Banca de DEFESA: JANA DARA FREIRES DE QUEIROZ

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : JANA DARA FREIRES DE QUEIROZ
DATA : 27/04/2018
HORA: 09:00
LOCAL: Sala de Videoconferência POP-RN
TÍTULO:

EVALUATION OF BIOMATERIALS FOR BONE REGENERATION PURPOSES


PALAVRAS-CHAVES:

Biomaterials, Surface Modification, Human Mesenchymal Stem Cells, Osteoinduction, Genotoxicity.


PÁGINAS: 150
GRANDE ÁREA: Ciências da Saúde
ÁREA: Farmácia
RESUMO:

Different types of biomaterials have been developed over the years with various biomedical applications mainly for bone regeneration purposes. Technological evolution has led to the development of new and better biomaterials. Among the various types of biomaterials currently available, the nano and microstructured surfaces and nano and micrometric scale materials have gained prominence. LASER beam treatment is a controllable and flexible approach to modifying surfaces that creates a complex nano and micro-structured topography and thanks to its properties various types of particles have been widely developed. Although many studies have been conducted to evaluate the response to differentiation, little attention was paid to the genotoxic potential during this process. Therefore, assays to evaluate biocompatibility, including genotoxic studies, should be performed. The behavior of human mesenchymal stem cells was analyzed after exposure to surface modified laser discs and hydroxyapatite particles. Titanium disks were evaluated by electron microscopy, x-ray diffraction and contact angle measurement. The surface generated by the creep of 235 J / cm2 was used in the biological assays: MTT, mineralization, alkaline phosphatase activity and qRT-PCR for osteogenic markers. The nanoparticles (nanoXIM • HAp102®, Fluidinova, S.A.) and commercially available hydroxyapatite microparticles (Biotal Plasma) at concentrations of 0.1, 1 and 10 μg / ml were used and analyzed after 1, 3 and 7 days. The analysis of the data of the modified laser titanium a cell type dependent behavior reducing the proliferation of the mesenchymal stem cells and increasing the expression of the osteogenic markers and alkaline phosphatase activity in these cells. Particle evaluation showed that these did not affect the viability of hMSC (p <0.05), however, the higher concentrations used seem to induce an early osteogenic differentiation. This was evidenced by anticipation of the expected maximum levels of alkaline phosphatase activity (p <0.05) and extracellular matrix mineralization (p <0.01). No significant changes were observed in the oxidative state and the evaluated genotoxic potential. Interestingly, the frequencies of nucleoplasmic bridges (NPB) and DNA damage by the comet test were higher after 7 days under control conditions, suggesting that these bridges are characteristic of isolated hMSCs and tend to disappear during the differentiation process. Our findings show that laser irradiated titanium can modulate cell behavior in a cell type dependent manner and stimulate osteogenic differentiation. In addition, particle data suggest that the exposure induces a sufficient cellular response to prevent genetic instability and does not have prolonged genotoxic effects during osteogenic differentiation. Thus, the analyzed biomaterials demonstrate potential for its use in regenerative medicine and insofar as the particles appear to be safe in relation to genotoxicity


MEMBROS DA BANCA:
Presidente - 1199127 - SILVIA REGINA BATISTUZZO DE MEDEIROS
Externo ao Programa - 2220417 - CARLOS AUGUSTO GALVAO BARBOZA
Externo ao Programa - 1544647 - MATHEUS DE FREITAS FERNANDES PEDROSA
Externo à Instituição - ALEXANDRE MALTA ROSSI - CBPF
Externo à Instituição - MELISSA CAMASSOLA - ULBRA
Notícia cadastrada em: 20/04/2018 15:40
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