Laser therapy and Photobiomodulation (PBM) describe the use of coherent light sources (often red or near-infrared) to stimulate, heal, regenerate, and protect tissue that has either been injured, is degenerating, or else is at risk of dying.1 One of the most reproducible effects of PBM is an overall reduction in inflammation, which is particularly important for disorders of the joints, traumatic injuries, lung disorders, and in the brain.2 Clinical studies in patients suffering from the long term effects of traumatic brain injury have reported improvements in executive function, working memory, and sleep.3
There are several known ways that laser light affects cells. The primary light sensors in cells (chromophores) are cytochrome c oxidase in mitochondria (energy producing structures) and calcium ion channels (possibly mediated by light absorption by opsins). Secondary effects of photon absorption include increases in ATP (energy molecule), a brief burst of reactive oxygen species, an increase in nitric oxide, and modulation of calcium levels. Tertiary effects include activation of a wide range of transcription factors leading to improved cell survival, increased proliferation and migration, and new protein synthesis.
Photodynamic therapy (PDT) was discovered more than 100 years ago, and has since become a well-studied therapy for cancer and various non-malignant diseases including infections. PDT uses photosensitizers (PSs, non-toxic dyes) that are activated by absorption of visible light to initially form the excited singlet state, followed by transition to the long-lived excited triplet state. This triplet state can undergo photochemical reactions in the presence of oxygen to form reactive oxygen species (including singlet oxygen) that can destroy cancer cells, pathogenic microbes and unwanted tissue.4 PDT has been shown to be potentially helpful in treating certain types of cancers, especially those that are close to the surface, as well as certain infections5-7.
We have a class IV infrared laser (1-15W at 810 and 980nm wavelengths, and with variable frequency modulation) for musculoskeletal, transcranial and certain PDT apllications and a Weber Endolaser https://webermedical.com/en/clinic/products/weberneedle-endolaser with fibre optic lasers ranging from ultraviolet to blue, green, yellow, red and infrared frequencies which have the potential to be used for various indications, including infections5-7, fatigue, fibromyalgia, inflammatory bowel disease and depression8,9, as well as PDT for superficial (non-melanoma) skin cancers and IV laser therapy10. We also have 2 laser helmets with 250 laser diodes and may be of benefit for traumatic brain injury and some neuro-degenerative conditions11-13.
References
1. Hamblin MR. Shining light on the head: Photobiomodulation for brain disorders. BBA clinical 2016;6:113-124.
2. Hamblin MR. Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS biophysics 2017;4(3):337-361.
3. Hamblin MR. Photobiomodulation for traumatic brain injury and stroke. Journal of neuroscience research 2018;96(4):731-743.
4. Abrahamse H, Hamblin MR. New photosensitizers for photodynamic therapy. The Biochemical journal 2016;473(4):347-364.
5. Dos Santos AF, de Almeida DRQ, Terra LF, Baptista MS, Labriola L. Photodynamic therapy in cancer treatment – an update review. Journal of Cancer Metastasis and Treatment 2019;5:25.
6. Conrado PCV, et al. A systematic review of photodynamic therapy as an antiviral treatment: Potential guidance for dealing with SARS-CoV-2. Photodiagnosis Photodyn Ther. 2021 Jun;34:102221. doi: 10.1016/j.pdpdt.2021.102221.
7. Barra F, Roscetto E, et al. Photodynamic and Antibiotic Therapy in Combination to Fight Biofilms and Resistant Surface Bacterial Infections. Int J Mol Sci. 2015 Aug 28;16(9):20417-30. doi: 10.3390/ijms160920417.
8. Momenzadeh S, Abbasi M, Ebadifar A, Aryani M, Bayrami J, Nematollahi F. The intravenous laser blood irradiation in chronic pain and fibromyalgia. J Lasers Med Sci. 2015 Winter;6(1):6-9. PMID: 25699161
9. Laakso, E.-L.; Ewais, T. A Holistic Perspective on How Photobiomodulation May Influence Fatigue, Pain, and Depression in Inflammatory Bowel Disease: Beyond Molecular Mechanisms. Biomedicines 2023, 11, 1497. doi.org/10.3390/biomedicines11051497
10. Díaz L, Chaple Gil A, et al. The clinical efficacy of intravascular laser irradiation of blood (ILIB): a narrative review of randomized controlled trials. Photodiagn Photodyn Ther 2025;53:104618.
11. Berman MH, Halper JP, Nichols TW, Jarrett H, Lundy A, Huang JH. Photobiomodulation with Near Infrared Light Helmet in a Pilot, Placebo Controlled Clinical Trial in Dementia Patients Testing Memory and Cognition. J Neurol Neurosci. 2017;8(1):176. doi: 10.21767/2171-6625.1000176.
12. Fernandes, F., Oliveira, S., Monteiro, F. et al. Devices used for photobiomodulation of the brain—a comprehensive and systematic review. J NeuroEngineering Rehabil 21, 53 (2024). https://doi.org/10.1186/s12984-024-01351-8
13. Lim L. Traumatic Brain Injury Recovery with Photobiomodulation: Cellular Mechanisms, Clinical Evidence, and Future Potential. Cells. 2024 Feb 23;13(5):385. doi: 10.3390/cells13050385.