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Browsing by Author "Berberich, Thais Sayuri"

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  • Development and functionalization of magnetic nanomaterials for biomedicine applications
    Publication . Berberich, Thais Sayuri; Gomes, Helder; Tuesta Triviño, José Luis Diaz de; Inglez, Simone Delezuk
    During the past decade, researchers have shown an increased interest in multifunctional nanomaterials. Magnetic Nanoparticles (MNP) have been one of the most attractive types of nanomaterials used in different fields, as in environmental protection and biomedical applications. These applications include drug delivery, magnetic resonance imaging, magnetic hyperthermia, among others. MNPs have been synthesized by various methods. Amongst the most common may be referred: thermal decomposition, microemulsion, coprecipitation, solution combustion and sonochemical synthesis. The main objective of this MSc thesis is the development of biocompatible MNPs with high potential for the controlled release of drugs. For this purpose, a magnetic core based on magnetite is developed by two different approaches of Solution Combustion Synthesis. In the first approach, the synthesis of MNPs is obtained by reduction of Fe (III) using citric acid, and the in second approach, the MNPs are synthesized using tangerine peel extract for the reduction of Fe (III). However, the material produced with the extract was not magnetic, and it was decided to not continue the methodology with it. Then, the magnetic core, produced with citric acid, is coated with a resin prepared from formaldehyde, resorcinol and TEOS, which is later carbonized by pyrolysis at 600 ºC. Subsequently, the silica generated from TEOS is removed by etching with NaOH in order to create a void inside the particle, which take the known yolk-shell shape. Finally, the materials are functionalized with nitric acid and subsequent pluronic F-127, for its biocompatibility and dispersibility. These materials are then assessed in the controlled release of two different drugs to test the potential of the developed magnetic nanostructures for drug delivery applications: Doxorubicin (DOX) and Omeprazole (OME). Drug Loading Capacity and Efficiency of 0.936 μg·μg -1 and 93.6% for DOX and 0.335 μg·μg-1 and 33.5% for OME are obtained at pH 7.4, respectively. Finally, the drug release is tested at the pH of the normal tissue (pH 7.4) and at the pH of the extracellular environment of the tumor (pH < 6.5), simulating different circumstances of the human body.
    2020Master thesis Open access Show more