Evaluation of light-emitting diode (LED-835 NM) application over human gingival fibroblast: an in vitro study

Since the laser and photomodulation were discovered over 50 years, they have been used for many applications in medicine and in dentistry also. In particular, light-emitting diodes therapy (LT) achieved a great success in medical treatment and photo-therapy. In the decades, LT has been used for several therapeutic purposes. Many beneficial effects have been demonstrated in vitro and in vivo, including antibacterial, antiviral, antitumor, cell differentiation, immune potentiating and tissue repair activities. Beneficial effects of LT have also been observed in clinical settings. Although there are lots of cell culture studies in low-level laser therapy, there are only a few cell culture studies in LT that have similar characteristics. The aim of this study was to investigate the effects of LT on primary human gingival fibroblast cells (HGF) on elastin (ELN) gene activation using Real Time PCR. ELN gene activation is directly connected with elastin protein production and HGF functionality. Human gingival tissue biopsies were obtained from three healthy patients during tooth extraction. The gingival specimens were fragmented with a scalpel and transferred in culture dishes containing Dulbecco’s modified Eagle medium supplemented with 20% fetal calf serum (FBS) and antibiotics, i.e. penicillin 100U/ml and streptomycin 100μg/ml. Cells were incubated in a humidified atmosphere of 5% CO2 at 37C. The medium was changed the next day and twice a week. After 15 days, the samples of gingival tissue were removed from the culture dishes. Cells were harvested after an additional 24 h incubation. Human gingival fibroblasts at the second passage were seeded on multiple 6-well plates. The cells stimulation was performed with a light-emitting diodes (LEDs) medical device type E-Light. The LED irradiation seems to be directly correlated with the elastin (ELN) gene activation. Interestingly, ELN gene expression in the cultured human gingival fibroblasts seems to be inversely related to the patients’ age; in fact, its expression tends to decrease with aging. In summary, the result of the present study shows that LED irradiation promoted ELN gene expression more in elderly than in younger adults.