Experimental Study on Blue Light Interaction with Human Keloid-Derived Fibroblasts.

Giada Magni,Francesco S Pavone,Elisabetta Coppi,Francesca Rossi,Federica Cherchi,Marco Fraccalvieri,Domenico Alfieri,Anna Maria Pugliese,Martina Banchelli,Francesca Tatini,Roberto Pini,Duccio Rossi Degl’Innocenti,Michele Rossi,Paolo Matteini

doi:10.3390/biomedicines8120573

Abstract

Keloids are an exuberant response to wound healing, characterized by an exaggerated synthesis of collagen, probably due to the increase of fibroblasts activity and to the reduction of their apoptosis rate: currently no standard treatments or pharmacological therapies are able to prevent keloid recurrence. To reach this goal, in recent years some physical treatments have been proposed, and among them the PhotoBioModulation therapy (PBM). This work analyses the effects of a blue LED light irradiation (410–430 nm, 0.69 W/cm2 power density) on human fibroblasts, isolated from both keloids and perilesional tissues. Different light doses (3.43–6.87–13.7–20.6–30.9 and 41.2 J/cm2) were tested. Biochemical assays and specific staining were used to assess cell metabolism, proliferation and viability. Micro-Raman spectroscopy was used to explore direct effects of the blue LED light on the Cytochrome C (Cyt C) oxidase. We also investigated the effects of the irradiation on ionic membrane currents by patch-clamp recordings. Our results showed that the blue LED light can modulate cell metabolism and proliferation, with a dose-dependent behavior and that these effects persist at least till 48 h after treatment. Furthermore, we demonstrated that the highest fluence value can reduce cell viability 24 h after irradiation in keloid-derived fibroblasts, while the same effect is observed 48 h after treatment in perilesional fibroblasts. Electrophysiological recordings showed that the medium dose (20.6 J/cm2) of blue LED light induces an enhancement of voltage-dependent outward currents elicited by a depolarizing ramp protocol. Overall, these data demonstrate the potentials that PBM shows as an innovative and minimally-invasive approach in the management of hypertrophic scars and keloids, in association with current treatments.

Highlights

The word “keloid” appeared for the first time in 1817, when Alibert used this term to describe the lesions as cancroid, or “crab claw-like appearance” lesions, to define the lateral expansion of an excessive scar into the surrounding healthy tissue [1].Years later, Mancini and Peacock introduced different definitions to identify keloids and hypertrophic scars [2]
In the present study we investigate the effects of different doses of blue LED light (410–430 nm) on fibroblasts isolated from keloids and perilesional tissues, at different irradiation doses, to point out whether PhotoBioModulation therapy (PBM) with blue light can be applied in keloid scars to prevent their reappearance
As shown in the following figures, we found a cytosolic signal of type I collagen-positive cells and Heat Shock Protein-47 (HSP47)-positive cells both in fibroblasts isolated from keloid tissue (Figure 2D,J) and from perilesional tissue (Figure 3D,J)

Summary

Introduction

The word “keloid” appeared for the first time in 1817, when Alibert used this term to describe the lesions as cancroid, or “crab claw-like appearance” (as the original meaning in ancient Greek) lesions, to define the lateral expansion of an excessive scar into the surrounding healthy tissue [1].Years later, Mancini (in 1962) and Peacock (in 1970) introduced different definitions to identify keloids and hypertrophic scars [2]. Keloids are clinically described as human fibroproliferative benign dermal tumors characterized by an excessive synthesis and accumulation both of collagen and extracellular matrix (ECM) elements [3] For these reasons, keloids can extend beyond the edge of the original wound, they do not spontaneously regress and increase their dimensions steadily. Keloids exhibit peculiar features: the dimensions are in the range from few millimeters to several centimeters, depending on the site of the lesion; their surface is smooth and shiny, with different thickness, and a compactness ranging from mildly tender to firm; the borders are delineated, but irregular in outline; the color can vary from purple to pink and generally it is always highly pigmented in respect to the healthy surrounding skin [6]. In some preliminary studies [14,15]

Methods

Results

Discussion

Conclusion