Photobiomodulation alters the viability of HUVECs cells

Abstract

The aim of the present study was to investigate the influence of low-level red (660nm) and infrared (780nm) laser with four different radiance exposures on human umbilical vein endothelial cells (HUVECs) in vitro. HUVECs (1.5 × 104) were incubated in 96-well culture plates. The cells were maintained in M199 medium supplemented with 20% fetal bovine serum, 1% antibiotic (penicillin), 1% anti-mycotic (Fungizone), and 1% endothelial cell growth supplement. After centrifugation, irradiations (660/780nm, 40mW, 1, 5, 10, and 20J/cm2, 1s, 5s, 10s, and 20s, respectively, total energy 0.4J, 2J, 4J, and 8J, and beam spot size at target 0.04cm2) were performed at the bottom of Falcon tubes such that the laser beam directly reached the cell without passing through the culture medium. The cells were divided into groups based on radiant exposures. Cell viability and protein concentration were verified after 1, 2, 3, 6, 8, and 10days. Red laser increased the cell viability and protein concentration in all groups (three-way ANOVA, p < 0.05) beginning on the second day. The greatest peak compared with the control was found when the radiant exposure was 5J/cm2 and 10J/cm2. Infrared laser inhibited cell viability and modulated the protein concentration in the cells, with the highest peak protein concentration found on the second day in the group with radiant exposure of 1J/cm2 and 10J/cm2 (three-way ANOVA, p < 0.05). Red laser increased the viability and concentration of total proteins in HUVECs, whereas infrared laser had an inhibitory effect on cell viability, while maintaining the total protein concentration similar to that found in the control group.