ANGELICA TAMIÃO ZAFALON
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Artigo IPEN-doc 25734 Stability of the neomycin antibiotic in irradiated polymeric biomaterials2018 - ZAFALON, ANGELICA T.; SANTOS, VINICIUS J. dos; LUGAO, ADEMAR B.; RANGARI, VIJAYA; TEMESGEN, SAMUEL; PARRA, DUCLERC F.Hydrogels can be produced by gamma radiation at 25 kGy. Free radicals from water radiolysis are responsible by crosslinking of the polymer and chain scission. On the other hand, gamma radiation can lead degradation of pharmaceuticals. Neomycin loaded hydrogel was prepared and the stabity of neomycin was evaluaded. Excipents were used to measure radioprotector potencial each one. HPLC-MS/MS method and thermal analysis were used to analysis effect of gamma irradiation in neomycin stability. PEG was a excipients in hydrogel formulation and showed to be a radioprotector. Neomycin was stable under gamma radiation when loaded in hydrogel.Tese IPEN-doc 25615 Synthesis and characterization of hydrogels loaded neomycin for infection topic treatment and veterinary use2018 - ZAFALON, ANGELICA T.Hydrogels are natural or synthetic polymer systems that have been vastly applied in the pharmaceutical industry due to their high soft tissue biocompatibility. These hydrogels have been used in dressings as a controlled drug release system. In this study, hydrogels were prepared using poly (N-vinyl-2-pyrrolidone) (PVP), poly (ethylene glycol) (PEG), agar and neomycin followed by gamma irradiation to promote crosslinking and sterilization. The influence of the irradiation process at 25 kGy dose was investigated. The gel fraction and maximum swelling were estimated using physicochemical methods and found about 95% gel fraction and 1100% swelling after 8 hours of immersion. Neomycin released from the hydrogel was measured by the Liquid Chromatography-Mass Spectrometry method and the drug concentration remained constant for 48 hours. Hydrogel / neomycin exhibited antibacterial effect against bacteria and biofilm of Pseudomonas aeruginosa and Staphylococcus aureus. The hydrogel was used in the treatment of pododermatitis in penguins healing process without signs of contamination. With these results, it can be inferred that the hydrogel / neomycin is a suitable candidate for wound dressings.Artigo IPEN-doc 24193 Influence of gamma irradiation dose and concentration of laponite clay on poly (N-vinyl-2-pyrrolidone) hydrogels2017 - SANTOS, VINICIUS J.; ZAFALON, ANGELICA T.; LUGAO, ADEMAR B.; PARRA, DUCLERC F.Hydrogels are polymeric biomaterials widely used in biomedicine and defined as an insoluble system of one or more crosslinked hydrophilic polymers, capable of absorbing large amounts of fluids without losing their physical integrity. Composed by one three-dimensional network of crosslinked polymer chains they can be synthesized by various physical and chemical methods including radiation. One of these methods is the gamma irradiation process, which forms the crosslinked network and sterilizes the material in a single step. In the biomedical field one of hydrogels applications is the transdermal dressings, these systems have an impact of great value in the treatment of wounds, as they can protect regions injured by burns, cuts and even chronic wounds. The association of clay to hydrogels promotes a modification of properties of these materials, such as swelling and gel fraction. Thus, the objective of this work was to evaluate the swelling properties and gel fraction of hydrogels based on polymer formulation of poly (N-vinyl-2-pyrrolidone), poly (ethylene glycol), agar containing nano-clay laponite RD in Different concentrations (0, 0.01, 0.1, 0.5, 1, 2, 5, 10, 20%). The materials were mixed by stirring and heating and then processed by gamma radiation from Co-60 at doses of 10, 25, 50 and 70 kGy. To evaluate the gel fraction, the membranes were immersed in water for 3 weeks. The swelling was evaluated after 48 hours of immersion in distilled water at room temperature. It was observed that as the clay concentration increases regardless of the irradiation dose the amount of gel fraction decreased and the amount of water absorption increased.