Banca de DEFESA: KARINA FELICIANO SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : KARINA FELICIANO SANTOS
DATA : 03/09/2021
HORA: 13:00
LOCAL: https://conferenciaweb.rnp.br/webconf/juliana-kelmy-macario-barboza-daguano
TÍTULO:

Development of a sacrificial paint based on PEG - Laponite to obtain ceramic scaffolds using Robocasting

PÁGINAS: 80
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Biomédica
SUBÁREA: Engenharia Médica
ESPECIALIDADE: Biomateriais e Materiais Biocompatíveis
RESUMO:

Biosilicate® has been extensively investigated in the regeneration of bone and dental tissue, due to its excellent bioactive and osteoinductive properties. However, most studies to obtain scaffolds of this bioceramic use methods with agents that do not allow safe control of pore size or techniques that demand time, cost or are difficult to process. As an alternative, the use of additive manufacturing (AM) techniques to obtain three-dimensional (3D) structures has been an approach explored as a field of tissue engineering. Commonly, the technique used to obtain ceramics, known as Robocasting, which uses extrusion-based 3D printing as a strategy, can be an interesting alternative. Thus, the use of hydrogels (polymeric networks capable of absorbing and retaining large amounts of water) offer the potential to design scaffolds using the extrusion technique due to their pseudoplastic behavior, a characteristic not inherent to ceramic materials. Furthermore, materials such as Laponite, a two-dimensional nanosilicate, allow the rheological control of gels creating an optimized condition for 3D printing. Thus, this work aimed to study hydrogels developed as sacrificial paint to obtain a Biosilicate ceramic scaffold using the robocasting technique. For this purpose, paints based on Polyethylene Glycol (PEG) were developed, with different additions of Laponite, as a rheological modifier. Initially, the rheological behavior of precursor gels with different levels of Laponite 5, 7.5 and 10% (m/m) was evaluated. The viscosity of the PEG 80% solution (v/v) increased with the addition of nanosilicate, demonstrating pseudoplastic and thixotropic behavior, ideal for 3D printing. Then, shape fidelity tests were carried out by printing filaments, to evaluate the composition with the greatest potential for application as a sacrificial ink to be used in obtaining the ceramic paste. It was observed that the ink containing 7.5% (P7.5L) showed promising results and was chosen for the concept test, that is, the development of printed scaffolds of Biosilicate® with a content of 70% (v/v) of ceramic charge. The three-dimensional structures were dried at 20°C and sintered at 900°C for a period of 5h, according to the result of optical dilatometry. The samples obtained in this process were analyzed for their rheology, chemical composition by FTIR, microstructure by SEM, crystalline phases present by XRD, and for their cytotoxicity by means of an in vitro test with fibroblasts. Finally, it was possible to demonstrate the construction of scaffolds from P7L paint associated with Biosilicate®, with good shape fidelity, with the sacrificial paint being removed by means of heat treatment, without compromising the structures or changing the final composition of the material . In conclusion, the use of LP gels combined with Biosilicate proved to be promising for the composition of a ceramic paint aiming at obtaining 3D structures by robocasting, aiming at bone tissue regeneration.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1903304 - JULIANA KELMY MACARIO BARBOZA DAGUANO
Membro Titular - Examinador(a) Externo à Instituição - MARINA TREVELIN SOUZA - UFSCAR
Membro Titular - Examinador(a) Externo à Instituição - CLAUDINEI DOS SANTOS - UERJ
Membro Suplente - Examinador(a) Interno ao Programa - 1604317 - SONIA MARIA MALMONGE
Membro Suplente - Examinador(a) Externo à Instituição - DAVINSON MARIANO DA SILVA
Membro Suplente - Examinador(a) Externo à Instituição - JANAINA DE ANDREA DERNOWSEK