Effects of light-emitting diode (led 640nm) on human gingival fibroblasts: a comparative in vitro study

The light-emitting diodes (LEDs) have been applied in oral surgery for tissue stimulation and wound healing. Several Authors have highlighted that fibroblasts subjected to phototherapy have an increased viability, proliferation, biomodulation of inflammatory cytokines and genes expression. It remains to be determined which are the best irradiation parameters (energy, wavelength, power) for each type of cell in order to obtain the best bio-stimulation. The aim of this study was to investigate the effects of LED irradiation on primary human gingival fibroblast cells (HGF) on DSP, ELN, HAS1, ELANE, HYAL1, RPL13 genes activation using Real Time PCR. These genes activation is directly connected with elastin protein production and HGF functionality.

Human gingival tissue biopsies were obtained from three healthy patients during extraction of teeth. The gingival pieces were fragmented with a scalpel and transferred in culture dishes for allow the cells growth. Human gingival fibroblasts at the second passage were seeded on multiple 6-well plates and were stimulated with three different light-emitting diodes (LEDs) fixture. After irradiation, the cells were trypsinized, harvested and lysed for RNA extraction. Genes expression was quantified using Real Time PCR.

We didn't found significant differences in genes activation of HGF of the three different LEDs. The LED irradiation seems to be directly correlated with the elastin and hyaluronoglucosaminidase 1 genes activation that are directly connected with proteins production and HGF functionality.

HGF show an increased deposition of elastin as well as enhanced expression of collagen type I, which is the main protein related to the synthesis and of the collagen-rich matrix.