Banca de DEFESA: KATHARINA GABRIELA SPANIOL

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : KATHARINA GABRIELA SPANIOL
DATA : 03/08/2018
HORA: 14:00
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

Production of ceramic tapes based on TCP/PVA with addition of silver particles via tape casting for bone dressing

PALAVRAS-CHAVES:

TCP, PVA, Silver, tape casting, ceramic sheets.

PÁGINAS: 70
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

Bone defect repair procedures present many challenges due to low cure rates, which has a negative impact on patients' quality of life and hospital costs. A promising alternative for the regeneration of these damaged tissues has been the use of biomaterials in the engineering of bone tissue, especially with the use of barrier membranes. For the production of these membranes, tricalcium phosphate (TCP) has been widely investigated for their chemical and biological similarity to bone tissues and excellent properties of biocompatibility and cell adhesion. However, there are some drawbacks in its use: it degrades a little faster than bone regeneration and its mechanical resistance is relatively low. To overcome these shortcomings, much research has been done to produce composites formed by TCP and polymers with the purpose of improving its mechanical properties. Among these polymers, polyvinyl alcohol (PVA) is a synthetic material that has properties of biocompatibility and non-toxicity being an important raw material for film making. However, its rapid degradability interferes negatively with osteogenesis due to a reduced time of interaction between the material and the bone. A possible solution to this problem is the use of a crosslinking agent, for example citric acid. Infections are considered to be one of the most serious complications during the postoperative period. One answer to this problem is the use of an antibacterial system. The antibacterial activity of silver ions is known to have strong bactericidal effects as well as a broad spectrum of antimicrobial activities. Regarding the methods of film production, tape casting technique has the advantage of producing thin films, of homogeneous structure, with controlled thickness and in large scale. Therefore, the objective of this work is to produce ceramic tapes based on a ceramic, tricalcium phosphate, and a polymer, PVA, containing silver nanoparticles through the production of thin films by the tape casting method with the potential to be used as barrier membranes, with antibacterial effect. The methodology consisted in the production of suspensions (characterized by rheological tests) and ceramic sheets, submitted to thermal analysis (ATG and ATD), X-ray diffraction (XRD), X-ray fluorescence (FRX) scanning electron microscopy (SEM-FEG), bioactivity and cytotoxicity assays. The results show that the suspensions exhibit pseudoplastic behavior, suitable for the process via tape casting. The ATG curves of the tapes show similar profiles, in which the total mass loss process occurred in the temperature range of 30 ° C to 450 ° C. The XRD patterns of the ceramic tapes reveal the formation of β-TCP phase according to standard form (JCPDS 009-0169). The chemical composition of the material confirms the presence of the elements composing the β-TCP phase and the silver element for compositions containing the antimicrobial agent. The water uptake of the samples validates that crosslinking of the sheets by increasing the water resistance of the compositions containing the crosslinking agent. It is possible to observe in the SEM images homogeneous structures and the presence of macropores and that the citric acid modifies the structure of the samples, making it more compact and less porous. The bioactivity assay reveals the formation of a precipitate on the surfaces of the ceramic tapes, proving that the material is bioactive. The results obtained from the cytotoxicity analysis confirm that the material enables cell propagation. It is concluded that the method employed and the processing conditions favored the production of ceramic tapes based on TCP/PVA with potential to be used as barrier membrane for bone regeneration.

MEMBROS DA BANCA:
Externo à Instituição - Ana Paula da Silva Peres - UFRN
Externo à Instituição - EDUARDO GALVAO RAMALHO - IFRN
Externo ao Programa - 2941160 - JOSE HERIBERTO OLIVEIRA DO NASCIMENTO
Presidente - 1149564 - WILSON ACCHAR