Interaction of the AKT and ß-catenin signalling pathways and the influence of photobiomodulation on cellular signalling proteins in diabetic wound healing.

The induction of a cells destiny is a tightly controlled process that is regulated through communication between the matrix and cell signalling proteins. Cell signalling activates distinctive subsections of target genes, and different signalling pathways may be used repeatedly in different settings. A range of different signalling pathways are activated during the wound healing process, and dysregulated cellular signalling may lead to reduced cell function and the development of chronic wounds. Diabetic wounds are chronic and are characterised by the inability of skin cells to act in response to reparative inducements. Serine/threonine kinase, protein kinase B or AKT (PKB/AKT), is a central connection in cell signalling induced by growth factors, cytokines and other cellular inducements, and is one of the critical pathways that regulate cellular proliferation, survival, and quiescence. AKT interacts with a variety of other pathway proteins including glycogen synthase kinase 3 beta (GSK3ß) and ß-catenin. Novel methodologies based on comprehensive knowledge of activated signalling pathways and their interaction during normal or chronic wound healing can facilitate quicker and efficient diabetic wound healing. In this review, we focus on interaction of the AKT and ß-catenin signalling pathways and the influence of photobiomodulation on cellular signalling proteins in diabetic wound healing.

Current Therapeutic Modalities for the Management of Chronic Diabetic Wounds of the Foot.

Impaired wound healing is common in patients with diabetes mellitus (DM). Different therapeutic modalities including wound debridement and dressing, transcutaneous electrical nerve stimulation (TENS), nanomedicine, shockwave therapy, hyperbaric (HBOT) and topical (TOT) oxygen therapy, and photobiomodulation (PBM) have been used in the management of chronic diabetic foot ulcers (DFUs). The selection of a suitable treatment method for DFUs depends on the hosts' physiological status including the intricacy and wound type. Effective wound care is considered a critical component of chronic diabetic wound management. This review discusses the causes of diabetic wounds and current therapeutic modalities for the management of DFUs, specifically wound debridement and dressing, TENS, nanomedicine, shockwave therapy, HBOT, TOT, and PBM.

Clinical Effect of Photobiomodulation on Wound Healing of Diabetic Foot Ulcers: Does Skin Color Needs to Be Considered?

Diabetic foot ulcers (DFUs) are one of the most common complications of diabetes. DFUs impede patients' quality of life and are known to be unresponsive to conventional therapy. Photobiomodulation (PBM) is a pain-free, noninvasive treatment method that has been shown to promote chronic wound healing and has been successfully used for the treatment of DFUs. Since skin tone and color can affect the way light interacts with tissue, studies should take this into consideration when determining protocols for the use of PBM. This review is aimed at critically evaluating data of existing studies conducted to evaluate the clinical effect of PBM on DFUs, taking skin color into consideration. A literature search was conducted and resulted in articles on cell studies, animal studies, and clinical trials. Only 13 clinical trials and 2 clinical case studies were adopted and used in this review. All the clinical trials adopted for this review show evidence that PBM together with conventional treatment results in an increased healing rate of DFUs; however, only one study adjusted their protocol according to skin color. There are not enough studies conducted on people of color to determine the safety and efficacy of PBM therapy in such ethnic groups. Future randomized, placebo-controlled clinical trials are necessary on PBM and DFUs and should take skin color into consideration.

Photobiomodulation activates the PI3K/AKT pathway in diabetic fibroblast cells in vitro.

Photobiomodulation (PBM) has been known to facilitate the healing of numerous ailments including diabetic wounds. PBM is not broadly acknowledged largely due to scepticism regarding its mechanism of action, including the specific molecular targets and the effects rendered at a tissue, cellular and molecular level. Diabetes mellitus (DM) reduces cellular signalling, including the phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT) signalling pathway that is critical during wound healing. In DM, wound chronicity is common and may lead to non-traumatic limb amputation. This study investigated the hypothesis that PBM at 660 nm activates PI3K/AKT and downstream signalling proteins in fibroblast cells in vitro. Cells were incubated for 24 and 48 h after PBM (660 nm and 5 J/cm2), followed by evaluation of activated PI3K/AKT and downstream mammalian target of rapamycin (mTOR) and glycogen synthase kinase-3 beta (GSK3ß) signalling proteins using western blotting and ELISA. Irradiated cell models displayed increased activation of PI3K/AKT and downstream mTOR and GSK3ß signalling proteins. Our findings suggest that the therapeutic effects of PBM in stressed cells are through activation of the PI3K/AKT cell signalling pathway and downstream GSK3ß and mTOR signalling proteins. This study provides a novel understanding into one of the probable molecular mechanisms in which PBM at a wavelength of 660 nm (5 J/cm2) enhances therapeutic activities in diabetic wound healing.

Photobiomodulation at 830 nm Stimulates Migration, Survival and Proliferation of Fibroblast Cells.

Purpose: Photobiomodulation (PBM) promotes diabetic wound healing by favoring cell survival and proliferation. This study aimed to investigate the potential of PBM in stimulating cellular migration, viability, and proliferation using the transforming growth factor-ß1 (TGF-ß1)/Smad signaling pathway. Methods: The study explored the in vitro effects of near infrared (NIR) light on cell viability (survival) and proliferation as well as the presence of TGF-ß1, phosphorylated TGF-ß receptor type I (pTGF-ßR1) and phosphorylated mothers against decapentaplegic-homolog (Smad)-2/3 (p-Smad2/3) in different fibroblast cell models. Results: Results show a significant increase in cellular migration in wounded models, and increased viability and proliferation in irradiated cells compared to their respective controls. An increase in the presence of TGF-ß1 in the culture media, a reduction in pTGF-ßR1 and a slight presence of p-Smad2/3 was observed in the cells. Conclusion: These findings show that PBM at 830 nm using a fluence of 5 J/cm2 could induce cell viability, migration and proliferation to favor successful healing of diabetic wounds. This study contributes to the growing body of knowledge on the molecular and cellular effect of PBM and showcases the suitability of PBM at 830 nm in managing diabetic wounds.

The Effects of Blue Light on Human Fibroblasts and Diabetic Wound Healing.

Diabetes is a serious threat to global health and is among the top 10 causes of death. The Diabetic foot ulcer (DFU) is among the most common and severe complications of the disease. Bacterial infections are common; therefore, timely aggressive management, using multidisciplinary management approaches is needed to prevent complications, morbidity, and mortality, particularly in view of the growing cases of antibiotic-resistant bacteria. Photobiomodulation (PBM) involves the application of low-level light at specific wavelengths to induce cellular photochemical and photophysical responses. Red and near-infrared (NIR) wavelengths have been shown to be beneficial, and recent studies indicate that other wavelengths within the visible spectrum could be helpful as well, including blue light (400-500 nm). Reports of the antimicrobial activity and susceptibility of blue light on several strains of the same bacterium show that many bacteria are less likely to develop resistance to blue light treatment, meaning it is a viable alternative to antibiotic therapy. However, not all studies have shown positive results for wound healing and fibroblast proliferation. This paper presents a critical review of the literature concerning the use of PBM, with a focus on blue light, for tissue healing and diabetic ulcer care, identifies the pros and cons of PBM intervention, and recommends the potential role of PBM for diabetic ulcer care.

Regulatory Processes of the Canonical Wnt/ß-Catenin Pathway and Photobiomodulation in Diabetic Wound Repair.

Skin is a biological system composed of different types of cells within a firmly structured extracellular matrix and is exposed to various external and internal insults that can break its configuration. The restoration of skin's anatomic continuity and function following injury is a multifaceted, dynamic, well-coordinated process that is highly dependent on signalling pathways, including the canonical Wnt/ß catenin pathway, all aimed at restoring the skin's protective barrier. Compromised and inappropriate tissue restoration processes are often the source of wound chronicity. Diabetic patients have a high risk of developing major impediments including wound contamination and limb amputation due to chronic, non-healing wounds. Photobiomodulation (PBM) involves the application of low-powered light at specific wavelengths to influence different biological activities that incite and quicken tissue restoration. PBM has been shown to modulate cellular behaviour through a variety of signal transduction pathways, including the Wnt/ß catenin pathway; however, the role of Wnt/ß catenin in chronic wound healing in response to PBM has not been fully defined. This review largely focuses on the role of key signalling pathways in human skin wound repair, specifically, the canonical Wnt/ß-catenin pathway, and the effects of PBM on chronic wound healing.

Photobiomodulation in diabetic wound healing: A review of red and near-infrared wavelength applications.

The development of a painless, non-invasive, and faster way to diabetic wound healing is at the forefront of research. The complexity associated with diabetic wounds makes it a cause for concern amongst diabetic patients and the world at large. Irradiation of cells generates a photobiomodulatory response on cells and tissues, directly causing alteration of cellular processes and inducing diabetic wound repair. Photobiomodulation therapy (PBMT) using red and near-infrared (NIR) wavelengths is being considered as a promising technique for speeding up the rate of diabetic wound healing, eradication of pain and reduction of inflammation through the alteration of diverse cellular and molecular processes. This review presents the extent to which the potential of red and NIR wavelengths have been harnessed in PBMT for diabetic wound healing. Important research challenges and gaps are identified and discussed, and future directions mapped out. This review thus provides useful insights and strategies into improvement of PBMT, including its acceptance within the global medical research community.

Photobiomodulation reduces oxidative stress in diabetic wounded fibroblast cells by inhibiting the FOXO1 signaling pathway.

This study aimed to elucidate the underlying molecular mechanism of photobiomodulation (PBM) in attenuating oxidative stress in diabetic wounded fibroblast cells. Cell models were exposed to PBM at a wavelength of 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). Non-irradiated cell models were used as controls. Cellular migration was determined at regular time intervals (0, 12, 24 and 48 h) using inverted light microscopy. Cell viability was determined by the Trypan blue exclusion assay. The levels of enzymic antioxidants superoxide dismutase (SOD), catalase (CAT), and heme oxygenase (HMOX1) were determined by the enzyme linked immunosorbent assay (ELISA). The alteration in the levels of AKT and FOXO1 was determined by immunofluorescence and western blotting. Upon PBM treatment, elevated oxidative stress was reversed in diabetic and diabetic wounded fibroblast cells. The reduced oxidative stress was represented by decreased FOXO1 levels and increased levels of SOD, CAT and HMOX1. This might be due to the activation of the AKT signaling pathway. This study concluded that treatment with PBM progressed diabetic wound healing by attenuating oxidative stress through inhibition of the FOXO1 signaling pathway.

Selective Laser Efficiency of Green-Synthesized Silver Nanoparticles by Aloe arborescens and Its Wound Healing Activities in Normal Wounded and Diabetic Wounded Fibroblast Cells: In vitro Studies.

INTRODUCTION: Silver nanoparticles (AgNPs) have been extensively used in wound healing applications owing to their valuable physicochemical and biological properties. The main objective of this study was to evaluate the combined effects of green-synthesized silver nanoparticles (G-AgNPs) and photobiomodulation (PBM; laser irradiation at 830 nm with 5 J/cm2) in normal wounded and diabetic wounded fibroblast cells (WS1). METHODS: The combined effect of G-AgNPs and PBM was studied by various in vitro wound healing studies including cell morphology, cell migration rate and percentage wound closure, cell viability, cell proliferation, and filamentous (F)-actin and nuclear morphology staining. RESULTS: Cell viability results revealed good cellular compatibility of G-AgNPs to WS1 cells. The combined therapy of G-AgNPs and PBM demonstrated promising results to achieve progressive migration and wound closure in both normal wounded and diabetic wounded cell models. G-AgNPs alone and in combination with PBM had no negative effect on cell viability and proliferation, and there was an increase in cell migration. CONCLUSION: Overall, these findings demonstrate that the combined treatment of G-AgNPs and PBM does not display any adverse effects on wound healing processes in both normal wounded and diabetic wounded cell models.

Photobiomodulation and the expression of genes related to the JAK/STAT signalling pathway in wounded and diabetic wounded cells.

Photobiomodulation therapy (PBMT) is a curative technique that uses low intensity light to relegate pain and inflammation, and accelerate tissue repair. At a molecular level, the effects of photobiomodulation (PBM) are not fully established. The present study aimed to assess the impact of PBM on the alteration of genes linked to Janus kinase-Signal transducer and activator of transcription (JAK-STAT) signalling in wounded and diabetic wounded cells in vitro. Cells were irradiated using a diode laser at a wavelength of 660 nm and an energy density of 5 J/cm2. RNA was extracted from cells 48 h post-irradiation, and was used to synthesise complementary deoxyribonucleic acid (cDNA) that was used in PCR arrays to profile for 84 JAK/STAT signalling related genes. Irradiation at a wavelength of 660 nm and an energy density of 5 J/cm2 significantly regulated genes related to the JAK/STAT signalling pathway in wounded and diabetic wounded cells. In irradiated wounded cells, 19 genes were significantly regulated, of which two were up-regulated and 17 were down-regulated, while 73 genes were significantly regulated in irradiated diabetic wounded cells of which 46 were up-regulated and 27 were down-regulated. This data suggests that PBM modulates gene transcription for protein synthesis and activates cellular signalling, and may indeed be helpful in enhancing diabetic wound repair.

Natural deep eutectic solvent supported targeted solid-liquid polymer carrier for breast cancer therapy.

Solid-liquid nanocarriers (SLNs) are at the front of the rapidly emerging field of medicinal applications with a potential role in the delivery of bioactive agents. Here, we report a new SLN of natural deep eutectic solvent (NADES) and biotin-conjugated lysine-polyethylene glycol copolymer. The SLN system was analyzed for its functional groups, thermal stability, crystalline nature, particle size, and surface morphology through the instrumental analysis of FT-IR, TGA, XRD, DLS, SEM, and TEM. Encapsulation of PTX (paclitaxel) and 7-HC (7-hydroxycoumarin) with the SLN was carried out by dialysis, and UV-visible spectra evidenced the drug loading capacity and higher encapsulation efficiency obtained. The enhanced anticancer potential of PTX- and 7-HC-loaded SLN was assessed in vitro, and the system reduces the cell viability of MDA-MB-231 cells. The PTX- and 7-HC-loaded SLN system was investigated in a breast cancer-induced rat model via in vivo studies. It shows decreased lysosomal enzymes and increased levels of caspase to cure breast tumors. It very well may be reasoned that the designed PTX- and 7-HC-loaded SLN system has strong anticancer properties and exhibits potential for delivery of drug molecules in cancer treatment.

The link between advanced glycation end products and apoptosis in delayed wound healing.

Advanced glycation end products (AGEs) are naturally occurring molecules that start to accumulate from embryonic developmental stages and form as part of normal ageing. When reducing sugars interact with and modify proteins or lipids, AGE production occurs. AGE formation accelerates in chronic hyperglycemic conditions, and high AGE levels have been associated with the pathogenesis of various diseases. In addition, enhanced levels of AGEs have been linked to delayed wound healing as seen in patients with diabetes mellitus. Research has provided numerous ways in which a high AGE concentration results in impaired wound healing, including oxidative stress, structural and functional changes to proteins important in wound repair, an enhanced inflammatory response by activation of transcription factors, and possible exaggerated apoptosis of cells necessary to the wound repair process. Apoptosis is a naturally occurring cell death process that is significant for normal tissue functioning and plays an important role in wound repair by preventing a prolonged inflammatory response and excessive scar formation. Abnormal apoptosis affects wound healing, resulting in slow healing wounds. This review will summarize the role of AGEs in wound healing, focusing on the mechanisms by which AGEs lead to apoptosis in various cell types. The review provides the way forward for medical research and molecular studies as it focuses on the mechanisms by which AGEs induce apoptosis in various cell types, including fibroblasts, osteoblasts, neuronal cells, and endothelial cells. Reviewing the mechanisms of AGE-linked apoptosis is important in understanding the impact of high AGE levels in delayed wound healing in diabetic patients due to abnormal apoptosis of cells necessary to the wound healing process.

The use of lasers and light sources in skin rejuvenation.

Smooth, wrinkle-free skin is associated with supposed attractiveness, youthfulness, and health, while rhytids have a negative impact on one's perceived appearance, image, and self-esteem. Noninvasive esthetic procedures such as laser or light therapy have been used to achieve and attain a more youthful appearance. Currently, there is a wide range of lasers and devices available for the regeneration and healing of skin. Lasers and light sources for skin rejuvenation involve the removal of aged skin tissue via thermal heat from high-powered lasers, stimulating the surrounding tissues to recover through natural wound-healing processes. In contrast, photobiomodulation, which makes use of low energy lasers or light emitting diodes, uses no heat and has shown positive effects in the reduction of wrinkles and improving skin laxity.

Genetic Aberrations Associated with Photodynamic Therapy in Colorectal Cancer Cells.

Photodynamic therapy (PDT) is a cancer treatment modality that utilizes three components: light (λ 650-750 nm), a photosensitizer (PS) and molecular oxygen, which upon activation renders the modality effective. Colorectal cancer has one of the highest incident rates as well as a high mortality rate worldwide. In this study, a zinc (Zn) metal-based phthalocyanine (ZnPcSmix) PS was used to determine its efficacy for the treatment of colon adenocarcinoma cells (DLD-1 and Caco-2). Photoactivation of the PS was achieved by laser irradiation at a wavelength of 680 nm. Dose responses were performed to establish optimal PS concentration and irradiation fluence. A working combination of 20 µM ZnPcSmix and 5 J/cm2 was used. Biochemical responses were determined after 1 or 24 h incubation post-treatment. Since ZnPcSmix is localized in lysosomes and mitochondria, mitochondrial destabilization analysis was performed monitoring mitochondrial membrane potential (MMP). Cytosolic acidification was determined measuring hydrogen peroxide (H2O2) levels in the cytoplasm. Having established apoptotic cell death induction, an apoptosis PCR array was performed to establish the apoptotic mechanism. In DLD-1 cells, expression of genes included 3 up-regulated and 20 down-regulated genes while in Caco-2 cells, there were 16 up-regulated and 22 down-regulated genes. In both cell lines, in up-regulated genes, there was a combination of pro- and anti-apoptotic genes that were significantly expressed. Gene expression results showed that more tumorigenic cells (DLD-1) went through apoptosis; however, they exhibit increased risk of resistance and recurrence, while less tumorigenic Caco-2 cells responded better to PDT, thus being suggestive of a better prognosis post-PDT treatment. In addition, the possible apoptotic mechanisms of cell death were deduced based on the genetic expression profiling of regulatory apoptotic inducing factors.

Therapeutic Efficacy of Home-Use Photobiomodulation Devices: A Systematic Literature Review.

Objective: Perform systematic literature review on photobiomodulation (PBM) devices used at home for nonesthetic applications. Background: Home-use PBM devices have been marketed for cosmetic and therapeutic purposes. This is the first systematic literature review for nonesthetic applications. Methods: A systematic literature search was conducted for PBM devices self-applied at home at least thrice a week. Two independent reviewers screened the articles and extracted the data. Treatment dosage appropriateness was compared to the World Association for Laser Therapy (WALT) recommendations. The efficacy was evaluated according to the relevant primary end-point for the specific indication. Results: Eleven studies were suitable. Devices were applied for a range of indications, including pain, cognitive dysfunction, wound healing, diabetic macular edema, and postprocedural side effects, and were mostly based on near-infrared, pulsed light-emitting diodes with dosages within WALT recommendations. Regarding efficacy, studies reported mostly positive results. Conclusions: Home-use PBM devices appear to mediate effective, safe treatments in a variety of conditions that require frequent applications. Conclusive evaluation of their efficacy requires additional, randomized controlled studies.

Understanding the perspectives of forkhead transcription factors in delayed wound healing.

Wound healing is a complex overlapping biological process that involves a sequence of events coordinated by various cells, proteins, growth factors, cytokines and signaling molecules. Recent evidence indicates that forkhead box O1 (FOXO1) transcription factors play an important role in organizing these events to stimulate wound healing. The ubiquitously expressed forkhead box, class O (FOXO) transcription factors act as cell signaling molecules in various transcriptional processes that are involved in diverse cellular activities, including cell death, cell differentiation, DNA repair, apoptosis, and oxidative stress in response to stimuli, and interact with numerous proteins. Due to the activation of FOXO targeted genes, FOXOs are involved in maintaining the balance between oxidative stress and antioxidants. In humans, different isoforms of FOXO namely FOXO1, FOXO3, FOXO4 and FOXO6 are present, however only FOXO1 and FOXO3 possess biological functions such as morphogenesis, maintenance and tissue regeneration. This might make FOXOs an important therapeutic target to enhance wound healing in diabetes, and to avoid over scarring. In spite of extensive literature, little is known regarding the role of FOXO and its relationship in wound healing. This review provides a summary of FOXO proteins and their biological role in wound healing and oxidative stress.

Therapeutic Efficacy of Home-Use Photobiomodulation Devices: A Systematic Literature Review.

OBJECTIVE: Perform systematic literature review on photobiomodulation (PBM) devices used at home for nonesthetic applications. BACKGROUND: Home-use PBM devices have been marketed for cosmetic and therapeutic purposes. This is the first systematic literature review for nonesthetic applications. METHODS: A systematic literature search was conducted for PBM devices self-applied at home at least thrice a week. Two independent reviewers screened the articles and extracted the data. Treatment dosage appropriateness was compared to the World Association for Laser Therapy (WALT) recommendations. The efficacy was evaluated according to the relevant primary end-point for the specific indication. RESULTS: Eleven studies were suitable. Devices were applied for a range of indications, including pain, cognitive dysfunction, wound healing, diabetic macular edema, and postprocedural side effects, and were mostly based on near-infrared, pulsed light-emitting diodes with dosages within WALT recommendations. Regarding efficacy, studies reported mostly positive results. CONCLUSIONS: Home-use PBM devices appear to mediate effective, safe treatments in a variety of conditions that require frequent applications. Conclusive evaluation of their efficacy requires additional, randomized controlled studies.

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

BACKGROUND: 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 µM 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). METHODS: Cell damage was assessed by inverted light microscopy for cell morphology; the Apoptox-Glo triple assay was used for cell viability, caspase activity and identification of cytodamage markers; flow cytometric analysis for cell death pathways and mitochondrial membrane potential; the enzyme linked immunosorbent assay (ELISA) for cytochrome C release; and real-time reverse transcriptase polymerase chain reaction (RT-PCR) array for gene expression. RESULTS: Laser activated-MPDC induced a significant change in morphology of PDT-treated cells, with the appearance of apoptotic like morphological features. An increase in cytotoxicity, caspase activity, cell depolarization and cytochrome C release were identified in PDT-treated cells. Finally, the upregulation of BAX, BCL-2, CASP-2 and ULK-1 genes was observed. CONCLUSION: The MPDC yielded a successful and stable hybrid agent with potent photodynamic abilities.

Therapeutic Potential and Recent Advances of Curcumin in the Treatment of Aging-Associated Diseases.

Curcumin, a low molecular weight, lipophilic, major yellow natural polyphenolic, and the most well-known plant-derived compound, is extracted from the rhizomes of the turmeric (Curcuma longa) plant. Curcumin has been demonstrated as an effective therapeutic agent in traditional medicine for the treatment and prevention of different diseases. It has also shown a wide range of biological and pharmacological effects in drug delivery, and has actively been used for the treatment of aging-associated diseases, including cardiovascular diseases, atherosclerosis, neurodegenerative diseases, cancer, rheumatoid arthritis, ocular diseases, osteoporosis, diabetes, hypertension, chronic kidney diseases, chronic inflammation and infection. The functional application and therapeutic potential of curcumin in the treatment of aging-associated diseases is well documented in the literature. This review article focuses mainly on the potential role of plant-derived natural compounds such as curcumin, their mechanism of action and recent advances in the treatment of aging-associated diseases. Moreover, the review briefly recaps on the recent progress made in the preparation of nanocurcumins and their therapeutic potential in clinical research for the treatment of aging-associated diseases.