Banca de DEFESA: LAURA PRISCILA BARBOZA DE CARVALHO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : LAURA PRISCILA BARBOZA DE CARVALHO
DATA : 31/10/2018
HORA: 08:30
LOCAL: DEPARTAMENTO DE ODONTOLOGIA DA UFRN
TÍTULO:

EFFECT OF DIFFERENT DOSES OF LASER THERAPY ON DENTAL STEM CELLS CULTURED ON POLYLACTIC ACID SCAFFOLDS

PALAVRAS-CHAVES:

Stem cells; biomaterials; polylactic acid; low-level laser; cell proliferation.

PÁGINAS: 72
GRANDE ÁREA: Ciências da Saúde
ÁREA: Odontologia
RESUMO:

Dental mesenchymal stem cells (dMSCs) have been widely used in tissue engineering for their capacity for self-renewal and multi-lineage potential. Among the dMSCs, the stem cells from human exfoliated deciduous teeth (SHEDs) are highlighted for their ease of collection, proliferative capacity and survival time. The aim of the study was to evaluate, through in vitro experiments, the effect of different doses of low intensity laser (LLLI) on the biological activity of SHEDs cultured on polylactic acid (PLA) scaffolds. Pre-isolated and characterized cells were cultured on PLA films and irradiated or not (control) with an InGaAlP diode laser (660 nm, 30 mW, continuous action mode) in a dose screening (1, 4, 7.5, 15, 22.5 and 30 J/cm²). Cell proliferation and viability were analyzed at 24, 48 and 72 hr using the Alamar Blue and Live/Dead assays. Cell morphology was evaluated by SEM at 72 h. The evaluation of oxidative stress was performed through the dosages of malondialdehyde (MDA) and glutathione (GSH). Energy densities of 1 J/cm² and 4 J/cm² promoted a stimulating effect on cell proliferation in all intervals when compared to the control group and the other irradiated groups. On the other hand, high doses of irradiation (22.5 and 30 J/cm²) promoted significant reduction of the cells. It was verified that cell viability was affected throughout the experiment in groups L22.5 and L30, which presented a higher number of dead cells in the interval of 72h. The SEM analysis showed a greater cell density in L1 and L4 groups, opposing the SHEDs arranged more sparsely in L22.5 and L30 groups. Regarding to oxidative stress, in L1 and L4 groups there was elevation of GSH levels and reduction of MDA, showing a cytoprotective effect of these doses. Conversely, in groups L22.5 and L30 there was a reduction of GSH levels and elevation of MDA, corroborating with the results of the aforementioned assays. It is concluded that low doses of LLLI (1 and 4 J/cm²) promote proliferation of SHEDs on PLA scaffolds, while high doses (22.5 and 30 J/cm²) promote cytotoxic and anti-proliferative action in these cells.

MEMBROS DA BANCA:
Presidente - 2220417 - CARLOS AUGUSTO GALVAO BARBOZA
Externo à Instituição - FERNANDO JOSE DE OLIVEIRA NOBREGA - UERN
Interno - 1258693 - LELIA MARIA GUEDES QUEIROZ
Externo à Instituição - MANUEL ANTONIO GORDON NUNEZ - UEPB
Interno - 350484 - ROSEANA DE ALMEIDA FREITAS