DIW was only 0.62 cN/dtex.
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Affiliation(s)
- Yan Li
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China; State Key Laboratory of Bio-fibers and Eco-textiles, Marine Fiber New Material Institute, Qingdao University, Qingdao 266071, China
| | - Yuzhi Wu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China; State Key Laboratory of Bio-fibers and Eco-textiles, Marine Fiber New Material Institute, Qingdao University, Qingdao 266071, China
| | - Hongjie Zhai
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China; State Key Laboratory of Bio-fibers and Eco-textiles, Marine Fiber New Material Institute, Qingdao University, Qingdao 266071, China
| | - Cuixia Qiao
- Department of Traditional Chinese Medicine, the Affiliated Hospital of Qingdao University, Qingdao University, Qingdao 266071, China
| | - Gang Zhao
- Department of Traditional Chinese Medicine, the Affiliated Hospital of Qingdao University, Qingdao University, Qingdao 266071, China
| | - Zhixin Xue
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China; State Key Laboratory of Bio-fibers and Eco-textiles, Marine Fiber New Material Institute, Qingdao University, Qingdao 266071, China; Department of Traditional Chinese Medicine, the Affiliated Hospital of Qingdao University, Qingdao University, Qingdao 266071, China.
| | - Yanzhi Xia
- State Key Laboratory of Bio-fibers and Eco-textiles, Marine Fiber New Material Institute, Qingdao University, Qingdao 266071, China
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Lin HTV, Tsai JS, Liao HH, Sung WC. The Effect of Hydrocolloids on Penetration Tests and Syneresis of Binary Gum Gels and Modified Corn Starch-Gum Gels. Gels 2023; 9:605. [PMID: 37623060 PMCID: PMC10453816 DOI: 10.3390/gels9080605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/20/2023] [Accepted: 07/23/2023] [Indexed: 08/26/2023] Open
Abstract
The interactions among agar, gellan gum, gelatin, and modified waxy corn starch in the formation of mixed gels were examined in five different ratios. Binary hydrocolloid gels were prepared using three ingredients: two hydrocolloids (total hydrocolloid concentration: 0.5 wt%, ratios of mixture: 0/0.5, 0.1/0.4, 0.2/0.3, 0.3/0.2, 0.4/0.1, and 0.5/0) and water. The textural properties of the hydrocolloid gels were studied by measuring the gel strength, rigidity, breaking force, breaking point, and syneresis as functions of the mixing ratio. The higher syneresis percentage of binary modified waxy corn starch and gum gels than that of mixed gum gels after cold storage was mainly due to the retrogradation of amylopectin. Agar was shown be the most influential with regards to increasing the gel strength, breaking force, and rigidity among the three kinds of gum, while gellan gum was more effective against syneresis than agar and gelatin for storage periods of 7 and 14 days. In the mixed gels, a dramatic increase in the breaking point from 0 to 0.5% was only exhibited for gellan gum. The results provided useful information, including gel strength, rigidity, breaking force, breaking point, and syneresis, for gum and modified corn starch ingredients selected from refrigerated binary gum gels such as pudding for food product development.
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Affiliation(s)
- Hong-Ting Victor Lin
- Department of Food Science, National Taiwan Ocean University, Keelung 202301, Taiwan; (H.-T.V.L.); (J.-S.T.)
- Center of Excellence for the Oceans, National Taiwan Ocean University, No. 2, Pei-Ning Road, Keelung 202301, Taiwan
| | - Jenn-Shou Tsai
- Department of Food Science, National Taiwan Ocean University, Keelung 202301, Taiwan; (H.-T.V.L.); (J.-S.T.)
| | - Hsiao-Hui Liao
- Weichuan Foods Corporation, New Taipei City 22102, Taiwan;
| | - Wen-Chieh Sung
- Department of Food Science, National Taiwan Ocean University, Keelung 202301, Taiwan; (H.-T.V.L.); (J.-S.T.)
- Center of Excellence for the Oceans, National Taiwan Ocean University, No. 2, Pei-Ning Road, Keelung 202301, Taiwan
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de Sousa Ferreira M, de Oliveira Silva Ribeiro F, Dourado FF, de Jesus Oliveira AC, Araújo TDS, Brito LM, Pessoa C, de Lima LRM, de Paula RCM, Silva-Filho EC, da Silva DA. Production of galactan phthalates derivatives extracted from Gracilaria birdie: Characterization, cytotoxic and antioxidant profile. Int J Biol Macromol 2023; 243:125254. [PMID: 37295699 DOI: 10.1016/j.ijbiomac.2023.125254] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/11/2023] [Accepted: 06/06/2023] [Indexed: 06/12/2023]
Abstract
The present work explores the esterification reaction in the polysaccharide extracted from the seaweed Gracilaria birdiae and investigates its antioxidant potential. The reaction process was conducted with phthalic anhydride at different reaction times (10, 20 and 30 min), using a molar ratio of 1:2 (polymer: phthalic anhydride). Derivatives were characterized by FTIR, TGA, DSC and XRD. The biological properties of derivatives were investigated by assays of cytotoxicity and antioxidant activity (2,2-diphenyl-1-picrylhydroxyl - DPPH and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt - ABTS). The results obtained by FT-IR confirmed the chemical modification, there was a reduction related to the presence of carbonyl and hydroxyl groups when compared to the in nature polysaccharide spectrum. TGA analysis showed a change in the thermal behavior of the modified materials. X-ray diffraction, it was shown that the in nature polysaccharide appeared as an amorphous material, while the material obtained after the chemical modification process had increased crystallinity, due to the introduction of phthalate groups. For the biological assays, it was observed that the phthalate derivative was more selective than the unmodified material for the murine metastatic melanoma tumor cell line (B16F10), revealing a good antioxidant profile for DPPH and ABTS radicals.
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Affiliation(s)
- Michelle de Sousa Ferreira
- Research Center on Biodiversity and Biotechnology, BIOTEC, Parnaíba Delta Federal University, UFDPar, Parnaíba, PI, Brazil; Interdisciplinary Laboratory for Advanced Materials - LIMAV, Federal University of Piaui, Teresina, PI, Brazil
| | - Fábio de Oliveira Silva Ribeiro
- Research Center on Biodiversity and Biotechnology, BIOTEC, Parnaíba Delta Federal University, UFDPar, Parnaíba, PI, Brazil; Center for Research in Applied Morphology and Immunology, NuPMIA, University of Brasilia, Brasilia, Brazil
| | - Flaviane França Dourado
- Research Center on Biodiversity and Biotechnology, BIOTEC, Parnaíba Delta Federal University, UFDPar, Parnaíba, PI, Brazil
| | - Antônia Carla de Jesus Oliveira
- Research Center on Biodiversity and Biotechnology, BIOTEC, Parnaíba Delta Federal University, UFDPar, Parnaíba, PI, Brazil; Interdisciplinary Laboratory for Advanced Materials - LIMAV, Federal University of Piaui, Teresina, PI, Brazil
| | - Thaís Danyelle Santos Araújo
- Research Center on Biodiversity and Biotechnology, BIOTEC, Parnaíba Delta Federal University, UFDPar, Parnaíba, PI, Brazil
| | - Lucas Moreira Brito
- Department of Physiology and Pharmacology, Federal University of Ceará, UFC, Fortaleza, CE, Brazil
| | - Claudia Pessoa
- Department of Physiology and Pharmacology, Federal University of Ceará, UFC, Fortaleza, CE, Brazil
| | | | | | | | - Durcilene Alves da Silva
- Research Center on Biodiversity and Biotechnology, BIOTEC, Parnaíba Delta Federal University, UFDPar, Parnaíba, PI, Brazil; Interdisciplinary Laboratory for Advanced Materials - LIMAV, Federal University of Piaui, Teresina, PI, Brazil.
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Ma C, Tan C, Xie J, Yuan F, Tao H, Guo L, Cui B, Yuan C, Gao W, Zou F, Wu Z, Liu P, Lu L. Effects of different ratios of mannitol to sorbitol on the functional properties of sweet potato starch films. Int J Biol Macromol 2023:124914. [PMID: 37217055 DOI: 10.1016/j.ijbiomac.2023.124914] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 05/06/2023] [Accepted: 05/13/2023] [Indexed: 05/24/2023]
Abstract
Sorbitol as a plasticizer is easily crystallized from starch film, resulting in the reduction in plasticizing effect. To improve the plasticizing performance of sorbitol in starch films, mannitol, an acyclic hexahydroxy sugar alcohol, was used to cooperate with sorbitol. The effects of different ratios of mannitol (M) to sorbitol (S) as a plasticizer on mechanical properties, thermal properties, water resistance and surface roughness of sweet potato starch films were investigated. The results showed that the surface roughness of starch film with M:S (60:40) was the smallest. The number of hydrogen bonds between plasticizer and starch molecule was proportional to the mannitol content starch film. With the decrease of mannitol contents, the tensile strength of starch films gradually decreased except for M:S (60:40). Moreover, the transverse relaxation time value of starch film with M:S (100:0) was the lowest, indicating that it had the lowest degree of freedom of water molecules. Starch film with M:S (60:40) is the most effective in delaying the retrogradation of starch film. This study offered a new theoretical basis that different ratios of mannitol to sorbitol improve different performances of starch films.
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Affiliation(s)
- Chenyu Ma
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353
| | - Congping Tan
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353
| | - Jixun Xie
- School of Materials Science and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353.
| | - Fang Yuan
- School of Chemistry and Chemical Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353
| | - Haiteng Tao
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353
| | - Li Guo
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353.
| | - Bo Cui
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353.
| | - Chao Yuan
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353
| | - Wei Gao
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353
| | - Feixue Zou
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353
| | - Zhengzong Wu
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353
| | - Pengfei Liu
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353
| | - Lu Lu
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology, Shandong Academy of Sciences, No.3501, Daxue Rd., Changqing District, Jinan, Shandong Province, China, 250353
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Zhang L, Xiao Q, Xiao Z, Zhang Y, Weng H, Chen F, Xiao A. Hydrophobic modified agar: Structural characterization and application in encapsulation and release of curcumin. Carbohydr Polym 2023; 308:120644. [PMID: 36813337 DOI: 10.1016/j.carbpol.2023.120644] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/26/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023]
Abstract
In this study, three kinds of anhydrides with different structures were introduced into agar molecules to study the effects of varying degrees of substitution (DS) and anhydride structures on the physicochemical properties and curcumin (CUR) loading capacity. Increasing the carbon chain length and saturation of the anhydride affects the hydrophobic interaction and hydrogen bonding of the esterified agar, thereby changing the stable structure of the agar. Although the gel performance declined, the hydrophilic carboxyl group and the loose porous structure provide more binding sites for the adsorption of water molecules, hence providing excellent water retention (1700 %). Next, CUR was used as a hydrophobic active ingredient to study agar microspheres' drug encapsulation and in vitro release ability. Results showed that the excellent swelling and hydrophobic structure of esterified agar could promote the encapsulation of CUR (70.3 %). The release process is controlled by pH, and the release of CUR under weak alkaline conditions is significant, which can be explained by the pore structure, swelling characteristics, and carboxyl binding of agar. Therefore, this study shows the application potential of hydrogel microspheres in loading hydrophobic active ingredients and sustained release and provides the possibility for the application of agar in drug delivery systems.
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Affiliation(s)
- Luyao Zhang
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China
| | - Qiong Xiao
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China
| | - Zhechen Xiao
- College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yonghui Zhang
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China
| | - Huifen Weng
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China
| | - Fuquan Chen
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China.
| | - Anfeng Xiao
- College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen 361021, China.
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de Aguiar ALL, Araújo MLH, Benevides NMB, Mattos ALA, da Silva Araújo IM, da Silva EMC. Sequential extraction process and physicochemical characterization of R-phycoerythrin and agar from red macroalgae Gracilaria birdiae. ALGAL RES 2022. [DOI: 10.1016/j.algal.2022.102920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Liu SH, Ku CY, Chiang MT. Polysaccharide-Rich Red Algae ( Gelidium amansii) Hot-Water Extracts Alleviate Abnormal Hepatic Lipid Metabolism without Suppression of Glucose Intolerance in a Streptozotocin/Nicotinamide-Induced Diabetic Rat Model. Molecules 2022; 27:1447. [PMID: 35209236 PMCID: PMC8875162 DOI: 10.3390/molecules27041447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/12/2022] [Accepted: 02/18/2022] [Indexed: 02/01/2023] Open
Abstract
This study was designed to investigate the effects of polysaccharide-rich red algae (Gelidium amansii) hot-water extracts (GHE) on lipid and glucose metabolism in rats with streptozotocin (STZ)/nicotinamide (NA)-induced diabetes. Rats were divided into three groups: NC-normal control group), DM-diabetic group, and DG-diabetic group supplemented with GHE (5%). The experimental diet and drinking water were available ad libitum for 10 weeks. After the 10-week feeding duration, the body weight, liver weight, total adipose tissue weight, and hepatic TBARS and cholesterol levels were significantly increased, and hepatic glycogen content and adipose lipolysis rate were significantly decreased in the DM group, which could be effectively reversed by supplementation of GHE. However, GHE supplementation could not improve the glucose intolerance in DM rats. It was interesting to note that GHE supplementation could decrease the liver glucose-6-phosphotase activity, which was increased in DM rats. Taken together, these results suggested that GHE feeding may ameliorate abnormal hepatic lipid metabolism, but not glucose intolerance, in diabetic rats induced by STZ/NA.
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Affiliation(s)
- Shing-Hwa Liu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan;
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan
- Department of Pediatrics, College of Medicine, National Taiwan University Hospital, Taipei 10051, Taiwan
| | - Chia-Yu Ku
- Department of Food Science, National Taiwan Ocean University, Keelung 20224, Taiwan;
| | - Meng-Tsan Chiang
- Department of Food Science, National Taiwan Ocean University, Keelung 20224, Taiwan;
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Fabra MJ, Talens-Perales D, Roman-Sarmiento A, López-Rubio A, Polaina J. Effect of biopolymer matrices on lactose hydrolysis by enzymatically active hydrogel and aerogels loaded with β-galactosidase nanoflowers. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2020.106220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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10
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Single step immobilization of CMCase within agarose gel matrix: Kinetics and thermodynamic studies. Colloids Surf B Biointerfaces 2021; 200:111583. [PMID: 33548892 DOI: 10.1016/j.colsurfb.2021.111583] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/01/2021] [Accepted: 01/12/2021] [Indexed: 01/01/2023]
Abstract
In the current study, CMCase from Bacillus licheniformis KIBGE-IB2 was immobilized within the matrix of agarose gel through entrapment technique. Maximum immobilization yield (%) of the enzyme was obtained when 2.0 % agarose was used. The activation energy (Ea) of the enzyme increased from 16.38 to 44.08 kJ mol-1 after immobilization. Thermodynamic parameters such as activation energy of deactivation (ΔGd), enthalpy (ΔHd) and entropy (ΔSd) of deactivation, deactivation rate constant (Kd), half-life (t1/2), D-value and z-value were calculated for native/free and immobilized CMCase. The maximum reaction rate (Vmax) of the native enzyme was found to be 8319.47 U ml-1 min-1, which reduced to 7218.1 U ml-1 min-1after immobilization process. However, the Michaelis-Menten constant (Km) value of the enzyme increased from 1.236 to 2.769 mg ml-1 min-1 after immobilization. Immobilized enzyme within agarose gel matrix support can be reuse up to eight reaction cycles. Broad stability profile and improved catalytic properties of the immobilized CMCase indicated that this enzyme can be a plausible candidate to be used in various industrial processes.
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Thompson BR, Zarket BC, Lauten EH, Amin S, Muthukrishnan S, Raghavan SR. Liposomes Entrapped in Biopolymer Hydrogels Can Spontaneously Release into the External Solution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:7268-7276. [PMID: 32543183 DOI: 10.1021/acs.langmuir.0c00596] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Hydrogels of biopolymers such as agar and gelatin are widely used in many applications, and in many cases, the gels are loaded with nanoparticles. The polymer chains in these gels are cross-linked by physical bonds into three-dimensional networks, with the mesh size of these networks typically being 10-100 nm. One class of "soft" nanoparticles are liposomes, which have an aqueous core surrounded by a lipid bilayer. Solutes encapsulated in the liposomal core can be delivered externally over time. In this paper, we create liposomes with diameters ∼150 nm from an unsaturated phospholipid (lecithin) and embed them in agar gels (the aqueous phase also contains 0-50% of glycerol, which is an active ingredient in cosmetic products). Upon placing this gel in quiescent water, we find that the liposomes release out of the gel into the water over a period of 1-3 days, even though the gel remains intact. This is a surprising result that runs contrary to our expectation that the liposomes would simply remain immobilized in the gel. We show that the release rate of liposomes can be tuned by several variables: for example, the release rate increases as the agar concentration is lowered and the rate increases steadily with temperature. In addition to agar, release of liposomes also occurs out of other physical gels including those of agarose and gelatin. However, liposomes made from a saturated phospholipid do not release out of any gels. We discuss a possible mechanism for liposomal release, which involves intact liposomes deforming and squeezing through transient large pores that arise in physical networks such as agar. Our findings have relevance to transdermal delivery: they suggest the possibility of systematically delivering liposomes loaded with actives out of an intact matrix.
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Affiliation(s)
- Benjamin R Thompson
- Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Brady C Zarket
- L'Oréal Research and Innovation, Clark, New Jersey 07066, United States
| | - E Hunter Lauten
- L'Oréal Research and Innovation, Clark, New Jersey 07066, United States
| | - Samiul Amin
- L'Oréal Research and Innovation, Clark, New Jersey 07066, United States
| | | | - Srinivasa R Raghavan
- Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States
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12
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Bertasa M, Dodero A, Alloisio M, Vicini S, Riedo C, Sansonetti A, Scalarone D, Castellano M. Agar gel strength: A correlation study between chemical composition and rheological properties. Eur Polym J 2020. [DOI: 10.1016/j.eurpolymj.2019.109442] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Yang TH, Chiu CY, Lu TJ, Liu SH, Chiang MT. The Anti-Obesity Effect of Polysaccharide-Rich Red Algae ( Gelidium amansii) Hot-Water Extracts in High-Fat Diet-Induced Obese Hamsters. Mar Drugs 2019; 17:md17090532. [PMID: 31540318 PMCID: PMC6780553 DOI: 10.3390/md17090532] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/12/2019] [Accepted: 09/12/2019] [Indexed: 12/17/2022] Open
Abstract
This study investigated the anti-obesity effect of a polysaccharide-rich red algae Gelidium amansii hot-water extract (GHE) in high-fat (HF) diet-induced obese hamsters. GHE contained 68.54% water-soluble indigestible carbohydrate polymers. Hamsters were fed with a HF diet for 5 weeks to induce obesity, and then randomly divided into: HF group, HF with 3% guar gum diet group, HF with 3% GHE diet group, and HF with orlistat (200 mg/kg diet) group for 9 weeks. The increased weights of body, liver, and adipose in the HF group were significantly reversed by GHE supplementation. Lower plasma leptin, tumor necrosis factor-α, and interleukin-6 levels were observed in the GHE+HF group compared to the HF group. GHE also increased the lipolysis rate and decreased the lipoprotein lipase activity in adipose tissues. GHE induced an increase in the phosphorylation of AMP-activated protein kinase (AMPK) and the protein expressions of peroxisome proliferator-activated receptor alpha (PPARα) and uncoupling protein (UCP)-2 in the livers. The decreased triglyceride and total cholesterol in the plasma and liver were also observed in obese hamsters fed a diet with GHE. These results suggest that GHE exerts a down-regulation effect on hepatic lipid metabolism through AMPK phosphorylation and up-regulation of PPARα and UCP-2 in HF-induced obese hamsters.
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Affiliation(s)
- Tsung-Han Yang
- Department of Food Science, National Taiwan Ocean University, Keelung 20224, Taiwan.
| | - Chen-Yuan Chiu
- Medical and Pharmaceutical Industry Technology and Development Center, New Taipei City 24886, Taiwan.
| | - Ting-Jang Lu
- Institute of Food Science and Technology, National Taiwan University, Taipei 10617, Taiwan.
| | - Shing-Hwa Liu
- Graduate Institute of Toxicology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan.
- Department of Pediatrics, College of Medicine, National Taiwan University Hospital, Taipei 10051, Taiwan.
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan.
| | - Meng-Tsan Chiang
- Department of Food Science, National Taiwan Ocean University, Keelung 20224, Taiwan.
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14
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Kim C, Jeong D, Kim S, Kim Y, Jung S. Cyclodextrin functionalized agarose gel with low gelling temperature for controlled drug delivery systems. Carbohydr Polym 2019; 222:115011. [PMID: 31320040 DOI: 10.1016/j.carbpol.2019.115011] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 12/19/2022]
Abstract
Conventional agaroses with high gelling temperature are limited to apply to the field of drug delivery. In this study, β-cyclodextrin (βCD) functionalized agarose (CFA) with low gelling temperature was successfully prepared from ethylenediamine-functionalized agarose using mono-succinyl βCD. The gelling temperature of CFA dramatically decreased to 26.7 °C from 65 °C and the melting temperature declined from 95 °C to 66.1 °C. Upon drug loading, CFA can be used at 30 °C because of its low gelling temperature compared to agarose. CFA gel could be used both for bovine serum albumin as a full release, and for the doxorubicin (DOX) for sustained release, via inclusion complexation of βCD. Furthermore, cytotoxicity tests revealed that CFA was noncytotoxic. DOX in the CFA gel could retain the anti-cancer activity. Newly synthesized CFA with low gelling temperature offer a new means for the development of hydrogel-based delivery systems for a variety of therapeutic drugs.
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Affiliation(s)
- Chulgu Kim
- Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea
| | - Daham Jeong
- Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea; Institute for Ubiquitous Information Technology and Applications (UBITA), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul, 05029, South Korea
| | - Seonmok Kim
- Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea
| | - Yohan Kim
- Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea
| | - Seunho Jung
- Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea; Institute for Ubiquitous Information Technology and Applications (UBITA), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul, 05029, South Korea.
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15
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Hou X, Xue Z, Xia Y, Qin Y, Zhang G, Liu H, Li K. Effect of SiO2 nanoparticle on the physical and chemical properties of eco-friendly agar/sodium alginate nanocomposite film. Int J Biol Macromol 2019; 125:1289-1298. [DOI: 10.1016/j.ijbiomac.2018.09.109] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 09/16/2018] [Accepted: 09/18/2018] [Indexed: 02/02/2023]
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16
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Hou X, Xue Z, Liu J, Yan M, Xia Y, Ma Z. Characterization and property investigation of novel eco‐friendly agar/carrageenan/TiO
2
nanocomposite films. J Appl Polym Sci 2018. [DOI: 10.1002/app.47113] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- X. Hou
- College of Chemistry and Chemical Engineering Qingdao University Qingdao, 266071 China
- Institute of Marine Biobased Material Qingdao University Qingdao, 266071 China
- State Key Laboratory of Biopolysaccharide Fibers and Ecological Textiles Qingdao University Qingdao, 266071 China
| | - Z. Xue
- College of Chemistry and Chemical Engineering Qingdao University Qingdao, 266071 China
- Institute of Marine Biobased Material Qingdao University Qingdao, 266071 China
- State Key Laboratory of Biopolysaccharide Fibers and Ecological Textiles Qingdao University Qingdao, 266071 China
| | - J. Liu
- College of Chemistry and Chemical Engineering Qingdao University Qingdao, 266071 China
- Institute of Marine Biobased Material Qingdao University Qingdao, 266071 China
- State Key Laboratory of Biopolysaccharide Fibers and Ecological Textiles Qingdao University Qingdao, 266071 China
| | - M. Yan
- College of Chemistry and Chemical Engineering Qingdao University Qingdao, 266071 China
- Institute of Marine Biobased Material Qingdao University Qingdao, 266071 China
- State Key Laboratory of Biopolysaccharide Fibers and Ecological Textiles Qingdao University Qingdao, 266071 China
| | - Y. Xia
- Institute of Marine Biobased Material Qingdao University Qingdao, 266071 China
- State Key Laboratory of Biopolysaccharide Fibers and Ecological Textiles Qingdao University Qingdao, 266071 China
| | - Z. Ma
- College of Chemistry and Chemical Engineering Qingdao University Qingdao, 266071 China
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17
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Rani GU, Konreddy AK, Mishra S. Novel hybrid biosorbents of agar: Swelling behaviour, heavy metal ions and dye removal efficacies. Int J Biol Macromol 2018; 117:902-910. [DOI: 10.1016/j.ijbiomac.2018.05.163] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 05/14/2018] [Accepted: 05/22/2018] [Indexed: 01/31/2023]
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18
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Höft S, Waluga T, Scholl S. Der Einfluss von Beanspruchungsgeschwindigkeit und Partikelgröße auf das Bruchverhalten von Agarperlen. CHEM-ING-TECH 2018. [DOI: 10.1002/cite.201800004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Steffi Höft
- Technische Universität Braunschweig; Institut für Chemische und Thermische Verfahrenstechnik; Langer Kamp 7 38106 Braunschweig Deutschland
| | - Thomas Waluga
- Technische Universität Braunschweig; Institut für Chemische und Thermische Verfahrenstechnik; Langer Kamp 7 38106 Braunschweig Deutschland
- Technische Universität Hamburg Harburg; Institut für Prozess- und Anlagentechnik; Am Schwarzenberg-Campus 4 21073 Hamburg Deutschland
| | - Stephan Scholl
- Technische Universität Braunschweig; Institut für Chemische und Thermische Verfahrenstechnik; Langer Kamp 7 38106 Braunschweig Deutschland
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19
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Wang Z, Yang K, Li H, Yuan C, Zhu X, Huang H, Wang Y, Su L, Fang Y. In situ observation of sol-gel transition of agarose aqueous solution by fluorescence measurement. Int J Biol Macromol 2018; 112:803-808. [DOI: 10.1016/j.ijbiomac.2018.02.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 01/25/2018] [Accepted: 02/04/2018] [Indexed: 11/30/2022]
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20
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Liu HC, Chang CJ, Yang TH, Chiang MT. Long-term feeding of red algae ( Gelidium amansii ) ameliorates glucose and lipid metabolism in a high fructose diet-impaired glucose tolerance rat model. J Food Drug Anal 2017; 25:543-549. [PMID: 28911640 PMCID: PMC9328806 DOI: 10.1016/j.jfda.2016.06.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 05/24/2016] [Accepted: 06/14/2016] [Indexed: 11/03/2022] Open
Abstract
This study was designed to investigate the effect of Gelidium amansii (GA) on carbohydrate and lipid metabolism in rats with high fructose (HF) diet (57.1% w/w). Five-week-old male Sprague-Dawley rats were fed a HF diet to induce glucose intolerance and hyperlipidemia. The experiment was divided into three groups: (1) control diet group (Con); (2) HF diet group (HF); and (3) HF with GA diet group (HF + 5% GA). The rats were fed the experimental diets and drinking water ad libitum for 23 weeks. The results showed that GA significantly decreased retroperitoneal fat mass weight of HF diet-fed rats. Supplementation of GA caused a decrease in plasma glucose, insulin, tumor necrosis factor-α, and leptin. HF diet increased hepatic lipid content. However, intake of GA reduced the accumulation of hepatic lipids including total cholesterol (TC) and triglyceride contents. GA elevated the excretion of fecal lipids and bile acid in HF diet-fed rats. Furthermore, GA significantly decreased plasma TC, triglyceride, low density lipoprotein plus very low density lipoprotein cholesterol, and TC/high density lipoprotein cholesterol ratio in HF diet-fed rats. HF diet induced an in plasma glucose and an impaired glucose tolerance, but GA supplementation decreased homeostasis model assessment equation-insulin resistance and improved impairment of glucose tolerance. Taken together, these results indicate that supplementation of GA can improve the impairment of glucose and lipid metabolism in an HF diet-fed rat model.
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21
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Monrrabal G, Guzmán S, Hamilton I, Bautista A, Velasco F. Design of gel electrolytes for electrochemical studies on metal surfaces with complex geometry. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.10.081] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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22
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Qi G, Li N, Sun XS, Shi YC, Wang D. Effects of glycerol and nanoclay on physiochemical properties of camelina gum-based films. Carbohydr Polym 2016; 152:747-754. [DOI: 10.1016/j.carbpol.2016.07.068] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 07/08/2016] [Accepted: 07/17/2016] [Indexed: 11/25/2022]
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23
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Structure characterization by means of rheological and NMR experiments as a first necessary approach to study the l-(+)-ascorbic acid diffusion from pectin and pectin/alginate films to agar hydrogels that mimic food materials. J FOOD ENG 2015. [DOI: 10.1016/j.jfoodeng.2015.05.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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24
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Frank D, Eyres GT, Piyasiri U, Cochet-Broch M, Delahunty CM, Lundin L, Appelqvist IM. Effects of Agar Gel Strength and Fat on Oral Breakdown, Volatile Release, and Sensory Perception Using in Vivo and in Vitro Systems. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:9093-9102. [PMID: 26435196 DOI: 10.1021/acs.jafc.5b03441] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The density and composition of a food matrix affect the rates of oral breakdown and in-mouth flavor release as well as the overall sensory experience. Agar gels of increasing concentration (1.0, 1.7, 2.9, and 5% agarose) with and without added fat (0, 2, 5, and 10%) were spiked with seven aroma volatiles. Differences in oral processing and sensory perception were systematically measured by a trained panel using a discrete interval time intensity method. Volatile release was measured in vivo and in vitro by proton transfer reaction mass spectrometry. Greater oral processing was required as agar gel strength increased, and the intensity of flavor-related sensory attributes decreased. Volatile release was inversely related to gel strength, showing that physicochemical phenomena were the main mechanisms underlying the perceived sensory changes. Fat addition reduced the amount of oral processing and had differential effects on release, depending on the fat solubility or lipophilicity of the volatiles.
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Affiliation(s)
- Damian Frank
- CSIRO, 11 Julius Avenue, North Ryde, New South Wales, Australia 2113
| | - Graham T Eyres
- CSIRO, 11 Julius Avenue, North Ryde, New South Wales, Australia 2113
| | | | | | - Conor M Delahunty
- CSIRO, 11 Julius Avenue, North Ryde, New South Wales, Australia 2113
| | - Leif Lundin
- CSIRO, 11 Julius Avenue, North Ryde, New South Wales, Australia 2113
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25
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Yang TH, Yao HT, Chiang MT. Red algae (Gelidium amansii) reduces adiposity via activation of lipolysis in rats with diabetes induced by streptozotocin-nicotinamide. J Food Drug Anal 2015; 23:758-765. [PMID: 28911493 PMCID: PMC9345456 DOI: 10.1016/j.jfda.2015.06.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 05/25/2015] [Accepted: 06/11/2015] [Indexed: 12/30/2022] Open
Abstract
Gelidium amansii (GA) is an edible red algae that is distributed mainly in northeastern Taiwan. This study was designed to investigate the effects of GA on plasma glucose, lipids, and adipocytokines in rats with streptozotocin-nicotinamide-induced diabetes. Rats were divided into four groups: (1) rats without diabetes fed a high-fat diet (control group); (2) rats with diabetes fed a high-fat diet; (3) rats with diabetes fed a high-fat diet with thiazolidinedione in the diet; and (4) rats with diabetes fed a high-fat diet and GA. The experimental diet and drinking water were available ad libitum for 11 weeks. After the 11-week feeding study, plasma glucose, triglyceride, and cholesterol concentrations were lower in rats with diabetes fed the GA diet than in animals with diabetes fed the control diet. In addition, cholesterol and triglyceride excretion were significantly higher in rats with diabetes fed the GA diet. Moreover, GA feeding induced lipolysis in both paraepididymal and perirenal adipose tissues. Adipose tissue (paraepididymal and perirenal) weight and triglyceride contents were lower after GA treatment. Plasma adipocytokines including tumor necrosis factor-alpha, interleukin-6, and plasminogen activator inhibitor-1 were reduced by GA feeding in rats with diabetes. The results of the current study suggest that GA feeding may regulate plasma glucose and lipid levels and prevent adipose tissue accumulation in rats with diabetes.
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Affiliation(s)
- Tsung-Han Yang
- Department of Food Science, National Taiwan Ocean University, Keelung,
Taiwan
| | - Hsien-Tsung Yao
- Department of Nutrition, China Medical University, Taichung,
Taiwan
| | - Meng-Tsan Chiang
- Department of Food Science, National Taiwan Ocean University, Keelung,
Taiwan
- Corresponding author. Department of Food Science, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung, Taiwan. E-mail address: (M.-T. Chiang)
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26
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Cao M, Liu X, Luan J, Zhang X. Characterization of physicochemical properties of carboxymethyl agar. Carbohydr Polym 2014; 111:449-55. [DOI: 10.1016/j.carbpol.2014.04.036] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/13/2014] [Accepted: 04/07/2014] [Indexed: 10/25/2022]
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27
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Irradiation of silver and agar/silver nanoparticles with argon, oxygen glow discharge plasma, and mercury lamp. SPRINGERPLUS 2014; 3:443. [PMID: 25184109 PMCID: PMC4150921 DOI: 10.1186/2193-1801-3-443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 07/23/2014] [Indexed: 11/10/2022]
Abstract
The irradiation effect of argon, oxygen glow discharge plasma, and mercury lamp on silver and agar/silver nanoparticle samples is studied. The irradiation time dependence of the synthesized silver and agar/silver nanoparticle absorption spectra and their antibacterial effect are studied and compared. In the agar/silver nanoparticle sample, as the irradiation time of argon glow discharge plasma or mercury lamp increases, the peak intensity and the full width at half maximum, FWHM, of the surface plasmon resonance absorption band is increased, however a decrease of the peak intensity with oxygen glow plasma has been observed. In the silver nanoparticle sample, as the irradiation time of argon, oxygen glow discharge plasma or mercury lamp increases, the peak intensity of the surface plasmon resonance absorption band is increased, however, there is no significant change in the FWHM of the surface plasmon resonance absorption band. The SEM results for both samples showed nanoparticle formation with mean size about 50 nm and 40 nm respectively. Throughout the irradiation time with the argon, oxygen glow discharge plasma or mercury lamp, the antibacterial activity of several kinds of Gram-positive and Gram-negative bacteria has been examined.
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28
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Xia K, Liu X, Zhao J, Zhang X. The physicochemical property characterization of agar acetate. Carbohydr Polym 2014; 110:32-7. [DOI: 10.1016/j.carbpol.2014.03.036] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 02/22/2014] [Accepted: 03/05/2014] [Indexed: 11/26/2022]
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29
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Usha Rani G, Konreddy AK, Mishra S, Sen G. Synthesis and applications of polyacrylamide grafted agar as a matrix for controlled drug release of 5-ASA. Int J Biol Macromol 2014; 65:375-82. [DOI: 10.1016/j.ijbiomac.2014.01.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 01/05/2014] [Accepted: 01/17/2014] [Indexed: 10/25/2022]
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30
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Mango pulp-agar based model gel: textural characterisation. Journal of Food Science and Technology 2014; 51:75-82. [PMID: 24426050 DOI: 10.1007/s13197-011-0486-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 07/24/2011] [Accepted: 08/01/2011] [Indexed: 10/17/2022]
Abstract
The textural properties of a model gel system have been investigated by employing an experimental design concerning the effect of agar (1-3%), mango pulp (0-50%) and sugar (0-20%). A gel characterization method, based on the principle of penetration-shearing, has been applied to determine the response functions (fracture strain, fracture stress, energy for penetration-shearing and firmness). These textural indices can be fitted well (0.858 ≤ r ≤ 0.953, p ≤ 0.01) to second order polynomials. Agar possesses the maximum effect and an increase in agar content markedly increases these indices while sugar imparts mostly a curvilinear effect; a failure strain as high as 33% has been achieved by increasing the agar content. The individual optimization (maximization), based on canonical analysis, on these indices indicates that agar content to be more than 2.8%. Gels with extensively varying textural properties can be achieved by changing the proportions of these ingredients.
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31
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Russ N, Zielbauer BI, Koynov K, Vilgis TA. Influence of nongelling hydrocolloids on the gelation of agarose. Biomacromolecules 2013; 14:4116-24. [PMID: 24131228 DOI: 10.1021/bm4012776] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The combination of different gelling and nongelling hydrocolloids is known to yield complex systems with a wide range of mechanical properties. Here, the influence of the nongelling hydrocolloids sodium-alginate and xanthan on the gelation of agarose is investigated. The two polyelectrolytes differ significantly in their flexibility, leading to opposing effects on the thermomechanical properties of the resulting composite gels. The network structure of the agarose as well as viscoelasticity, gelling temperature, and thermal stability of the gels are altered. These properties are investigated by strain and temperature dependent oscillatory rheological measurements as well as confocal laser scanning microscopy. A phenomenological model to describe the network formation of agarose in the presence of alginate or xanthan respectively is presented.
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Affiliation(s)
- Natalie Russ
- Max Planck Institute for Polymer Research , Ackermannweg 10, 55128 Mainz, Germany
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32
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Rani GU, Mishra S, Pathak G, Jha U, Sen G. Synthesis and applications of poly(2-hydroxyethylmethacrylate) grafted agar: A microwave based approach. Int J Biol Macromol 2013; 61:276-84. [DOI: 10.1016/j.ijbiomac.2013.07.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 07/01/2013] [Accepted: 07/02/2013] [Indexed: 10/26/2022]
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33
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Sen G, Rani GU, Mishra S. Microwave assisted synthesis of poly(2-hydroxyethylmethacrylate) grafted agar (Ag-g-P(HEMA)) and its application as a flocculant for wastewater treatment. Front Chem Sci Eng 2013. [DOI: 10.1007/s11705-013-1344-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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34
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Sousa AMM, Borges J, Silva AF, Gonçalves MP. Influence of the extraction process on the rheological and structural properties of agars. Carbohydr Polym 2013; 96:163-71. [PMID: 23688466 DOI: 10.1016/j.carbpol.2013.03.070] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 03/20/2013] [Accepted: 03/23/2013] [Indexed: 11/29/2022]
Abstract
Agars obtained by traditional hot-water (TWE) and microwave-assisted (MAE) extractions were compared in terms of their rheological and physicochemical properties and molecular self-association in solutions of low (0.05%, w/w) and high (1.5%, w/w) polymer concentrations. At low concentration, thin gelled layers were imaged by AFM. Slow or rapid cooling of the solutions influenced structure formation. In each case, TWE and MAE agar structures were different and apparently larger for MAE. At high concentration, progressive structural reinforcement was seen; while TWE agar showed a more open and irregular 3D network, MAE agar gel imaged by cryoSEM was denser and fairly uniform. The rheological (higher thermal stability and consistency) and mechanical (higher gel strength) behaviors of MAE agar seemed consistent with a positive effect of molecular mass and 3,6-anhydro-α-l-galactose content. MAE produced non-degraded agar comparable with commercial ones and if properly monitored, could be a promising alternative to TWE.
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Affiliation(s)
- Ana M M Sousa
- REQUIMTE, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
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35
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Skelhon TS, Olsson PKA, Morgan AR, Bon SAF. High internal phase agar hydrogel dispersions in cocoa butter and chocolate as a route towards reducing fat content. Food Funct 2013; 4:1314-21. [DOI: 10.1039/c3fo60122f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Dai B, Matsukawa S. Elucidation of gelation mechanism and molecular interactions of agarose in solution by 1H NMR. Carbohydr Res 2013. [DOI: 10.1016/j.carres.2012.10.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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37
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Pavan TZ, Madsen EL, Frank GR, Jiang J, Carneiro AAO, Hall TJ. A nonlinear elasticity phantom containing spherical inclusions. Phys Med Biol 2012; 57:4787-804. [PMID: 22772074 PMCID: PMC3413382 DOI: 10.1088/0031-9155/57/15/4787] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The strain image contrast of some in vivo breast lesions changes with increasing applied load. This change is attributed to differences in the nonlinear elastic properties of the constituent tissues suggesting some potential to help classify breast diseases by their nonlinear elastic properties. A phantom with inclusions and long-term stability is desired to serve as a test bed for nonlinear elasticity imaging method development, testing, etc. This study reports a phantom designed to investigate nonlinear elastic properties with ultrasound elastographic techniques. The phantom contains four spherical inclusions and was manufactured from a mixture of gelatin, agar and oil. The phantom background and each of the inclusions have distinct Young's modulus and nonlinear mechanical behavior. This phantom was subjected to large deformations (up to 20%) while scanning with ultrasound, and changes in strain image contrast and contrast-to-noise ratio between inclusion and background, as a function of applied deformation, were investigated. The changes in contrast over a large deformation range predicted by the finite element analysis (FEA) were consistent with those experimentally observed. Therefore, the paper reports a procedure for making phantoms with predictable nonlinear behavior, based on independent measurements of the constituent materials, and shows that the resulting strain images (e.g., strain contrast) agree with that predicted with nonlinear FEA.
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Affiliation(s)
- Theo Z. Pavan
- Medical Physics Department, University of Wisconsin, Room 1005, Wisconsin Institutes for Medical Research, 1111 Highland Avenue, Madison, WI, 53705 US
- Departamento de Física, FFCLRP , Universidade de São Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirão Preto, SP, Brazil
| | - Ernest L. Madsen
- Medical Physics Department, University of Wisconsin, Room 1005, Wisconsin Institutes for Medical Research, 1111 Highland Avenue, Madison, WI, 53705 US
| | - Gary R. Frank
- Medical Physics Department, University of Wisconsin, Room 1005, Wisconsin Institutes for Medical Research, 1111 Highland Avenue, Madison, WI, 53705 US
| | - Jingfeng Jiang
- Medical Physics Department, University of Wisconsin, Room 1005, Wisconsin Institutes for Medical Research, 1111 Highland Avenue, Madison, WI, 53705 US
| | - Antonio Adilton O. Carneiro
- Departamento de Física, FFCLRP , Universidade de São Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirão Preto, SP, Brazil
| | - Timothy J. Hall
- Medical Physics Department, University of Wisconsin, Room 1005, Wisconsin Institutes for Medical Research, 1111 Highland Avenue, Madison, WI, 53705 US
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Tiwari S, Ravi R, Bhattacharya S. Dehumidifier Assisted Drying of a Model Fruit Pulp-Based Gel and Sensory Attributes. J Food Sci 2012; 77:S263-73. [DOI: 10.1111/j.1750-3841.2012.02760.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Boral S, Bohidar HB. Effect of water structure on gelation of agar in glycerol solutions and phase diagram of agar organogels. J Phys Chem B 2012; 116:7113-21. [PMID: 22657388 DOI: 10.1021/jp3022024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A comprehensive study of hydration of polyanionic agar molecules in its solution and gel phase in glycerol-water binary solvent is reported. Raman spectroscopy results predict differential water structure arrangement for glycerol-water binary solvent, 0.02% (w/v) agar in glycerol solution and 0.3% (w/v) agar organogel. The 3200 cm(-1) Raman band pertaining to ice-like structure of water was found to increase in gel phase alike in glycerol-water solvent while it decreased in agar solutions with increase in glycerol concentration. In contrast, the partially structured water corresponding to the component 3310 cm(-1) of Raman spectra increased in agar solution, and decreased in gel phase similar to glycerol-water solvent case. We have explained these observations based on a simple model where the available oxygen to hydrogen atom ratio in a given solvent-polymer system uniquely defines hydration in solution and gel phases. The gelation concentration was found to increase from 0.18 (for water) to 0.22% (w/v) (50% v/v glycerol solution) as the glycerol concentration was raised. Correspondingly, the gelation temperature, T(g), showed a decline from 40 to 20 °C, and the gel melting temperature, T(m), revealed a reduction from 81 to 65 °C in the same glycerol concentration regime. Two distinctive features are evident here: (i) presence of glycerol as a cosolvent does not favor the gelation of agar as compared to water and (ii) agar organogels are softer than their hydrogels. A unique 3D phase diagram for the agar organogel is proposed. Circular dichroism data confirmed that the agar molecules retained their biological activity in these solvents. Thus, it is shown that thermo-mechanical properties of these organogels could be systematically tuned and adapted as per application requirement.
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Affiliation(s)
- Shilpi Boral
- Polymer and Biophysics Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110 067, India
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Nayar V, Weiland J, Nelson C, Hodge A. Elastic and viscoelastic characterization of agar. J Mech Behav Biomed Mater 2012; 7:60-8. [DOI: 10.1016/j.jmbbm.2011.05.027] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 04/23/2011] [Accepted: 05/17/2011] [Indexed: 11/26/2022]
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Collin JRT, Coussios CC. Quantitative observations of cavitation activity in a viscoelastic medium. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2011; 130:3289-96. [PMID: 22088001 DOI: 10.1121/1.3626156] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Quantitative experimental observations of single-bubble cavitation in viscoelastic media that would enable validation of existing models are presently lacking. In the present work, single bubble cavitation is induced in an agar gel using a 1.15 MHz high intensity focused ultrasound transducer, and observed using a focused single-element passive cavitation detection (PCD) transducer. To enable quantitative observations, a full receive calibration is carried out of a spherically focused PCD system by a bistatic scattering substitution technique that uses an embedded spherical scatterer and a hydrophone. Adjusting the simulated pressure received by the PCD by the transfer function on receive and the frequency-dependent attenuation of agar gel enables direct comparison of the measured acoustic emissions with those predicted by numerical modeling of single-bubble cavitation using a modified Keller-Miksis approach that accounts for viscoelasticity of the surrounding medium. At an incident peak rarefactional pressure near the cavitation threshold, period multiplying is observed in both experiment and numerical model. By comparing the two sets of results, an estimate of the equilibrium bubble radius in the experimental observations can be made, with potential for extension to material parameter estimation. Use of these estimates yields good agreement between model and experiment.
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Affiliation(s)
- Jamie R T Collin
- Institute of Biomedical Engineering, Department of Engineering Science, Oxford, OX1 3PJ, United Kingdom.
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Rhim JW. Effect of clay contents on mechanical and water vapor barrier properties of agar-based nanocomposite films. Carbohydr Polym 2011. [DOI: 10.1016/j.carbpol.2011.05.010] [Citation(s) in RCA: 199] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Chang YH, Shiau SY, Chen FB, Lin FR. Effect of microbial transglutaminase on the rheological and textural characteristics of black soybean packed tofu coagulating with Agar. Lebensm Wiss Technol 2011. [DOI: 10.1016/j.lwt.2010.10.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Rhim JW, Lee SB, Hong SI. Preparation and Characterization of Agar/Clay Nanocomposite Films: The Effect of Clay Type. J Food Sci 2011; 76:N40-8. [DOI: 10.1111/j.1750-3841.2011.02049.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Davies E, Huang Y, Harper JB, Hook JM, Thomas DS, Burgar IM, Lillford PJ. Dynamics of water in agar gels studied using low and high resolution 1H NMR spectroscopy. Int J Food Sci Technol 2010. [DOI: 10.1111/j.1365-2621.2010.02448.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Prebiotics from marine macroalgae for human and animal health applications. Mar Drugs 2010; 8:2038-64. [PMID: 20714423 PMCID: PMC2920542 DOI: 10.3390/md8072038] [Citation(s) in RCA: 174] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 06/11/2010] [Accepted: 06/28/2010] [Indexed: 12/13/2022] Open
Abstract
The marine environment is an untapped source of bioactive compounds. Specifically, marine macroalgae (seaweeds) are rich in polysaccharides that could potentially be exploited as prebiotic functional ingredients for both human and animal health applications. Prebiotics are non-digestible, selectively fermented compounds that stimulate the growth and/or activity of beneficial gut microbiota which, in turn, confer health benefits on the host. This review will introduce the concept and potential applications of prebiotics, followed by an outline of the chemistry of seaweed polysaccharides. Their potential for use as prebiotics for both humans and animals will be highlighted by reviewing data from both in vitro and in vivo studies conducted to date.
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Pavan TZ, Madsen EL, Frank GR, Carneiro AAO, Hall TJ. Nonlinear elastic behavior of phantom materials for elastography. Phys Med Biol 2010; 55:2679-92. [PMID: 20400811 PMCID: PMC3326409 DOI: 10.1088/0031-9155/55/9/017] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The development of phantom materials for elasticity imaging is reported in this paper. These materials were specifically designed to provide nonlinear stress/strain relationship that can be controlled independently of the small strain shear modulus of the material. The materials are mixtures of agar and gelatin gels. Oil droplet dispersions in these materials provide further control of the small strain shear modulus and the nonlinear parameter of the material. Since these materials are mostly water, they are assumed to be incompressible under typical experimental conditions in elasticity imaging. The Veronda-Westman model for strain energy density provided a good fit to all materials used in this study. Materials with a constant gelatin concentration (3.0% dry weight) but varying agar concentration (0.6-2.8% dry weight) demonstrated the same power law relationship between elastic modulus and agar concentration found for pure agar (1.89 +/- 0.02), consistent with percolation theory, and provided a consistent nonlinearity parameter of 4.5 +/- 0.3. The insights provided by this study will form the basis for stable elastography phantoms with stiffness and nonlinear stress/strain relationships in the background that differ from those in the target.
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Affiliation(s)
- Theo Z. Pavan
- Medical Physics Department, University of Wisconsin, Room 1005, Wisconsin Institutes for Medical Research, 1111 Highland Avenue, Madison, WI 53705, USA
- Departamento de Fisica e Matematica, FFCLRP, Universidade de Sao Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirao Preto, Sao Paulo, Brazil
| | - Ernest L. Madsen
- Medical Physics Department, University of Wisconsin, Room 1005, Wisconsin Institutes for Medical Research, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Gary R. Frank
- Medical Physics Department, University of Wisconsin, Room 1005, Wisconsin Institutes for Medical Research, 1111 Highland Avenue, Madison, WI 53705, USA
| | - Antonio Adilton O. Carneiro
- Departamento de Fisica e Matematica, FFCLRP, Universidade de Sao Paulo, Av. Bandeirantes, 3900, Monte Alegre, Ribeirao Preto, Sao Paulo, Brazil
| | - Timothy J. Hall
- Medical Physics Department, University of Wisconsin, Room 1005, Wisconsin Institutes for Medical Research, 1111 Highland Avenue, Madison, WI 53705, USA
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Becker PM, Widjaja-Greefkes HCA, van Wikselaar PG. Inhibition of binding of the AB5-type enterotoxins LT-I and cholera toxin to ganglioside GM1 by galactose-rich dietary components. Foodborne Pathog Dis 2010; 7:225-33. [PMID: 19919285 DOI: 10.1089/fpd.2009.0387] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cholera, travelers' diarrhea, or colibacillosis in pigs can possibly be prevented or attenuated by dietary provision of competitive inhibitors that react with the GM1-binding sites of the enterotoxins cholera toxin (CT), human Escherichia coli heat-labile enterotoxin of serogroup I (LTh-I), and porcine LT-I (LTp-I). The interfering efficiency of natural substances with binding of the toxins to the gangliosid receptor GM1 was tested using a specially adapted GM1-coated-microtiter-well enzyme-linked immunosorbent assay. The substances tested for their GM1 displacing capacity were galactose-containing or -related saccharides from bovine milk, skim milk powder, galactan from gum arabic, food stabilizers as well as ground fenugreek seed and soy bean constituents that contain galactomannans, the galactopolysaccharides agar and agarose, and larch wood and other plant materials that contain arabinogalactans. Skim milk powder, compared with the pure milk saccharides tested, interfered to a higher extent with LTh-I (65-66% inhibition at 5 mg test substance/mL) and CT binding (63-67% inhibition at 5 mg test substance/mL) when supplied before or simultaneously with the toxins in the GM1-enzyme-linked immunosorbent assay. Ground fenugreek seed counteracted GM1 binding of 5 ng LTh-I/mL as well as 5 ng and 1 microg LTp-I/mL (43-65% inhibition at 5 mg test substance/mL), and 4 ng CT/mL (61-92% inhibition at 5 mg test substance/mL) very efficiently when supplied before the toxin-GM1 complex had formed. With 50 mg/mL fenugreek seed, inhibition percentages of even 92-99% were reached for LTh-I and CT binding. Efforts to resolve already bound toxin from GM1 with the test substances were less effective than preincubations and concurrent incubations.
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Affiliation(s)
- Petra M Becker
- Animal Sciences Group, Wageningen UR, Lelystad, The Netherlands
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Development and characterisation of an agar--polyvinyl alcohol blend hydrogel. J Mech Behav Biomed Mater 2008; 2:485-93. [PMID: 19627855 DOI: 10.1016/j.jmbbm.2008.12.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 12/03/2008] [Accepted: 12/04/2008] [Indexed: 11/23/2022]
Abstract
Numerous authors have reported on hydrogel technologies providing products suitable for applications in biomedical, personal care as well as in nano-sensor applications. Hydrogels fabricated from single polymers have been extensively investigated. However, in many cases a single polymer alone cannot meet divergent demands in terms of both properties and performance. In this work, hydrogels were prepared by physically blending the natural polymer agar with polyvinyl alcohol in varying ratios to produce a new biosynthetic polymer applicable for a variety of purposes. Hydrogen bonding was observed to take place between the polyvinyl alcohol and the agar molecules in the composite materials leading to changes in the thermal, mechanical and swelling characteristics of the composite hydrogels. The composite hydrogels exhibited a slightly higher melting temperature than pure agar (116.81 degrees C). Irreversible compressive damage was found to occur at lower strain levels during compression testing of the dehydrated samples consisting of higher PVOH concentrations. Rheological analysis of hydrated sample revealed G' values of between 5000 and 10,000 Pa for the composite blends, with gels containing higher PVOH percentages exhibiting poorer mechanical strength.
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