The Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, was established in 2003. The centre was established under the direction of Prof. Heidi Abrahamse to initiate research in the greatly underutilized area of laser-tissue interaction, in the medical field in South Africa. In 2007 it gained official Research Centre status and in 2016 was awarded a DST/NRF SARChI Chair: Laser Applications in Health. The LRC currently employs 5 staff members and hosts 22 postgraduate students and post-doctorate fellows. The Laser Research Centre investigates phototherapy with specific emphasis on Photobiomodulation (PBM), Photodynamic Therapy (PDT) and Stem Cell Therapy. The therapeutic value of PBM for application in cancer, wound healing and stem cell therapy (regenerative medicine) is explored by evaluating biochemical responses of cells in culture when treated. PDT on the other hand requires the use of a photosensitizer that, upon entry into a cancer cell, is targeted by laser irradiation to set off a series of events that contribute to cancer cell death.
Photobiomodulation involves the application of light, at a particular wavelength and low intensity, to tissue to stimulate biological processes that augments wound healing. These processes include; clotting, inflammation, cell differentiation, migration and proliferation, angiogenesis, tissue granulation formation, re-epithelization, collagen synthesis and tissue re-modelling. Phototherapy has been shown to positively affect the healing process in wounds that are associated with diabetes, amongst other disorders.
PDT involves 3 components; a photochemotherapeutic agent called a photosensitizer (PS), laser light to activate the PS, and oxygen that is converted to reactive oxygen species. These 3 components together induce cell damage leading to the destruction of tumours. Each PS is activated by light of a specific wavelength, this wavelength determines how far the light can travel into the body and, therefore, specific PS and wavelengths of light are used to treat different areas of the body. PDT has fewer side-effects than conventional cancer treatments, it can be done relatively quickly and is less invasive than surgical resection. Specific antibodies in conjugation with nanoparticles and PSs increase the host PS accumulation by targeting tumour cells and ensures specific delivery and enhanced destruction.
Stem Cell Differentiation
Tissue engineering and regenerative medicine is a multi-disciplinary science that has evolved in parallel with recent biotechnological advances that combines biomaterials, growth factors and stem cells to repair organs.
Photobiomodulation induces improved viability and proliferation in stem cells, and enhances their differentiation potential. Autologous grafts of stem cells, obtained from a patient, can be used to induce differentiation into a cell type that can replace diseased tissue.
Cancer Stem Cells
Cancer stem cells may cause tumour recurrence and metastasis. Having similar characteristics to normal stem cells it can differentiate and self-renew, and are found in tumour tissue. Cancer stem cells are typically resistant to conventional cancer therapy. PDT has the potential to target cancer stem cells, and eradicate cancer at the stem cell level.
Phytochemicals & Photodynamic Therapy
Photosensitizing compounds of plant origin are of diverse chemical structure. The combination of photodynamic therapy with other conventional therapies is a novel approach in cancer treatment. The phototoxic effects on cancer cells are analysed with or without conjugating the phytochemicals or plant extracts with known PS. Photosensitizers and phytochemicals can lead to several cell death mechanisms including autophagy, apoptosis and necrosis based on their cellular localization. However, the compounds of plant origin may be active than an existing PS when irradiated with laser of specific wavelength.
Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein, Johannesburg, South Africa, 2028, (Tel): 27 11 559-6406 (Fax): 27 11 559-6884.