Effect of He-Ne Laser (632.8 nm) and Polygen™ on CHO Cells

Objective: We determined the effect of He-Ne laser biostimulation in combination with Polygen™ (PG) on Chinese hamster ovary (CHO) cells. Background Data: Several studies have shown that He-Ne laser (632.8 nm), growth factors, and growth hormone can enhance cellular proliferation and that the use of low-level laser stimulation combined with growth factor stimulation has scientific support. PG, an animal protein extract containing a blend of growth factors and growth hormone, was used together with a He-Ne laser to determine their efficacy in the enhancement of cellular proliferation. Methods: The dose–response curves for the colony-forming ability of CHO cells in 5% FCS-MEM with 6–125 μg/ml PG and He-Ne laser with an optimum power density of 1.25 mW/cm² and cumulative doses of 60–600 mJ/cm² was given for 3 consecutive days. The combined effects of He-Ne laser 180 mJ/cm² with 6 and 12 μg/ml PG were determined. Quadruplicate cultures were performed. The student's t-test was used to ascertain differences of treated groups from controls. Results: The mean number of colonies (MNC) was increased using 180 mJ/cm² laser by 13.2% (p < 0.01); 6 and 12 μg/ml PG by 19.2% (p < 0.0025) and 13.2% (p = 0.01); laser + PG 6 μg/ml by 23.2% (p < 0.001) and laser + PG 12 μg/ml by 20.5% (p < 0.001). An additional significant increase of 8.8% (p < 0.05) and an insignificant 6.4% (p = 0.086) by laser + PG 6 μg/ml and laser + PG 12 μg/ml were observed, respectively, when compared to the solitary effect of laser. Conclusions: Results suggest that the He:Ne laser or PG can stimulate CHO cell proliferation and that further stimulation can be achieved by using the He:Ne laser and PG simultaneously. This combination could be useful as a new treatment modality.