MARIA JOSE ALVES DE OLIVEIRA

MARIA JOSE ALVES DE OLIVEIRA

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Silver nanoparticles-based hydrogels synthetized by ionizing radiation for cleaning of tangible cultural heritage surfaces
2022 - OLIVEIRA, MARIA J.A.; OTUBO, LARISSA; PIRES, ADRIANA; BRAMBILLA , RODRIGO F.; CARVALHO, ANA C.; SANTOS, PAULO S.; OLIVEIRA NETO, ALMIR; VASQUEZ, PABLO
The surfaces of the works of art are one of their most important parts since they interact directly with the observer's perception. On the other hand, they are also in direct contact with physical, chemical and biological agents that can induce degradation and signs of aging. Dust deposits, stains and aged layers of protection can degrade, causing irreversible damage to works of art. In this way, the removal of undesirable materials from artistic surfaces is essential to preserve cultural heritage articles. The aim of this work was to develop silver nanoparticles-based hydrogels and to study the behavior regarding solvent concentration, stability and ability to clean dirt samples based on paper and canvas. The hydrogels were synthesized (reticulated) by gamma rays having the simultaneous formation of silver nanoparticles (AgNP) in the same process. The samples were characterized by swelling tests, attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, differential scanning calorimetry (DSC), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and optical microscopy (OM). The results showed the removal of dirt from the paper samples, as well as the softening of the dirt from the canvas, without leaving residues and without affecting the integrity of the art works submitted to treatment.
Poly(vinyl alcohol) (PVAl) and poly(N-2-vinyl-pyrrolidone) hydrogels nanostructured by laponite clay for drug delivery
2022 - OLIVEIRA, MARIA J.A.; SANTOS, VINICIUS J.; FREITAS, LUCAS F. de; LUGAO, ADEMAR B.; PARRA, DUCLERC F.
Hydrogels for wound dressings are usually developed for contact surfaces where mechanical properties are conveniently required. In this sense nanocomposite hydrogels based on PVAl (poly(vinyl alcohol) and PVP (poly(N-2-vinil-pirrolidone)) containing 0.5-1.5 wt% of the synthetic laponite RD clay were prepared by a gamma radiation process and compared with similar membranes composed separately of PVP or PVAl. This study aimed to evaluate the effect of clay on the properties and the differences of the polymer blend instead of a unique polymer. The morphology of the hydrogels was evaluated by spectrometric techniques using XRD (X-ray diffraction), SEM (scanning electron microscopy), swelling assay, and FTIR (infrared spectroscopy). The swelling kinetics at 22 °C and the mechanical properties by a tensile test comprised the structural properties that were assessed. The results showed PVA/PVP network depends directly on the clay concentration in the nanocomposite hydrogels. The blend PVP/PVAl proved to have potentially efficient mechanical properties for drug delivery in the treatment of wounds.
Influence of gamma radiation on Amphotericin B incorporated in PVP hydrogel as an alternative treatment for cutaneous leishmaniosis
2021 - OLIVEIRA, MARIA J.A. de; VILLEGAS, GETHZEMANI M.E.; MOTTA, FLAVIA D.; FABELA-SANCHEZ, OMAR; ESPINOSA-ROA, ARIAN; FOTORAN, WESLEY L.; PEIXOTO, JANAINA C.; TANO, FABIA T.; LUGAO, ADEMAR B.; VASQUEZ, PABLO A.S.
Amphotericin B (Amph-B) is an antifungal drug used intravenously for the treatment of leishmaniasis. Side-effects from Amph-B treatment can arise such as cardiac arrhythmia and renal dysfunctions, which will lead to discontinuation of treatment. Unfortunately, patients in endemic countries do not have access to alternative therapies. The objective of this study was to analyze the effects of Cobalt-60 gamma irradiation on crosslinking polymeric hydrogels (Hydg) and the incorporation of Amph-B into the gel as a controlled-release drug delivery alternative. Polyvinylpyrrolidone (PVP)/Amph-B solutions were irradiated with 15 kGy at 0 °C and 25 °C. The drug's stability was ascertained by UV–visible spectrometry, liquid chromatography/mass spectrometry and proton nuclear magnetic resonance. Irradiated Hydg/Amph-B achieved similar stability to the standard Amph-B solution and was enough to promote hydrogel crosslinking. In vitro trials were carried out to ensure Amph-B was still biologically active after irradiation. The results from flow cytometry and MTT assay show that Amph-B had an IC50 = 16.7 nM. A combination of Hydg at 1.324 gmL−1 and Amph-B at 25.1 nM for 24 h lead to the greatest inhibition of L. amazonensis promastigotes, and could be used as an alternative treatment method for cutaneous leishmaniosis.
PVGA/Alginate-AgNPs hydrogel as absorbent biomaterial and its soil biodegradation behavior
2020 - ESTRADA-VILLEGAS, G.M.; MORSELLI, G.; OLIVEIRA, M.J.A.; GONZALEZ-PEREZ, G.; LUGAO, A.B.
PVGA, silver nitrate ( AgNO3) and alginate (Alg) were cross-linked by using γ-ray radiation to obtain Alg/PVGA/AgNPs as a potential biomaterial. The hydrogel composition was characterized by several analytics methods, and the morphology was evaluated by scanning electron microscopy. The swelling behavior was tested in different mediums. The stability of AgNPs was followed by UV–Vis at 400 nm for 1 month. The hydrogel soil biodegradation was analyzed by visual observation, weight loss, Fourier transform infrared spectroscopy and thermogravimetric analysis for 120 days. A simple biodegradation mechanism has been proposed based on results. Additionally, cytotoxicity assays were carried out using NCTC 929 cells to observe cell viability.
Effectiveness of the hydrogel dressing crosslinked and sterilized by gamma radiation
2019 - GEMELLI, KARINE K.; SOUSA, GRAZIELLY M. de; GEMELLI, TIAGO F.; FERREIRA, OBEDE R.; OLIVEIRA, MARIA J.A. de; ALCANTARA, MARA T.S.; LUGAO, ADEMAR B.
Chronic wounds of difficult cicatrization are more incidents with an increased in life expectancy. The hydrogel with silver nanoparticles developed at the Nuclear Energetic Research Institute, crosslinked and sterilized by Gamma radiation, is inexpensive and has a simple manufacturing process that seems to be an alternative to the treatment of injuries. This experimental study compared the healing process of second intention of skin wounds of 4cm² on the back of 69 Wistar rats, considering the effectiveness of hydrogel dressings with silver nanoparticles. The animals were distributed in three groups that received treatment with hydrogel dressing, hydrogel with 22ppm of silver nanoparticles and hydrogel with 44ppm of silver nanoparticles, and the dressings were performed every 48 hours. The project was approved by the Animal Experiments Committee. Hydrogel dressings are transparent and allow accurate visualization of the center of the lesion. The part of the dressing in contact with the wound kept the medium moist, promoting interaction with the fluid of the lesion, besides adsorbing the moisture produced. The dressing replacement didn’t cause discomfort or pain, since the animals were manually contained during the procedure, and the cover is easy to remove without causing trauma to the healing tissue. Wounds remained free of fibrin formation and necrosis, and serous exudation of lesions was scarce. At 21 days all the lesions were healed showing that dressings weren’t negative to the second intention healing process.
Toxicity study using rat (WISTAR) model of a hydrogel dressing with silver nanoparticles crosslinked and sterilized by gamma radiation
2019 - SOUSA, GRAZIELLY M. de; GEMELLI, KARINE K.; MARTINS, OZENILDE A.R.; OLIVEIRA, MARIA J.A. de; ALCANTARA, MARA T.S.; LUGAO, ADEMAR B.; ROGERO, JOSE R.
Silver nanoparticles (NPAg) have a bactericidal and bacteriostatic action in combination with hydrogels to recover the damaged tissue, promoting healing of the wound. The objective of this study was to evaluate the toxicity of the hydrogel dressing with NPAg from the analysis of possible toxic effects on renal and hepatic functions. It is an experimental study with 85 male Wistar rats, young adults. Nanoprate hydrogel and bidrogel dressings were used at concentrations of 22 and 44 ppm, both crosslinked and sterilized by irradiation with gamma rays at the 25 kGy dose at the center of radiation technology (CTR). The animals were distributed according to the treatment received after surgical induction of the wound on the animal's back. They were euthanized with 24 hours, 3, 7, 14, 21 and 30 days and after collecting the blood to determine the biochemical parameters. The project was approved by CEUA FAPAC ITPAC PORTO. Data were analyzed using the Past, Shapiro-Wilk and Kruskal-Wallis programs. For distribution and comparison data ANOVA and Tukey test with a significance level of 95%. No changes were observed in relation to biochemical parameters (TGP, TGO, urea and creatinine), and there were no statistically significant differences between the three groups of animals, independent of time. It was possible to observe that the animals treated with 44 ppm had always lower mean values than the other two groups in all analyzes. The study showed that the dressings of NPAg tested may not induce toxicity, being necessary to complement with other tests, such as histopathological study and atomic absorption spectroscopy.
Synthesis and in vivo behavior of PVP/CMC/agar hydrogel membranes impregnated with silver nanoparticles for wound healing applications
2018 - LIMA, GABRIEL G. de; LIMA, DARLLA W.F. de; OLIVEIRA, MARIA J.A. de; LUGAO, ADEMAR B.; ALCANTARA, MARA T.S.; DEVINE, DECLAN M.; SA, MARCELO J.C. de
The field of wound healing has seen an increase in research activity in wound care and hydrogel-based dressings have been targeted as a solution for these applications. Hydrogels with silver nanoparticles can present many advantages for this field. However, if the aggregation and sterilization of this product have not been carefully considered, the effectiveness or use could be limited. Therefore, in the current study, a hydrogel-based wound dressing membrane was developed using polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), agar, and carboxymethyl cellulose (CMC). Silver ions (Ag+) were dispersed in the polymer matrix and its reduction with formation of a hydrogel and silver nanoparticles was performed using 60Co gamma irradiation to enhance the dressings antimicrobial properties. The resulting hydrogel presented a high degree of swelling and a good size control of silver nanoparticles. The incorporation of AgNPs was confirmed via Raman spectroscopy and the samples presented no signs of toxicity in vitro as assessed using an elution assay with neutral red uptake as the cytotoxic end point. Membranes were tested in vivo using a full thickness defeat model in rabbits. Postmortem histopathological analysis indicated that the use of the hydrogel membranes that incorporated AgNPs had a stimulatory action on wound healing as evidenced by a high intensity of fibroblasts and neovascularization in the tissue, which promoted a faster healing process when compared to the untreated wounds. We demonstrate the possibility of producing a hydrogel with good size control of AgNPs, which can also be directly sterilized within the formation of this material via gamma irradiation. Furthermore, the mechanism of hydrogel healing, in vivo, with silver nanoparticles was found to have a direct correlation of silver nanoparticles with in vitro cell results.
Effect of gamma irradiation on polymeric gel with glucantime and silver for the alternative treatment of cutaneous leishmania
2018 - OLIVEIRA, M.J.A.; VASQUEZ, P.A.S.; ALCANTARA, M.T.S.; LUGAO, A.B.
The drugs used to treat leishmania are in injectable form and the applications are painful that many patients give up during the treatment. The treatment requires hospitalization to monitor the side effects caused by the drugs, such as cardiac arrhythmia, renal dysfunction, among others. In addition to this situation, if the patient has symptoms such as cardiac arrhythmia, renal dysfunction they can not make use of the treatment. For these reasons finding new forms of treatments with minor side effects as alternative treatments for leishmaniasis has been the object of study of many research laboratories. The objective of this work was to analyze the effects of gamma irradiation on polymeric gel with glucantime and silver as the alternative treatment of cutaneous leishmania. In this case, the polymeric gel prevents the drug from falling directly into the bloodstream, avoiding the side effects, which would make unnecessary the patient's hospitalization. For the development of the gels was used, alginate, polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), laponite clay, silver ions, and glucantime. The cobalt-60 source gamma irradiation was used for gel formation, silver nanoparticles and simultaneous sterilization. The physico-chemical characterizations were elemental analysis for quantification of Sb(V) and Sb(III) antimoniate, infrared spectroscopy (FTIR), dispersive energy spectrometry (EDS), transmission electron microscope (TEM). The results are promising, they show that the irradiation does not interfere with the drug's active principle, as expected in this study.
Nanocomposite polymer clay to support the release of drug
2017 - OLIVEIRA, MARIA J.A.; LUGAO, ADEMAR B.; PARRA, DUCLERC F.
It is estimated that there are about 300,00 products named biomaterials that are used in the area of Health. Although they are widely used they have yet to be optimized for therapeutic use. Hence, the objective of this work was to develop nanocomposites hydrogels with poly (vinyl alcohol) (PVAl), glucantime, chitosan and synthetic clay Laponite RD, processed by gamma irradiation. To compare the behavior of drug release two systems were compared, PVAl / chitosan / clay and PVAl / clay. The morphology of the nanocomposites hydrogel was understood by using characterization techniques: X-ray diffraction, scanning electron microscopy (SEM) and atomic force microscopy (AFM) and gel fraction. The release kinetics was analyzed at 37 °C for period of 48 hours. It was observed that the slower release of the drug occurs in the delivery system composed by PVAl / chitosan / clay with correlation of the crosslink type formed by chitosan.
Effect of gamma radiation on polyvinylpyrrolidone hydrogels
2017 - OLIVEIRA, M.J.A.; VASQUEZ, P.A.S.; ALCANTARA, M.T.S.; MUNHOZ, M.M.L.; LUGAO, A.B.
Polyvinylpyrrolidone (PVP) hydrogels have been investigated as drug delivery matrices for the treatment of wounds, such as cutaneous leishmaniasis, and matrices with silver nanoparticles for chronic wounds and burns. The preparation of such hydrogels can occur by various cross-linking methods, such as gamma, chemical, physical, among others. The most feasible for wound dressings is gamma irradiation from cobalt-60, because gamma irradiation simultaneously promotes crosslinking and sterilization, leaving the wound dressing ready for use. The objective of this work was to investigate the effect on physico- chemical properties of gamma radiation on PVP hydrogel according to the radiation absorbed dose variation. The PVP hydrogels were irradiated with doses of 5, 15, 25, 35, 45, 55, 65, 75 and 95kGy at dose rate of 5 kGy/h and characterized by swelling, thermogravimetric and mechanical analysis. Results shown a favorable dose range window for processing of these hydrogels related to the application. The results showed that mechanical strength was affected at doses starting at 25 kGy.