Photobiomodulation of Human Fibroblasts and Keratinocytes with Blue Light: Implications in Wound Healing

Abstract

In recent years, photobiomodulation (PBM) has been recognized as a physical therapy in wound management. Despite several published research papers, the mechanism underlying photobiomodulation is still not completely understood. The investigation about application of blue light to improve wound healing is a relatively new research area. Tests in selected patients evidenced a stimulation of the healing process in superficial and chronic wounds treated with a blue LED light emitting at 420 nm; a study in animal model pointed out a faster healing process in superficial wound, with an important role of fibroblasts and myofibroblasts. Here, we present a study aiming at evidencing the effects of blue light on the proliferation and metabolism in fibroblasts from healthy skin and keratinocytes. Different light doses (3.43, 6.87, 13.7, 20.6, 30.9 and 41.2 J/cm2) were used to treat the cells, evidencing inhibitory and stimulatory effects following a biphasic dose behavior. Electrophysiology was used to investigate the effects on membrane currents: healthy fibroblasts and keratinocytes showed no significant differences between treated and not treated cells. Raman spectroscopy revealed the mitochondrial Cytochrome C (Cyt C) oxidase dependence on blue light irradiation: a significant decrease in peak intensity of healthy fibroblast was evidenced, while it is less pronounced in keratinocytes. In conclusion, we observed that the blue LED light can be used to modulate metabolism and proliferation of human fibroblasts, and the effects in wound healing are particularly evident when studying the fibroblasts and keratinocytes co-cultures.

Blue-LED-Light Photobiomodulation of Inflammatory Responses and New Tissue Formation in Mouse-Skin Wounds

“…These cells stimulated (i) an early inflammatory response; (ii) angiogenesis, thanks to the secretion of TNF-α [ 36 ]; and (iii) the response of fibroblasts that switched into myofibroblasts, which played a role in wound closure, evidenced by re-epithelialization and collagen deposition [ 36 , 37 , 38 , 39 , 40 , 41 ]. Therefore, together with our previous investigation [ 15 , 16 , 19 , 41 , 42 , 43 ], these results show that blue-LED-light irradiation induces a quicker healing process.…”

Photobiomodulation Therapy: A New Light in the Treatment of Systemic Sclerosis Skin Ulcers

“…Some authors have recently reported observations of an improved healing process when superficial wounds are treated with blue LED light with wavelengths in the range 410–430 nm, and a study in an animal model indicated that blue light led to a faster healing process in superficial lesions, with fibroblasts and myofibroblasts playing an important role [ 19 ]. After a critical literature review [ 22 ], further analyses of this group focused on the effects of blue light on fibroblasts and keratinocytes; it was observed that blue LED light may be used to modulate the metabolism and proliferation of human fibroblasts, and its effects on wound healing seemed to be particularly evident when studying fibroblast and keratinocyte co-cultures [ 20 , 21 ].…”

Progress of phototherapy for osteosarcoma and application prospect of blue light photobiomodulation therapy

“…Considerable research showed that phototherapy based on blue light has produced beneficial consequences such as treatment of neonatal jaundice ( 123 – 125 ), regulation of melatonin and circadian rhythm ( 126 – 128 ), anti-inflammation ( 129 – 131 ), immunomodulation ( 132 ), wound healing ( 133 – 135 ), tissue regeneration, and anticancer therapies ( 103 , 114 , 133 , 136 ). Furthermore, blue light reduced the follicular colonization of Propionibacterium acnes by activating the endogenous bacterial porphyrin and inhibiting acne development, while possibly interfering with lipogenesis in adipocytes and suppressing sebum formation for acne treatment ( 137 ).…”