Academic literature on the topic 'Chitosan, hydroxyapatite, nanoparticles, composites'
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Journal articles on the topic "Chitosan, hydroxyapatite, nanoparticles, composites"
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Ai, Jafar, Mostafa Rezaei-Tavirani, Esmaeil Biazar, Saeed Heidari K, and Rahim Jahandideh. "Mechanical Properties of Chitosan-Starch Composite Filled Hydroxyapatite Micro- and Nanopowders." Journal of Nanomaterials 2011 (2011): 1–5. http://dx.doi.org/10.1155/2011/391596.
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Hydroxyapatite is a biocompatible ceramic and reinforcing material for bone implantations. In this study, Starch-chitosan hydrogel was produced using the oxidation of starch solution and subsequently cross-linked with chitosan via reductive alkylation method (weight ratio (starch/chitosan): 0.38). The hydroxyapatite micropowders and nanopowders synthesized by sol-gel method (10, 20, 30, 40 %W) were composited to hydrogels and were investigated by mechanical analysis. The results of SEM images and Zetasizer experiments for synthesized nanopowders showed an average size of 100 nm. The nanoparticles distributed as uniform in the chitosan-starch film. The tensile modulus increased for composites containing hydroxyapatite nano-(size particle: 100 nanometer) powders than composites containing micro-(size particle: 100 micrometer) powders. The swelling percentage decreased for samples containing hydroxyapatite nanopowder than the micropowders. These nanocomposites could be applied for hard-tissue engineering.
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Li, Ying Hua, Li Yun Cao, Jian Feng Huang, and Xie Rong Zeng. "Preparation of Hydroxyapatite/Chitosan Biological Coatings on Carbon/Carbon Composites." Key Engineering Materials 434-435 (March 2010): 502–5. http://dx.doi.org/10.4028/www.scientific.net/kem.434-435.502.
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Hydroxyapatite/Chitosan (HAp/CS) bio-coatings were prepared on the surface of carbon/ carbon (C/C) composites by hydrothermal electrophoretic deposition, using sonochemical process resulted HAp nanoparticles, isopropyl alcohol and chitosan as raw materials. The influences of hydro- thermal conditions and deposition voltage on the microstructures and morphologies of the as-prepared coatings were investigated. It was shown that homogenous and dense HAp/CS coatings on C/C composites are obtained by hydrothermal electrophoretic deposition. With the increase of deposition voltage, density and homogeneity of the as-prepared HAp/CS composite coatings are well improved. Due to the growth of HAp nanoparticles in the hydrothermal condition, the subsequent heat treatment of the HAp/CS coatings is not needed.
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Boudemagh, Djalila, Pierre Venturini, Solenne Fleutot, and Franck Cleymand. "Elaboration of hydroxyapatite nanoparticles and chitosan/hydroxyapatite composites: a present status." Polymer Bulletin 76, no. 5 (August 22, 2018): 2621–53. http://dx.doi.org/10.1007/s00289-018-2483-y.
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Huang, Zhipeng, Haoyuan Sun, Yang Lu, Fengnian Zhao, Chang Liu, Qinglong Wang, Changming Zheng, Renpei Lu, and Keguan Song. "Strontium/Chitosan/Hydroxyapatite/Norcantharidin Composite That Inhibits Osteosarcoma and Promotes Osteogenesis In Vitro." BioMed Research International 2020 (January 31, 2020): 1–9. http://dx.doi.org/10.1155/2020/9825073.
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Hydroxyapatite can deliver drugs, and its composite material is capable of repairing bone defects in tumors. This study was conducted to evaluate the effect of composite materials on tumor growth inhibition and bone growth induction. Composites containing drug delivery compounds were synthesized by coprecipitation and freeze-drying and then characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). In addition, the effect of hydroxyapatite nanoparticles (nano-SHAP) on proliferation of an osteosarcoma cell line (MG-63) and an osteoblast cell line (MC3T3-E1) was evaluated, and its mechanism was studied. The use of nano-SHAP alone did not affect the proliferation of normal cell lines. However, nanoparticles containing different amounts of norcantharidin in the composite materials and had different inhibitory effects on osteosarcoma and different effects on osteoblasts. And, with the increase of the content of norcantharidin, the antitumor performance of the composite has been enhanced. In summary, the nano-SHAP system developed in this study is a drug delivery material that can inhibit the growth of tumors and induce the proliferation of osteoblasts.
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Lakrat, Mohammed, Soufiane Fadlaoui, Mohamed Aaddouz, Ouahid El Asri, Mohammed Melhaoui, and Mejdoubi El Miloud. "SYNTHESIS AND CHARACTERIZATION OF COMPOSITES BASED ON HYDROXYAPATITE NANOPARTICLES AND CHITOSAN EXTRACTED FROM SHELLS OF THE FRESHWATER CRAB Potamon algeriense." Progress on Chemistry and Application of Chitin and its Derivatives XXV (September 30, 2020): 132–42. http://dx.doi.org/10.15259/pcacd.25.010.
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Nanocrystalline hydroxyapatite (n-HAp), which has low crystallinity, has attracted great attention due to its similarity to the inorganic part of human bone. Therefore, many studies have focused on creating new formulations combining n-HAp with some biopolymers, such as chitosan, in order to imitate biological bone tissue. The importance of chitosan and its derivatives in biomedical applications has grown significantly in the last three decades due to its biodegradability and renewable source. Besides, chitosan and its derivatives present excellent biocompatibility and biofunctionality, which make them promising materials in bone tissue engineering. In the present study, the chitosan was, first, extracted from the shell of the freshwater crab species Potamon algeriense following demineralization, deproteinization, decolouration (raw chitin) and deacetylation (chitosan) steps. Then, a novel composite based on n-HAp and extracted chitosan (CTS) with varying chitosan contents, from 5% to 20% (w/w), was synthesized and characterized for potential application in tissue regeneration. The obtained composites were characterized using X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. The precipitated n-HAp/CTS nanocomposites similar to natural bone are promising composites for bone tissue engineering applications.
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Sun, Tao, Tareef Hayat Khan, and Naznin Sultana. "Fabrication andIn VitroEvaluation of Nanosized Hydroxyapatite/Chitosan-Based Tissue Engineering Scaffolds." Journal of Nanomaterials 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/194680.
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Composite scaffolds based on biodegradable natural polymer and osteoconductive hydroxyapatite (HA) nanoparticles can be promising for a variety of tissue engineering (TE) applications. This study addressed the fabrication of three-dimensional (3D) porous composite scaffolds composed of HA and chitosan fabricated via thermally induced phase separation and freeze-drying technique. The scaffolds produced were subsequently characterized in terms of microstructure, porosity, and mechanical property.In vitrodegradation andin vitrobiological evaluation were also investigated. The scaffolds were highly porous and had interconnected pore structures. The pore sizes ranged from several microns to a few hundred microns. The incorporated HA nanoparticles were well mixed and physically coexisted with chitosan in composite scaffold structures. The addition of 10% (w/w) HA nanoparticles to chitosan enhanced the compressive mechanical properties of composite scaffold compared to pure chitosan scaffold.In vitrodegradation results in phosphate buffered saline (PBS) showed slower uptake properties of composite scaffolds. Moreover, the scaffolds showed positive response to mouse fibroblast L929 cells attachment. Overall, the findings suggest that HA/chitosan composite scaffolds could be suitable for TE applications.
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Anjaneyulu, U., B. Priyadarshini, and U. Vijayalakshmi. "Preparation of Ag Doped Hydroxyapatite- Fe3O4-Chitosan Composites: In Vitro Biocompatibility Study on MG-63 Cells for Orthopedic Applications." Advanced Science Letters 24, no. 8 (August 1, 2018): 5901–6. http://dx.doi.org/10.1166/asl.2018.12217.
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Present paper deals with the development of hybrid nanocomposites which combination of Ag doped Hydroxyapatite (Ag:HAP)-Magnetite nanoparticles (Fe3O4NPs) and Chitosan. In this present investigation, we have employed sol–gel method to synthesize Ag:HAP using 5% of Ag concentrations. Furthermore, co-precipitation technique was employed to prepare Fe3O4 NPs and Ag doped HAP was mixed with it to develop hybrid composites. The planetary ball milling technique was used to incorporate the fabricated Ag:HAP-Fe3O4 composite material into the biopolymer chitosan at wt% of 50:25:25 respectively. In Vitro biocompatibility of Ag:HAP-Fe3O4 CS hybrid composites were evaluated by MTT assay using MG-63 cell lines for 24–48 h at 200–1000 μg/ml concentrations. Further, these hybrid composites were characterized by using ATR-FTIR, XRD and SEM techniques. The fabricated hybrid composite was found to be biologically compatible with MG-63 osteoblast cell lines to use in biomedical applications.
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Vissarionov, Sergey V., Marat S. Asadulaev, Anton S. Shabunin, Vladimir E. Yudin, Moisei B. Paneiakh, Pavel V. Popryadukhin, Yury A. Novosad, Vasili A. Gordienko, and Aleksandr G. Aganesov. "Experimental evaluation of the efficiency of chitosan matrixes under conditions of modeling of bone defect in vivo (preliminary message)." Pediatric Traumatology, Orthopaedics and Reconstructive Surgery 8, no. 1 (April 6, 2020): 53–62. http://dx.doi.org/10.17816/ptors16480.
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Background. Despite the wide range of studies, the development of osteoplastic material, which has not only osteoconductive but also osteoinductive properties, remains an extremely topical issue in modern medical materials science. This work is devoted to experimental evaluation of the effectiveness of synthetic osteoplastic composite material based on chitosan and hydroxyapatite.
Aim. This study aimed to determine the effects of spongy implants based on chitosan and its composite with hydroxyapatite nanoparticles in an amount of 50 wt. % on early osteogenesis in the area of the through defect of the ileum.
Materials and methods. The studied materials were sponge implants based on chitosan and its composite with hydroxyapatite nanoparticles in an amount of 50 wt. %. Comparison groups include those without implant placement and those with replacement with commercial Reprobone osteoplastic material. Materials were implanted into the zone of the through defect of the ileum of rabbits for a period of 28 days.
Results. A high rate of resorption of materials based on chitosan in bone tissue and active growth of reticulofibrotic bone tissue along the edges of the defect was established, and the formation of cartilaginous islands and bone marrow was recorded in the group of chitosan implants with hydroxyapatite. The aseptic effect was observed with the use of implants made of chitosan and hydroxyapatite.
Conclusions. The data obtained allow us to argue about the osteoconductivity of the studied materials and the prospects for further development in this direction.
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Fekry, Amany M. "Electrochemical behavior of a novel nano-composite coat on Ti alloy in phosphate buffer solution for biomedical applications." RSC Advances 6, no. 24 (2016): 20276–85. http://dx.doi.org/10.1039/c6ra01064d.
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A novel nano-composite film coat of organic/inorganic composition including chitosan (CS), TiO2 nanoparticles (TO) and hydroxyapatite (HA) nanoparticles, was synthesized on a Ti–6Al–4V alloy surface.
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Elhendawi, Habiba, R. M. Felfel, Bothaina M. Abd El-Hady, and Fikry M. Reicha. "Effect of Synthesis Temperature on the Crystallization and Growth of In Situ Prepared Nanohydroxyapatite in Chitosan Matrix." ISRN Biomaterials 2014 (February 24, 2014): 1–8. http://dx.doi.org/10.1155/2014/897468.
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Hydroxyapatite nanoparticles (nHA) have been used in different biomedical applications where certain particle size distribution and morphology are required. Chitosan/hydroxyapatite (CS/HA) nanocomposites were prepared using in situ coprecipitation technique and the effect of the reaction temperature on the crystallization and particle growth of the prepared nanohydroxyapatite particles was investigated. The composites were prepared at different synthesis temperatures (−10, 37, and 60°C). XRD, FTIR, thermal analysis, TEM and SEM techniques were used to characterize the prepared specimens. It was found that the increase in processing temperature had a great affect on particle size and crystal structure of nHA. The low temperature (−10°C) showed inhabitation of the HA growth in c-direction and low crystallinity which was confirmed using XRD and electron diffraction pattern of TEM. Molar ratio of the bone-like apatite layer (Ca/P) for the nanocomposite prepared at 60°C was higher was higher than the composites prepared at lower temperatures (37 and −10°C).
Dissertations / Theses on the topic "Chitosan, hydroxyapatite, nanoparticles, composites"
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Rusu, Viorel Marin. "Composite materials made of chitosan and nanosized apatite : preparation and physicochemical characterization." Phd thesis, Universität Potsdam, 2004. http://opus.kobv.de/ubp/volltexte/2005/231/.
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Taking inspiration from nature, where composite materials made of a polymer matrix and inorganic fillers are often found, e.g. bone, shell of crustaceans, shell of eggs, etc., the feasibility on making composite materials containing chitosan and nanosized hydroxyapatite were investigated. A new preparation approach based on a co-precipitation method has been developed. In its earlier stage of formation, the composite occurs as hydrogel as suspended in aqueous alkaline solution. In order to get solid composites various drying procedures including freeze-drying technique, air-drying at room temperature and at moderate temperatures, between 50oC and 100oC were used. Physicochemical studies showed that the composites exhibit different properties with respect to their structure and composition. IR and Raman spectroscopy probed the presence of both chitosan and hydroxyapatite in the composites. Hydroxyapatite as dispersed in the chitosan matrix was found to be in the nanosize range (15-50 nm) and occurs in a bimodal distribution with respect to its crystallite length. Two types of distribution domains of hydroxyapatite crystallites in the composite matrix such as cluster-like (200-400 nm) and scattered-like domains were identified by the transmission electron microscopy (TEM), X-ray diffraction (XRD) and by confocal scanning laser microscopy (CSLM) measurements. Relaxation NMR experiments on composite hydrogels showed the presence of two types of water sites in their gel networks, such as free and bound water. Mechanical tests showed that the mechanical properties of composites are one order of magnitude less than those of compact bone but comparable to those of porous bone. The enzymatic degradation rates of composites showed slow degradation processes. The yields of degradation were estimated to be less than 10% by loss of mass, after incubation with lysozyme, for a period of 50 days. Since the composite materials were found biocompatible by the in vivo tests, the simple mode of their fabrication and their properties recommend them as potential candidates for the non-load bearing bone substitute materials.Inspiriert von Natur, bei der Kompositmaterialien aus Polymermatrices und anorganischen Füllstoffen z.B. in Knochen, Krustentieren und Eierschalen vorzufinden sind, wurde die Herstellungsmöglichkeit von Kompositmaterial aus Chitosan und Hydroxyapatitdispersionen untersucht. Basierend auf einem Kopräzipitationsverfahren wurde eine neue Herstellungsmethode entwickelt, die als flexibler Zugang zu einem Spektrum von Komposittypen führt. In den frühen Phasen der Kompositbildung entsteht ein in der wässrigen alkalischen Lösung suspendiertes Hydrogel, das durch Filtration und Zentrifugation isoliert werden kann. IR und Ramanspektroskopie klären das Vorhandensein von Chitosan und Hydroxyapatit im Kompositmaterial. Hydroxyapatit ist als Nanopartikel der Größe von 15-50 nm in bimodaler Verteilung in der Chitosanmatrix dispersiert, und in durch Transmissionselektronenmikroskopie (TEM), X-Ray Diffraction (XRD) und Konfokaler Laserscanmikroskopie (CSLM) nachweisbaren 200-400 nm großen Clustern assembliert. NMR-Relaxationsmessungen an Hydrogelkompositmaterial decken die Existenz zweier Klassen vorkommenden Wassers im Netzwerk auf, gebundenes und freies Wasser. Mechanische Tests zeigen, dass die mechanische Festigkeit etwa eine Größenordnung unter der von massivem Knochen liegt, der Festigkeit von porösem Knochen aber gleichkommt. Enzymatische Abbauraten des Kompostimaterials sind als langsam einzuschätzen. Eine 50-tägige Einwirkzeit von Lysozym führte zu einem Abbau von 10 % der Kompositmasse. Die sich durch in vivo Tests herausstellende Biokompatibilität, die einfachen Herstellungsmöglichkeiten und die physikochemischen Eigenschaften empfehlen dieses Material als vielversprechenden Kandidaten für Knochenersatzmaterial in mäßig belasteten Bereichen.
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Boulila, Salha. "Comportement "in vitro" et "in vivo" de verres composites poreux : assimilation osseuse, explorations physiologiques et physico-chimiques." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S105/document.
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L'application des biomatériaux est de plus en plus élargie. Le progrès médical suggère l'utilisation des biomatériaux (verres bioactifs, apatites,..) en tant qu'implants selon le besoin de l'organisme. L'objectif de notre travail est de mettre en évidence l'influence biologique des molécules organiques (bisphosphonates, biopolymères et antibiotiques) incorporés dans des matrices de verres bioactifs. De même, notre étude vise à optimiser les meilleures techniques de synthèse et d'association des verres bioactifs à ces molécules. La détoxification des rats mâles de souche « Wistar » exposés au chlorure de nickel par une apatite synthétique a aussi fait l'objet de ce travail. Suite à une perte osseuse provoquée, nous avons démontré que l'utilisation des antibiotiques associés à des verres bioactifs en tant qu'implants osseux, chez des rattes ovariectomisées, permet d'éliminer certains effets indésirables par voie systémique. Ceci a été mis en évidence par l'évaluation des paramètres biochimiques et histologiques du foie et du rein. Aucune variation significative en comparaison avec ceux du témoin négatif n'a été révélée. L'étude in vitro a montré d'une part que l'introduction du Chitosan et surtout de l'antibiotique dans la matrice vitreuse font augmenter l'activité antibactérienne in vitro. Cette étude in vitro a montré d'autre part que la Ciprofloxacine induit un effet néfaste sur les cellules ostéoblastiques et endothéliales. Cet effet est local lorsqu'il s'agit des expérimentations in vivo. Ceci est mis en évidence lors des évaluations du statut oxydant. Les marqueurs du remodelage osseux, l'histologie de l'os et les paramètres physico-chimiques montrent l'effet retardateur de cet antibiotique sur la dissolution de l'implant et par conséquent sur son ossification. La synthèse par le procédé de sol-gel provoque une bioactivité plus importante que celle obtenue par fusion. La bioactivité des verres bioactifs étudiés diffère selon la molécule introduite. Celle-ci est réduite dans le cas de l'association du Clodronate et de Ciprofloxacine in vitro et in vivo. Alors que, le Polyvinyl Alcohol et surtout le Chitosan font modifier la cinétique de cette bioactivité in vivo. Concernant l'hydroxyapatite, nous avons essayé d'explorer son effet détoxifiant chez des rats reçevant le chlorure de nickel. Nos résultats ont montré que le nickel induit un stress oxydant au niveau du foie, du rein, de la rate et du culot érythrocytaire. Des troubles physiologiques ont été observés chez les rats exposés au nickel. Cependant, l'implantation de l'hydroxyapatite protège les rats intoxiqués par le nickel contre ses effets toxiques en diminuant l'état du stress. Le biomatériau utilisé s'avère efficace pour corriger l'équilibre ferrique et phosphocalcique, protéger les fonctions rénale et hépatique, abaisser le taux du nickel osseux et corriger l'anémieThe application of biomaterials is increasingly widened. Medical progress suggest the use of biomaterials (bioactive glasses, apatites,..) as implants according to the need of the body. The aim of our work is to highlight the biological influence of organic molecules (bisphosphonates, biopolymers and antibiotics) incorporated into matrix of bioactive glasses. Similarly, our study aims to optimize the best synthesis and combination technique of bioactive glasses to these molecules. The detoxification of male rats strain "Wistar" exposed to nickel chloride by a synthetic apatite also has been the object of this work. Following the bone loss induced, we have demonstrated that the use of antibiotics associated with bioactive glass as bone implants, in ovariectomised rats, eliminates some adverse effects systemic. This has been highlighted by the evaluation of biochemical and histological parameters of liver and kidney. Any significant changes in comparison with those of the negative control was revealed. The in vitro study showed in the one hand that the introduction of Chitosan and especially of the antibiotic in the glass matrix can increase antibacterial activity. This in vitro study showed in the other hand that the Ciprofloxacin induces a negative effect on osteoblastic and endothelial cells. This effect is local when it has been an in vivo experiments. This is highlighted by the oxidative status evaluation. Markers of bone turnover, bone histology and physicochemical parameters show the retarding effect of this antibiotic on the dissolution of the implant and consequently on its bone formation. Synthesis by sol-gel method causes a more important bioactivity than melting. The bioactivity of elaborated bioactives glasses will differ depending on the molecule introduced. It is reduced in the case of combination of Clodronate and Ciprofloxacin in vitro and in vivo. While, Polyvinyl Alcohol and especially Chitosan modify the kinetic of the bioactivity in vivo. Concerning the hydroxyapatite, we tried to explore its detoxifying effect in rats receiving nickel chloride. Our results showed that nickel induces an oxidative stress in the liver, kidney, spleen and red cell pellet. Physiological disorders were observed in rats exposed to nickel. However, implantation of hydroxyapatite protects rats intoxicated by nickel against its toxic effects by decreasing the stress status. The used biomaterial is effective to correct ferric phosphate balance, protect kidney and liver function, reduce level of bone nickel and correct anemia
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De, Araújo Júnior José Vitor. "Chitosan/carrageenan-based polyelectrolyte complexes and their composites with calcium phosphate for bone tissue engineering." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608264.
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Upadhyay, Prabhat Kumar. "Design, Synthesis, and Characterization of Aqueous Polymeric Hybrid Composites and Nanomaterials of Platinum(II) and Gold(I) Phosphorescent Complexes for Sensing and Biomedical Applications." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc822788/.
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The two major topics studied in this dissertation are the gold(I) pyrazolate trimer {[Au(3-R,5-R’)Pz]3} complexes in aqueous chitosan polymer and phosphorescent polymeric nanoparticles based on platinum(II) based complex. The first topic is the synthesis, characterization and optical sensing application of gold(I) pyrazolate trimer complexes within aqueous chitosan polymer. A gold(I) pyrazolate trimer complex, {[Au(3-CH3,5-COOH)Pz]3}, shows high sensitivity and selectivity for silver ions in aqueous media, is discussed for optical sensing and solution-processed organic light emitting diodes (OLEDs) applications. Gold(I) pyrazolate trimer complexes are bright red emissive in polymeric solution and their emission color changes with respect to heavy metal ions, pH and dissolved carbon dioxide. These photophysical properties are very useful for designing the optical sensors. The phosphorescent polymeric nanoparticles are prepared with Pt-POP complex and polyacrylonitrile polymer. These particles show excellent photophysical properties and stable up to >3 years at room temperature. Such nanomaterials have potential applications in biomedical and polymeric OLEDs. The phosphorescent hybrid composites are also prepared with Pt-POP and biocompatible polymers, such as chitosan, poly-l-lysine, BSA, pnipam, and pdadmac. Photoluminescent enhancement of Pt-POP with such polymers is also involved in this study. These hybrid composites are promising materials for biomedical applications such as protein labeling and bioimaging.
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Hijazi, Nibal. "Développement de composites nanostructurés à base de biopolyesters et de nanoparticules de chitosane générées par des procédés assistés par CO2 supercritique." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2014. http://www.theses.fr/2014EMAC0016/document.
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Dans une logique d’éco-conception et de développement durable, de nombreux travaux ont pour objectif l’étude de polymères biosourcés. Parmi les recherches menées à ce jour, une piste d’étude consiste à les structurer aux échelles micro et nanoscopiques tout en valorisant certaines de leurs propriétés spécifiques, l’objectif étant la création de matériaux à propriétés fonctionnelles originales et performantes. Dans ce contexte, une attention particulière a été portée sur l’utilisation du dioxyde de carbone supercritique (CO2-sc). En effet, sa capacité à se solubiliser en grande quantité dans de nombreux polymères et donc d’en modifier les propriétés (viscosité, tension interfaciale, …) peut permettre une amélioration des matériaux composites fabriqués. Ce projet s’intéresse plus particulièrement à l’élaboration d’assemblages de biopolymères nanostructurés et revêt deux enjeux principaux : (1) la synthèse de nanoparticules de biopolymères (dans notre cas, du chitosane), (2) l’élaboration d’assemblages de biopolymères nanostructurés. La première étape a consisté à concevoir et développer de nouveaux procédés de génération de nanoparticules de chitosane par des procédés utilisant le CO2-sc soit comme antisolvant soit comme agent de dissolution et d'atomisation. Pour la deuxième étape, des films composites à base de poly (acide lactique) PLA et de poly (hydroxybutyrate-co-valérate) PHBV ont été préparés par la voie hot-melt par extrusion bi-vis. Des analyses thermiques, moléculaires et structurales, morphologiques et de granulométrie ont permis de caractériser les films biocomposites ainsi produitsIn a logic of eco-design and sustainable development, many works aim to study the bio-sourced polymers. Among these studies, a promising concept consists in structuring materials at micro and nanoscales while enhancing some of their properties, the objective being the creation of original materials with improved functional properties and performance. In this context, particular attention has been paid to the use of supercritical carbon dioxide (sc-CO2). Its ability to dissolve into many polymers in large quantities and thus to change their properties (viscosity, interfacial tension, ...), can improve both the composite material and its manufacturing process. This project focuses on the development of nanostructured biopolymers and addresses two main issues: (1) the synthesis of biopolymer nanoparticles (in this case, chitosan), and (2) the development of nanostructured biopolymers. The first step consisted in designing and developing new processing methods to generate biopolymer nanoparticles, using sc-CO2 as antisolvent agent or as dissolving and atomizing agent. For the second step, poly (lactic acid) PLA and poly (hydroxybutyric-co-hydroxyvaleric acid) PHBV based composite films were prepared by a hot-melt process by twin-screw extrusion of the nanoparticles and the matrix. Thermal, molecular and structural analysis, as well as morphological and particle size distribution studies allowed a good characterization of the biocomposite films
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Roux, Rémi. "Élaboration d'assemblages colloïdaux à partir de nanoparticules de poly(acide lactique) et de chitosane." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10088/document.
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Les assemblages colloïdaux représentent une nouvelle piste très prometteuse dans le domaine de l'ingénierie tissulaire. Idéalement, ce type d'assemblage permet l'obtention de matériaux injectables et gélifiants sur le site lésionnel, favorisant par la suite le développement de néo-tissus viables. Ce travail porte sur la formation de tels assemblages à base de chitosane et de poly(acide lactique) (PLA). Deux types d'assemblages ont été conçus et étudiés dans ce travail. Dans une première approche, le mélange de particules anioniques de poly (acide lactique) (PLA) avec du chitosane en solution faiblement acide conduit à la formation de « gels composites », résultant des interactions colloïde-polymère. Des analyses rhéologiques et de diffusion des rayons X aux petits angles ont permit de mettre en évidence le mode de formation et l'influence de plusieurs paramètres sur les propriétés finales de ces gels. Notamment, ils présentent des propriétés rhéofluidifiantes et un caractère réversible, c'est-à-dire que le gel peut se reformer après déstructuration mécanique. Le second type d'assemblage résulte du mélange de particules anioniques de PLA et de nanogels cationiques de chitosane, conduisant à la formation de « gels colloïdaux », par interactions colloïde-colloïde. L'influence de plusieurs facteurs sur la formation et les propriétés de ces gels a également été étudiée par mesures rhéologiques. Notre étude s'est notamment orientée sur la caractérisation et la stabilité des hydrogels physiques de chitosane sous forme colloïdale, ainsi que sur l'optimisation de leur cohésionColloidal assemblies may be a promising pathway to obtain injectable scaffolds favoring the development of neo-tissue in regenerative medicine. This work investigates the formation of such assemblies composed of chitosan, soluble or in suspension (nano-hydrogel), and poly(lactic acid) (PLA) nanoparticles. Two types of assemblies are studied. As a first approach, mixing negatively charged PLA particles and chitosan solution leads to the formation of “composite gels”, based on colloidpolymer interactions. Rheological and Small Angle X-Ray Scattering measurements highlighted the formation process and the influence of various parameters on final properties of these gels, which features shear-thinning and reversibility behavior, that is, the capacity to gel again after yielding. PLA nanoparticles could also be mixed with cationic chitosan nanoparticles, which are crosslinker free nano-hydrogels, leading to the formation of “colloidal gels”, based on colloid-colloid interactions. Influence of various parameters on gel synthesis and properties are investigated through rheological measurements. The study also focuses on the characterization and control of the morphological and cohesion properties of chitosan nanogel
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Hsu, You-ning, and 許祐寧. "Preparation and Characterization of Acrylic Bone Cement Modified by Chitosan/ Hydroxyapatite Composites." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/50558688492797054402.
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碩士國立雲林科技大學
化學工程與材料工程系碩士班
100
In this study, we used hydroxylapatite (HA), which possesses bioactivity, and chitosan (CS), which is biopolymer, to modify acrylic bone cement. Chitosan/hydroxylapatite composites were first fabricated by co-precipitation method and characterized using thermogravimetric analyzer, Scanning Electron Microscope, X-ray diffractometer, and Energy Dispersive Spectrometer. The ratio of Ca/P in hydroxylapatite which we prepared was 1.67. We investigated the properties of the acrylic bone cement modified by 10 wt. % of chitosan/hydroxyapatite composites. Several bone cement systems were prepared: (1) Cement HA100 (only 10 wt. % of HA), (2) Cement CH2080 (10 wt. % of CS/HA composite at wt. ratio of 20/80), (3) Cement CH5050 (10 wt. % of CS/HA composite at wt. ratio of 50/50), and (4) Cement CH8020 (10 wt. % of CS/HA composite at wt. ratio of 80/20). The results show that (1) the temperature elevation caused by bone cement polymerization decreases with the increase of chitosan/hydroxyapatite composites, (2) the water adsorption of the modified bone cements is higher than that of the conventional bone cement, (3) the roughness of the modified bone cements increases with the increase of CS, (4) the addition of HA in bone cement reduces the compressive strength of the modified bone cements, while the addition of CS in bone cement can sustain the compressive strength of the modified bone cements, (5) Cement HA100 and Cement CH5050 have higher release behavior of calcium ions, and (6) the bioactivity of acrylic bone cement modified by chitosan/ hydroxyapatite composites is improved. In addition, the modified bone cement provides the property of bacteriostasis.
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Cheng, Yu-Mei, and 程鈺媚. "Electrolytic deposition of doxorubicin-chitosan composites on post hydroxyapatite coated titanium alloy." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/25787065489442915839.
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碩士國立中興大學
材料科學與工程學系所
104
Cancer is one of the four major non-communicable diseases. In order to reduce the side effects caused by chemotherapy, various target treatments and drug-delivery system have being studied. In this study, the doxorubicin-chitosan composite is deposited on the post hydroxyapatite Ti alloy applied to vascular stents for the tumor treatment by sustaining release of drug at local location to achieve the inhibition of cancer or apoptosis of cancer. In the experiment, cathodic polarization tests coupled with electrochemical reactions were analyzed to speculate the deposition mechanism of doxorubicin, spectrophotometer (UV visible spectrometer) to measure doxorubicin loading and release, field emission scanning electron microscope (FESEM) to observe surface morphology, Fourier transform infrared spectroscopy (FTIR) for chemical bonding of composites, and X-ray diffractometry (XRD) for crystal structure. The MTT Assay was carried out to analyze cell viability for drug efficacy. It is concluded that doxorubicin-chitosan composites can be successfully deposited on the titanium alloy by electrochemical method and the post hydroxyapatite coated specimen with high porosity can enhance the drug loading to 66 μg /cm2 and reveal the complete drug release. Besides, the electrochemical deposition does not vary any chemical bonding or destroy any medical function of doxorubicin, revealing a practical method for drug loading.
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Li, Jo-Hao, and 李若豪. "The physical properties and drug permeation of nanosize Calcium-deficient Hydroxyapatite/Chitosan composites." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/vjcgw2.
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Mahanta, Debajyoti. "Synthesis And Environmental Applications Of Polyaniline And Its Nanocomposites." Thesis, 2011. http://etd.iisc.ernet.in/handle/2005/2410.
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The present thesis is focused on the synthesis and environmental applications of polyaniline and its nanocomposites. It is organized in six chapters and brief discussions of the contents of the individual chapters are given below. Chapter 1 reviews two important water purification methods: adsorption and photocatalysis, which are widely discussed in literature. A general introduction to conducting polymers has been given and their photocatalytic activity has been described. Chapter 2 reports the application of polyaniline emeraldine salt for the removal of anionic dyes from aqueous solutions by adsorption. A possible mechanism for the anionic dye adsorption by PANI emeraldine salt has been proposed. The electrostatic interaction between the positively charged PANI backbone and dye anions is responsible for significant dye adsorption. The kinetic parameters for the adsorption of anionic dyes on PANI have also been determined. In Chapter 3, we investigate the adsorption and desorption of anionic dyes from aqueous solution by PANI doped with different protonic acids. PANI with three dopants, namely p-toluene sulfonic acid (PTSA), camphor sulfonic acid (CSA) and dodecyl benzene sulfonic acid (DBSA) were used to adsorb various dyes. The adsorbed dyes were desorbed from the polymer by using a basic aqueous solution. It was found that the adsorption of dye is dependent on the size and nature of the dopant acids. The influence of different dopants on the adsorption and desorption kinetic parameters was also examined. In chapter 4, the inherent property of PANI to adsorb dyes has been explored for the detection of dyes by electrochemical method. The changes in the CV of PANI film coated on Pt electrodes on addition of dye have been employed for detection of dye in aqueous solution. Furthermore, PANI coated stainless steel (SS) electrodes show a change in current intensity of Fe2+/Fe3+ redox peaks due to addition of dye in the electrolyte solution. Chapter 5 describes the synthesis and characterization of polyaniline-grafted-chitosan (CPANI) with different grafting ratios. The mechanical properties and the crystallinity of CPANI were investigated by means of nanoindentation and X-ray diffraction experiments, respectively. CPANI has been further self-assembled into multilayer thin film via versatile and simple layer-by-layer (LbL) approach. Negatively charged hyaluronic acid (HUA) was used as complementary polyelectrolyte for the self-assembly. LbL growth of the multilayer thin films has been monitored with UV-vis spectral analysis as well as by AFM. The formation of thin film has been further characterized by SEM. The pH responsive behavior of CPANI/HUA multilayer thin film has been investigated. Reusability of this thin film has been investigated by repeating the pH responsive experiments for 10 cycles. Chapter 6 is focused on the preparation of nanocomposite thin films of CPANI/PSS/TiO2 via LbL approach. LbL growth of this self-assembly was monitored by UV-vis spectral analysis and porous nature was observed from SEM images. Poly (styrene sulfonate) (PSS) was used as bridging layer between TiO2 nanoparticles and CPANI for the multilayer self-assembly. Incorporation of CPANI within this LbL self-assembly enhanced the dye degradation ability of the thin film by increasing the availability of dye molecules around the TiO2 nanoparticles. Furthermore, CPANI may act as a sensitizer to enhance the photocatalytic activity of TiO2. The effects of surface area of the multilayer thin film and amount of catalysts (TiO2 nanoparticles) incorporated in the self-assembly were described based on the kinetics of the dye degradation reactions. The same multilayer thin film can be efficiently used for dye degradation several times. The work presented in this thesis utilizes unique dye adsorption properties of PANI and its copolymers. The change in conductivity of PANI after dye adsorption and the electrochemical dye detection in aqueous medium promise the potential of PANI as a dye sensing material in waste water at very low concentration. The nanocomposites of CPANI/PSS/TiO2 present a novel material for photocatalysis.
Book chapters on the topic "Chitosan, hydroxyapatite, nanoparticles, composites"
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Salar Hosseini, Fatemeh, Navid Ramezanian, and Zoheir Shokouh Saljoghi. "Synthesis of Chitosan/Zeolite/Silver Nanoparticles Composites: Antibacterial Activity Against Aquatic Bacteria." In Eco-friendly and Smart Polymer Systems, 306–9. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45085-4_73.
Full textConference papers on the topic "Chitosan, hydroxyapatite, nanoparticles, composites"
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BOLTOVETS, P., and S. SEVOSTYANOV. "HYBRID COMPOSITES BASED ON CHITOSAN/ORGANOSILAN FILMS AND Au NANOPARTICLES." In Proceedings of International Conference Nanomeeting – 2011. WORLD SCIENTIFIC, 2011. http://dx.doi.org/10.1142/9789814343909_0094.
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Bliznakova, I., A. Daskalova, A. Zhelyazkova, A. Trifonov, L. Angelova, I. Buchvarov, and L. Avramov. "LIPSS formation of chitosan/hydroxyapatite composites via femtosecond laser processing for bone tissue engineering applications." In 10th Jubilee International Conference of the Balkan Physical Union. Author(s), 2019. http://dx.doi.org/10.1063/1.5091153.
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Narayan, R. J. "Novel Nanostructural Biomaterial Composites." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-39374.
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Hydrogen-free diamondlike carbon (DLC), with hardness values close to that of diamond, possess many desirable biocompatible properties for a variety of biomedical applications. The DLC coatings can be applied to joints prostheses, heart valves, and other medical devices. Unfortunately, hydrogen-free DLC coatings have a large compressive stresses which result in poor adhesion and wear characteristics. In this paper, we present results on silver doping of DLC to alleviate internal stresses as well as create DLC-Ag nanocomposites where Ag is in the form of nanoparticles. The Ag nanoparticles are expected to impart antimicrobial properties by providing sources of electrons. In the second part of the paper, we have created DLC and nanotube composites where nanotubes grow normal to the surface. This novel architecture not only alleviates internal stresses, but DLC + Nanotube composites have enhanced hardness and unique antimicrobial properties. Finally, we discuss novel multilayer DLC and hydroxyapatite (HA) composite where HA and DLC films are deposited sequentially at room temperature. The HA films with composites close to that of bone is considered very desirable for biocompatibility and integration with base structures. We discuss novel processing, characterization, hardness and bioeompatible properties of all these composites in detail.