Banca de DEFESA: DHIEGO MARADONA ARRUDA COELHO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : DHIEGO MARADONA ARRUDA COELHO
DATE: 30/07/2024
TIME: 09:00
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:

METALLOGELS CONTAINING LANTANIDE IONS: FROM STRUCTURAL ELUCIDATION TO POSSIBLE APPLICATIONS IN BIOLOGICAL SYSTEMS

KEY WORDS:

Iminodiacetic Acid. Lanthanides. Structural Elucidation. Photothermal Therapy.

PAGES: 137
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

The present work reports the synthesis of hydrogels with lanthanide ions (Ln = Gd3+, Eu3+ and Tb3+) with iminodiacetic acid (IDA), 3(1H-imidazol-2-yl) benzoic acid (IBA) in proportions 5 and 25% of the IBA ligand by the microwave-assisted hydrothermal method. As well as the synthesis of gold nanorods (AuNRs) and the combination of the drug methotrexate (MTX) with hydrogel. Infrared analyzes were able to confirm the progression of the ligands with lanthanide ions. Rheological tests made it possible to observe the behavior as non-Newtonian fluids and the storage modulus (G’) greater than the loss modulus (G”) and mechanical properties of viscoelastic solids typical of gels. The emission spectra of hydrogels containing Eu3+ were observed as transitions 5D0→7FJ (J = 0-4) with the transition 5D0→7F2 (red color) more intense. For Tb3+ hydrogels, the emission spectrum was distributed over the transitions 5D4 → 7FJ (J = 6-0) of Tb3+ with the transition 5D4→7F5 (green color). Hydrogels containing Gd3+ did not provide transfers or transitions in the visible spectrum region. The cell prediction tests ranged from 70.42% (HL60-IBA) to 55.97% (HeLa-IBA/MTX), which indicates that in vitro tests demonstrate cytotoxicity of the hydrogels for the majority of strains tested, with a reduction in cell forecast above 30%. Theoretical methodologies are useful for complementary experimental investigations. The LUMPAC software is a very useful tool for calculating the geometry of the ground state, calculating the intensity parameters (Ωλ), radiative (Arad) and non-radiative (Anrad) emission rates, and quantum efficiency (η), calculating the of energy transfer and emission quantum yield (q), so that it was possible to elucidate the structures for the hydrogel systems and their variations in the method, as well as corroborate that the system had 3 water molecules coordinated to the Eu3+ ion. And the system with deuterated water showed a quantum efficiency of approximately 76%. The synthesized gold nanorods (AuNRs) showed optical absorption of radiation in a wide range of the infrared region. One absorption band at 510 nm attributed to transverse surface plasma resonance (TSPR) and another band centered at 906 nm referring to longitudinal surface plasma resonance (LSPR). AuNRs demonstrate the potential to be used as photosensitizers for diagnosis and photothermal (TFT)/photodynamic (TFD) therapy for the treatment of tumors and pathogens.

COMMITTEE MEMBERS:
Interno - 2457389 - EDUARDO PADRON HERNANDEZ
Externo à Instituição - LUIZ GONZAGA DE FRANCA LOPES - UFC
Externo à Instituição - RICARDO OLIVEIRA FREIRE - UFS
Externo à Instituição - RODRIGO DA SILVA VIANA - UFAL
Presidente - 1354207 - SEVERINO ALVES JUNIOR