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.
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.
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.
Síntese e caracterização de hidrogéis contendo anti-microbiano neomicina
2016 - SANTOS, V.J.; ZAFALON, A.T.; PARRA, D.F.
Hidrogéis são biomateriais poliméricos vastamente utilizados para aplicações biomédicas como sistemas de liberação de fármaco. São materiais altamente hidrofílicos, com uma estrutura molecular reticulada e capacidade de absorver grandes quantidades de fluidos. Em geral hidrogéis são compostos por mais de um polímero sintético ou natural a fim modificar suas propriedades físico-químicas. Estes materiais podem ser produzidos através do uso de radiação ionizante, onde a radiação gama é uma das mais eficientes para a produção desses materiais. O objetivo deste trabalho foi sintetizar membranas de hidrogel a base de poli (N-vinil-2-pirrolidona), polietileno glicol e Agar, contendo antibiótico neomicina. As membranas de hidrogel foram produzidas por radiação gama de fontes de Co60 em doses de 25 kGy. Os hidrogéis foram caracterizados por meio da análise termogravimétrica (TGA) em que se identificou o antibiótico neomicina.
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.