Shedding Light on a New Treatment for Diabetic Wound Healing: A Review on Phototherapy

Impaired wound healing is a common complication associated with diabetes with complex pathophysiological underlying mechanisms and often necessitates amputation. With the advancement in laser technology, irradiation of these wounds with low-intensity laser irradiation (LILI) or phototherapy, has shown a vast improvement in wound healing. At the correct laser parameters, LILI has shown to increase migration, viability, and proliferation of diabetic cells in vitro; there is a stimulatory effect on the mitochondria with a resulting increase in adenosine triphosphate (ATP). In addition, LILI also has an anti-inflammatory and protective effect on these cells. In light of the ever present threat of diabetic foot ulcers, infection, and amputation, new improved therapies and the fortification of wound healing research deserves better prioritization. In this review we look at the complications associated with diabetic wound healing and the effect of laser irradiation both in vitro and in vivo in diabetic wound healing

Irradiation at 636nm positively affects diabetic

Objective: This study investigated the effect of low-intensity laser irradiation (LILI) on pro-inflammatory cytokines involved in wound healing processes in diabetes and hypoxia. Background data: Diabetes is associated with impaired wound healing and a prolonged inflammatory phase. Pro-inflammatory cytokines such as interleukin (IL)-1b, tumor necrosis factor (TNF)-a and IL-6 are elevated in diabetes. LILI has been reported to accelerate wound healing and decrease inflammatory cytokines. Methods: A human skin fibroblast cell line (WS1) was used in vitro. Cells were exposed to various insults, namely, wounding, and a diabetic or hypoxic environment. Experimental cells were exposed to an energy density of 5 J/cm2 using a continuous wave 636-nm diode laser at an average power of 95mW, an illuminated area of 9.05 cm2, and an irradiance of 11 mW/cm2 (irradiation time, 476 sec). The effect of laser irradiation on cytokine expression was examined at 1 or 24 h postirradiation. Cellular morphology, viability, proliferation, and cytokine expression (IL-1b, IL-6, and TNF-a) were investigated. Translocation of nuclear factor – kappa B (NF-kB) was also determined. Results: There was a higher rate of migration in irradiated wounded cultures, and irradiated hypoxic cells showed an improvement in cellular morphology. All cell models showed an increase in proliferation. Normal wounded cells showed a decrease in apoptosis, TNF-a, and IL-1b. Diabetic wounded cells showed an increase in viability and a decrease in apoptosis and IL-1b, whereas hypoxic cells showed an increase in viability and IL-6, and a decrease in apoptosis and TNF-a. NF-kB was translocated into the nucleus post-irradiation. Conclusions: Phototherapy resulted in hastened wound closure, increased proliferation, and normalization of cellular function. The decrease in the different pro-inflammatory cytokines and NF-kB translocation was model and time dependent. Overall, laser irradiation resulted in a reduction in inflammatory cytokines and directed cells into the cell survival pathway

Laser irradiation alters the expression profile of genes involved in the extracellular matrix in vitro

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Influence of low intensity laser irradiation on isolated human adipose derived stem cells over 72 hours and their differentiation potential into smooth muscle cells using retinoic acid

Human adipose derived stem cells (hADSCs), with their impressive differentiation potential, may be used in autologous cell therapy or grafting to replace damaged tissues. Low intensity laser irradiation (LILI) has been shown to influence the behaviour of various cells, including stem cells. This study aimed to investigate the effect of LILI on hADSCs 24, 48 or 72 h post-irradiation and their differentiation potential into smooth muscle cells (SMCs). Methodology: hADSCs were exposed to a 636 nm diode laser at a fluence of 5 J/cm2. hADSCs were differentiated into SMCs using retinoic acid (RA). Morphology was assessed by inverted light and differential interference contrast (DIC) microscopy. Proliferation and viability of hADSCs was assessed by optical density (OD), Trypan blue staining and adenosine triphosphate (ATP) luminescence. Expression of stem cell markers, β1-integrin and Thy-1, and SMC markers, smooth muscle alpha actin (SM-αa), desmin, smooth muscle myosin heavy chain (SM-MHC) and smoothelin, was assessed by immunofluorescent staining and real-time reverse transcriptase polymerase chain reaction (RT-PCR). Results: Morphologically, hADSCs did not show any differences and there was an increase in viability and proliferation post-irradiation. Immunofluorescent staining showed expression of β1-integrin and Thy-1 72 h post-irradiation. RT-PCR results showed a down regulation of Thy-1 48 h post-irradiation. Differentiated SMCs were confirmed by morphology and expression of SMC markers. Conclusion: LILI at a wavelength of 636 nm and a fluence of 5 J/cm2 does not induce differentiation of isolated hADSCs over a 72 h period, and increases cellular viability and proliferation. hADSCs can be differentiated into SMCs within 14 days using RA

Cell adhesion molecules are mediated by photobiomodulation at 660 nm in diabetic wounded fibroblast cells

Abstract: Diabetes affects extracellular matrix (ECM) metabolism, contributing to delayed wound healing and lower limb amputation. Application of light (photobiomodulation, PBM) has been shown to improve wound healing. This study aimed to evaluate the influence of PBM on cell adhesion molecules (CAMs) in diabetic wound healing. Isolated human skin fibroblasts were grouped into a diabetic wounded model. A diode laser at 660 nm with a fluence of 5 J/cm2 was used for irradiation and cells were analysed 48 h post-irradiation. Controls consisted of sham-irradiated (0 J/cm2) cells. Real-time reverse transcription (RT) quantitative polymerase chain reaction (qPCR) was used to determine the expression of CAM-related genes. Ten genes were up-regulated in diabetic wounded cells, while 25 genes were down-regulated. Genes were related to transmembrane molecules, cell–cell adhesion, and cell–matrix adhesion, and also included genes related to other CAM molecules. PBM at 660 nm modulated gene expression of various CAMs contributing to the increased healing seen in clinical practice. There is a need for new therapies to improve diabetic wound healing. The application of PBM alongside other clinical therapies may be very beneficial in treatment

Laser Irradiation Alters the Expression Profile of Genes Involved in the Extracellular Matrix In Vitro

The extracellular matrix (ECM) forms the basis of every phase in wound healing. Healing may be impaired if some of these components are destroyed. Photobiostimulation has demonstrated a stimulatory response in biological processes. This study aimed to evaluate various genes involved in the ECM, in response to laser irradiation. Isolated human skin fibroblasts were used in three different cell models, namely, normal, normal wounded, and diabetic wounded. Cells were irradiated with 5 J/cm2 using a continuous wave diode laser emitting at a wavelength of 660 nm and incubated for 48 h. Nonirradiated (0 J/cm2) normal and diabetic wounded cells served as the control. Real-time reverse transcription (RT) quantitative polymerase chain reaction (qPCR) was used to determine the expression of 84 genes in a PCR array. There was a significant upregulation of 29 genes in the normal cells, 32 genes in the normal wounded cells, and 18 genes in the diabetic wounded cells as well as a downregulation of 19 genes (normal), 6 genes (normal wounded), and 31 genes (diabetic wounded). Low intensity laser irradiation (LILI) stimulates gene expression in various cell adhesion molecules (CAMs) and extracellular proteins at 660 nm in wounded fibroblasts in vitro

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

Diabetic foot ulcers (DFUs) are open chronic wounds that affect diabetic patients due to hyperglycaemia. DFUs are known for their poor response to treatment and frequently require amputation, which may result in premature death. The present study evaluated the effect of photobiomodulation (PBM) at 660 nm on wound healing via activation of Ras/MAPK signalling in diabetic wounded cells in vitro. This study used four human skin fibroblast cell (WS1) models, namely normal (N), wounded (W), diabetic (D), and diabetic wounded (DW). Cells were irradiated at 660 nm with 5 J/cm2. Non-irradiated cells (0 J/cm2) served as controls. Cells were incubated for 24 and 48 h post-irradiation, and the effect of PBM on cellular morphology and migration rate, viability, and proliferation was assessed. Basic fibroblast growth factor (bFGF), its phosphorylated (activated) receptor FGFR, and phosphorylated target proteins (Ras, MEK1/2 and MAPK) were determined by enzyme-linked immunosorbent assay (ELISA) and Western blotting; nuclear translocation of p-MAPK was determined by immunofluorescence. PBM resulted in an increase in bFGF and a subsequent increase in FGFR activation. There was also an increase in downstream proteins, p-Ras, p-MEK1/2 and p-MAPK. PBM at 660 nm led to increased viability, proliferation, and migration as a result of increased bFGF and subsequent activation of the Ras/MAPK signalling pathway. Therefore, this study can conclude that PBM at 660 nm stimulates in vitro diabetic wound healing via the bFGF-activated Ras/MAPK pathway

The prevalence of osteoarthritic symptoms of the hands amongst female massage therapists

Background: Numerous occupations increase one's risk of developing osteoarthritis. Massage therapists rely heavily on their hands and cumulative hand strain injuries that occur whilst performing a massage may lead to the development of osteoarthritic symptoms. Females are at greater risk of developing osteoarthritis. Furthermore age weight, genetic predisposition; working years, working hours as well as body mass index all increase the risk of developing osteoarthritis. Objective: This study sought to investigate the prevalence of osteoarthritic symptoms of the hands amongst female massage therapists, as well as to establish both an average age of symptomatic onset and whether their daily work productivity was influenced. Materials and methods: Since the massage industry is predominantly practiced by females, female massage therapists, irrespective of age and registered with a South African Regulating Body were included. Participants were required to complete a self-administered questionnaire which evaluated age, self-reported symptomatic presence of and family history of osteoarthritis, and body mass index. Participants also completed the AUSCAN™ Hand Osteoarthritis Index LK3.1 (Australian/Canadian Hand Osteoarthritis Index) which assesses pain, disability and joint stiffness of the hands. The sample was divided into two groups based on the presence or absence of self-reported symptoms. All gathered data was analysed by the University of Johannesburg's statistics department (Statkon) by use of IBMSPSS Statistics software version 21. Results: The mean age of symptomatic presentation was 43 years. The AUSCAN™ Index found that more than half of the total sample reported osteoarthritic symptoms in their hands. Participants in the non-symptomatic group also indicated a positive response to symptoms on the AUSCAN™ Index although they did not self-report a symptomatic onset age. Conclusion: In this sample, massage therapists experienced osteoarthritic symptoms that cause pain and stiffness in their hands. It also seemed evident that the symptoms experienced were also responsible for placing strain on their ability to perform daily tasks. This study serves as a basis for further dialogue, research and professional awareness

In Vitro Wound Healing Potential of Photobiomodulation Is Possibly Mediated by Its Stimulatory Effect on AKT Expression in Adipose-Derived Stem Cells

Increasing evidence suggests that adipose-derived stem cells (ADSCs) serve as a therapeutic approach for wound healing. The aim of this study was to determine the effect of photobiomodulation (PBM) on antioxidant enzymes in ADSCs. Four ADSC cell models, namely, normal, wounded, diabetic, and diabetic wounded, were irradiated with 660 nm (fluence of 5 J/cm2 and power density of 11.2 mW/cm2) or 830 nm (fluence of 5 J/cm2 and power density of 10.3 mW/cm2). Nonirradiated cells served as controls. Cell morphology and wound migration were determined using light microscopy. Cell viability was determined by the trypan blue exclusion assay. The enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of antioxidants (superoxide dismutase (SOD), catalase (CAT), and heme oxygenase (HMOX1)). AKT activation and FOXO1 levels were determined by immunofluorescence and western blotting. The gaps (wound) in PBM-treated wounded and diabetic wounded cell models closed faster than the controls. PBM treatment significantly increased antioxidant levels in all cell models. This reflects that oxidative stress is reduced on the counterpart of increased antioxidant levels. This might be due to the activation of the AKT signaling pathway as evidenced by the increased AKT signals via western blotting and immunofluorescence. This data suggests that PBM promotes wound healing by increasing antioxidant levels by activating AKT signaling