Letteratura scientifica selezionata sul tema "Alginate"
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Articoli di riviste sul tema "Alginate"
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Rizfa, Mila Safitri, Ervia Yudiati e Diah Permata Wijayanti. "Improving The Antioxidant Activity of Sodium Alginate from Sargassum sp. by Thermal Heating and Chemical Methods". Jurnal Kelautan Tropis 23, n. 3 (14 novembre 2020): 284–90. http://dx.doi.org/10.14710/jkt.v23i3.8946.
Testo completoAbstract (sommario):
The relationship between molecular structure and bioactivity was evaluated for sodium alginates obtained under different degradation treatment (raw alginates, heat-treated, and chemical-treated) from Sargassum sp. This study was conducted to identify the antioxidant activities of the degraded sodium alginate from Sargassum sp. compared to raw extract. Raw alginate as the control treatment was dried overnight at 60 °C, while heat-treated was heated raw alginate at 140oC in a laboratory oven (4.5 hours). Two chemical-treated were applied. Raw alginate added hydrogen peroxide and raw alginat with hydrogen peroxide plus ascorbic acid. This treatments were replicated three times. All the parameters were evaluated spectrophotometrically. The spectroscopy results from the degradation methods showed a new absorbance spectra pattern. The FT-IR spectrum revealed that treatment affects the structure of the alginates. Heat treated and chemical treated sodium alginates showed non significantly different on DPPH radical scavenging activity. Meanwhile, the combination of alginate and hydrogen peroxide treatment was at the lowest scavenging ability. Therefore, alginate oligosaccharides (AOS) produced by heating or adding chemical reagents could be considered as a stronger antioxidant than raw alginate, which may be applied in the industry and biomedical
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Adamiak, Katarzyna, e Alina Sionkowska. "State of Innovation in Alginate-Based Materials". Marine Drugs 21, n. 6 (8 giugno 2023): 353. http://dx.doi.org/10.3390/md21060353.
Testo completoAbstract (sommario):
This review article presents past and current alginate-based materials in each application, showing the widest range of alginate’s usage and development in the past and in recent years. The first segment emphasizes the unique characteristics of alginates and their origin. The second segment sets alginates according to their application based on their features and limitations. Alginate is a polysaccharide and generally occurs as water-soluble sodium alginate. It constitutes hydrophilic and anionic polysaccharides originally extracted from natural brown algae and bacteria. Due to its promising properties, such as gelling, moisture retention, and film-forming, it can be used in environmental protection, cosmetics, medicine, tissue engineering, and the food industry. The comparison of publications with alginate-based products in the field of environmental protection, medicine, food, and cosmetics in scientific articles showed that the greatest number was assigned to the environmental field (30,767) and medicine (24,279), whereas fewer publications were available in cosmetic (5692) and food industries (24,334). Data are provided from the Google Scholar database (including abstract, title, and keywords), accessed in May 2023. In this review, various materials based on alginate are described, showing detailed information on modified composites and their possible usage. Alginate’s application in water remediation and its significant value are highlighted. In this study, existing knowledge is compared, and this paper concludes with its future prospects.
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Ochbaum, Guy, Maya Davidovich-Pinhas e Ronit Bitton. "Tuning the mechanical properties of alginate–peptide hydrogels". Soft Matter 14, n. 21 (2018): 4364–73. http://dx.doi.org/10.1039/c8sm00059j.
Testo completoAbstract (sommario):
Covalent bonding peptides to alginates is routinely used to tailor alginate's biofunctionality. Here, we investigate the possibility of tuning the mechanical properties of alginate–peptide gels by altering the sequence of the covalently bound peptide.
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Abourehab, Mohammad A. S., Rahul R. Rajendran, Anshul Singh, Sheersha Pramanik, Prachi Shrivastav, Mohammad Javed Ansari, Ravi Manne, Larissa Souza Amaral e A. Deepak. "Alginate as a Promising Biopolymer in Drug Delivery and Wound Healing: A Review of the State-of-the-Art". International Journal of Molecular Sciences 23, n. 16 (12 agosto 2022): 9035. http://dx.doi.org/10.3390/ijms23169035.
Testo completoAbstract (sommario):
Biopolymeric nanoparticulate systems hold favorable carrier properties for active delivery. The enhancement in the research interest in alginate formulations in biomedical and pharmaceutical research, owing to its biodegradable, biocompatible, and bioadhesive characteristics, reiterates its future use as an efficient drug delivery matrix. Alginates, obtained from natural sources, are the colloidal polysaccharide group, which are water-soluble, non-toxic, and non-irritant. These are linear copolymeric blocks of α-(1→4)-linked l-guluronic acid (G) and β-(1→4)-linked d-mannuronic acid (M) residues. Owing to the monosaccharide sequencing and the enzymatically governed reactions, alginates are well-known as an essential bio-polymer group for multifarious biomedical implementations. Additionally, alginate’s bio-adhesive property makes it significant in the pharmaceutical industry. Alginate has shown immense potential in wound healing and drug delivery applications to date because its gel-forming ability maintains the structural resemblance to the extracellular matrices in tissues and can be altered to perform numerous crucial functions. The initial section of this review will deliver a perception of the extraction source and alginate’s remarkable properties. Furthermore, we have aspired to discuss the current literature on alginate utilization as a biopolymeric carrier for drug delivery through numerous administration routes. Finally, the latest investigations on alginate composite utilization in wound healing are addressed.
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Putri, Tansza S., Deviyanti Pratiwi, Eddy, Rosalina Tjandrawinata, Dewi L. Margaretta, Florencia L. Kurniawan e Octarina. "Pengaruh suhu air terhadap setting time dari bahan cetak alginat". e-GiGi 12, n. 1 (1 settembre 2023): 74–78. http://dx.doi.org/10.35790/eg.v12i1.47105.
Testo completoAbstract (sommario):
Abstract: Irreversible hydrocolloid impression materials or alginate is commonly used in dental practice. Its setting time range is 1–4.5 minutes. The setting time is affected by several factors such as water temperature mixed with the alginate powder. There are previous studies evaluated the effect of water temperature on the alginate’s setting time, however, the collected data is still minimal. Therefore, this study aimed to evaluate the effect of water temperature on alginate’s setting time on larger scale. There were total of 423 samples divided into three groups: cold, moderate, and warm temperature of water mixed with alginate; each group consisted of 141 samples. Differences in setting times of the qroups were analyzed with the Kruskal-Wallis test and the Tukey’s HSD. Alginate powder used in this study was the normal-set type. Mixing the alginate powder with water was performed as the factory instruction, and then the mixture was poured into molds and the setting times were measured. The results showed that the setting times of the three groups were significantly different. Group I (cold) had the highest setting time (211 seconds), followed by Group II (room temperature) which was 147 seconds, and Group III (warm) had a setting time of 106 seconds. In conclusion, water temperature has an effect on setting time, that is, the higher the temperature, the faster the setting time, and vice versa. Keywords: alginate; irreversible hydrocolloid; setting time; water temperature Abstrak: Bahan cetak hidrokoloid ireversibel atau alginat merupakan bahan umum yang digunakan di praktek kedokteran gigi, dan memiliki setting time antara 1–4,5 menit. Setting time ditentukan oleh beberapa faktor di antaranya suhu air yang digunakan dalam mencampur bahan cetak tersebut. Terdapat penelitian-penelitian terdahulu yang mengevaluasi efek suhu terhadap setting time, namun data yang dikumpulkan masih minimal. Penelitian ini bertujuan untuk mengetahui efek suhu terhadap setting time bahan cetak alginat dalam skala besar. Terdapat tiga kelompok penelitian yaitu menggunakan suhu air yang dicampurkan dengan alginat dingin, sedang (suhu ruang), dan hangat. Besar sampel penelitian ini ialah 141 sampel per kelompok, sehingga total sampel ialah 423 sampel. Perbandingan setting time dari tiga kelompok kemudian dianalisis secara statistik menggunakan uji Kruskal-Wallis dan Tukey’s HSD untuk mengetahui ada tidaknya perbedaan bermakna dari kelompok-kelompok tersebut. Bubuk alginat yang digunakan merupakan alginat tipe normal. Pencampuran bubuk alginat dengan air dilakukan sesuai dengan instruksi pabrik. Adonan yang telah diaduk dituang ke dalam cetakan dan dilakukan pengukuran setting time. Hasil penelitian mendapatkan setting time dari ketiga kelompok berbeda secara bermakna. Kelompok I (dingin) memiliki setting time tertinggi yaitu selama 211 detik, diikuti kelompok II (sedang) selama 147 detik, dan kelompok III (hangat) selama 106 detik. Simpulan penelitian ini ialah suhu air memiliki efek terhadap setting time, yaitu semakin tinggi suhu air maka semakin singkat setting time, demikian pula sebaliknya. Kata kunci: alginat; hidrokoloid ireversibel; setting time; suhu air
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Fischer, Melissa, Florian Gebhard, Timo Hammer, Christian Zurek, Guido Meurer, Christoph Marquardt e Dirk Hoefer. "Microbial alginate dressings show improved binding capacity for pathophysiological factors in chronic wounds compared to commercial alginate dressings of marine origin". Journal of Biomaterials Applications 31, n. 9 (29 marzo 2017): 1267–76. http://dx.doi.org/10.1177/0885328217702173.
Testo completoAbstract (sommario):
Marine alginates are well established in wound management. Compared with different modern wound dressings, marine alginates cannot prove superior effects on wound healing. Alginates from bacteria have never been studied for medical applications so far, although the microbial polymer raises expectations for improved binding of wound factors because of its unique O-acetylation. Due to its possible positive effects on wound healing, alginates from bacteria might be a superior future medical product for clinical use. To prove the binding capacity of microbial alginates to pathophysiological factors in chronic wounds, we processed microbial alginate fibres, produced from fermentation of the soil bacterium Azotobacter vinelandii ATCC 9046, into needle web dressings and compared them with commercial dressings made of marine alginate. Four dressings were assessed: Marine alginate dressings containing either ionic silver or zinc/manganese/calcium, and microbial alginate dressings with and without nanosilver. All dressings were tested in an in vitro approach for influence on chronic wound parameters such as elastase, matrix metalloproteases-2, tumour necrosis factor-α, interleukin-8, and free radical formation. Despite the alginate origin or addition of antimicrobials, all dressings were able to reduce the concentration of the proinflammatory cytokines TNF-α and IL-8. However, microbial alginate was found to bind considerable larger amounts of elastase and matrix metalloproteases-2 in contrast to the marine alginate dressings. The incorporation of zinc, silver or nanosilver into alginate fibres did not improve their binding capacity for proteases or cytokines. The addition of nanosilver slightly enhanced the antioxidant capacity of microbial alginate dressings, whereas the marine alginate dressing containing zinc/manganese/calcium was unable to inhibit the formation of free radicals. The enhanced binding affinity by microbial alginate of Azotobacter vinelandii to pathophysiological factors may be interesting to support optimal conditions for wound healing.
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Wibowo, Agung Ari, Ade Sonya Suryandari, Eko Naryono, Vania Mitha Pratiwi, Muhammad Suharto e Naila Adiba. "Encapsulation of Clove Oil within Ca-Alginate-Gelatine Complex: Effect of Process Variables on Encapsulation Efficiency". Jurnal Teknik Kimia dan Lingkungan 5, n. 1 (29 aprile 2021): 71. http://dx.doi.org/10.33795/jtkl.v5i1.214.
Testo completoAbstract (sommario):
Karena memiliki khasiat seperti analgesik, minyak cengkeh biasa digunakan sebagai obat, antibakteri, antioksidan, dan antimikroba. Kemungkinan enkapsulasi minyak cengkeh sebagai makrokapsul padat dipelajari dengan pembuatan makrokapsul Ca-Alginate-Gelatine. Variabel proses yang digunakan adalah variasi konsentrasi alginat 1% dan 1,5% b / v, dan perbandingan massa antara alginat-gelatin divariasikan antara 1: 4, 1: 6, dan 1: 8 w /w. Selain itu, variasi konsentrasi CaCl2 (10%, 20% dan 30% w / v) sebagai cross-linking agent pembentukan kompleks Ca-Alginate juga digunakan sebagai variabel proses. Peningkatan konsentrasi alginat, gelatin dan CaCl2 nampaknya menurunkan efisiensi enkapsulasi karena terbatasnya volume ruang bebas yang terbentuk pada matriks Ca-Alginat-Gelatin. Efisiensi enkapsulasi tertinggi (93,08%) diperoleh pada penggunaan Alginat 1% w / v, dengan perbandingan alginat dengan gelatin 1: 4 dan ikatan silang dalam larutan CaCl2 10% w / v selama 15 menit.Owing to the properties such as analgesic, clove oil is commonly used as medicine, antibacterial, antioxidant, and antimicrobial drugs. The possibility of clove oil encapsulation as a solid macrocapsule was studied by making Ca-Alginate-Gelatine macrocapsules. The process variables used were variations in Alginate concentration of 1% and 1.5% w/v, and the mass ratio between alginate-gelatine was varied between 1: 4, 1: 6, and 1: 8 w/w. In addition, variations in the concentration of CaCl2 (10%, 20% and 30% w/v) as a cross-linking agent for the formation of Ca-Alginate complexes were also used as process variables. The increase of alginate, gelatine and CaCl2 concentration seems to decreased the encapsulation efficiency because of the limitation of the free space volume formed in the Ca-Alginate-Gelatine matrix. The highest encapsulation efficiency (93.08%) was obtained in the use of Alginate 1% w/v, with a ratio of alginate to gelatine 1: 4 and cross-linking in a 10% w/v CaCl2 solution for 15 minutes.
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Rokhati, Nur, Bambang Pramudono, Nyoman Widiasa e Heru Susanto. "KARAKTERISASI FILM KOMPOSIT ALGINAT DAN KITOSAN". Reaktor 14, n. 2 (8 ottobre 2012): 158. http://dx.doi.org/10.14710/reaktor.14.2.158-164.
Testo completoAbstract (sommario):
CHARACTERIZATION OF ALGINATE AND CHITOSAN COMPOSITE FILM. Due to the specific characteristics of (thin) films, the use of polymer films in various aplications has singnificantly increased. Alginate and chitosan are natural polymers, which have potential as a raw material for the manufacture of composite films. This paper presents the preparation and characterization of alginate, chitosan and chitosan-alginate composite films. The film characterization included permeability test, degree of swelling, mechanical property, morphology (by SEM), and surface chemistry (by FTIR). The results showed that alginate films have a higher permeability and degree of swelling (DS) than chitosan films. Both permeability and DS decreased with increasing concentration for both alginate and chitosan films. DS experiments showed that the films have the highest DS in water followed by ethanol 95% and ethanol >99.9%, respectively. The mechanical strength of chitosan films was larger than alginate films. Alginate-chitosan composite films prepared by layer by layer method showed better characteristics than the composite films prepared by blending of alginate and chitosan solutions. Meningkatnya aplikasi film polimer di berbagai industri tidak terlepas dari keunggulan yang dimiliki. Alginat dan kitosan merupakan polimer alam yang mempunyai potensi sebagai bahan dasar pembuatan film komposit. Pada penelitian ini dilakukan pembuatan dan karakterisasi film komposit berbasis alginat dan kitosan. Karakterisasi film yang dilakukan meliputi uji: permeabilitas, derajat swelling, mekanik, morfologi (dengan SEM), dan struktur kimia permukaan (dengan FTIR). Hasil penelitian menunjukkan bahwa film alginat mempunyai nilai permeabilitas maupun derajat swelling yang lebih tinggi dibanding dengan film kitosan. Baik pada kitosan maupun alginat memberikan fenomena bahwa semakin besar konsentrasi larutan maka semakin kecil nilai permeabilitas maupun derajat swelling, dengan derajat swelling terhadap air adalah yang paling besar kemudian diikuti oleh ethanol teknis (± 95%) dan yang terkecil adalah ethanol PA (> 99,9%). Kekuatan mekanik film kitosan lebih besar dibanding dengan film alginat. Film komposit alginat-kitosan yang dibuat dengan metode layer by layer memberikan karakteristik yang lebih baik dibanding dengan film komposit yang dibuat dengan pencampuran larutan alginat dan larutan kitosan.
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Kulašević, Lazar N. "Alginate: Applications in the modern world". Chemia Naissensis 1, n. 1 (2018): 187–97. http://dx.doi.org/10.46793/chemn1.1.187k.
Testo completoAbstract (sommario):
Alginate is a natural polysaccharide extracted from the cell walls of brown algae. Thanks to its biocompatibility, biodegradability, nontoxicity, and low cost, this biopolymer is widely applicable across various fields of biomedical science and bioengineering. Alginates are used as a gelling agent in food industry. Alginate hydrogels are an appealing scaffold material because of their resemblance with natural tissues. Consequently, alginates are widely used in tissue engineering and alginate gel beads as transport vehicles in drug delivery systems. Nonetheless, alginate hydrogels are used in nanotechnology to build artificial capillary blood vessels.
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Sumantri, Dedi, e Prima Suci Waldiatma. "Perbedaan stabilitas dimensi cetakan alginat yang disemprot dan direndam dengan natrium hipoklorit dan ekstrak buah mengkudu: studi eksperimental". Padjadjaran Journal of Dental Researchers and Students 7, n. 3 (2 novembre 2023): 300. http://dx.doi.org/10.24198/pjdrs.v7i3.49983.
Testo completoAbstract (sommario):
ABSTRAKPendahuluan: Alginat merupakan bahan cetak yang paling umum digunakan pada kedokteran gigi, namun cetakan alginat dapat menjadi media penularan infeksi silang, oleh karena itu perlu didesinfeksi terlebih dahulu. Natrium hipoklorit dan ekstrak buah mengkudu merupakan desinfektan untuk alginat. Alginat mempunyai sifat imbibisi yang mempengaruhi stabilitas dimensi cetakan alginat, sehingga akurasi dan stabilitas dimensi cetakan alginat tetap perlu dipertahankan setelah proses desinfeksi. Tujuan penelitian menganalisis perbandingan stabilitas dimensi cetakan alginat yang direndam dan disemprot dengan natrium hipoklorit 0,5%, ekstrak buah mengkudu 12%, dan ekstrak buah mengkudu 16%. Metode: Penelitian eksperimental laboratorium dengan rancangan post test only group design dengan 12 kelompok uji dan total jumlah sampel 60. Cetakan alginat yang direndam dan disemprot dengan natrium hipoklorit 0,5%, ekstrak buah mengkudu 12%, dan ekstrak buah mengkudu 16% diisi gips, dengan masing-masing diuji pada perbedaan waktu 5 menit dan 10 menit kemudian diukur stabilitas dimensinya menggunakan jangka sorong digital. Data dianalisis dengan Two Way Anova, kemudian uji Post hoc Bonferroni. Hasil: Cetakan alginat yang direndam dengan sodium hipoklorit 0,5%, ekstrak buah mengkudu 12%, dan 16% mengalami perubahan dimensi yang lebih besar dibandingkan dengan yang disemprot dengan menggunakan sodium hipoklorit 0,5%, ekstrak buah mengkudu 12%, dan 16%. Uji Two Way Anova menunjukkan terdapat perbedaan yang signifikan (p<0,05) antara cetakan alginat yang direndam dan disemprot. Simpulan: Terdapat perbedaan stabilitas dimensi antara cetakan alginat yang direndam dan disemprot dengan natrium hipoklorit 0,5%, ekstrak buah mengkudu 12%, dan ekstrak buah mengkudu 16%, selama 5 dan 10 menit.KATA KUNCI: cetakan alginat, desinfeksi, ekstrak buah mengkudu, natrium hipoklorit, stabilitas dimensi.Comparison of dimensional stability between sprayed and immersed alginate impression with sodium hypochlorite and an extract of Morinda citrifolia: an experimental study ABSTRACTIntroduction: Alginate is the most common impression material used in dentistry; however, alginate impression results can be media transmission for cross infection, therefore it is important for disinfection. Sodium hypochlorite and the extract of morinda citrifolia are disinfectants for alginate. Alginate has some characteristics, such as imbibition, that can influence the dimensional stability and accuracy of the alginate impression. The purpose of this study was to determine the difference between the dimensional stability of immersed and sprayed alginate impressions with 0,5% sodium hypochlorite, 12%, and 16% Morinda citrifolia extract, with each tested at a time difference of 5 minutes and 10 minutes. Methods: Laboratory experiment with a posttest-only group design with a total of 60 samples in 12 groups. The alginate impression was immersed and sprayed with 0,5% sodium hypochlorite, 12% extract of Morinda citrifolia, and 16% extract of Morinda citrifolia, filled with gypsum, then measured for the dimensional stability using a digital caliper. Data were analyzed with Two Way Anova test and Post hoc Bonferroni test. Results: The dimension stability of an immersed alginate impression with 0.5% sodium hypochlorite, 12% extract of Morinda citrifolia, and 16% extract of Morinda citrifolia was greater than that of a sprayed alginate impression with 0.5% sodium hypochlorite, 12% extract of Morinda citrifolia, and 16% extract of morinda citrifolia. The Two Way Anova test showed significant difference (p<0,05) between the immersed and sprayed alginate impression. Conclusion: There are differences in the dimensional stability of alginate impression that was immersed and sprayed with 0.5% sodium hypochlorite, 12% extract of Morinda citrifolia, and 16% extract of Morinda citrifolia for 5 and 10 minutes.KEY WORDS: impression alginate, desinfection, extract of morinda citrifolia, sodium hypochlorite, dimensional stability.
Tesi sul tema "Alginate"
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Márquez, Maqueda Augusto. "Alginate and silk fibroin based technologies for biosensing". Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/670117.
Testo completoAbstract (sommario):
A causa de el fort impacte de la diabetis com a malaltia d’extensió mundial ia les perspectives d’increment en el nombre de persones afectades durant els propers anys, especialment en països subdesenvolupats, hi ha una gran necessitat de producció de sistemes de detecció i quantificació de glucosa, que puguin ser implementats en dispositius portables robustos, miniaturitzats, de baix cost i llarga durada, tipus Point of Care (POC).
En aquest sentit, en aquesta tesi es proposa l’ús de biomaterials d’origen natural, com l’alginat i la fibroïna de seda, procedents de l’alga bruna (classe Phaeophyceae) i de l’cuc de seda (Bombyx mori) respectivament, i la seva combinació amb tecnologies de microfabricació per a la producció d’una nova generació de dispositius POC.Debido al fuerte impacto de la diabetes como enfermedad de extensión mundial y a las perspectivas de incremento en el número de personas afectadas durante los próximos años, especialmente en países subdesarrollados, existe una gran necesidad de producción de sistemas de detección y cuantificación de glucosa, que puedan ser implementados en dispositivos portables robustos, miniaturizados, de bajo coste y larga duración, tipo Point of Care (POC). En ese sentido, en esta tesis se propone el uso de biomateriales de origen natural, como el alginato y la fibroína de seda, procedentes del alga parda (clase Phaeophyceae) y del gusano de seda (Bombyx mori) respectivamente, y su combinación con tecnologías de microfabricación para la producción de una nueva generación de dispositivos POC.
Due to the impact of diabetes as a worldwide disease and the expected increment in the number of people affected in the following years, especially in underdeveloped countries, there is a need for the production of precise and long-life glucose biosensors to be implemented in simple, low-cost, robust, miniaturized and portable point of care systems. In that sense, this thesis proposes the use of biomaterials of natural origin, such as alginate and silk fibroin, from brown algae (Phaeophyceae class) and silkworm (Bombyx mori) respectively, and their combination with microfabrication technologies for the production of the new generation of electrochemial and optical point of care devices.
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Aarstad, Olav Andreas. "Alginate sequencing : Block distribution in alginates and its impact on macroscopic properties". Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for bioteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-20246.
Testo completo
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Hadjialirezaei, Soosan. "Coating of alginate capsules". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for bioteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-22908.
Testo completoAbstract (sommario):
Alginate is a popular candidate for encapsulation of cells due to the formation of gels with divalent ions under physiological conditions. Stable alginate gels can be formed by the selection of alginates with a high content of guluronic acid (G) and gelling in a mixture of calcium and barium. These alginate gels have been proposed as immune protective barriers for the transplantation of human pancreatic islets (insulin producing cells) for the treatment of type 1 diabetes where the alginate gel protects the transplant from the host immune system. Microencapsulation can thus provide a way to overcome the need for immunosuppressive drugs. Although showing promising results in animal models, there are potential limitations of the Ca2+/Ba2+-beads concerning growth of host cells on the surface of capsules in primate models. Development of coating strategies for alginate based capsules could thus be beneficial for reducing the attachment of host cells. Alginate microbeads/capsules were formed by electrostatic bead generator producing beads of 400µm. Afterward, the alginate beads were coated by fluoresceinamine labeled alginate that was visualized by confocal laser scanning microscopy (CLSM) and quantified by fluorescent spectroscopy. The binding of coating alginate to alginate-poly-L-lysine (PLL) capsules was also studied.In this project, in the optimalisation of coating of alginate beads some parameters were studies such as concentration of coating alginate, different gelling ions both for core and coating alginate, exposure time for gelling solution for fixation of coating layer and different washing solution.The long-term stability of coating layer of coated alginate beads was determined by measuring the fluorescent intensity of fluorescently labeled of coating alginate during a period of forty nine days. A stability study of alginate-alginate capsules revealed that Ca2+/Ba2+ alginate coated with high-G alginate and washed with saline and used Ca2+ and Ba2+ with ratio 50:1 for fixation of coating layer were more stable coating than other capsules. The alginate beads coated with high-M or epimerized alginate were produced. It shows higher intensity of coating layer in both capsules coated with high-M or epimerized alginate than alginate beads coated with high-G alginate. In continue of the study, the alginate-PLL capsules were coated with high-G, high-M, and epimerized and sulfated alginate. Alginate-PLL capsules coated with high-G, high-M and epimerized alginate shows no detective signal by confocal images and sulfated alginate coating shows some signal of coating. The stability of coating for alginate-PLL-alginate capsules and alginate beads coated with epimerized or high-M alginate revealed that both kind of coating have high-stability over one week screening.Three dimensional images of capsules, in confocal microscope, both epimerized and high-M coating alginates cover whole of capsules. However, in 3D images we have seen some fragment of coating gelling in the surround solution and attached to the capsules which can make disturbance in spectroscopy measurement. 3D images of alginate-PLL capsules coated with sulfated alginate show evenly distribution of coating.
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Brivonese, Anne Caterina. "Alginate biosynthesis in Azotobacter vinelandii". Thesis, University of Edinburgh, 1985. http://hdl.handle.net/1842/16946.
Testo completo
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Lima, Caroline Santos Alves de. "Estudo do desenvolvimento de microcápsulas de polímeros naturais para aplicação em têxteis médicos". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/100/100133/tde-01112017-144224/.
Testo completoAbstract (sommario):
A indústria têxtil busca recuperar a diminuição do ritmo dos negócios, notado principalmente em países desenvolvidos devido ao cenário da economia mundial, por meio da elaboração de têxteis com maior valor agregado. A microencapsulação é uma técnica versátil e flexível que apresenta diversas vantagens, como evitar que o princípio ativo reaja com outros compostos presentes no sistema e possibilitar a liberação controlada, que aumenta potencialmente a eficiência do produto. O principal objetivo deste trabalho foi desenvolver microcápsulas de quitosana e alginato com incorporação de Triclosan, que possui propriedades bactericida e fungicida, para aplicação em substratos têxteis para utilizações médicas. As microcápsulas foram produzidas a partir do método de emulsificação e reticulação, e caracterizadas por Termogravimetria (TG), Calorimetria Exploratória Diferencial (DSC), Espectroscopia no Infravermelho com Transformada de Fourier (FTIR), capacidade de absorção de água e perda de massa, Microscopia Eletrônica de Varredura (MEV), ensaio de atividade bactericida e liberação in vitro. Após caracterizadas, as microcápsulas foram impregnadas em tecidos 100% algodão com ligamentos tela e sarja. Estes foram submetidos a testes físicos e análise de resistência à lavagem. As microcápsulas produzidas apresentaram forma esférica e tiveram 80,78% de eficiência de encapsulação do fármaco. Os ensaios de liberação mostraram que o fármaco não foi liberado em 24h, entretanto, o material apresentou atividade bactericida contra a bactéria gram-positiva S. aureus, com halo de inibição de até 60 mm e também contra a bactéria gram-negativa E. coli, com halo de até 25 mm. Os resultados de resistência à lavagem avaliados por MEV mostraram que as microcápsulas não permenceram no substrato. Entretanto, o material apresentou atividade antibacteriana podendo ser interessante para aplicação em materiais têxteis descartáveis, como bandagens utilizadas na área médicaThe textile industry seeks to recover the decrease of the pace of business, noted mainly in developed countries due to the scenario of the world economy, through the development of textiles with higher added value. The microencapsulation is a versatile and flexible technique that presents several advantages such as to avoid that the active ingredient react with other compounds present in the system, and allow controlled release that potentially increases the efficiency of the product. The main objective of this work was to develop microcapsules of chitosan and alginate with incorporation of triclosan, which has bactericidal and fungicide properties, for use in textile substrates for medical uses. The microcapsules were produced from the method of emulsification and crosslinking, and characterized by Thermogravimetry (TG), Differential Scanning Calorimetry (DSC), Infrared Spectroscopy Fourier Transform (FTIR), water absorption capacity and mass loss, Scanning Electron Microscopy (SEM), bactericidal activity assay and in vitro release. After characterized, the microcapsules were impregnated in 100% cotton twill and taffeta woven. Physical tests and analysis of resistance to washing were carried out. The microcapsules produced presented spherical shape and had 80.78% of drug encapsulation efficiency. Release tests showed that the drug was not released in 24 hours, however, the material presented bactericidal activity against the gram-positive bacterium S. aureus, with inhibition halo up to 60 mm and also against the gram-negative bacterium E. coli, with halo of up to 25 mm. The results of washing resistance evaluated by SEM showed that the microcapsules did not remain in the substrate. However, the material showed antibacterial activity and may be interesting for application in disposable textiles, such as bandages used in the medical field
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Reehorst, Camilla M. "The Mucin-Alginate Interplay : Investigating the Rheological Impact of Alginates and Their Influence on Particle Mobility". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for bioteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-24921.
Testo completoAbstract (sommario):
Mucus is a hydrogel that covers epithelial cells and acts as an intermediary between the exterior and interior surfaces of the human body. It is complex and diverse, comprised of various compounds and serves as a selective barrier to pathogens, nutrients and administered substances. It is therefore important to circumvent or penetrate this barrier to increase drug bioavailability. The most important constituent of mucus is mucin glycoprotein that enables gel formation. Due to the molecular nature of mucin, it interacts with most substances including polyanionic biopolymers like alginates. Alginate molecules have been extensively used in pharmaceutical and medical industries as mediators because they possess suitable characteristics for a variety of biomedical applications. They have also been shown to influence mucus rheology, and could hold potential to alter other properties of mucus as well, such as particle mobility. In this thesis, the effect of different molecular weight alginates were investigated on the rheology of porcine gastric (PG) mucin, porcine small intestinal mucus (PSIM), porcine tracheobronchial mucus (PTBM) and bio-similar mucus. In addition, the effect of alginate on particle mobility in PG mucin samples were investigated using multiple particle tracking (MPT). The rheological effect of alginate G-block DPn 12, DPn 24, DPn 33 and alginate LFR 5/60 on PG mucin was inconclusive as the sample suffered from pH and mechanical instabilities. Particle mobility was greatest for G-block DPn 12 and G-block DPn 33 treated PG mucin at long time scales. In addition, their mean-square displacement (MSD) trajectories were more narrowly distributed than the other samples, which correlates to a higher degree of uniform pore sizes. The rheological behaviour of bio-similar mucus and PSIM after treatment of G-block DPn 12, G-block DPn 33 and LFR 5/60 did not coincide, despite bio-similar mucus being a model system for porcine intestinal mucus (PIM). This was ascribed interactions between alginate and polyacrylate in the bio-similar mucus causing phase separation. Alginate G-block DPn 12 weakened the PSIM and PTBM gel, while G-block DPn 33 and LFR 5/60 had minor strengthening effects on PSIM.
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Silva, Adriana Navarro da [UNESP]. "Substratos alternativos para a produção de poli-hidroxibutirato e alginato por Azotobacter vinelandii". Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/100889.
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Atualmente a destinação do lixo é uma das grandes preocupações da organização urbana e os problemas ambientais causados pela produção e acúmulo de materiais plásticos de origem petroquímica têm incentivado muitos países a realizarem estudos de gerenciamento do volume de lixo sólido, incluindo a diminuição de resíduos plásticos por meio do desenvolvimento de bioplásticos. Os bioplásticos possuem propriedades semelhantes às dos plásticos convencionais e apresentam a vantagem de serem facilmente degradados pela ação de microrganismos no ambiente, podendo citar como exemplo os poli-hidroxialcanoatos (PHA), dentre eles o poli-hidroxibutirato (PHB). Estes polímeros podem representar até 80% da massa seca total da célula, tendo como característica principal a biodegradabilidade em solos e a biocompatibilidade com o tecido animal. Entre os microrganismos produtores de PHAs, a bactéria Azotobacter vinelandii pode acumular grandes quantidades de PHB intracelular com a vantagem de utilizar durante seu crescimento uma ampla variedade de açúcares como os encontrados em melaço de cana-de-açúcar, beterraba e xarope de milho, além de resíduos da suinocultura, agroindustriais, etc. Além do PHB, a bactéria A. vinelandii é capaz de produzir alginato, composto muito empregado na área de análogos de frutas ou produtos tipo imitação como: fatias de pimentão para recheios de azeitonas, imitação de anéis de cebola, imitações de caviar, carne, pescados, produtos marinhos, etc. Tendo em vista que os principais fatores limitantes para a produção de biopolímeros estão associados, principalmente, com os custos dos substratos e ao fato de que muitos microrganismos são patogênicos dificultando a sua aceitação pela comunidade em geral, este trabalho teve como objetivo utilizar...
Currently, the waste disposal is a major concern of urban organization and the environmental problems caused by production and accumulation of petrochemical plastics have encouraged many countries to management studies of the solid waste volume, including the waste plastics reduction through the bioplastics development. Bioplastics have similar properties to conventional plastics and the advantage of being easily degraded by the microorganisms action in the environment, for example, poly-hydroxyalcanoatos (PHA), including poly-hydroxybutyrate (PHB). These polymers can represent up to 80% of total dry mass of the cell, having as main feature the biodegradability in soil and the biocompatibility with animal tissue. Among the microorganisms producing PHAs, the bacterium Azotobacter vinelandii can accumulate large amounts of intracellular PHB with the advantage that they grow a wide sugars variety like those found in molasses cane sugar, beet sugar and corn syrup, and swine waste, agribusiness, etc.. Besides the PHB, the bacterium A. vinelandii is able to produce alginate, a very useful compound in the similar area of type of fruit and imitation as sliced peppers for stuffing olives, onion rings imitation, caviar, meat, fish and marine products imitation, etc.. Given that the main limiting factors for the biopolymers production are mainly associated with the substrates costs and the fact that many microorganisms are pathogenic hindering its acceptance by the community in general, this study aimed to use the pollutant by-products environment (residual oil frying, glycerin, cassava wastewater – “manipueira”, vinasse and wastewater industry carbonated beverages or soft drinks) as a substrate for the poly-hydroxybutyrate and alginate production by non-pathogenic bacterium Azotobacter vinelandii. Fermentations... (Complete abstract click electronic access below)
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Dumont, Mélanie. "Élaboration et caractérisation de fibres mixtes Alginate / Chitosane". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1303/document.
Testo completoAbstract (sommario):
Dans ces travaux de recherche, la préparation de fibres d'alginate de calcium revêtues de chitosane par un procédé de filage par mouillage et la caractérisation de ces fibres dont leur activité antibactérienne sont présentées. Un métier à filer à l'échelle pilote a été conçu et développé au cours de ces travaux de thèse pour l'élaboration de fibres d'alginate de calcium. Ces dernières, préalablement fabriquées, sont immergées dans une solution d'acétate de chitosane. Trois méthodes de coagulation de l'enduit de chitosane ont été explorés dont deux consistent en l'immersion des fibres dans un bain neutralisant : une solution de dihydroxyde de calcium ou une solution d'hydroxyde de potassium. La dernière méthode consistait à neutraliser le chitosane par séchage sous air chaud soufflé. Une caractérisation structurelle, mécanique et d'absorption des fibres, ainsi qu'un dosage du chitosane revêtu ont été réalisés. De plus, une évaluation antibactérienne a été accomplie par une méthode de comptage des UFC (Unité Formant Colonie) après 6 h d'incubation à 37 °C. L'incorporation de chitosane aux fibres d'alginate de calcium apporte une activité antibactérienne contre Staphylococcus epidermidis, Escherichia coli et divers Staphylococcus aureus tels que MSSA (Methicillin Sensitive Staphylococcus aureus), CA-MRSA (Community Associated Methicillin Resistant Staphylococcus aureus) et HA-MRSA (Healthcare Associated Methicillin Resistant Staphylococcus aureus). Ces fibres revêtues sont alors des candidats de choix pour l'élaboration de tissus destinés à la cicatrisation des plaies. Développer des compresses avec les propriétés hémostatiques et cicatrisantes de l'alginate de calcium combinées aux propriétés antibactériennes du chitosane peut être envisagé pour lutter contre les infections et plus particulièrement les maladies nosocomialesIn this work, the preparation of chitosan-coated alginate fibers by a wet spin process and the characterization of these fibers, particularly their antibacterial activities are presented. A pilot scale spinning machine was developed during this thesis for the elaboration of calcium alginate fibers. These last, preformed produced were immersed in chitosan acetate solutions. Three coagulation methods of the chitosan coating were explored two of which consist to the immersion of the fibers in a neutralizing bath: a calcium hydroxide solution or a potassium hydroxide solution. The last method is to neutralize chitosan by drying under hot air blown. Structural, mechanical and absorption characterization of fibers and a dose of the coated chitosan have been made. Furthermore, the antibacterial evaluation was achieved by a CFU (Colony-Forming Units) counting method after 6 h of incubation at 37 °C. The incorporation of chitosan on calcium alginate fibers brings antibacterial activities against Staphylococcus epidermidis, Escherichia coli and various Staphylococcus aureus strains namely MSSA (Methicillin Sensitive Staphylococcus aureus), CA-MRSA (Community Associated Methicillin Resistant Staphylococcus aureus) and HA-MRSA (Healthcare Associated Methicillin Resistant Staphylococcus aureus) which make these chitosan-coated fibers potential candidates for wound dressing materials. Developing a wound dressing with the haemostatic and healing properties of alginate combined with antibacterial properties of chitosan can be envisioned for fighting against the infections and more particularly nosocomial infections
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Monteiro, Centeno da Costa Filipe. "Procédé d’immobilisation de levures pour applications oenologiques. Etudes des paramètres du procédé. Validations experimentales". Thesis, Toulouse, INPT, 2011. http://www.theses.fr/2011INPT0061.
Testo completoAbstract (sommario):
L'étude et le développement des procédés de fabrication de levures immobilisées en vue de la réalisation de fermentations de vins a débuté au milieu des années 80. Malgré les bénéfices potentiels que cette technologie pouvait apporter pour le secteur œnologique, peu de procédés d'immobilisation ont réussi à dépasser l'échelle laboratoire ou pilote et ceux qui sont arrivés à l'échelle industrielle n'ont pas eu le succès désiré pour des questions d'ordre technique ou économique. Le premier objectif de ce travail concerne la mise au point du procédé industriel en insistant sur les aspects les plus sensibles, et qui comme tels ont exigé des études complémentaires. Le deuxième objectif de ce travail vise à caractériser du point de vue cinétique et lorsque possible sensoriel, les fermentations avec les levures immobilisées pour la production de vins effervescents et pour la désacidification biologique de moûts. Le troisième et dernier objectif de ce travail consiste à évaluer l'utilisation de levures immobilisées pour la réalisation de la fermentation alcoolique en continu de moût. Pour cela on a fait appel à des fermenteurs continus à lit fixe et à lit fluidiséThe study and development of yeast immobilization processes for wine fermentations started in the mid 80’s. Even though this technology could be of great benefit for the oenological sector very few process left the laboratory or pilot scale and those which arrived to industrial scale didn’t have the ambitioned success due to technical or economical constraints. The first goal of this work was to develop an industrial process for yeast immobilisation with emphasis on the most sensitive aspects which required further studies. The second objective of this work was to characterise the fermentation kinetics of immobilised yeasts cells during the production sparkling wines and during the deacidification of grape must. Whenever possible the wines produced were also characterised from a sensorial point of view. The third and last goal was to evaluate the use of immobilised yeast cells for continuous fermentation of grape must. For that we have used continuous fixed bed and fluidized bed fermenters
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Govan, John R. W. "Pseudomonas, alginate biosynthesis and cystic fibrosis". Thesis, University of Edinburgh, 1994. http://hdl.handle.net/1842/28137.
Testo completoLibri sul tema "Alginate"
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Jana, Sougata, e Subrata Jana, a cura di. Alginate Biomaterial. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6937-9.
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Rogerson, Frank Steven Scott. Modifications to alginate. Birmingham: University of Birmingham, 1988.
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DiGiacomo, Ellen G. Alginate impression and diagnostic study model techniques. Chicago, IL: American Dental Assistants Association, 1997.
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Philp, Kevin. The preparation and properties of novel alginate derivatives. Birmingham: University of Birmingham, 1990.
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Coppen, J. J. W. Agar and alginate production from seaweed in India. Madras: Bay of Bengal Programme, 1991.
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Hofmann, Martin John. The controlled release of drugs and dyes from alginate matrices. Birmingham: University of Birmingham, 1989.
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Smedley, Yvonne Mary. A study of the interaction between pseudomonas aeruginosa alginate and bronchial mucins. [Brighton]: Brighton Polytechnic Dept. of Pharmacy, 1986.
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Dowsett, Jill. The use of alginate gels in the isolation of insulin and other proteins. Birmingham: Universityof Birmingham, 1986.
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Matthew, Ian Richard. A histopathological study of the tissue response to an alginate wound dressing in the mouth and jaws. Birmingham: University of Birmingham, 1993.
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Ahmed, Shakeel, a cura di. Alginates. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2019. http://dx.doi.org/10.1002/9781119487999.
Testo completoCapitoli di libri sul tema "Alginate"
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Piacentini, Emma. "Alginate". In Encyclopedia of Membranes, 50–52. Berlin, Heidelberg: Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-44324-8_2018.
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Piacentini, Emma. "Alginate". In Encyclopedia of Membranes, 1–4. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-40872-4_2018-1.
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Gooch, Jan W. "Alginate". In Encyclopedic Dictionary of Polymers, 26. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_408.
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Petrash, Daniel A. "Alginate". In Encyclopedia of Astrobiology, 1–2. Berlin, Heidelberg: Springer Berlin Heidelberg, 2019. http://dx.doi.org/10.1007/978-3-642-27833-4_5391-1.
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Petrash, Daniel A. "Alginate". In Encyclopedia of Astrobiology, 83–84. Berlin, Heidelberg: Springer Berlin Heidelberg, 2023. http://dx.doi.org/10.1007/978-3-662-65093-6_5391.
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Dmour, Isra, e Mutasem Taha. "Alginate Nanoparticles". In Alginates, 389–418. Includes bibliographical references and index.: Apple Academic Press, 2019. http://dx.doi.org/10.1201/9780429023439-13.
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Li, Hao-Ying. "Alginate-Based Inhalable Particles for Controlled Pulmonary Drug Delivery". In Alginate Biomaterial, 207–40. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6937-9_9.
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Mittal, Pooja, Ramit Kapoor e Brahmeshwar Mishra. "Alginate Based Interpenetrating Polymer Network (IPN) in Drug Delivery and Biomedical Applications". In Alginate Biomaterial, 135–53. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6937-9_6.
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Vikas, Abhishesh Kumar Mehata, Chandrasekhar Singh, Ankit Kumar Malik, Aseem Setia e Madaswamy S. Muthu. "Alginate in Cancer Therapy". In Alginate Biomaterial, 267–95. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6937-9_11.
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Parmar, Gourav, Manish Kumar, Abhishek Jha e Brahmeshwar Mishra. "Alginate Based Carriers for Topical Drug Delivery". In Alginate Biomaterial, 85–107. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6937-9_4.
Testo completoAtti di convegni sul tema "Alginate"
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Suzery, Meiny, Bambang Cahyono, Widayat e Lina Apriliana. "Encapsulation of hyptolide coated alginate, chitosan, and alginate-chitosan". In VIII INTERNATIONAL ANNUAL CONFERENCE “INDUSTRIAL TECHNOLOGIES AND ENGINEERING” (ICITE 2021). AIP Publishing, 2022. http://dx.doi.org/10.1063/5.0106801.
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Yan, Jingyuan, Hemanth Gudapati, Yong Huang e Changxue Xu. "Effect of Sodium Alginate Concentration During Laser-Assisted Printing of Alginate Tubes". In ASME/ISCIE 2012 International Symposium on Flexible Automation. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/isfa2012-7253.
Testo completoAbstract (sommario):
For the free-form fabrication of various tissue constructs, three-dimensional (3D) additive printing technology has emerged as a promising approach for organ fabrication. This study aims to print a tube structure using a laser-assisted orifice-free printing technique and further investigate the effect of sodium alginate concentration on the tube wall thickness. Alginate tubes have been successfully printed. It is found that highly viscous materials can be laser printed into well-defined tube structures. A higher concentration solution such as the 8% sodium alginate solution leads to a thin wall, meaning a better resolution. Imaging analysis also illustrates that higher concentration solutions help develop smooth, slim jets upon the incidence of laser pulse.
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Bhatia, Surita R., Soumitra Choudhary e Jason Reck. "Modified Alginate for Biomedical Applications". In 2008 MRS Fall Meetin. Materials Research Society, 2008. http://dx.doi.org/10.1557/proc-1140-hh06-17-dd03-17.
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Lee, Eun Yeol, e Hee Sook Kim. "Molecular Characterization of Exolytic Alginate Lyase for Saccharification of Alginate into Unsaturated Uronic Acid". In 14th Asia Pacific Confederation of Chemical Engineering Congress. Singapore: Research Publishing Services, 2012. http://dx.doi.org/10.3850/978-981-07-1445-1_626.
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Adjuik, Toby A., Sue E. Nokes e Michael D. Montross. "Lignin-alginate-based Biopolymers for the Bioencapsulation of Rhizobium". In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/ojme7252.
Testo completoAbstract (sommario):
Cell immobilization provides a physical protection for viable Rhizobial cells in a confined carrier material allowing for the cells’ slow release into the environment. While several petroleum-based polymers have been tested for encapsulating microbes, they are often less biodegradable in the environment and may adversely affect viability of cells. One material that is biobased and has been underutilized for Rhizobium cell carriers is lignin. The present study was conducted to evaluate the feasibility of using lignin-alginate biopolymers with a starch additive to bioencapsulate and release Rhizobium cells.Rhizobium cells were bioencapsulated into the lignin-alginate starch beads and their efficiency i.e [(log of number of cells in wet beads/log of number of cells in solution matrix) x 100%] and release kinetics were determined. Light microscopy and scanning electron microscopy were also used to investigate the surface morphology of the beads. Our results show that all variations (alginate, lignin-alginate, and lignin-alginate with starch additive) of the wet bioencapsulated beads achieved a similar efficiency 97%. However, the presence of starch in the lignin-alginate beads increased the survival of Rhizobium cells after drying from 61 to 84% compared to only alginate encapsulation. These results imply that lignin, a readily available biopolymer is a potential component for the manufacture of carrier materials for encapsulating Rhizobium cells.
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Jarvis, P. M., D. A. J. Galvin, S. D. Blair e C. N. McCollum. "HOW DOES CALCIUM ALGINATE ACHIEVE HAEMOSTASIS IN SURGERY?" In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643074.
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Calcium alginate (Kaltostat, Cair Ltd) is a new absorbable material for topical haemostasis in surgery. The possible mode of action, release of calcium ions in exchange for sodium was investigated in human blood.Calcium release was measured in 15 mg samples of calcium alginate placed in 20 ml of 0.9% saline, for intervals of 1, 3 or 10 minutes. To assess the effect on platelets, 3 mg of calcium alginate or surgical gauze were added to 5 ml of Heparinised (100 units) fresh blood for 2 minutes and platelet counts then made using plain blood as a control. Finally using a thrombelastograph, the activation of whole blood coagulation was assessed after a 2 minute contact with 3 mg of calcium alginate, surgical gauze or no additive as control.When calcium alginate was placed in saline, 26% of calcium ions were released in 1 minute giving a calcium ion concentration of 4.62 t 0.02 mmol/L, with only slight further release after 10 minutes to 4.82 ± 0.004 mmol/L. There was a corresponding decrease in sodium ion concentration. Adding calcium alginate to whole blood reduced the platelet count from a control value of 248 i 16 × 109/L to 222 f 15 × 109/L (p< 0.05) compared to 241 ± 15 × 109/L for surgical gauze. Similarly calcium alginate shortened whole blood coagulation time from 17-7 i 1.0 minutes control, to 12.9 ± 1-32 mins (p< 0.001) compared to 15.0 ± 1.5 mins (p< 0.02) for surgical gauze.Calcium alginate rapidly releases calcium ions in exchange for sodium on contact with blood stimulating both platelet activation and whole blood coagulation, significantly more than simple contact activation by surgical gauze.
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Li, Xiangpeng, Jihua Gou e Olusegun J. Ilegbusi. "Synthesis-Structure-Property Relationship for Ultra-Soft Tissue-Equivalent Alginate Hydrogel". In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-70392.
Testo completoAbstract (sommario):
Abstract Alginate hydrogels have properties that are similar to extra cellular matrix (ECM). Thus, their mechanical behavior approximates soft tissue, which makes them desirable for production of tissue-equivalent soft deformable structures. This study aims to determine the synthesis-structure-property relationship for alginate hydrogel with Young’s modulus in the range of 100∼101 kPa, equivalent to that of human lung tissue. Hydrogels are hydrophilic polymers with 3D network. Homogeneous alginate hydrogels are synthesized by direct mixture of sodium alginate and CaCO3, followed by the addition of D-glucono-δ-lactone to initiate in-situ Ca2+ release and gelation. The influence of alginate concentration and molar ratio of the constituent calcium ion to carboxyl group are evaluated while the Young’s modulus of the hydrogel is carefully controlled within the desired range. Elongation testing is performed to determine the initial-stage Young’s modulus of the material. FTIR is used to characterize the influence of synthesis parameters on the chemical bonds. Empirical relations are established between synthesis parameters and the mechanical property. The result of the study will be subsequently used to guide the additive manufacturing of soft deformable structures based on alginate hydrogels.
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Qi, Yusha, Lu Lu, Changren Zhou e Binghong Luo. "Purification of Alginate for Tissue Engineering". In 2009 3rd International Conference on Bioinformatics and Biomedical Engineering (iCBBE). IEEE, 2009. http://dx.doi.org/10.1109/icbbe.2009.5163263.
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Kameniku, Jurgen, e Sujata K. Bhatia. "Characterization of compressibility in alginate microspheres". In 2014 40th Annual Northeast Bioengineering Conference (NEBEC). IEEE, 2014. http://dx.doi.org/10.1109/nebec.2014.6972831.
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Silva, Joao, Dorinda Marques-da-Silva, Vania Ribeiro e Ricardo Lagoa. "Experimental Development of Antioxidant Alginate Films". In 2019 IEEE 6th Portuguese Meeting on Bioengineering (ENBENG). IEEE, 2019. http://dx.doi.org/10.1109/enbeng.2019.8692575.
Testo completoRapporti di organizzazioni sul tema "Alginate"
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Fernando, P. U. Ashvin Iresh, Rebecca Crouch, Bobbi Stromer, Travis Thornell, Johanna Jernberg e Erik Alberts. Scaled-up synthesis of water-retaining alginate-based hydrogel. Engineer Research and Development Center (U.S.), dicembre 2023. http://dx.doi.org/10.21079/11681/48032.
Testo completoAbstract (sommario):
Synthesis of a scaled-up version of a lithium-ion-based alginate/poly(acrylamide-co-stearyl methacrylate) [Li-alginate/P(AAm-co-SMA)] hydrogel with several optimizations for thermal signature investigations on various environmental substrates.
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Yoncheva, Krassimira. Benefits and Perspectives of Nanoparticles Based on Chitosan and Sodium Alginate. "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences, marzo 2020. http://dx.doi.org/10.7546/crabs.2020.03.01.
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Gerstl, Zev, Thomas L. Potter, David Bosch, Timothy Strickland, Clint Truman, Theodore Webster, Shmuel Assouline, Baruch Rubin, Shlomo Nir e Yael Mishael. Novel Herbicide Formulations for Conservation-Tillage. United States Department of Agriculture, giugno 2009. http://dx.doi.org/10.32747/2009.7591736.bard.
Testo completoAbstract (sommario):
The overall objective of this study was to develop, optimize and evaluate novel formulations, which reduce herbicide leaching and enhance agronomic efficacy. Numerous studies have demonstrated that CsT promotes environmental quality and enhances sustainable crop production, yet continued use of CsT-practices appears threatened unless cost effective alternative weed control practices can be found. The problem is pressing in the southern portion of the Atlantic Coastal Plain region of the eastern USA where cotton and peanut are produced extensively. This research addressed needs of the region’s farmers for more effective weed control practices for CsT systems. HUJI: CRFs for sulfentrazone and metolachlor were developed and tested based on their solubilizion in cationic micelles and adsorption of the mixed micelles on montmorillonite. A better understanding of solubilizing anionic and nonionic organic molecules in cationic micelles was reached. Both CRFs demonstrated controlled release compared to the commercial formulations. A bioassay in soil columns determined that the new sulfentrazone and metolachlor CRFs significantly improve weed control and reduced leaching (for the latter) in comparison with the commercial formulations. ARO: Two types of CRFs were developed: polymer-clay beads and powdered formulations. Sand filter experiments were conducted to determine the release of the herbicide from the CRFs. The concentration of metolachlor in the initial fractions of the effluent from the commercial formulation reached rather high values, whereas from the alginate-clay formulations and some of the powdered formulations, metolachlor concentrations were low and fairly constant. The movement of metolachlor through a sandy soil from commercial and alginate-clay formulations showed that the CRFs developed significantly reduced the leaching of metolachlor in comparison to the commercial formulation. Mini-flume and simulated rainfall studies indicated that all the CRFs tested increased runoff losses and decreased the amount of metolachlor found in the leachate. ARS: Field and laboratory investigations were conducted on the environmental fate and weed control efficacy of a commercially available, and two CRFs (organo-clay and alginate-encapsulated) of the soil-residual herbicide metolachlor. The environmental fate characteristics and weed control efficacy of these products were compared in rainfall simulations, soil dissipations, greenhouse efficacy trials, and a leaching study. Comparisons were made on the basis of tillage, CsT, and conventional, i.e no surface crop residue at planting (CT). Strip-tillage (ST), a commonly used form of CsT, was practiced. The organo-clay and commercial metolachlor formulations behaved similarly in terms of wash off, runoff, soil dissipation and weed control efficacy. No advantage of the organo-clay over the commercial metolachlor was observed. Alginate encapsulated metolachlor was more promising. The dissipation rate for metolachlor when applied in the alginate formulation was 10 times slower than when the commercial product was used inferring that its use may enhance weed management in cotton and peanut fields in the region. In addition, comparison of alginate and commercial formulations showed that ST can effectively reduce the runoff threat that is commonly associated with granular herbicide application. Studies also showed that use of the alginate CRF has the potential to reduce metolachlor leaching. Overall study findings have indicated that use of granular herbicide formulations may have substantial benefit for ST-system weed management for cotton and peanut production under Atlantic Coastal Plain conditions in the southeastern USA. Commercial development and evaluation at the farm scale appears warranted. Products will likely enhance and maintain CsT use in this and other regions by improving weed control options.
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Shpigel, Muki, Allen Place, William Koven, Oded (Odi) Zmora, Sheenan Harpaz e Mordechai Harel. Development of Sodium Alginate Encapsulation of Diatom Concentrates as a Nutrient Delivery System to Enhance Growth and Survival of Post-Larvae Abalone. United States Department of Agriculture, settembre 2001. http://dx.doi.org/10.32747/2001.7586480.bard.
Testo completoAbstract (sommario):
The major bottlenecks in rearing the highly priced gastropod abalone (Haliotis spp.) are the slow growth rate and the high mortality during the first 8 to 12 weeks following metamorphosis and settling. The most likely reason flor these problems is related to nutritional deficiencies in the diatom diet on which the post larvae (PL) feed almost exclusively in captivity. Higher survival and improved growth rate will reduce the considerable expense of hatchery-nursery resisdence time and thereflore the production costs. BARD supported our research for one year only and the support was given to us in order to prove that "(1) Abalone PL feed on encapsulated diatoms, and (2) heterotrophic diatoms can be mass produced." In the course of this year we have developed a novel nutrient delivery system specifically designed to enhance growth and survival of post-larval abalone. This approach is based on the sodium-alginate encapsulation of heterotrophically grown diatoms or diatom extracts, including appetite-stimulating factors. Diatom species that attract the PL and promote the highest growth and survival have been identified. These were also tested by incorporating them (either intact cells or as cell extracts) into a sodium-alginate matrix while comparing the growth to that achieved when using diatoms (singel sp. or as a mixture). A number of potential chemoattractants to act as appetite-stimulating factors for abalone PL have been tested. Preliminary results show that the incorporation of the amino acid methionine at a level of 10-3M to the sodim alginate matrix leads to a marked enhancement of growth. The results ol these studies provided basic knowledge on the growth of abalone and showed that it is possible to obtain, on a regular basis, survival rates exceeding 10% for this stage. Prior to this study the survival rates ranged between 2-4%, less than half of the values achieved today. Several diatom species originated from the National Center for Mariculture (Nitzchia laevis, Navicula lenzi, Amphora T3, and Navicula tennerima) and Cylindrotheca fusiformis (2083, 2084, 2085, 2086 and 2087 UTEX strains, Austin TX) were tested for heterotrophic growth. Axenic colonies were initially obtained and following intensive selection cycles and mutagenesis treatments, Amphora T3, Navicula tennerima and Cylindrotheca fusiformis (2083 UTEX strain) were capable of growing under heterotrophic conditions and to sustain highly enriched mediums. A highly efficient selection procedure as well as cost effective matrix of media components were developed and optimized. Glucose was identified as the best carbon source for all diatom strains. Doubling times ranging from 20-40 h were observed, and stable heterotroph cultures at a densities range of 103-104 were achieved. Although current growth rates are not yet sufficient for full economical fermentation, we estimate that further selections and mutagenesis treatments cycles should result in much faster growing colonies suitable for a fermentor scale-up. As rightfully pointed out by one of the reviewers, "There would be no point in assessing the optimum levels of dietary inclusions into micro-capsules, if the post-larvae cannot be induced to consume those capsules in the first place." We believe that the results of the first year of research provide a foundationfor the continuation of this research following the objectives put forth in the original proposal. Future work should concentrate on the optimization of incorporation of intact cells and cell extracts of the developed heterotrophic strains in the alginate matrix, as well as improving this delivery system by including liposomes and chemoattractants to ensure food consumption and enhanced growth.
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Cerdá-Bernad, Débora, Ioanna Pitterou, Andromachi Tzani, Anastasia Detsi e María José Frutos. Novel chitosan/alginate hydrogels as carriers of phenolic-enriched extracts from saffron floral by-products using natural deep eutectic solvents as green extraction media. Peeref, giugno 2023. http://dx.doi.org/10.54985/peeref.2306p2939837.
Testo completo
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Poverenov, Elena, Tara McHugh e Victor Rodov. Waste to Worth: Active antimicrobial and health-beneficial food coating from byproducts of mushroom industry. United States Department of Agriculture, gennaio 2014. http://dx.doi.org/10.32747/2014.7600015.bard.
Testo completoAbstract (sommario):
Background. In this proposal we suggest developing a common solution for three seemingly unrelated acute problems: (1) improving sustainability of fast-growing mushroom industry producing worldwide millions of tons of underutilized leftovers; (2) alleviating the epidemic of vitamin D deficiency adversely affecting the public health in both countries and in other regions; (3) reducing spoilage of perishable fruit and vegetable products leading to food wastage. Based on our previous experience we propose utilizing appropriately processed mushroom byproducts as a source of two valuable bioactive materials: antimicrobial and wholesome polysaccharide chitosan and health-strengthening nutrient ergocalciferol⁽ᵛⁱᵗᵃᵐⁱⁿ ᴰ2⁾. ᴬᵈᵈⁱᵗⁱᵒⁿᵃˡ ᵇᵉⁿᵉᶠⁱᵗ ᵒᶠ ᵗʰᵉˢᵉ ᵐᵃᵗᵉʳⁱᵃˡˢ ⁱˢ ᵗʰᵉⁱʳ ᵒʳⁱᵍⁱⁿ ᶠʳᵒᵐ ⁿᵒⁿ⁻ᵃⁿⁱᵐᵃˡ ᶠᵒᵒᵈ⁻ᵍʳᵃᵈᵉ source. We proposed using chitosan and vitamin D as ingredients in active edible coatings on two model foods: highly perishable fresh-cut melon and less perishable health bars. Objectives and work program. The general aim of the project is improving storability, safety and health value of foods by developing and applying a novel active edible coating based on utilization of mushroom industry leftovers. The work plan includes the following tasks: (a) optimizing the UV-B treatment of mushroom leftover stalks to enrich them with vitamin D without compromising chitosan quality - Done; (b) developing effective extraction procedures to yield chitosan and vitamin D from the stalks - Done; (c) utilizing LbL approach to prepare fungal chitosan-based edible coatings with optimal properties - Done; (d) enrichment of the coating matrix with fungal vitamin D utilizing molecular encapsulation and nano-encapsulation approaches - Done, it was found that no encapsulation methods are needed to enrich chitosan matrix with vitamin D; (e) testing the performance of the coating for controlling spoilage of fresh cut melons - Done; (f) testing the performance of the coating for nutritional enhancement and quality preservation of heath bars - Done. Achievements. In this study numerous results were achieved. Mushroom waste, leftover stalks, was treated ʷⁱᵗʰ ᵁⱽ⁻ᴮ ˡⁱᵍʰᵗ ᵃⁿᵈ ᵗʳᵉᵃᵗᵐᵉⁿᵗ ⁱⁿᵈᵘᶜᵉˢ ᵃ ᵛᵉʳʸ ʰⁱᵍʰ ᵃᶜᶜᵘᵐᵘˡᵃᵗⁱᵒⁿ ᵒᶠ ᵛⁱᵗᵃᵐⁱⁿ ᴰ2, ᶠᵃʳ ᵉˣᶜᵉᵉᵈⁱⁿᵍ any other dietary vitamin D source. The straightforward vitamin D extraction procedure and ᵃ ˢⁱᵐᵖˡⁱᶠⁱᵉᵈ ᵃⁿᵃˡʸᵗⁱᶜᵃˡ ᵖʳᵒᵗᵒᶜᵒˡ ᶠᵒʳ ᵗⁱᵐᵉ⁻ᵉᶠᶠⁱᶜⁱᵉⁿᵗ ᵈᵉᵗᵉʳᵐⁱⁿᵃᵗⁱᵒⁿ ᵒᶠ ᵗʰᵉ ᵛⁱᵗᵃᵐⁱⁿ ᴰ2 ᶜᵒⁿᵗᵉⁿᵗ suitable for routine product quality control were developed. Concerning the fungal chitosan extraction, new freeze-thawing protocol was developed, tested on three different mushroom sources and compared to the classic protocol. The new protocol resulted in up to 2-fold increase in the obtained chitosan yield, up to 3-fold increase in its deacetylation degree, high whitening index and good antimicrobial activity. The fungal chitosan films enriched with Vitamin D were prepared and compared to the films based on animal origin chitosan demonstrating similar density, porosity and water vapor permeability. Layer-by-layer chitosan-alginate electrostatic deposition was used to coat fruit bars. The coatings helped to preserve the quality and increase the shelf-life of fruit bars, delaying degradation of ascorbic acid and antioxidant capacity loss as well as reducing bar softening. Microbiological analyses also showed a delay in yeast and fungal growth when compared with single layer coatings of fungal or animal chitosan or alginate. Edible coatings were also applied on fresh-cut melons and provided significant improvement of physiological quality (firmness, weight ˡᵒˢˢ⁾, ᵐⁱᶜʳᵒᵇⁱᵃˡ ˢᵃᶠᵉᵗʸ ⁽ᵇᵃᶜᵗᵉʳⁱᵃ, ᵐᵒˡᵈ, ʸᵉᵃˢᵗ⁾, ⁿᵒʳᵐᵃˡ ʳᵉˢᵖⁱʳᵃᵗⁱᵒⁿ ᵖʳᵒᶜᵉˢˢ ⁽Cᴼ2, ᴼ²⁾ ᵃⁿᵈ ᵈⁱᵈ not cause off-flavor (EtOH). It was also found that the performance of edible coating from fungal stalk leftovers does not concede to the chitosan coatings sourced from animal or good quality mushrooms. Implications. The proposal helped attaining triple benefit: valorization of mushroom industry byproducts; improving public health by fortification of food products with vitamin D from natural non-animal source; and reducing food wastage by using shelf- life-extending antimicrobial edible coatings. New observations with scientific impact were found. The program resulted in 5 research papers. Several effective and straightforward procedures that can be adopted by mushroom growers and food industries were developed. BARD Report - Project 4784
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Restrepo-Villamizar, Claudia Elena. Guía práctica para la toma de impresión en alginato. Ediciones Universidad Cooperativa de Colombia, dicembre 2019. http://dx.doi.org/10.16925/gcgp.18.
Testo completo
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Ardakani, O. H. Organic petrography and thermal maturity of the Paskapoo Formation in the Fox Creek area, west-central Alberta. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/330296.
Testo completoAbstract (sommario):
The Paskapoo Formation, which ranges in age from middle to upper Paleocene, is the major shallow aquifer in Alberta. This study is part of a larger GSC-led study on the potential environmental impact of hydrocarbon development in the Fox Creek area (west-central Alberta) on shallow aquifers. Fox Creek is located near the northern limit of the Paskapoo Formation. In addition to the underlying organic-rich source rocks in the study area, including the Duvernay Formation that is currently exploited for hydrocarbon resources, the Paskapoo Formation contains organic-rich intervals and coal seams. In order to investigate any potential internal hydrocarbon sources within the Paskapoo Formation, ninety-seven (97) cutting samples from the formation obtained from eight shallow monitoring wells (50-90 m) in the study area were studied for total organic carbon (TOC) content, organic matter composition and thermal maturity of coal seams using programmed pyrolysis analysis and organic petrography. The TOC content of all samples ranges from 0.2 to 8.8 wt. %, with a mean value of 0.95 ± 1.6 wt. % (n=97). The Tmax values of studied samples range from 347 to 463 °C, with a mean value of 434 ± 20 °C that suggest a range of thermal maturity from immature to peak oil window. The random reflectance (Rr) measurement and fluorescence microscopy on eighteen (18) selected samples with TOC content &gt; ~1 wt. % shows a mean Rr value of 0.27% and 0.42% for the overlying till deposits and the underlying shallow depth sandstone, siltstone, shale and coal seams respectively, indicating a low rank coal ranging from lignite to sub-bituminous coal. Blue to green and yellow fluorescing liptinite macerals further confirmed the low maturity of studied samples. The low S2 yield of a large part of the samples (65%) resulted in unreliable Tmax values that overestimated the thermal maturity. Although the organic matter in the studied intervals are immature, exsudatinite, as secondary liptinite maceral, was observed in samples from the lower parts of the studied monitoring wells. Exsudatinite generally derives from the transformation of sporinite, alginite, resinite and varieties of vitrinite, which is a resinous or asphalt like material. Considering the thickness and distribution of coal seams in the studied samples, it is unlikely the exsudatinite will be a major source for aquifer hydrocarbon contamination in the study area. Additional stratigraphic studies and molecular geochemical analysis could provide an estimate of the total volume of possible organic compounds contribution to the aquifer in the study area. Due to the presence of coal seams in the studied intervals of the Paskapoo Formation, it is important to investigate the possibility of biogenic methane formation in Paskapoo shallow aquifers.