Photobiomodulation Therapy in Tissue Regeneration

Photobiomodulation therapy harnesses red to near-infrared light to stimulate cellular processes critical for tissue repair and regeneration. At the core of its mechanism is photon absorption by mitochondrial chromophores—chiefly cytochrome c oxidase—leading to enhanced ATP synthesis, transient reactive oxygen species signalling and nitric oxide release. These primary effects trigger downstream activation of transcription factors, promoting cell survival, proliferation, migration and extracellular matrix remodelling. The resultant modulation of inflammatory pathways further supports a pro-regenerative milieu. Clinically, photobiomodulation has been explored across a broad spectrum of indications, from chronic wound healing and musculoskeletal injuries to neural repair and stem cell-based therapies. Parameters such as wavelength, fluence and delivery mode must be carefully optimised to elicit stimulatory rather than inhibitory responses, with emerging spectroscopic techniques offering real-time insights into mitochondrial-haemodynamic coupling.

Research from Nature Portfolio

Studies of human adipose-derived stem cells have shown that blue (420 nm) and green (540 nm) light preferentially drive osteogenic differentiation by activating light-gated calcium channels, upregulating transcription factors RUNX2 and osterix, and increasing osteocalcin expression. In contrast, red (660 nm) and near-infrared (810 nm) wavelengths stimulate proliferation through biphasic increases in ATP and mitochondrial membrane potential. Complementing these cellular findings, broadband near-infrared spectroscopy applied to human forearm tissue has revealed a linear interplay between increases in cytochrome c oxidase concentration and oxygenated haemoglobin during photobiomodulation, demonstrating a tightly coupled mitochondrial-haemodynamic response in vivo.

Photobiomodulation Therapy in Tissue Regeneration publication trend

The graph below shows the total number of articles in photobiomodulation therapy in tissue regeneration across all publications each year (not limited to Nature Index journals).

Technical terms

Photobiomodulation: Non-thermal modulation of cellular function by low-power light in the red to near-infrared spectrum.

Cytochrome c oxidase: Mitochondrial terminal enzyme that absorbs red/NIR light to regulate respiration and energy production.

Reactive oxygen species (ROS): Electrically charged molecules generated during mitochondrial activity that act as secondary messengers.

Osteogenic differentiation: Process by which multipotent stem cells develop into bone-forming osteoblasts under specific stimuli.

Light-gated ion channel: Membrane protein that opens in response to specific wavelengths, permitting ion flux and downstream signalling.

References

1. Modulation of mitochondrial function with near-infrared light reduces brain injury in a translational model of cardiac arrest. Critical Care (2023).
2. Photobiomodulation—Underlying Mechanism and Clinical Applications. Journal of Clinical Medicine (2020).
3. Photobiomodulation (blue and green light) encourages osteoblastic-differentiation of human adipose-derived stem cells: role of intracellular calcium and light-gated ion channels. Scientific Reports (2016).
4. Interplay between up-regulation of cytochrome-c-oxidase and hemoglobin oxygenation induced by near-infrared laser. Scientific Reports (2016).
5. Red (660 nm) or near-infrared (810 nm) photobiomodulation stimulates, while blue (415 nm), green (540 nm) light inhibits proliferation in human adipose-derived stem cells. Scientific Reports (2017).