MARGARETH KAZUYO KOBAYASHI DIAS FRANCO

MARGARETH KAZUYO KOBAYASHI DIAS FRANCO

Página do item completo

Resultados de Busca

Agora exibindo 1 - 10 de 55

A study by SAXS of silver nanoparticles produced by biogenic synthesis
2024 - RIBEIRO JUNIOR, ARI; YOKAICHIYA, FABIANO; KELLERMANN, GUINTHER; LIMA, RENATA de; GUILGER-CASAGRANDE, MARIANA; FRANCO, MARGARETH K.K.D.; FRACETO, LEONARDO F.; MONERJAN, ENELI; LEMKE, KARINA
Nanotechnology applied to the agriculture has highlighted in recent decades, making important contributions, for example, the use of nanoparticles produced by biogenic processes to control phytopathogens. This demonstrates the need of better understand the composition, mechanisms of action and toxicity of these nanoparticles. Their capping by biomolecules, derived from the organism used in the synthesis, contributes to their stability and biological activity. In particular, previous studies demonstrated the potential of Ag nanoparticles to combat the white mold [1], a disease that affects important agricultural species. In this study, Ag nanoparticles were produced by the fungus Trichoderma harzianum in aqueous solutions containing silver nitrate as a precursor for the silver nanoparticles. Some of the samples were exposed to the phytopathogenic fungus Sclerotinia sclerotiorum responsible for the white mold. After preparation, a fraction of the samples was submitted to physico-chemical processes to remove organic cap layer on nanoparticles surface formed during the preparation process. We used the small angle X-ray scattering (SAXS) technique to determine the effects of the phytopathogenic fungus and cap removal process in the average radius, radius dispersion, and number density of the nanoparticles. The SAXS data analyses suggest that the presence of the pathogenic fungus results in a decrease in number and total volume of Ag NPs without significant changes on average radius and radius dispersion. Our results also indicate that the physical-chemical process applied to remove the organic cap surrounding the Ag NPs leads to a decrease in the fraction of the smaller nanoparticles.
Influence of structural organization on mucoadhesive properties of poloxamer-hyaluronic acid-based micelles and hydrogels
2024 - SEPULVEDA, ANDERSON F.; SILVA, JESSICA B. da; BRUSCHI, MARCOS L.; FRANCO, MARGARETH K.K.D.; YOKAICHIYA, FABIANO; TOFOLI, GIOVANA R.; CEREDA, CINTIA M.S.; ROSSO, ANABELLA P.; GIACOMELLI, FERNANDO C.; SCOTT, ANA L.; ARAUJO, DANIELE R. de
New pharmaceutical formulations have been proposed as strategies to improve transport and provide best conditions to control the drug release rate in specific biological environments, such as mucosa surfaces. Herein, formulations containing binary systems Poloxamer (PL) 407 15 % and PL 338 15 %, combined with hyaluronic acid, carrying the local anesthetic bupivacaine (BVC), were studied by molecular dynamics, while other structural parameters were determined by Dynamic Light Scattering for stablishing relationships with mucoadhesive properties and cytotoxicity evaluation. The binary system PL 407 15 %/PL 338 15 % exhibited a well-organized structural morphology, with more hydrated corona, and increased mucoadhesive properties over mucin layers. After hyaluronic acid (HA) incorporation, it was observed an increase on the force of detachment, possibly due to HA role as a linker among mucin layers independently of PL supramolecular structures. On the other hand, the addition of BVC or HA/BVC into the binary system decreased the force of detachment, as a response of augmented of compactness of these hydrogels caused by desolvation of PO core, showing the influence of all components and their chemical interactions into the structural organization and their biopharmaceutical performance relationships.
Fresh carrier for an old topical local anesthetic
2024 - SOUZA, A.D.; SILVA, G.H.R. da; RIBEIRO, L.N.M.; MITSUTAKE, H.; BORDALLO, H.N.; BREITKREITZ, M.C.; FERNANDES, P.C.L.; MOURA, L.D.; YOKAICHIYA, F.; FRANCO, M.; PAULA, E. de
Nanostructured lipid carriers (NLC) have emerged as innovative drug delivery systems, offering distinct advantages over other lipid-based carriers, such as liposomes and solid lipid nanoparticles. Benzocaine (BZC), the oldest topical local anesthetic in use, undergoes metabolism by pseudocholinesterase, leading to the formation of p-aminobenzoic acid, a causative agent for allergic reactions associated with prolonged BZC usage. In order to mitigate adverse effects and enhance bioavailability, BZC was encapsulated within NLC. Utilizing a 23 factorial design, formulations comprising cetyl palmitate (solid lipid), propylene glycol monocaprylate (liquid lipid), and Pluronic F68 as surfactants were systematically prepared, with variations in the solid/liquid lipid mass ratios (60:40-80:20%), total lipid contents (15-25%), and BZC concentrations (1-3%). The optimized formulation underwent characterization by dynamic light scattering, differential scanning calorimetry, Raman imaging, X-ray diffraction, small-angle neutron scattering, nanotracking analysis, and transmission electron microscopy (TEM)/cryo-TEM, providing insights into the nanoparticle structure and the incorporation of BZC into its lipid matrix. NLCBZC exhibited a noteworthy encapsulation efficiency (%EE = 96%) and a 1 year stability when stored at 25 °C. In vitro kinetic studies and in vivo antinociceptive tests conducted in mice revealed that NLCBZC effectively sustained drug release for over 20 h and prolonged the anesthetic effect of BZC for up to 18 h. We therefore propose the use of NLCBZC to diminish the effective anesthetic concentration of benzocaine (from 20 to 3% or less), thus minimizing allergic reactions that follow the topical administration of this anesthetic and, potentially, paving the way for new routes of BZC administration in pain management.
Cronpes
2024 - BULLA, M.A.; OLIVIERA, T.; FRANCO, M.K.K.D.; YOKAICHIYA, F.
Several public schools and also universities in Brazil have few or none financial resources to acquire certain equipment for teaching physics. Nevertheless, it is extremely important that institutions, schools and universities offer laboratory conditions for the students, mainly in engineering courses, in order to get the first contact with physics concepts in practice. For this purposes, it was proposed to develop a simple construction, low-cost and easy maintenance photogate (Cronpes) device, so that teachers, technicians and even students from the basic and high education network can build them for their schools, institutions and universities, thus improving the quality of teaching physics. This study aims to implement a photogate Esp32 microcontroller based programmed in MicroPython with good resolution, accuracy and user friendly in order to apply in experiments like simple pendulum, spring oscillations and conservation of mechanical energy. The main focus of this research was to demonstrate, through the development of Cronpes, that we can create solutions for educational laboratories, in a viable, creative and inexpensive way.
Structural characterization of silver nanoparticles produced by biogenic synthesis using SAXS
2024 - RIBEIRO JUNIOR, ARI; YOKAICHIYA, FABIANO; MONERJAN, ENELI; LEMKE, KARINA; GUILGER-CASAGRANDE, MARIANA; LIMA, RENATA; FRACETO, LEONARDO; FRANCO, MARGARETH K.K.D.; KELLERMANN, GUINTHER
Nanotechnology applied to the agricultural sector has highlighted in recent decades, making important contributions, including systems for pest control as biogenic nanoparticles. These nanoparticles are used to control phytopathogens, demonstrating the need to understand its composition, mechanisms of action and toxicity. Their capping of biomolecules, derived from the organism used in the synthesis, contributes to their stability and biological activity. Ag nanoparticles were produced by the fungus Trichoderma harzianum in aqueous solutions containing silver nitrate as a precursor for the silver nanoparticles. Some of the samples were exposed to the phytopathogenic fungus Sclerotinia sclerotiorum responsible for the white mold. After preparation, a fraction of the samples was submitted to physico-chemical processes to remove organic cap layer on nanoparticles surface formed during the preparation process. In this study we determined the effect of the phytopathogenic fungus and cap removal process in the average radius, radius dispersion, number density of the nanoparticles using small angle X-ray scattering (SAXS), where we considered their almost spherical shape in aqueous solution obtained by the biogenic route. The SAXS data analyses suggest that the presence of the pathogenic fungus results in a diminution of number and total volume of Ag NPs without significant effects on average radius and radius dispersion. Our results also indicate that the physic-chemical process to remove the organic cap surrounding the Ag NPs leads to a decrease in the fraction of the smaller nanoparticles.
Low-cost experiments for teaching eletrostatics in Brazilian high school
2024 - JULIATTO, HENRIQUE M.; MARTINS, MATHEUS A.; KUSMAN, MATHEUS; YOKAICHIYA, FABIANO; FRANCO, MARGARETH K.K.D.
Many public schools in Brazil do not have the financial resources to obtain certain equipment for teaching physics. Considering that the Brazilian National Common Curricular Base, a normative document that defines the organic and progressive set of essential learning that all students must develop, determines that the curriculum for teaching electromagnetism for high school encompass electrostatics. It is very important that schools offer laboratory conditions. For this reason, it was proposed to design simple and low-cost construction equipment, so that teachers from the basic education network can build them for their schools, thus improving the quality of teaching for their students. This study aims to gather equipment and experiments, such as electroscope, electrophorus, Leyden jar and Van de Graaf generator, which can be used in the classroom for didactic purposes in physics teaching. The main focus of this work is the construction of equipment for the implementation of a laboratory for the study of electrostatics, which addresses physical concepts seen by high school students of the basic network in Brazil.
Effect of irradiation and chemically aggressive environment on Brazilian mortar cement
2024 - YOKAICHIYA, FABIO; FERREIRA, EDUARDO A.G.; VICENTE, ROBERTO; CERCEAU, AUGUSTA; MARUMO, JULIO T.; FRANCO, MARGARETH K.K.D.
Radioactive waste disposal, considered a major technical problem, has as one of the solutions, the construction of repositories that will be exposed to a range of environmental conditions in a timescale which involve thousands of years. Cement-based materials, used in the repositories, have a complex porous structure that changes over time and their durability strongly correlates to the transport of water and ions throughout the pore structure. In this study, the influence of the repository's environment was simulated using two different solution conditions: Water and Na2SO4 at different gamma irradiated condition. Two X-Ray techniques were performed simultaneously: (i) diffraction to characterize the phases contents on cement mortar samples; (ii) tomography to investigate the differences between the pore structure and pores volume. The combination's advantage of the XRay techniques shows their potential application to determine the relation amongst the phases and the pores structures, to demonstrate how the environment and the irradiation modify the structure of mortar.
Feasibility of teaching experimental physics during Covid-19 pandemic
2023 - FRANCO, MARGARETH K.K.D.; SERBENA, JOSE PEDRO M.; MATTOSO FILHO, NEY P.; WIENER, DENIS de O.; YOKAICHIYA, FABIANO; FUJIMOTO, MILTON M.
At the beginning of 2020, the COVID-19 pandemic surprised the world, affecting activities that promote attendance, including abruptly impacting the education area. Educational institutions, from preschool to university, were required to adopt alternative teaching methods to continue their activities. Distance learning has been adopted by educators to address this unprecedented challenge. Our University, more specifically the Department of Physics, reacted to the problem in an ambitious and creative way, taking advantage of it as an opportunity to put into practice methodologies related to the teaching of disciplines that were only practiced in person, such as the discipline of Experimental Physics. This study aims to describe the implementation of the discipline of Experimental Physics I at our University, promoted remotely by professors of the Department of Physics. We verified: (i) that the choice of the best technologies as a tool for teaching is fundamental for the better dissemination of knowledge, (ii) that inclusive programs for each course are very important, (iii) the importance of prior presentation of a schedule, (iv) the importance of defining clear assessment rules for students on remote teaching. We also evaluated the number of accesses as a measure of student participation and analysed the statistics of the discipline in several engineering courses.
Hyaluronic acid incorporation modulates rheological and drug release properties in Poloxamer-based hydrogels
2022 - SEPULVEDA, ANDERSON F.; VOLLRATH-KUMPGDEE, MONT; FRANCO, MARGARETH K.K.D.; YOKAICHIYA, FABIANO; ARAUJO, DANIELE R. de
INTRODUCTION: Synthetic polymer Poloxamer (PL) 407 (15% and 30% w/w) and binary formulation PL 407 15% + PL 338 15% (BF), with natural polymer hyaluronic acid 0.5% w/w, were designed as bupivacaine or ropivacaine thermosensitive release systems. OBJECTIVES: The aim of this work is to characterize structure and stability of drug delivery systems. MATERIALS AND METHODS: These systems were characterized by calorimetry, rheology, SANS, and release profile. DISCUSSION AND RESULTS: Calorimetry results demonstrated all formulations are stable at storage and physiological temperatures. PL 407 30% and BF systems are structurally more organized and with higher consistency (G’/G’’ ~ 50) at 37 °C and with lower gelation temperature (Tg ~ 14 °C) than PL 407 15% ones (G’/G’’ ~ 0.30 and Tg ~ 45 °C, respectively), however BFs have increased viscosity and slightly higher stiffness (G’/G’’ ~ 60) when compared to PL 407 30% formulations, due to more hydrophilicity of PL 338 chains than PL 407. Adding HA, it is observed enhanced viscosity but diminished consistency (G’/G’’ ~ 0.40). When a drug is incorporated, it is seen that it promotes increased interaction between chains. Although material alteration when incorporating HA or drug is observed, SANS results showed that the type of supramolecular structure is dependent on the concentration of Poloxamer. Systems with low concentration of Poloxamer have lamellar type, while formulations with 30% of Poloxamer have both cubic and hexagonal structures. In addition, PL 407 30% formulations undergo greater compression when bupivacaine is added (~ 29.7 nm at 25 °C and 37 °C). As drug release profiles showed, BFs release drugs in a more controlled way than other formulations. Moreover, HA hinders the release of both drugs. CONCLUSION: Thus, it is clear that the incorporation of more hydrophilic polymers is able to modulate the drug release rate according to the hydrogels rheological parameters.
Supramolecular structure organization and rheological properties modulate the performance of hyaluronic acid-loaded thermosensitive hydrogels as drug-delivery systems
2023 - SEPULVEDA, ANDERSON F.; KUMPGDEE-VOLLRATH, MONT; FRANCO, MARGARETH K.K.D.; YOKAICHIYA, FABIANO; ARAUJO, DANIELE R. de
The challenges for developing new pharmaceutical formulations based on natural and synthetic polymers has led to innovation into the design of systems responsive environmental stimuli such as temperature. However, the presence of hydrophilic or hydrophobic molecules, charged groups, or metallic elements can affect their structural behavior and their biopharmaceutical performance This work aims to study and characterize the morphology and structure of polymeric formulations based on Poloxamer (PL) 407 (15 % and 30 % m/v) and its binary with PL 338 (15 % PL 407 + 15 % PL 338) and hyaluronic acid (0.5 % m/v), as drug delivery systems of local anesthetic bupivacaine (0.5 % m/v) and ropivacaine (0.5 % m/v) hydrochloride. For this, it was performed SANS analysis for determination of supramolecular organization and lattice parameters; calorimetry was done to characterize their thermodynamic parameters; rheological analysis flow curve, consistency and adhesion calculation, Maxwell model study. Also, it was performed drug release profiles and calculation of diffusion coefficients. It was identified lamellar structures in PL 407 15 % formulations, and coexistence of cubic and hexagonal phases in PL 407 30 % and binary formulations, however hyaluronic acid, bupivacaine or ropivacaine seem do not affect the type of supramolecular structure. In addition, these additives can modulate viscosity among poloxamers chains, increasing micelle-micelle interactions as it happens in presence of bupivacaine. On the other hand, addition of hyaluronic acid can promote increased structural stabilization by hydrophilic interactions between hyaluronic and micellar corona. It reflects the ability how to control the drug release, as in case of binary system that retained bupivacaine for longer time than other systems, as well it happens when hyaluronic acid is added in PL 407 15 % and PL 407 30 %.