Barboza, Carlos Augusto GalvãoSabino, Vladimir Galdino2020-07-292021-10-062020-07-292021-10-062020-07-17SABINO, Vladimir Galdino. Efeitos do laser de baixa intensidade na proliferação e viabilidade de células pré-osteoblásticas na superfície de filmes de ácido polilático. 2020. 32 f. Monografia (Graduação em Biomedicina) – Universidade Federal do Rio Grande do Norte, Natal, 2020.https://repositorio.ufrn.br/handle/123456789/43231Poly(lactic acid) (PLA) is a biomaterial used in many biomedical applications and has a promising future in tissue engineeringscaffolds. Low level laser irradiation (LLLI) has been suggested as a tool to promote in vitrobio-stimulation of various cell types. In this context, this study aimed to verify the efficacy of LLLIon the proliferation of MC3T3-E1 preosteoblasts cultured on a PLA film. The produced PLA films were characterized in terms of hydrophilicity by contact angle tests, surface morphology byscanning electron microscopy (SEM) and nanotopography by atomic force microscopy (AFM). The MC3T3-E1 cells were cultured as three different groups: Control –cells cultured on a polystyrene plastic surface; PLA –cells cultured on a PLA film; and PLA + Laser –cells cultured on a PLA film and submitted to a single irradiation with diode laser (InGaAIP; wavelength 660 nm; power 30 mW; energy density 4 J/cm²). Cell proliferation by the Alamar Blue assay at 24, 48, and 72 h intervals after irradiation. Cell viability was assessed by the Live/Dead assay, apoptosis-related events were evaluated by annexin V/PI expression and cell cycle events were analyzed by flow cytometry. Cell morphology on the surface of each film was assessed by SEM at 72 h. The produced films displayed a smooth and regular surface, with an average surface roughness (Ra) of 21.43 nm. Biochemical assay(Alamar Blue)results indicatedthat the PLA + Laser group exhibited higher proliferation (p <0.01) when compared to the Control and PLA groups. The Live/Dead and Annexin/PI assays indicated anincreased cell viability in the PLA + Laser group, that also presented a higher percentage of cells(p<0.05)in the proliferative cell cycle phases (S and G2/M). These findings were also confirmed by the higher cell density observed in the PLA + Laser group through SEM images. The evidence from this study supports the idea that LLLIincreases the proliferation of MC3T3-E1 cells on PLA surfaces, suggesting that it can be potentially applied in bone tissue engineering.BiomateriaisPolímerosLaserOsteoblastosProliferação CelularViabilidade CelularbachelorThesis