Low-level laser therapy for diabetic foot wound healing (Wound care)

An alternative to traditional treatment modalities for diabetic ulcers is low-level laser therapy (LLLT). A number of published studies demonstrate the beneficial effects of LLLT (Ribeiro et al, 2002), although several other studies also exist which indicate results to the contrary (Malm and Lundeberg, 1991; Loevschall and Arenholt-Bindslev, 1994). Further work focusing on cellular and molecular mechanisms of responses to laser irradiation is required to establish LLLT as a reliable, safe and inexpensive treatment modality. This article reviews LLLT as a treatment modality for diabetic ulcers

The use of phototherapy in the treatment of diabetic ulcers

Chronic ulcers are a common complication in diabetes. The nature of diabetic foot ulcers makes them difficult to manage and treat. A dynamic management plan is required to treat diabetic lower limb ulcerations. Thisinvolves a strategic approach, including mechanical offloading, wound debridement, wound dressing, patient education and surgical intervention. Alternative methods have been developed, of which phototherapy isone. Phototherapy, or low-level laser therapy (LLLT), is a therapeutic treatment modality that has been found to enhance wound healing. Its therapeutic properties have been determined by means of in vitro, in vivo and animal studies. Some studies have shown that the clinical application of phototherapy has a positive effect on the process of wound healing. Therefore, LLLT has the potential to decrease the level of secondary complications, improve wound regeneration, and ultimately improve patient quality of life. This review will discuss the concept of chronic wound management by means of LLLT in patients who suffer from type 2 diabetes

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

Resistance of lung cancer cells grown as multicellular tumour spheroids to Zinc sulfophthalocyanine photosensitization

Abstract: Photodynamic therapy (PDT) is phototherapeutic modality used in the treatment of neoplastic and non-neoplastic diseases. The photochemical interaction of light, photosensitizer (PS) and molecular oxygen produces singlet oxygen which induces cell death. Zinc sulfophthalocyanine (ZnPcSmix) has been shown to be effective in A549 monolayers, multicellular tumor spheroids (MCTSs) (250 μm) and not on MCTSs with a size of 500 μm. A549 cells used in this study were grown as MCTSs to a size of 500 μm in order to determine their susceptibility to PDT. ZnPcSmix distribution in MCTSs and nuclear morphology was determined using a fluorescent microscope. Changes in cellular responses were evaluated using cell morphology, viability, proliferation, cytotoxicity, cell death analysis and mitochondrial membrane potential. Untreated MCTSs, showed no changes in cellular morphology, proliferation, cytotoxicity and nuclear morphology. Photoactivated ZnPcSmix also showed no changes in cellular morphology and nuclear morphology. However, photoactivated ZnPcSmix resulted in a significant dose dependant decrease in viability and proliferation as well as an increase in cell membrane damage in MCTSs over time. ZnPcSmix photosensitization induces apoptotic cell death in MCTSs with a size of 500 μm and more resistantance when compared to monolayer cells and MCTS

Multiorganelle localization of metallated phthalocyanine photosensitizer in colorectal cancer cells (dld-1 and caco-2) enhances efficacy of photodynamic therapy

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Evaluation of cell damage induced by irradiated Zinc-Phthalocyanine-gold dendrimeric nanoparticles in a breast cancer cell line

Abstract: Cancer is a non-communicable disease that occurs following a mutation in the genes which control cell growth. Breast cancer is the most diagnosed cancer among South African women and a major cause of cancer-related deaths worldwide. Photodynamic therapy (PDT) is an alternative cancer therapy that uses photochemotherapeutic agents, known as photosensitizers. Drug-delivery nanoparticles are commonly used in nanomedicine to enhance drug-therapeutic efficiency. This study evaluated the photodynamic effects following treatment with 0.3 mM multiple particles delivery complex (MPDC) and irradiated with a laser fluence of 10 J/cm2 using a 680 nm diode laser in a breast cancer cell line (MCF-7)..

Review healing effects of photobiomodulation on diabetic wounds

Abstract: : Diabetic patients frequently develop chronic ulcers of the lower extremities, which are a frequent cause for hospitalization and amputation, placing strain on patients, their families, and healthcare systems. Present therapies remain a challenge, with high recurrence rates. Photobiomodulation (PBM), which is the non-invasive application of light at specific wavelengths, has been shown to speed up healing of chronic wounds, including diabetic foot ulcers (DFUs). PBM produces photophysical and photochemical changes within cells without eliciting thermal damage. It has been shown to promote tissue regeneration and speed up wound repair by reducing inflammation and oxidative stress, accelerating cell migration and proliferation, and promoting extracellular matrix production and release of essential growth factors. The shortage of rigorous, well-designed clinical trials makes it challenging to assess the scientific impact of PBM on DFUs, and lack of understanding of the underlying mechanisms also hinders the conventional use of this therapy. This review gives a glimpse into diabetic wound healing and PBM, and the effects of PBM on diabetic wound healing

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

Multiorganelle Localization of Metallated Phthalocyanine Photosensitizer in Colorectal Cancer Cells (DLD-1 and CaCo-2) Enhances Efficacy of Photodynamic Therapy

Colorectal cancer is the third most commonly diagnosed cancer. Amongst treatments that have been explored, photodynamic therapy (PDT) is a treatment that is of interest as it poses ideal advantages such as affinity for cancer cells. This study aimed to determine the correlation between the localization site of a sulfonated zinc phthalocyanine (ZnPcSmix) photosensitizer (PS) and its associated cell death pathway in vitro in colorectal cancer cell lines (DLD-1 and CaCo-2). Visible morphological changes were observed in PDT treated cells after 24 h. Reactive oxygen species (ROS) were detected and visualized 1 h after PDT. ZnPcSmix was predominantly localized in lysosomes and partially in the mitochondria. FITC Annexin V staining showed a significant decrease in the percentage of viable DLD-1 and CaCo-2 cells 24 h after PDT, with an increase in apoptotic cell population. Moreover, there was a significant increase in both cathepsin D and cytochrome C at 1 and 24 h. In conclusion, ZnPcSmix showed the ability of inducing apoptotic cell death features in PDT treated cells

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

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