Blue Light Enhancement of Salivary Gland Cells Proliferation Ability

Background: The salivary glands have a crucial role in maintaining oral cavity and upper gastrointestinal health. Several conditions bring about impaired salivary glands function among them irradiation of the head and neck in cancer patients. At present, no conventional beneficial treatment is available for these patients. We aim to develop a novel therapy using stem cell methodology in order to regenerate impaired salivary parenchymal tissue. Working hypothesis: We hypothesize that blue light may induce stressful condition followed by elevation of the proliferate potential of rat submandibular salivary gland (RSSG) epithelial cell. These cells may be used for autologous implantation to restore glands' function following irradiation therapy. Objective: To examine the effect of blue light on proliferation capability of RSSG epithelial cells. Methods: RSSG parenchymal cells were isolated using the Percoll gradient technique and seeded on collagen 1 pre-coated 96 well plates. Cells were exposed to a filtered xenon blue light source (400 to 500nm, peak 460 nm) (MSq, IL) for 120 seconds, equivalent to fluence of 46 J/cm2. Methylen blue proliferation assay of exposed RSSG cells versus control cells was utilized 1, 3, 5, 7, 10 and 15 days later. Results: RSSG cells demonstrated a shift in the peak of proliferation rate from day 10 (control group) to day 7 while maintaining similar proliferation rate. Conclusion: Our study demonstrates the ability of blue light to stimulate a more rapid proliferation capability of RSSG epithelial cells. Further work will assess the potential of this technique to enhance salivary gland cell regeneration capability as a future novel therapeutic tool for irradiated head and neck cancer patients.