Effect of low-level laser irradiation on proliferation and viability of human dental pulp stem cells.
A positive effect of low-level laser irradiation (LLLI) on the proliferation of some cell types has been observed, but little is known about its effect on dental pulp stem cells (DPSCs). The aim of this study was to identify the lowest energy density able to promote the proliferation of DPSCs and to maintain cell viability. Human DPSCs were isolated from two healthy third molars. In the third passage, the cells were irradiated or not (control) with an InGaAlP diode laser at 0 and 48 h using two different energy densities (0.5 and 1.0 J/cm²). Cell proliferation and viability and mitochondrial activity were evaluated at intervals of 24, 48, 72, and 96 h after the first laser application. Apoptosis- and cell cycle-related events were analyzed by flow cytometry. The group irradiated with an energy density of 1.0 J/cm² exhibited an increase of cell proliferation, with a statistically significant difference (p < 0.05) compared to the control group at 72 and 96 h. No significant changes in cell viability were observed throughout the experiment. The distribution of cells in the cell cycle phases was consistent with proliferating cells in all three groups. We concluded that LLLI, particularly a dose of 1.0 J/cm², contributed to the growth of DPSCs and maintenance of its viability. This fact indicates this therapy to be an important future tool for tissue engineering and regenerative medicine involving stem cells.
Postgraduate Program in Dentistry, Federal University of Rio Grande do Norte, Natal, RN, Brazil. ivana_zac@hotmail.com.
Ivana Maria
IM
Zaccara
Postgraduate Program in Oral Pathology, Federal University of Rio Grande do Norte, Natal, RN, Brazil. fernandaginani@hotmail.com.
Fernanda
F
Ginani
Faculty of Dentistry, Federal University of Rio Grande do Norte, Natal, RN, Brazil. haroldogmota@gmail.com.
Haroldo Gurgel
HG
Mota-Filho
Laboratory of Oral Pathogy, School of Dentistry, Federal University of Bahia, Salvador, BA, Brazil. aguidacgh@gmail.com.
Águida Cristina Gomes
ÁC
Henriques
Postgraduate Program in Oral Pathology, Federal University of Rio Grande do Norte, Natal, RN, Brazil. cbarboza@cb.ufrn.br.|Department of Morphology, Center of Biosciences, Federal University of Rio Grande do Norte, Natal, RN, Brazil. cbarboza@cb.ufrn.br.
Carlos Augusto Galvão
CA
Barboza
D049109:Cell Proliferation / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D003782:Dental Pulp / Q000166:cytology*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D054023:Lasers, Semiconductor; D013234:Stem Cells / Q000166:cytology* / Q000528:radiation effects*; D013997:Time Factors; D023822:Tissue Engineering
Dental pulp; Laser therapy; Lasers; Low level; Stem cells