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Liu Y, Qin Z, Wang C, Jiang Z. N-acetyl-d-glucosamine-based oligosaccharides from chitin: Enzymatic production, characterization and biological activities. Carbohydr Polym 2023; 315:121019. [PMID: 37230627 DOI: 10.1016/j.carbpol.2023.121019] [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: 03/10/2023] [Revised: 04/28/2023] [Accepted: 05/09/2023] [Indexed: 05/27/2023]
Abstract
Chitin, the second most abundant biopolymer, possesses diverse applications in the food, agricultural, and pharmaceutical industries due to its functional properties. However, the potential applications of chitin are limited owing to its high crystallinity and low solubility. N-acetyl chitooligosaccharides and lacto-N-triose II, the two types of GlcNAc-based oligosaccharides, can be obtained from chitin by enzymatic methods. With their lower molecular weights and improved solubility, these two types of GlcNAc-based oligosaccharides display more various beneficial health effects when compared to chitin. Among their abilities, they have exhibited antioxidant, anti-inflammatory, anti-tumor, antimicrobial, and plant elicitor activities as well as immunomodulatory and prebiotic effects, which suggests they have the potential to be utilized as food additives, functional daily supplements, drug precursors, elicitors for plants, and prebiotics. This review comprehensively covers the enzymatic methods used for the two types of GlcNAc-based oligosaccharides production from chitin by chitinolytic enzymes. Moreover, current advances in the structural characterization and biological activities of these two types of GlcNAc-based oligosaccharides are summarized in the review. We also highlight current problems in the production of these oligosaccharides and trends in their development, aiming to offer some directions for producing functional oligosaccharides from chitin.
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Affiliation(s)
- Yihao Liu
- College of Food Science and Engineering, State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science & Technology, Tianjin Economy Technological Development Area, No. 29, 13th Avenue, Tianjin 300222, People's Republic of China
| | - Zhen Qin
- School of Life Sciences, Shanghai University, Baoshan District, No.99 Shangda Road, Shanghai 200444, People's Republic of China
| | - Chunling Wang
- College of Food Science and Engineering, State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science & Technology, Tianjin Economy Technological Development Area, No. 29, 13th Avenue, Tianjin 300222, People's Republic of China.
| | - Zhengqiang Jiang
- Key Laboratory of Food Bioengineering (China National Light Industry), College of Food Science and Nutritional Engineering, China Agricultural University, Haidian District, No.17 Qinghua East Road, Beijing 100083, People's Republic of China.
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Zhen H, Yan Q, Liu Y, Li Y, Yang S, Jiang Z. Chitin oligosaccharides alleviate atherosclerosis progress in ApoE-/- mice by regulating lipid metabolism and inhibiting inflammation. FOOD SCIENCE AND HUMAN WELLNESS 2022. [DOI: 10.1016/j.fshw.2022.03.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Safarzadeh M, Sadeghi S, Azizi M, Rastegari-Pouyani M, Pouriran R, Haji Molla Hoseini M. Chitin and chitosan as tools to combat COVID-19: A triple approach. Int J Biol Macromol 2021; 183:235-244. [PMID: 33930442 PMCID: PMC8078037 DOI: 10.1016/j.ijbiomac.2021.04.157] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 04/21/2021] [Accepted: 04/25/2021] [Indexed: 12/18/2022]
Abstract
The progressive and fatal outbreak of the newly emerged coronavirus, SARS-CoV-2, necessitates rigorous collaboration of all health care systems and researchers from all around the world to bring such a devastating pandemic under control. As there is so far no officially approved drug or ideal vaccine for this disease, investigations on this infectious disease are actively pursued. Chitin and chitosan have shown promising results against viral infections. In this review, we first delve into the problematic consequences of viral pandemics followed by an introduction on SARS-CoV-2 taxonomical classification. Then, we elaborate on the immunology of COVID-19. Common antiviral therapies and their related limitations are described and finally, the potential applicability of chitin and chitosan to fight this overwhelming viral pandemic is addressed.
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Affiliation(s)
- Mehrnoush Safarzadeh
- Student Research Committee, Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sahar Sadeghi
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahdieh Azizi
- Department of Immunology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohsen Rastegari-Pouyani
- Student Research Committee, Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ramin Pouriran
- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mostafa Haji Molla Hoseini
- Medical Nanotechnology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Osho SO, Adeola O. Impact of dietary chitosan oligosaccharide and its effects on coccidia challenge in broiler chickens. Br Poult Sci 2019; 60:766-776. [PMID: 31483171 DOI: 10.1080/00071668.2019.1662887] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 07/16/2019] [Indexed: 12/24/2022]
Abstract
1. Two experiments were conducted, the first to determine the optimum inclusion of chitosan oligosaccharide (COS) in broiler diets to support growth performance, digestive functions, intestinal morphology, and immune organs. The second experiment evaluated the immune-protective properties of COS on broiler chickens during coccidia challenge (CC).2. Experiment 1 investigated the effect of graded dietary concentration of COS in the diets of broiler chickens using eight cage replicates for each of the six diets. A corn-soybean meal-based diet was used as the basal diet and supplemented with 0.0, 0.5, 1.0, 1.5, 2.0, or 2.5 g of COS/kg feed to form the six treatments.3. The diet supplemented with 1.0 g COS/kg of feed provided the optimal inclusion level for broiler chickens regarding body weight (BW) gain, jejunal villus height, villus height to crypt depth ratio, and ileal energy digestibility at d 22 of age.4. Experiment 2 investigated the immune-protective properties of COS in broiler chickens during CC. A total of 224 male broiler chicks were randomly assigned to eight replicate cages in a 2 × 2 factorial arrangement of treatments with two COS concentrations (0 or 1 g of COS/kg of diet), with or without CC.5. On d 18 of age, birds in the CC group received twice the recommended coccidia vaccine dose of 30 doses/kg BW.6. Coccidia challenge reduced (P < 0.05) and dietary COS increased (P < 0.05) BW gain, and feed intake. Dietary COS mitigated (P < 0.05) the CC-induced effects on gain:feed. Dietary COS supplementation attenuated the CC-induced effects (P < 0.05) on the expression of occludin genes.7. In conclusion, dietary COS improved performance, and the immune-related beneficial impact of COS supplementation was associated with reduced expression of pro-inflammatory cytokine genes.
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Affiliation(s)
- S O Osho
- Department of Animal Sciences, Purdue University, West Lafayette, IN, USA
| | - O Adeola
- Department of Animal Sciences, Purdue University, West Lafayette, IN, USA
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Alessandri G, Milani C, Duranti S, Mancabelli L, Ranjanoro T, Modica S, Carnevali L, Statello R, Bottacini F, Turroni F, Ossiprandi MC, Sgoifo A, van Sinderen D, Ventura M. Ability of bifidobacteria to metabolize chitin-glucan and its impact on the gut microbiota. Sci Rep 2019; 9:5755. [PMID: 30962486 PMCID: PMC6453949 DOI: 10.1038/s41598-019-42257-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/22/2019] [Indexed: 01/26/2023] Open
Abstract
Chitin-glucan (CG) represents a natural carbohydrate source for certain microbial inhabitants of the human gut and may act as a prebiotic for a number of bacterial taxa. However, the bifidogenic activity of this substrate is still unknown. In the current study, we evaluated the ability of chitin-glucan to influence growth of 100 bifidobacterial strains belonging to those species commonly identified within the bifidobacterial communities residing in the infant and adult human gut. Such analyses were coupled with transcriptome experiments directed to explore the transcriptional effects of CG on Bifidobacterium breve 2L, which was shown to elicit the highest growth performance on this natural polysaccharide. In addition, an in vivo trial involving a rat model revealed how the colonization efficiency of this bifidobacterial strain was enhanced when the animals were fed with a diet containing CG. Altogether our analyses indicate that CG is a valuable novel prebiotic compound that may be added to the human diet in order to re-establish/reinforce bifidobacteria colonization in the mammalian gut.
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Affiliation(s)
- Giulia Alessandri
- Department of Veterinary Medical Science, University of Parma, Parma, Italy
| | - Christian Milani
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
| | - Sabrina Duranti
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
| | - Leonardo Mancabelli
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
| | | | | | - Luca Carnevali
- Stress Physiology Laboratory, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Rosario Statello
- Stress Physiology Laboratory, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Francesca Bottacini
- APC Microbiome Institute and School of Microbiology, Bioscience Institute, National University of Ireland, Cork, Ireland
| | - Francesca Turroni
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
| | | | - Andrea Sgoifo
- Stress Physiology Laboratory, Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Douwe van Sinderen
- APC Microbiome Institute and School of Microbiology, Bioscience Institute, National University of Ireland, Cork, Ireland
| | - Marco Ventura
- Department of Veterinary Medical Science, University of Parma, Parma, Italy.
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Das P, Panda SK, Agarwal B, Behera S, Ali SM, Pulse ME, Solomkin JS, Opal SM, Bhandari V, Acharya S. Novel Chitohexaose Analog Protects Young and Aged mice from CLP Induced Polymicrobial Sepsis. Sci Rep 2019; 9:2904. [PMID: 30814582 PMCID: PMC6393422 DOI: 10.1038/s41598-019-38731-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 12/31/2018] [Indexed: 02/06/2023] Open
Abstract
In Gram-negative bacterial sepsis, production of excess pro-inflammatory cytokines results in hyperinflammation and tissue injury. Anti-inflammatory cytokines such as IL-10 inhibit inflammation and enhance tissue healing. Here, we report a novel approach to treat septicemia associated with intra-abdominal infection in a murine model by delicately balancing pro- and anti-inflammatory cytokines. A novel oligosaccharide compound AVR-25 selectively binds to the TLR4 protein (IC50 = 0.15 µM) in human peripheral blood monocytes and stimulates IL-10 production. Following the cecal ligation and puncture (CLP) procedure, intravenous dosing of AVR-25 (10 mg/kg, 6-12 h post-CLP) alone and in combination with antibiotic imipenem protected both young adult (10-12 week old) and aged (16-18 month old) mice against polymicrobial infection, organ dysfunction, and death. Proinflammatory cytokines (TNF-α, MIP-1, i-NOS) were decreased significantly and restoration of tissue damage was observed in all organs. A decrease in serum C-reactive protein (CRP) and bacterial colony forming unit (CFU) confirmed improved bacterial clearance. Together, these findings demonstrate the therapeutic ability of AVR-25 to mitigate the storm of inflammation and minimize tissue injury with high potential for adjunctive therapy in intra-abdominal sepsis.
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Affiliation(s)
- Pragnya Das
- Department of Pediatrics, Division of Neonatology, Drexel University School of Medicine, Philadelphia, PA, 19102, USA
| | - Santosh K Panda
- School of Medicine, Washington University, St. Louis, MO, 63110, USA
| | | | - Sumita Behera
- AyuVis Research Inc, 1120 South Freeway, Fort Worth, TX, 76104, USA.,University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Syed M Ali
- Department of Biotechnology, Jamia Millia Islamia, New Delhi, 110025, India
| | - Mark E Pulse
- Preclinical Service, University of North Texas Health Science Center, Fort Worth, Texas, 76107, USA
| | - Joseph S Solomkin
- University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - Steven M Opal
- The Warren Alpert Medical School, Brown University, Providence, RI, 02903, USA
| | - Vineet Bhandari
- Department of Pediatrics, Division of Neonatology, Drexel University School of Medicine, Philadelphia, PA, 19102, USA
| | - Suchismita Acharya
- AyuVis Research Inc, 1120 South Freeway, Fort Worth, TX, 76104, USA. .,Acceleration laboratory, University of North Texas Health Science Center, Fort Worth, Texas, 76107, USA.
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Albulov AI, Frolova MA, Grin AV, Kovaleva EI, Melnik NV, Krasochko PA. Application of Chitosan in Veterinary Vaccine Production. APPL BIOCHEM MICRO+ 2018. [DOI: 10.1134/s0003683818050034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Biodegradable Chitosan Decreases the Immune Response to Trichinella spiralis in Mice. Molecules 2017; 22:molecules22112008. [PMID: 29156562 PMCID: PMC6150330 DOI: 10.3390/molecules22112008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/12/2017] [Accepted: 11/16/2017] [Indexed: 12/16/2022] Open
Abstract
The purpose of this study was to evaluate the potential of chitosan units released during natural degradation of the polymer to activate the immune system against T. spiralis infection. High molecular weight chitosan was injected intraperitoneally into C57BL/6 mice. Flow cytometry and cytokine concentration, measured by ELISA, were used to characterize peritoneal cell populations during T. spiralis infection. The strong chemo-attractive properties of chitosan caused considerable infiltration into the peritoneal cavity of CD11b+ cells, with reduced expression of MHC class II, CD80, CD86, Dectin-1 or CD23 receptors in comparison to T. spiralis-infected mice. After prolonged chitosan biodegradation, cell populations expressing IL-4R, MR and Dectin-1 receptors were found to coexist with elevated IL-6, IL-10, TGF-β and IgA production. IgA cross-reacted with T. spiralis antigen and chitosan. It was found that chitosan treatment attracted immune cells with low activity, which resulted in the number of nematodes increasing. The glucosamine and N-acetyl-D-glucosamine residues were recognized by wheat germ agglutinin (WGA) lectin and therefore any biodegradable chitosan units may actively downregulate the immune response to the parasite. The findings are relevant for both people and animals treated with chitosan preparations.
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Hoseini MHM, Moradi M, Alimohammadian MH, Shahgoli VK, Darabi H, Rostami A. Immunotherapeutic effects of chitin in comparison with chitosan against Leishmania major infection. Parasitol Int 2016; 65:99-104. [DOI: 10.1016/j.parint.2015.10.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/20/2015] [Accepted: 10/24/2015] [Indexed: 11/27/2022]
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Li K, Xing R, Liu S, Li P. Advances in preparation, analysis and biological activities of single chitooligosaccharides. Carbohydr Polym 2016; 139:178-90. [DOI: 10.1016/j.carbpol.2015.12.016] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 12/07/2015] [Indexed: 02/07/2023]
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Friedman M, Juneja VK. Review of antimicrobial and antioxidative activities of chitosans in food. J Food Prot 2010; 73:1737-61. [PMID: 20828484 DOI: 10.4315/0362-028x-73.9.1737] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Interest in chitosan, a biodegradable, nontoxic, non-antigenic, and biocompatible biopolymer isolated from shellfish, arises from the fact that chitosans are reported to exhibit numerous health-related beneficial effects, including strong antimicrobial and antioxidative activities in foods. The extraordinary interest in the chemistry and application in agriculture, horticulture, environmental science, industry, microbiology, and medicine is attested by about 17,000 citations on this subject in the Scopus database. A special need exists to develop a better understanding of the role of chitosans in ameliorating foodborne illness. To contribute to this effort, this overview surveys and interprets our present knowledge of the chemistry and antimicrobial activities of chitosan in solution, as powders, and in edible films and coating against foodborne pathogens, spoilage bacteria, and pathogenic viruses and fungi in several food categories. These include produce, fruit juices, eggs and dairy, cereal, meat, and seafood products. Also covered are antimicrobial activities of chemically modified and nanochitosans, therapeutic properties, and possible mechanisms of the antimicrobial, antioxidative, and metal chelating effects. Further research is suggested in each of these categories. The widely scattered data on the multifaceted aspects of chitosan microbiology, summarized in the text and in 10 tables and 8 representative figures, suggest that low-molecular-weight chitosans at a pH below 6.0 presents optimal conditions for achieving desirable antimicrobial and antioxidative-preservative effects in liquid and solid foods. We are very hopeful that the described findings will be a valuable record and resource for further progress to improve microbial food safety and food quality.
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Affiliation(s)
- Mendel Friedman
- Produce Safety and Microbiology Research Unit, Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, California 94710, USA.
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Abstract
A chitosan, with citric acid cross-linked CMS grafted with methacrylic acid and poly(ethyleneglycol monomethyl ether methacrylate), was prepared for oral delivery of insulin. Increases in chitosan content increased the bioadhesivity. The equilibrium swelling and in vitro release profiles in enzyme-free simulated gastric (SGF) and intestinal fluids (SIF) by the insulin entrapped gels were established. Increasing the chitosan content in the copolymer enhanced the hydrolysis in the SIF. In all cases, the biological activity of insulin was retained. The antimicrobial activity of hydrogels was examined against a Staphylococcus aureus. Based on these results, new designs to improve insulin release behavior are being carried out.
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Affiliation(s)
- Mehrdad Mahkam
- Chemistry Department, Azarbaijan University of Tarbiat Moallem, Tabriz, Iran,
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Raafat D, Sahl HG. Chitosan and its antimicrobial potential--a critical literature survey. Microb Biotechnol 2009; 2:186-201. [PMID: 21261913 PMCID: PMC3815839 DOI: 10.1111/j.1751-7915.2008.00080.x] [Citation(s) in RCA: 432] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2008] [Revised: 12/02/2008] [Accepted: 12/08/2008] [Indexed: 11/30/2022] Open
Abstract
Chitosan, an aminopolysaccharide biopolymer, has a unique chemical structure as a linear polycation with a high charge density, reactive hydroxyl and amino groups as well as extensive hydrogen bonding. It displays excellent biocompatibility, physical stability and processability. The term 'chitosan' describes a heterogeneous group of polymers combining a group of physicochemical and biological characteristics, which allow for a wide scope of applications that are both fascinating and as yet uncharted. The increased awareness of the potentials and industrial value of this biopolymer lead to its utilization in many applications of technical interest, and increasingly in the biomedical arena. Although not primarily used as an antimicrobial agent, its utility as an ingredient in both food and pharmaceutical formulations lately gained more interest, when a scientific understanding of at least some of the pharmacological activities of this versatile carbohydrate began to evolve. However, understanding the various factors that affect its antimicrobial activity has become a key issue for a better usage and a more efficient optimization of chitosan formulations. Moreover, the use of chitosan in antimicrobial systems should be based on sufficient knowledge of the complex mechanisms of its antimicrobial mode of action, which in turn would help to arrive at an appreciation of its entire antimicrobial potential.
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Affiliation(s)
- Dina Raafat
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology Unit, University of Bonn, D-53115 Bonn, Germany.
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Juneja VK, Thippareddi H, Bari L, Inatsu Y, Kawamoto S, Friedman M. Chitosan Protects Cooked Ground Beef and Turkey Against Clostridium perfringens Spores During Chilling. J Food Sci 2006. [DOI: 10.1111/j.1750-3841.2006.00109.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Keely S, Rullay A, Wilson C, Carmichael A, Carrington S, Corfield A, Haddleton DM, Brayden DJ. In vitro and ex vivo intestinal tissue models to measure mucoadhesion of poly (methacrylate) and N-trimethylated chitosan polymers. Pharm Res 2005; 22:38-49. [PMID: 15771228 DOI: 10.1007/s11095-004-9007-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
PURPOSE The adhesion of a range of polymers based on poly(2-(dimethylamino-ethyl) methacrylate (pDMAEMA) was assessed using human mucus-secreting and non mucus-secreting intestinal cell monolayers, HT29-MTX-E12 (E12) and HT29 monolayers, as well as excised non-everted intestinal sacs from rats. Differentiation of mucoadhesion from bioadhesion was achieved by pre-treatment with the mucolytic agent, N-acetyl cysteine (NAC). Adherence of pDMAEMA polymers was compared to that obtained with the mucoadhesive, N-trimethylated chitosan (TMC). METHODS The quantity of adherent coumarin 343-conjugated polymers to HT29, E12, and intestinal sacs was measured by fluorescence. Confocal laser scanning microscopy (CLSM), light microscopy, and fluorescent microscopy were used to provide direct evidence. Measurements of transepithelial electrical resistance (TEER), permeability to FITC-dextran 4000 (FD-4), and the release of lactate dehydrogenase (LDH) were used to assess potential cytotoxicity of polymers. RESULTS Adherence of unquaternized and of 10%, 24%, and 32% methyl iodide-quaternized pDMAEMA polymers was measured in E12, HT29, and sacs. All pDMAEMA polymers showed significantly higher levels of adhesion to mucus (mucoadhesion) than to epithelium (bioadhesion). Colocalization of pDMAEMA with mucus was confirmed in E12 by microscopy. TMC showed equally high levels of mucoadhesion as unquaternized and 24% quaternized pDMAEMA, but displayed higher levels of bioadhesion. pDMAEMA-based polymers demonstrated lower levels of adherence to E12 and rat sacs in the presence of NAC, whereas adherence of TMC was unchanged. pDMAEMA significantly decreased the permeability of FD-4 across E12 monolayers and sacs and was less cytotoxic in E12 than in HT29. In contrast, TMC increased the permeability of FD-4 across E12 and sacs and was less cytotoxic in E12 than in HT29. CONCLUSIONS Human mucus-producing E12 monolayers can be used to assess polymer mucoadhesion and give similar data to isolated rat intestinal sacs. pDMAEMA displayed similar levels of mucoadhesion and lower levels of bioadhesion than a chitosan derivative and it was not cytotoxic. pDMAEMA decreased FD-4 flux in the presence of mucus, whereas TMC increased it. The combination of mucus and methacrylate polymers appears to increase barrier function of the apical membrane.
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Affiliation(s)
- Simon Keely
- Faculty of Veterinary Medicine, University College, Dublin, Ireland
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