Fluorescent light energy in wound healing: when is a photon something more?

Abstract

Fluorescent Light Energy (FLE) is a unique form of photobiomodulation that stimulates healing, reduces inflammation, and alleviates pain. The system works by exciting a chromophore in a topical substrate, which emits FLE with a broad spectral range (~400-700 nm) that is delivered to the target tissue below. Results from in vivo and in vitro studies have shown FLE modulates inflammation via down-regulation of pro-inflammatory cytokines such as IL-6 and TNF-α, and stimulates mitochondria biogenesis 1. A recent study showed FLE-stimulated cells responded more potently compared to cells treated with light from an LED light source ("Mimicking Lamp") designed to generate the same emission spectra and power intensity profile as FLE 2. FLE-treated human dermal fibroblasts (HDF) experienced up-regulated collagen production, while a minor and nonsignificant effect was observed for the Mimicking Lamp-treated HDFs. These results suggest that photons generated by FLE either penetrate tissue differently or are absorbed differently compared to photons from a LED light source. Photonic properties of FLE that could impact tissue penetration or absorption may include polarity or coherency, leading to different cellular responses. To investigate if light polarity may influence cellular responses to FLE stimulation, the present study applied linear and circular-polarizing filters to investigate the influence of FLE's polarity on immune parameters. The data suggest that FLE polarity contributes to its impact on biological systems. Furthermore, the immunemodulatory impact of FLE was investgated in a pilot study on a human ex vivo skin model suggesting that central myeloid immune surface markes are modulated by FLE.

Fluorescent light energy combined with systemic isotretinoin: A 52‐week follow‐up evaluating efficacy and safety in treatment of moderate‐severe acne

“…The clinical, cellular, and molecular pathways targeted and modulated by FLE are currently under investigation. Results so far indicate that FLE modulate activity and function of several skin cells as well as directly target bacterial viability, [17][18][19]49,62 suggesting that FLE improves acne symptoms by targeting several aspects of the disease. We speculate that the combined treatment of moderate-severe acne by FLE, targeting inflammation and likely other aspects of this complex condition in combination with initial isotretinoin that lower sebum production or tetracycline directly killing C acnes bacteria lay the basis for consistent normalization of the skin.…”

“…11 These factors are reflected in treatment options for acne, that target bacterial growth via antibiotics (eg, tetracycline), sebum production by isotretinoin therapy, and inflammation by corticosteroids [12][13][14] or by fluorescent light energy (FLE) that has reported efficacy against acne possibly in part through is recently described anti-inflammatory effects. 12,13,[15][16][17][18][19] In many cases of moderate-to-severe acne, antibiotics and retinoids as systemic therapies are well-established. 14,20 However, some patients are not eligible to standard dose of isotretinoin treatment due to collateral effects or do not reach a satisfying clearance with tetracycline or macrolides even when correctly combined with topical therapy.…”

“…19,[58][59][60][61] In vitro findings have reported that FLE lowers production of essential pro-inflammatory cytokines such as interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) in cultures of human epidermal keratinocytes and human dermal fibroblasts. [17][18][19] Finally, ongoing mechanistic studies suggest that FLE directly modify mitochondrial morphology and function. 18,62 We hypothesize that targeting several aspects of acne by initially lowering sebum production by low-dose isotretinoin treatment 63,64 or hampering bacterial growth by tetracycline in combination with the anti-inflammatory and homeostasis promoting properties of FLE will clear acne and normalize the skin long term.…”

“…[17][18][19] Finally, ongoing mechanistic studies suggest that FLE directly modify mitochondrial morphology and function. 18,62 We hypothesize that targeting several aspects of acne by initially lowering sebum production by low-dose isotretinoin treatment 63,64 or hampering bacterial growth by tetracycline in combination with the anti-inflammatory and homeostasis promoting properties of FLE will clear acne and normalize the skin long term. [15][16][17]19,62 This combination will initially target several pathways associated with acne and longer term FLE therapy will reprogram and balance skin cells and conditions ensuring no remission of disease.…”

“…Although the underlying reasons for development of acne are uncertain, the disease associates with increased sebum production, colonization of hair follicles by Cutibacterium acnes ( C acnes formerly named Propionibacterium acnes ), and ongoing inflammation 11 . These factors are reflected in treatment options for acne, that target bacterial growth via antibiotics (eg, tetracycline), sebum production by isotretinoin therapy, and inflammation by corticosteroids 12‐14 or by fluorescent light energy (FLE) that has reported efficacy against acne possibly in part through is recently described anti‐inflammatory effects 12,13,15‐19 …”