ABSTRACT
Low-level laser therapy (LLLT) has been used in several in vitro experiments in order to stimulate cell proliferation. Cells such as fibroblasts, keratinocytes, lymphocytes, and osteoblasts have shown increased proliferation when submitted to laser irradiation, although little is known about the effects of LLLT on stem cells. This study aims to assess, through a systematic literature review, the effects of LLLT on the in vitro proliferation of mesenchymal stem cells. Using six different terms, we conducted an electronic search in PubMed/Medline database for articles published in the last twelve years. From 463 references obtained, only 19 papers met the search criteria and were included in this review. The analysis of the papers showed a concentration of experiments using LLLT on stem cells derived from bone marrow, dental pulp, periodontal ligament, and adipose tissue. Several protocols were used to irradiate the cells, with variations on wavelength, power density, radiation time, and state of light polarization. Most studies demonstrated an increase in the proliferation rate of the irradiated cells. It can be concluded that the laser therapy positively influences the in vitro proliferation of stem cells studied, being necessary to carry out further experiments on other cell types and to uniform the methodological designs.
Subject(s)
Low-Level Light Therapy , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/radiation effects , Animals , Cell Proliferation/radiation effects , Cells, Cultured , Humans , MiceABSTRACT
Objetivo - Avaliar a influência do processo de envelhecimento sobre a capacidade de adesão e proliferação das células mesenquimais da medula óssea de camundongos, comparando-se dois grupos de animais: jovens (30 dias de idade) e senis (18 meses de idade). Métodos - Extratos de medula óssea foram coletados do canal medular de tíbia e fêmur de camundongos jovens (n=5) e senis (n=5) e as células mesenquimais foram cultivadas em meio de cultura alfa-MEM nos intervalos de 24, 48 e 72 horas. Resultados - Observou-se uma curva crescente de proliferação celular nos animais jovens, enquanto nos animais senis houve uma grande redução no número de células no intervalo de 72 horas.Conclusão - A idade do animal é um fator importante no rendimento in vitro de células mesenquimais da medula óssea nos períodos iniciais do cultivo, o que pode influenciar no resultado dos experimentos com este tipo celular.
Objective - To evaluate the influence of aging on the adhesion and proliferation of mesenchymal cells from mice bone marrow, comparing two groups: young (30 days old) and senile (18 months old) animals. Methods - Extracts of bone marrow were collected from the marrow cavity of the tibia and femur of young (n=5) and senile (n=5) mice and the mesenchymal cells were cultured in MEM for intervals of 24, 48 and 72 hours. Results - It was found an increased curve of cell proliferation in young animals while in senile animals there was a large reduction in cell number in the 72 hours period. Conclusion - The animal's age is an important factor in the in vitro yield of from bone marrow mesenchymal cells in the early periods of culture, which may influence the results of experiments with this cell population.
