Banca de DEFESA: MARINA ROCHA DO NASCIMENTO DANTAS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARINA ROCHA DO NASCIMENTO DANTAS
DATE: 14/02/2025
TIME: 10:00
LOCAL: Videoconferência - Link para acesso: https://meet.google.com/oho-gedu-uch
TITLE:

Evaluation of osteogenic and genotoxic potentials of nanostructured hydroxyapatite-based microspheres containing zinc

KEY WORDS:

Stemcell;Genotoxicity;Osteoinduction;Biomaterials.

PAGES: 83
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

A wide range of biomaterials is being studied as new alternatives in the field of bone regeneration. Among these, hydroxyapatite (HA) is a mineral component present in the inorganic phase of bones. HA is not only biocompatiblebut also possesses suitable physicochemical properties, allowing for ionic substitutions that enhance its performance for various applications. The REGENERA Institute has developed nanostructured hydroxyapatite (nHA) microspheres with different compositions, including zinc ions (Zn²⁺) incorporation,which are notable for their ability to increase cell viability and promote bone mineralization. However, any modification to HA results in the production of a newbiomaterial that, in addition to confirming its osteogenic capabilities, needs to have its biosafety tested. The osteogenic differentiation capacity of nHA-based microspheres containing zinc ions using stroma stem cells isolated from the Wharton's jelly of human umbilical cords (hWJ-MSCs) was evaluated in this study. Cytotoxicity results, assessed by the MTT assay (3-(4,5-dimethylthiazol-2- yl)-2,5-diphenyltetrazolium bromide), indicated that the samples did not significantly reduce the ability of hWJ-MSCs cells to reduce MTT, suggesting thatthe samples are not cytotoxic under the tested conditions. The bone mineralization results, alkaline phosphatase (ALP) activity, and gene expression quantification assay by qRT-PCR indicated that the samples, under the tested conditions, exhibited osteogenic activity by increasing extracellular matrix mineralization, ALP activity, and the expression of genes related to osteogenesis in hWJ-MSCs. Considering clinical applications, the genotoxic potential of these materials was also assessed. The genotoxicity results, evaluated by the Comet assay and the CBMN assay (cytokinesis-blocked micronucleus assay), showed that the samples do not exhibit genotoxic potential under the tested conditions. Therefore, it is expected that this biomaterial may have applications in bone regeneration.

COMMITTEE MEMBERS:
Externo ao Programa - 2220417 - CARLOS AUGUSTO GALVAO BARBOZA - nullExterno à Instituição - GILDACIO PEREIRA CHAVES FILHO - USP
Presidente - 2085604 - SUSANA MARGARIDA GOMES MOREIRA