SARS-CoV-2 is a pandemic that claimed millions of lives, and to date, there has been no identifiable cure for SARS-CoV- 2. LLLT is a thriving technology used to treat different kinds of conditions that require stimulation of healing, relief of pain and inflammation, and repair of function. LLLT has been used to treat wounds, sports injuries, chronic pain, dermatitis, and hair loss. Although LLLT can treat some medical conditions, it has been observed that it can cause an increase in blood antioxidants and heat shock protein expression. There are many kinds of stress caused by laser irradiation, and how a cell reacts to them depends on the kind and severity of the insult. The aim of this study is to investigate the effect of LLLT on SARS-CoV-2-infected HEK293/ACE2 cells. In this study, biological assays, including MTT assay, cell viability live/dead, green/deep red assay, and reactive oxygen species (ROS) detection assay, were used to determine the effects of laser irradiation on SARS-CoV-2 infected and uninfected HEK293/ACE2. HEK29/ACE2 cells were infected with SARS-CoV-2 and 48 hours post-infection they were subject to laser irradiation. After 24 hours post-irradiation, biological assays were performed. Both infected non-irradiated and irradiated cells displayed signs of cell stress and produced ROS. There were more dead cells observed in infected HEK293/ACE2 cells, while more viable cells were seen in the uninfected irradiated HEK293/ACE2 cells. LLLT can be used to explore the therapeutic qualities of laser light in SARS-CoV-2 research. LLLT can be used to explore the therapeutic effects of laser light in SARS-CoV-2 research.
Low-level laser therapy (LLLT) is a method of exposing cells or tissue to low levels of red and near-infrared light that has a high success rate for the treatment of various ailments. LLLT has been used to treat various diseases, including wounds, spinal cord injuries, and symptoms of viral conditions like blisters caused by the Herpes Simplex Virus. The aims of the study are to investigate the effect of laser irradiation on SARS-CoV-2 infected cells and on uninfected cells using a scanning electron microscope (SEM) and transmission electron microscopy (TEM) as analysis tools. SEM was used to determine the morphological differences caused by laser irradiation on SARS-CoV-2 infected HEK293/ACE2 cells as well as non-irradiated SARS-CoV-2 infected ones. In addition, the results obtained were compared to irradiated and non-irradiated uninfected cells. To further evaluate the effect of irradiation and SARS-CoV-2, the transmission electron microscope (TEM) was used to investigate the changes in the interior of the aforementioned cells. In preparation for SEM and TEM, HEK293/ACE2 cells were infected with SARS-CoV-2 and irradiated with a 640nm laser at different fluences. Following irradiation, the cells were then fixed and mounted. The data obtained using different magnifications in SEM, revealed differences in the occurrence of surface projections and shape of SARS-CoV-2 infected and uninfected cells, and in TEM they display clear difference in the interior structure of both SARS-CoV-2 infected and uninfected HEK29/ACE2 cells irradiated.
SARS-CoV-2 is a new threat to public health due to its increased transmissibility and immune evasion. Angiotensin converting enzyme 2 (ACE2) plays a critical role in SARS-CoV-2 infection as its serve as the virus's major entry receptor in humans. Vaccines have been authorized for emergency use to control the current pandemic and they have greatly reduced the spread of SARS-CoV-2 and mortality rates, nevertheless this coronavirus has shown the ability to endure crucial mutations that increases its infectivity which makes it likely that the virus will continue to mutate and disseminate. There is a need to find and introduce alternative and effective methods of controlling SARS-CoV-2. Notably, low-level laser therapy (LLLT) is a method of exposing cells or tissue to low levels of red and near infrared light which has a high success rate for treatment of other ailments. The aim of the study is to determine for the first time, the effects of LLLT on SARS-CoV-2 infected HEK293/ACE2 cells and compare them to uninfected ones. Both infected and uninfected HEK293/ACE2 cells were irradiated at a wavelength of 640 nm, at different doses. Then, the effects of laser irradiation on the cells and the virus were evaluated using luciferase, cytotoxicity, and cell viability assays. Preliminary results showed that irradiated uninfected cells had no changes in cell viability and cytotoxicity, while there were changes in irradiated infected cells. In addition, laser irradiation caused cell membrane damage in infected cells. Lastly, uninfected irradiated cells showed no luciferase activity while laser irradiation reduced luciferase activity in infected cells.
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