Abstract
M.Tech. (Biomedical Technology)
The Janus kinase/Signal transducer and activator of transcription (JAK/STAT) signalling pathway is utilised by the majority of growth factors and cytokines to pass extracellular signals to the nucleus for transcription. Growth factors and cytokines are crucial in the regulation of wound healing (Feng et al., 2016) via signalling pathways that induce the closing of wounds, removal of damaged cells, and regeneration of tissue through cell proliferation and migration. Recent literature suggests that JAK/STAT signalling is one of the major signalling pathways for cell proliferation and migration (Fortezza et al., 2016). Binding of Epidermal growth factor (EGF) to its receptor (EGFR) activates JAK, leading to downstream dimer formation of STAT proteins that translocate to the nucleus, where they attach to specific DNA sequences for gene transcription (Mutagenetix, 2016; He et al., 2016). EGF stimulates fibroblast proliferation, growth, migration and differentiation (Bodnar, 2013). Chronic wounds are one of the most debilitating complications related to diabetes mellitus (DM), and are mainly due to peripheral neuropathy, peripheral vascular disease, and immune suppression (Aumiller and Dollahite, 2015), as well as abnormal cellular function and growth factor or cytokine activity (Moura et al., 2013). Chronic wounds, including diabetic ulcers, exhibit reduced EGF, platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) (Pastar et al., 2014; Demidova-Rice et al., 2012).
Photobiomodulation (PBM) uses low power lasers or light-emitting diodes (LEDs) to regulate cellular molecular pathways and function, creating a promising mode of treatment for chronic diabetic wounds. PBM may either accelerate or hinder cellular processes, and is largely influenced by the wavelength and fluence (energy density). PBM is effective in wound healing in the visible red (600–700 nm) and near-infrared (NIR, 700–1,100 nm) spectrum, and the main chromophore associated with these wavelengths is thought to be cytochrome c oxidase (CoX), unit IV in the mitochondrial respiratory chain (Wang et al., 2017). Studies involving the irradiation of human dermal fibroblasts with visible red light at wavelengths of...