Low-Dose Blue Light (420 nm) Reduces Metabolic Activity and Inhibits Proliferation of Human Dermal Fibroblasts

Abstract

Hypertrophic scarring in burn wounds is caused by overactive fibroblasts and myofibroblasts. Blue light reveals wavelength- and dose-dependent antibacterial and antiproliferative effects and may serve as a therapeutic option against wound infection and fibrotic conditions. Therefore, we evaluated in this study the effects of single and multiple irradiations with blue light at 420 nm (BL420) on the intracellular ATP concentration, and on the viability and proliferation of the human skin fibroblast (HDFs). In addition, possible BL420-induced effects on the catalase expression and differentiation were assessed by immunocytochemical staining and western blot analyses. Furthermore, we used RNA-seq analyses to identify BL420-affected genes. We found that BL420 induced toxicity in HDFs (up to 83%; 180 J/cm2). A low dose of 20 J/cm2 reduced the ATP concentration by ~50%. Multiple irradiations (4 × 20 J/cm2) inhibited proliferation without visible toxicity and reduced catalase protein expression by ~37% without affecting differentiation. The expression of about 300 genes was significantly altered. Many downregulated genes have functions in cell division/mitosis. BL420 can strongly influence the fibroblast physiology and has potential in wound therapy. However, it is important to consider the possible toxic and antiproliferative effects, which could potentially lead to impaired wound healing and reduced scar breaking strength.

Photobiomodulation at 660 nm Stimulates In Vitro Diabetic Wound Healing via the Ras/MAPK Pathway

“…Blue light has been demonstrated to be beneficial for treating acute and chronic skin wounds, reducing inflammation, and promoting tissue regeneration [ 27 ]. Other studies have also reported that blue light holds some promise, particularly in the fight against excessive scarring and wound infections; however, it is crucial to consider the potential toxic and antiproliferative effects and to carefully consider the benefits and risks of using blue light to minimise the disturbances of skin physiology, which could result in impaired wound healing/closure and decreased scar breaking strength [ 28 ]. In this present study, a wavelength of 660 nm and a fluence of 5 J/cm 2 was used.…”

Promising Functions of Novel Vitamin D Derivatives as Cosmetics: A New Fountain of Youth in Skin Aging and Skin Protection

“…The loss of the internal skin barrier is caused by internal factors, such as the metabolism of the cells and genetics [86][87][88][89]. The loss of the external skin barrier is caused by external factors, such as radiation, UVA (315-400 nm), UVB (280 to 315 nm), UVC (190-280 nm), infrared (IR) (750 nm-1000 µm), blue light (400-500 nm) [90,91] and chemicals [86,92,93]. An integral part of this process is the prolonged exposure of the skin to UVA, UVB or blue light causing photo-aging, characterized by loss of skin elasticity, wrinkling and skin hyperpigmentation, primarily on the face [69,86,94,95].…”