ANGELICA TAMIÃO ZAFALON

ANGELICA TAMIÃO ZAFALON

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Stability of the neomycin antibiotic in irradiated polymeric biomaterials
2018 - 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.
Synthesis and characterization of PVP/CaCO3-Ag blend hydrogel by gamma irradiation
2019 - ZAFALON, ANGELICA T.; JUVINO, VINICIUS dos S.; KOMATSU, LUIZ G.H.; PARRA, DUCLERC F.; LUGAO, ADEMAR; SAMUEL, TEMESGEN; RANGARI, VIJAYA
Chronic wounds are skin injuries with failed healing. They have become a public health problem that affects more than 2% of the population and the presence of bacteria resistances difficult of treatment. Pseudomonas aeruginosa is opportunist pathogens and the treatment is difficult and requires a long period of treatment. Hydrogels are structure polymeric tridimensional and biocompatible. They have been used as a controlled delivery system for treatment of topic infection. Studies have reported calcium carbonate and silver ion can improve the mechanical properties and biocide activity of hydrogel. Here in this study, hydrogels loaded CaCO3-Ag were prepared using poly (N-vinyl-2-pyrrolidone), poly (ethylene glycol), agar, calcium carbonate, silver nitrate followed gamma irradiation with 25 kGy dose. The gel fraction, behavior swelling and biocide action against P. aeruginosawas investigated. The degree of swelling of the hydrogel loaded CaCO3-Ag was 12% higher than the unloaded and exhibited antibacterial effects against P. aeruginosa and biofilm.
Synthesis of polymeric hydrogel loaded with antibiotic drug for wound healing applications
2018 - ZAFALON, ANGELICA T.; SANTOS, VINICIUS J. dos; ESPOSITO, FERNANDA; LINCOPAN, NILTON; RANGARI, VIJAYA; LUGAO, ADEMAR B.; PARRA, DUCLERC F.
Polymeric hydrogels are natural or synthetic systems, which have gained interest due to their high biocompatibility with soft tissues. These types of hydrogels have been used for wound dressing as a drug delivery system. Here in this study the polymeric hydrogels based wound healing systems were prepared using poly (N-vinyl-2-pyrrolidone) (PVP), poly (ethylene glycol) (PEG), agar and neomycin drug followed by gamma irradiation to promote crosslinking and sterilization. The influence of irradiation process with 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 h of immersion. Neomycin released from hydrogel was carried out by Liquid Chromatography-Mass Spectrometry method and the drug concentration remained constant for 48 h. Hydrogel/neomycin exhibited antibacterial effects against Staphylococcus aureus. With these results, it can be inferred that hydrogel/neomycin is a suitable candidate for wound dressing.
Preparação e caracterização de hidrogel para liberação controlada de neomicina
2017 - ZAFALON, ANGELICA T.; SANTOS, VINICIUS J.; LINCOPAN, NILTON; ESPOSITO, FERNANDA; LUGAO, ADEMAR B.; PARRA, DUCLERC F.
Os hidrogéis têm sido empregados na medicina como biosensores, na engenharia de tecidos e como sistema de liberação de fármacos por serem biocompatíveis e atóxicos. Estudos recentes demonstram o uso de hidrogéis como curativos para a liberação controlada de antiinflamatórios, fatores de crescimentos e antibióticos para o tratamento tópico de infecções. Com o aumento de casos de bactérias super-resistentes, principalmente Staphylococcus aureus Meticilina Resistente (MRSA), o higrogel tornou-se uma ferramenta importante para superar esse problema, pois esses fármacos são liberados diretamente na região comprometida aumentando a efetividade do tratamento. Além disso, fornecem um ambiente úmido evitando a adesão ao local da ferida e apresentam boa barreira contra microrganismos. A presença do fármaco não alterou a fração gel. O intumescimento foi realizado com a imersão da membrana em água à temperatura ambiente e pesagem até peso constante. O intumescimento máximo foi atingido após 24 horas de imersão O intumescimento foi realizado com imersão da membrana em água. A liberação “in vitro” da neomicina foi avaliada empregando a técnica de cromatografia líquida de alta eficiência acoplada a espectrometria de massas (HPLC-MS/MS). Observou-se que o aumento da dose de irradiação influenciou na absorção de água e na fração gel devido ao aumento da densidade de ligações cruzadas. A presença do fármaco não alterou a fração gel. O intumescimento em solução salina foi 4% maor que o obtido em água. A liberação do fármaco foi avaliada “in vitro” empregando-se a técnica de cromatografia líquida de alta eficiência acoplada à espectrometria de massas (HPLC-MS/MS). O pico máximo de liberação foi alcançado após 8 horas e permaneceu constante até 48h. O teste microbiológico demonstrou que o hidrogel foi capaz de inibir o crescimento microbiológico.
Influence of gamma irradiation dose and concentration of laponite clay on poly (N-vinyl-2-pyrrolidone) hydrogels
2017 - 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.
Estudo da liberação de neomicina em hidrogéis de pvp contendo argila laponite
2016 - SANTOS, V.J.; ZAFALON, A.T.; PARRA, D.F.; LUGAO, A.B.
Hidrogel é uma classe de biomaterial definida como um sistema de um ou mais polímeros hidrofílicos, que podem ser usados como curativo devido seu sistema de liberação de drogas e sua biocompatibilidade. São materiais insolúveis, capazes de absorver grandes quantidades de fluidos sem perder sua integridade física. Hidrogéis possuem uma rede tridimensional permanente de cadeias polímericas reticuladas, e pode ser sintetizado através do processo de radiação gama, que formar ligações cruzadas entre as cadeias e esterilizar o material em uma única etapa. Hidrogéis utilizados em tratamento de feridas tópicas usualmente são produzidos com finalidade de realizar liberação de fármacos. Este estudo teve como objetivo a preparação de hidrogéis baseado em uma formulação polimérica de poli (N-vinil-2-pirrolidona), poli (etileno-glicol), ágar contendo nano-argila laponite RD e antimicrobiano neomicina. Os materiais foram processados por radiação gama de fontes de Co60 em diferentes doses. A influência da razão de argila/polímero foi investigada de acordo com a metodologia da fração de gel, testes intumescimento, difração de raios X (DRX) e microscopia eletrônica de varredura (MEV), HPLC para determinação da liberação de neomicina, teste de citotoxicidade e teste de efeito anti-microbiano.
Poly (N-vinyl-2-pyrrolidone) (PVP) and neomycin hydrogels as wound dressing obtained by gamma irradiation
2016 - ZAFALON, ANGELICA T.; SANTOS, VINICIUS J. dos; LUGAO, ADEMAR B.; PARRA, DUCLERC F.
Influence of dispersion process on the characteristics of PVP-CLAY hydrogel
2016 - SANTOS, VINICIUS J.; ZAFALON, ANGELICA T.; LUGAO, ADEMAR B.; PARRA, DUCLERC F.
Hydrogel is a hydrophilic material and can be used as wound dressing, since it can be biocompatible, potencial drug delivery system and absorbent of fluids. Hydrogels can be produced by one or more hydrophilic polymers; natural or synthetic. These materials have a three-dimensional network of cross-linked polymer chains, and may be synthetized by gamma radiation that crosslinks and sterilizes the hydrogel, in one step. PVP-clays composites show, through many ways of swellings tests, an increase of fluid absorption properties. These properties can be modified when using a mechanical or sonication dispersion process of clay in water, before polymer mixture preparation. The aim of the present study is to prepare a hydrogel with PVP-clay containing poly (N-vinyl-2-pyrrolidone), poly (ethylene glycol), Agar and Laponite clay processed by gamma radiation. The influence of clay dispersion process, clay/polymer ratio in the hydrogel and type of sample (dried or not) were investigate according to the methodology of gel fraction, swelling tests, Scanning electronic microscopy (SEM). According to the results of water swelling, the clay sonication process is more effective than mechanical dispersion, however, if the sample was dried in stove before the swelling test, the results were similar, probable owing to morphology modification promoted by the stove drying process.
Gamma radiation use for hydrogels of poly(N-vinyl 2-pyrrolidone) containing nanoclay laponite
2015 - SANTOS, VINICIUS J. dos; TAVARES, ANGELICA T.; LUGAO, ADEMAR B.; RANGARI, VIJAYA K.; PARRA, DUCLERC F.