Human immunodeficiency virus (HIV-1) infection remains a major health problem despite the use of highly active antiretroviral therapy (HAART), which has greatly reduced mortality rates. Due to the unavailability of an effective vaccine and treatment that would completely eradicate the virus in infected individuals, the quest for new therapies continues. Low level laser therapy (LLLT) involves the exposure of cells to low levels of red or infrared light. LLLT has been widely used in different medical conditions, but not in HIV-1 infection. This study aimed to determine the effects of LLLT on HIV-1 infected and uninfected TZM-bl cells. Both infected and uninfected cells were irradiated at a wavelength of 660 nm with different fluences from 2 J/cm to 10 J/cm . Changes in cellular responses were assessed using cell morphology, viability, proliferation, cytotoxicity and luciferase activity assays. Upon data analysis, uninfected irradiated cells showed no changes in cell morphology, viability, proliferation and cytotoxicity, while the infected irradiated cells did. In addition, laser irradiation reduced luciferase activity in infected cells. Finally, laser irradiation had no inhibitory effect in uninfected cells, whereas it induced cell damage in a dose dependent manner in infected cells.

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Viral infections pose significant health challenges globally by affecting millions of people worldwide and consequently resulting in a negative impact on both socioeconomic development and health. Corona virus disease 2019 (COVID-19) is a clear example of how a virus can have a global impact in the society and has demonstrated the limitations of detection and diagnostic capabilities globally. Another virus which has posed serious threats to world health is the human immunodeficiency virus (HIV) which is a lentivirus of the retroviridae family responsible for causing acquired immunodeficiency syndrome (AIDS). Even though there has been a significant progress in the HIV biosensing over the past years, there is still a great need for the development of point of care (POC) biosensors that are affordable, robust, portable, easy to use and sensitive enough to provide accurate results to enable clinical decision making. The aim of this study was to present a proof of concept for detecting HIV-1 pseudoviruses by using anti-HIV1 gp41 antibodies as capturing antibodies. In our study, glass substrates were treated with a uniform layer of silane in order to immobilize HIV gp41 antibodies on their surfaces. Thereafter, the HIV pseudovirus was added to the treated substrates followed by addition of anti-HIV gp41 antibodies conjugated to selenium nanoparticle (SeNPs) and gold nanoclusters (AuNCs). The conjugation of SeNPs and AuNCs to anti-HIV gp41 antibodies was characterized using UV–vis spectroscopy, transmission electron microscopy (TEM) and zeta potential while the surface morphology was characterized by fluorescence microscopy, atomic force microscopy (AFM) and Raman spectroscopy. The UV–vis and zeta potential results showed that there was successful conjugation of SeNPs and AuNCs to anti-HIV gp41 antibodies and fluorescence microscopy showed that antibodies immobilized on glass substrates were able to capture intact HIV pseudoviruses. Furthermore, AFM also confirmed the capturing HIV pseudoviruses and we were able to differentiate between substrates with and without the HIV pseudoviruses. Raman spectroscopy confirmed the presence of biomolecules related to HIV and therefore this system has potential in HIV biosensing applications.

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SARS-CoV-2 is a new threat to public health due to its increased transmissibility and immune evasion. Angiotensinconverting 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.