Banca de QUALIFICAÇÃO: SALOME RIBEIRO DA SILVA
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : SALOME RIBEIRO DA SILVA
DATE: 04/07/2022
TIME: 14:00
LOCAL: Link de acesso para videoconferência: https://meet.google.com/dvy-puem-jkp
TITLE:
In vitro and in vivo characterization and evaluation of the hydroxyapatite/niobium composite
KEY WORDS:
Hydroxyapatite, Niobium, bioceramics, implant.
PAGES: 56
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:
Hydroxypatite (Hap) is a composite product, much studied and used for the use of
a clinical component of bones, its use provides conditions for training, thus
allowing a biological formation of a mineral that is widely used for reconstruction of
organic tissues. , very little progress can be made in relation to materials capable
of fulfilling with excellence the function of new constituent elements of the
implanted ones, it appears as a motivation for boneintegrated studies, since it
provides the patient with new elements of choice for their treatments. In this
sense, a composite of Hydroxyapatite/Niobium was considered as a bioceramic
material, it was characterized in terms of its morphology [X-ray diffraction (XRD),
tension, cracking and toughness [Scanning electron microscopy (SEM)]. In vitro
analysis, 2 groups were used in cell culture: scaffold with pure hydroxyapatite
(G1), and a stabilized hybrid scaffold of hydroxyapatite/niobium (G2), the groups
were applied in culture of pre-osteoblast cells MC3T3 – E1 derived from calvaria
and analyzed for cell proliferation and viability, assay with Alizarin red dye and
osteogenic differentiation (Alkaline Phosphatase Assessment). The in vivo
evaluation was carried out in a model of the skull with a critical defect of 8 mm
performed in Wistar rats, with 3 experimental groups: Control (GC) -Group I
(positive control); Group II (hydroxyapatite standard) and Group III
(Hydroxyapatite/Niobio). After 90 days the animals will be euthanized and the
samples evaluated by Micro CT, HE, immunohistochemistry, RT PCR. The data
obtained were statistically evaluated through the ANOVA test and as results we
had: In the mechanical results of XRD, the presence of hexagonal crystalline Hap
and a P63/m space group was observed in the pure sample, while in the group
with Nb it was observed the presence of β-tricalcium phosphate (Ca3(PO4)2) and fersmite (CaNb2O6), which may be related to the decomposition of Hap in the
presence of Nb. In the XRF analysis, results were obtained close to those of
milling, proving that the technique used was efficient. Regarding the presence of
indentations and cracks, there was a small increase in fracture toughness from
Hap (0.78 MPa.m1/2) to Hap/Nb (0.82 MPa.m1/2). In the in vitro biological results:
for cell viability, it was observed that Hap and Hap/Nb presented higher values of
cell viability at 48h and 72h of exposure (p=0.001); for osteogenic differentiation, in
Hap samples we had greater cell differentiation when compared to the control
group. As in vivo results: for procollagen 1 it presented one (p < 0.05) and (p <
0.01) for procollagen 3 in the Hap/Nb sample; OSTERIX (p<0.01) in Hap/Nb
samples compared to Hap; For BPM2 we obtained (p<0.05) when comparing the
control with pure Hap; In the Nb/Hap group we had an expression of RUNX 2
(p<0.05). The findings point to satisfactory results for the material under study
Nb/Hap, so we suggest completion of the tests for better evaluation of the
material
COMMITTEE MEMBERS:
Externo ao Programa - 2220417 - CARLOS AUGUSTO GALVAO BARBOZA - nullInterna - 1055045 - MARCELA ABBOTT GALVAO URURAHY
Presidente - 1544647 - MATHEUS DE FREITAS FERNANDES PEDROSA