ANGELICA TAMIÃO ZAFALON

ANGELICA TAMIÃO ZAFALON

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Development of poly (n-vinyl-2-pyrrolidone) hydrogels containing nanosilver and laponite clay for modulation of neomycin
2020 - PARRA, DUCLERC F.; SANTOS, VINICIUS J. dos; TAMIÃO, ANGELICA
These Biomaterials widely used in biomedicine as wound dressings are composed by hydrogels. They offer ideal conditions for wound treatment, such as maintaining the wound environment humid, autolytic debridement, accelerated healing, ability to absorb large amounts of fluids without losing their physical integrity, drug release in a controlled manner protecting infected wounds that are constantly exposed to environment contaminated with microorganisms. These dressings are formed by one or more polymeric components which, when cross-linked, form three-dimensional networks. They have a high degree of flexibility that is very similar to natural living tissues. The general objective of this work was to synthesize by radiation hydrogel membranes containing PVP, PEG, agar, RD laponite in a neomycin and nanosilver release system that promotes a synergistic action between these two antimicrobial agents. Membranes with different concentrations of polymer matrix / clay were produced by irradiation at a dose of 25 kGy of gamma 60Co source, and characterized by techniques: swelling analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tensile tests, parallel plate rheometry. It can be seen that G 'and G "are approximately parallel within the studied range. G 'is greater than G' 'and both showed little frequency dependence. This performance is the expected for the gels, in which the elastic behavior of the sample predominates over its viscous behavior. The clay-polymer interactions increases gel cross-linking, which provides an increase in their mechanical properties. In parallel, nanoparticles of silver coupled to clay (Laponite) were synthesized in which their properties were verified by means of UV-Vis, MET, ICP-OES and microbiological activity. The study of the microbiological activity of AgNPs-Laponite nanoparticles on the reduction of microorganisms in culture indicated that most of the nanoparticles, synthesized from the reduction of silver ions on the surface of Laponite, have activity against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Candida albicans.
Application of natural nanoparticles in polymeric blend of HMSPP/SEBS for biocide activity
2019 - KOMATSU, L.G.H.; ZAFALON, A.T.; SANTOS, V.J.; LINCOPAN, N.; RANGARI, V.K.; PARRA, D.F.
The natural nanoparticles of CaCO3, from eggshell and CaCO3/Ag, were investigated as candidates for biocide nanoparticles in a blend of thermoplastic elastomer, styrene–ethylene/butadiene–styrene (SEBS), and polyolefin, high-meltstrength polypropylene (HMSPP). The nanoparticles with silver (Ag) were synthesized by metal precursor method, and before the application in the polymer matrix, the nanoparticles were analyzed on dynamic lighting scattering (DLS) and Raman spectroscopy. After DLS and Raman analyses, the nanoparticles were evaluated in biocide tests against P. aeruginosa and S. auerus. The aim of this investigation was the blending and the injection molding in dumbbell samples with the nanoparticles. The characterizations were carried out by differential scanning calorimetry (DSC), thermogravimetry analysis,mechanical tests, X-ray diffraction, Raman spectroscopy, scanning electronmicroscopy, and energy-dispersive scanning and biocide tests. Correlation between size and particle distribution on the polymerwas founded. However, samples at higher concentrations (>1 wt%) do not show biocide activity.
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 and characterization of hydrogels loaded neomycin for infection topic treatment and veterinary use
2018 - 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.
Avaliação do comportamento mecânico, térmico e de intumescimento dos hidrogéis contendo argila Laponite RD
2018 - SANTOS, V.J.; ZAFALON, A.T.; PARRA, D.F.
Hidrogéis são biomateriais amplamente utilizados na biomedicina, e possuem a capacidade de absorver grandes quantidades de fluidos sem perder sua integridade física. Esses materiais são constituídos por uma rede tridimensional de polímeros formada por ligações cruzadas, físicas ou químicas. Hidrogéis têm sido aplicados como curativos transdérmicos em sistemas de liberação de drogas. Esses materiais oferecem condições ideais para tratamento de feridas, pois mantém o ambiente da ferida úmido promovendo um debridamento autoclítico, acelerando a cicatrização. Argila Laponite (LP) é uma argila sintética nanométrica de aproximadamente 25 nm de diâmetro e 0,92 nm de espessura, é altamente hidrofílica e forma gel em solução aquosa. A associação de argila a hidrogéis promove modificação de propriedades como mecânica e inchaço quando macro-cadeias interagem com o espaço interlamelar. O objetivo deste trabalho foi avaliar a influência da nano-argila nas propriedades mecânicas, térmicas e de intumescimento de hidrogéis baseados em uma formulação polimérica de poli (N-vinil-2-pirrolidona), poli (etileno glicol) e agar contendo nano Laponite RD. As membranas de hidrogel foram reticuladas por radiação gama a 25 kGy. Foram realizados testes de tração de acordo com ASTM D638-03. O comportamento viscoelástico foi investigado usando um reômetro de placa paralela. O intumescimento foi avaliado após 72 horas e o comportamento entálpico foi avaliado pelo DSC.
Síntese e caracterização de nanopartículas de prata na superfície de argila Laponite RD para uso em membranas de hidrogel de PVP
2018 - SANTOS, V.J.; LOPES, P.; ZAFALON, A.T.; RANGARI, V.K.; PARRA, D.F.
Hidrogéis são biomateriais amplamente utilizados na biomedicina, e possuem a capacidade de absorver grandes quantidades de fluidos sem perder sua integridade física. Esses materiais são constituídos por uma rede tridimensional de polímeros formada por ligações cruzadas, físicas ou químicas. Hidrogéis têm sido aplicados como curativos transdérmicos em sistemas de liberação de drogas. Esses materiais oferecem condições ideais para tratamento de feridas, pois mantém o ambiente da ferida úmido promovendo um debridamento autoclítico, acelerando a cicatrização. Um grande problema da saúde publica, são as infecções relacionadas a assistência à saúde, que são frequentemente associadas à contaminação superficiais em ambientes hospitalares. Esse problema começa a se intensificar nas ultimas décadas devido ao grande desenvolvimento da medicina que depende de procedimentos invasivos que podem deixar um paciente mais susceptível a microrganismos. Nano Partículas Metálicas em geral tem reportados atividade biocida em bactérias Gram-positivos, Gram-negativos incluindo bactérias resistentes a antibióticos como MRSA e MRSE. Argila Laponite (LP) é uma argila sintética nanométrica de aproximadamente 25 nm de diâmetro e 0,92 nm de espessura, é altamente hidrofílica e forma gel em solução aquosa. Assim, o objetivo deste trabalho foi sintetizar partículas de nanoprata reduzindo-a na superfície da argila e estabilizando com Poli (N-vinil-2-pirrolidona) K30 e incorporar em uma membrana de hidrogel de PVP sintetizados via radiação gama, esse composto foi analisado por espectroscopia UV-Vis, Espalhamento dinâmico de luz (DLS), microscopia eletrônica de varredura (SEM) Microscopia eletrônica de transmissão (TEM) acoplada a EDS e difração de Raio-X. Foram realizados ensaios microbiológicos de atividade anti-microbiana em Escherichia coli, Pseudomonas aeruginosa e Staphylococcus aureus e Candida albicans, testes de citotoxicidade em células de tecido conectivos de camundongos (NCTC L929).
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.