Laser photobiomodulation in pressure ulcer healing of human diabetic patients: gene expression analysis of inflammatory biochemical markers

Abstract

Pressure ulcers (PU) are wounds located mainly on bone surfaces where the tissue under pressure suffers ischemia leading to cellular lesion and necrosis , its causes and the healing process depend on several factors. The aim of this study was evaluating the gene expression of inflammatory/reparative factors: IL6, TNF, VEGF, and TGF, which take part in the tissue healing process under effects of low-level laser therapy (LLLT). In order to perform lesion area analysis, PUs were photographed and computer analyzed. Biochemical analysis was performed sa.mpling ulcer border tissue obtained through biopsy before and after laser therapy and quantitative real-time PCR (qRT-PCR) analysis. The study comprised eight individuals, mean age sixty-two years old, and sacroiliac and calcaneous PU, classified as degree III and IV according to the National Pressure Ulcer Advisory Panel (NPUAP). PUs were irradiated with low-level laser (InGaAIP, 100 mW, 660 nm), energy density 2 J/cm, once a day, with intervals of 24 h, totaling 12 applications. The lesion area analysis revealed averaged improvement of the granulation tissue size up to 50% from pre- to post-treatment. qRT-PCR analysis revealed that IL6 values were not significantly different before and after treatment, TNF gene expression was reduced, and VEFG and TGF-β gene expression increased after treatment. After LLLT, wounds presented improvement in gross appearance, with increase in factors VEFG and TGF-β, and reduction of TNF; despite our promising results, they have to be analyzed carefully as this study did not have a control group.

Effects of Pulsed 810 nm Al‐Ga‐As Diode Laser on Wound Healing Under Immunosuppression: A Molecular Insight

“…In randomized clinical trials for treatment of pressure ulcer with PBM at different wavelengths—658, 808, and 940 nm (4 J/cm 2 ) showed augmented healing by lowering pro‐inflammatory markers IL‐2, IL‐6, and TNF‐α levels and increasing VEGF, TGFβ‐1 levels more effectively in 658 nm group compared with the sham‐control. 21,22 Similarly, in another clinical study, quantitative reverse transcription polymerase chain reaction analysis revealed that the TNF gene expression was reduced and VEGF and TGF‐β gene expression significantly increased in pressure ulcer after treatment with 660 nm (2 J/cm 2 ) laser . Efficacy of PBM with red light (660 ± 20 nm, 3 J/cm 2 ) on diabetic foot ulcer patients exhibited significant wound contraction and granulation tissue formation compared with placebo .…”

“…Furthermore, clinical studies also demonstrated that PBMT with red and NIR light significantly augmented acute as well as chronic dermal wound healing . In a clinical observation, PBM with NIR 808 nm laser has shown to reduce inflammation, seroma, and pain along with improved cicatrization in bariatric surgical wound .…”

Cell Adhesion Molecules are Mediated by Photobiomodulation at 660 nm in Diabetic Wounded Fibroblast Cells

“…The use of PBM both in vitro and in vivo has shown beneficial and simulative effects on wound healing [ 1 , 56 , 57 , 58 , 59 , 60 ]. Keshri et al [ 56 ] studied the effect of PBM at 810 nm (22.6 J/cm 2 ), using a pulsed (10 and 100 Hz, 50% duty cycle) diode laser, on full-thickness excision-type dermal wound healing in hydrocortisone-induced immunosuppressed rats.…”

Healing Effects of Photobiomodulation on Diabetic Wounds

“…A similar study showed a decrease in ulcer size in type 2 diabetic patients (40.24% as compared with 11.87% for the control group) [74]. Ruh et al [75] treated pressure ulcers, classified as degree III and IV according to the National Pressure Ulcer Advisory Panel (NPUAP), with PBM at 660 nm (100 mW, 2 J/cm 2 ) once a day, with intervals of 24 h, for a total of 12 applications. Wound closure analysis revealed improvement of the granulation tissue size up to 50%, and gene analysis of ulcer border tissue obtained through biopsy showed a down-regulation in TN-Fα and up-regulation in VEFG and TGF-β.…”

“…Wound size improved by around 50% after 7 days, and exhibited increased cellular activity at the wound edge and base, and faster formation of granulation tissue. [75] * Actual dose differed from incident dose due to losses due to the acrylic glass cage and reflection of light energy by the rat's skin. The actual doses were calculated and can be found in the original manuscript [49].…”