# Laser-stimulated human gingival fibroblasts: alterations in migration, secretome production, and induction of reactive oxygen species

## TL;DR

Low-level laser treatment changes human gum cell behavior, boosting growth and collagen production, with 940 nm lasers having the strongest effects.

## Contribution

This study reveals novel effects of low-level laser irradiation on fibroblast function and secretome-mediated communication.

## Key findings

- 940 nm laser treatment significantly increased cell proliferation and migration.
- Laser-stimulated secretome enhanced non-irradiated cell density.
- 940 nm lasers caused the most significant increases in ROS and mitochondrial membrane potential.

## Abstract

This study aimed to investigate the effects of low-level laser irradiation on human gingival fibroblasts, specifically examining changes in proliferation, morphology, migration, and reactive oxygen species (ROS) production. Additionally, we assessed the impact of the secretome from irradiated fibroblasts on non-irradiated cell proliferation and migration. Human gingival fibroblasts were exposed to 650–940 nm laser irradiation for 50 s. Cell proliferation was quantified using resazurin, while migration was evaluated through a wound generation assay and by treating non-irradiated cells with the secretome from irradiated fibroblasts. We also analysed changes in type I collagen (COL1A1) expression, ROS production, and mitochondrial membrane potential (ΔΨm). Both 650 nm and 940 nm laser treatments induced morphological changes and significantly enhanced cell proliferation, observed 10 days post-irradiation, without causing cell detachment or death. Non-irradiated cells treated with the secretome from 940 nm-irradiated fibroblasts exhibited increased cell density at five and 10 days post-irradiation. Laser treatment at both wavelengths significantly stimulated cell migration. Cells irradiated with the 650 nm laser showed increased COL1A1 expression at five days, while those treated with 940 nm demonstrated a marked increase at 10 days. Low-level laser treatment led to significant increases in both ROS production and ΔΨm. In conclusion, low-level laser treatment induced morphological changes and increased proliferation, cell migration, and COL1A1 expression in gingival fibroblasts. Treatment with laser-stimulated cell secretome significantly enhanced gingival fibroblast proliferation. The 940 nm laser treatment elicited the most pronounced cellular changes, particularly in relation to increased ROS production and ΔΨm.