Vagner Roberto Magri

Scopus Publications

Surfactant mediated intercalation of a hydrophobic drug into layered double hydroxides: Probing the structural features by the photophysical behaviour of piroxicam
Nawal Fodil Cherif, François Réveret, Anthony Barros, Vagner Roberto Magri, Fabrice Leroux, Damien Boyer, Vera Regina Leopoldo Constantino, Christine Taviot-Guého
Applied Clay Science, 2025
Pyrolysis of folic acid: Identification of gaseous/volatile products and structural evolution of N-doped graphitic carbon
Vagner R. Magri, Caroline S. de Matos, Michele A. Rocha, Christine Taviot-Gueho, Vera R.L. Constantino
Thermochimica Acta, 2024
Revisiting the Synthesis and Characterization of Hybrid Nanomaterial Constituted by Folate Intercalated into M2+/Al3+ (M2+ = Mg2+ and Zn2+) Layered Double Hydroxide
Vagner Magri, Caroline de Matos, Michele Rocha, Christine Taviot-Gueho, Vera Constantino
Journal of the Brazilian Chemical Society, 2024
Intercalation of deprotonated folic acid (FA; vitamin B9) is of great interest for nutraceutical and cosmeceutical purposes. Although some studies have already reported the intercalation of divalent (HFol2- ) or trivalent (Fol3- ) folate anions into layered double hydroxides (LDH), the structure, spectroscopic, and thermal behavior of such hybrid materials still need to be better understood. This work revisited the synthesis of LDH constituted by M2+/Al3+ (M2+ = Mg or Zn) intercalated with HFol2- or Fol3- . Insights concerning how the physicochemical properties of the materials are tuneable according to the synthetic approach (slow or fast coprecipitation) and pH value (7.5 or 9.0/9.5) of synthesis were pointed out. Materials synthesized at pH above 9.0 (Fol3- ) presented larger particles and lower loading capacity than the ones synthesized at pH 7.5 (HFol2- ). The fast coprecipitation approach led to the formation of materials with smaller particles. This work could address the following research concerning LDH-FA applications.
Biomaterials Based on Organic Polymers and Layered Double Hydroxides Nanocomposites: Drug Delivery and Tissue Engineering
Vera Regina Leopoldo Constantino, Mariana Pires Figueiredo, Vagner Roberto Magri, Denise Eulálio, Vanessa Roberta Rodrigues Cunha, Ana Clecia Santos Alcântara, Gustavo Frigi Perotti
Pharmaceutics, 2023
The development of biomaterials has a substantial role in pharmaceutical and medical strategies for the enhancement of life quality. This review work focused on versatile biomaterials based on nanocomposites comprising organic polymers and a class of layered inorganic nanoparticles, aiming for drug delivery (oral, transdermal, and ocular delivery) and tissue engineering (skin and bone therapies). Layered double hydroxides (LDHs) are 2D nanomaterials that can intercalate anionic bioactive species between the layers. The layers can hold metal cations that confer intrinsic biological activity to LDHs as well as biocompatibility. The intercalation of bioactive species between the layers allows the formation of drug delivery systems with elevated loading capacity and modified release profiles promoted by ion exchange and/or solubilization. The capacity of tissue integration, antigenicity, and stimulation of collagen formation, among other beneficial characteristics of LDH, have been observed by in vivo assays. The association between the properties of biocompatible polymers and LDH-drug nanohybrids produces multifunctional nanocomposites compatible with living matter. Such nanocomposites are stimuli-responsive, show appropriate mechanical properties, and can be prepared by creative methods that allow a fine-tuning of drug release. They are processed in the end form of films, beads, gels, monoliths etc., to reach orientated therapeutic applications. Several studies attest to the higher performance of polymer/LDH-drug nanocomposite compared to the LDH-drug hybrid or the free drug.
Folic acid and sodium folate salts: Thermal behavior and spectroscopic (IR, Raman, and solid-state 13C NMR) characterization
Vagner R. Magri, Michele A. Rocha, Caroline S. de Matos, Philippe A.D. Petersen, Fabrice Leroux, Helena M. Petrilli, Vera R.L. Constantino
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy, 2022
Layered double hydroxides: Characterization, biocompatibility, and therapeutic purposes
Vera R. L. Constantino, Vanessa R. R. Cunha, Michele A. Rocha, Mariana P. Figueiredo, Vagner R. Magri, Denise Eulálio, Gustavo F. Perotti, Marcos A. Bizeto, Willian F. Zambuzzi, Ivan H. J. Koh
Progress in Layered Double Hydroxides from Synthesis to New Applications, 2022
Departamento de Química Fundamental Instituto de Química Universidade de São Paulo (USP)
Investigation of thermal behavior of layered double hydroxides intercalated with carboxymethylcellulose aiming bio-carbon based nanocomposites
Vagner R. Magri, Alfredo Duarte, Gustavo F. Perotti, Vera R.L. Constantino
Chemengineering, 2019
Carboxymethylcellulose (CMC), a polymer derived from biomass, was intercalated into layered double hydroxides (LDH) composed by M2+/Al3+ (M2Al-CMC, M = Mg or Zn) and evaluated as precursors for the preparation of biocarbon-based nanocomposites by pyrolysis. M2Al-CMC hybrids were obtained by coprecipitation and characterized by X ray diffraction (XRD), vibrational spectroscopies, chemical analysis, and thermal analysis coupled to mass spectrometry. Following, pyrolyzed materials obtained between 500–1000 °C were characterized by XRD, Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Above 600 °C, Raman spectra of all samples showed the presence of graphitic carbon, which plays a role in the degree of crystallinity of produced inorganic phases (for comparison purposes, M2Al-CO3 materials were investigated after calcination in the same experimental conditions). XRD patterns of Mg2Al-CMC pyrolyzed between 600–1000 °C showed poorly crystallized MgO and absence of spinel reflections, whereas for Zn2Al-CMC, it was observed well crystallized nanometric ZnO at 800 °C, and ZnAl2O4 and γ-Al2O3 phases at 1000 °C. Above 800 °C, the carbothermic reaction was noticed, transforming ZnO to zinc vapour. This study opens perspectives for nanocomposites preparation based on carbon and inorganic (mixed) oxides through precursors having organic-inorganic interactions at the nanoscale domain.