Banca de QUALIFICAÇÃO: KARINA FELICIANO SANTOS
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.DISCENTE : KARINA FELICIANO SANTOS
DATA : 17/09/2020
HORA: 14:00
LOCAL: https://conferenciaweb.rnp.br/webconf/juliana-63
TÍTULO:
Development of PEG-Laponita bioink for application on osteochondral repair using bioprinting technique based on 3D extrusion
PÁGINAS: 71
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Biomédica
SUBÁREA: Engenharia Médica
ESPECIALIDADE: Biomateriais e Materiais Biocompatíveis
RESUMO:
Hydrogels are crosslinked polymeric networks capable of absorbing and retaining a large number of water due to their hydrophilic nature, which draws attention to the application in Tissue Engineering. Besides, these materials offer the potential to design scaffolds based on their pseudoplastic behavior, which is essential for extrusion-based three-dimensional (3D) printing. The addition of Laponite, a two-dimensional disk-shaped nanosilicate, allows modifying the rheological behavior of some gels, creating an optimized condition for 3D printing. In this study, the rheological characterization of the composite hydrogel PEG-Laponite-Alginate (PL-Alg) and its precursor gel PEG-Laponite (PL) was carried out, aiming in the future for 3D bioprinting of constructs. Initially, the rheological behavior of different concentrations of Laponite in the PL composite (5, 7.5, and 10% w/w) was evaluated. The viscosity of the PEG-400 solution (80% v/v) increased dramatically as a function of the addition of Laponite, characterizing a strong shear-thinning and solid-like rheological behavior, ideal for 3D printing. The effect of different levels of Laponite can also be noted for the composite (PL-Alg), keeping the concentration of PEG400 (80% v/v) and Alginate (2.5% w/w) fixed, the latter being added as a second network precursor to crosslink the PEG-Laponite hydrogel. Concerning thixotropy analysis, all composites showed a partial recovery of viscosity as a function of time after the application of shear. This rheological parameter must be considered in the development of a bioink. PL-Alg scaffolds containing (5, 7.5, and 10% w/w) Laponite were printed containing up to 10 layers and placed in a CaCl2 solution to promote crosslinking of the Alginate chains. Subsequently, in vitro degradation and swelling tests were performed in phosphate-buffered saline solution (PBS) at 37 °C, showing that the dissolution of the composite hydrogel network was more critical for the sample with 5% Laponite. In conclusion, for future work, the most appropriate way of crosslinking the PEG chain should be considered to improve the mechanical properties and the resistance to degradation, enabling the use of the PEG-Laponite-Alginate system as a bioink for 3D bioprinting applications for Tissue Engineering.
MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1604317 - SONIA MARIA MALMONGE
Membro Titular - Examinador(a) Externo ao Programa - 1850090 - ANNE CRISTINE CHINELLATO
Membro Titular - Examinador(a) Externo ao Programa - 1997753 - LUIZ FERNANDO GRESPAN SETZ
Membro Suplente - Examinador(a) Interno ao Programa - 2090031 - ILKA TIEMY KATO PRATES
Membro Suplente - Examinador(a) Externo à Instituição - JANAINA DE ANDREA DERNOWSEK