Photobiomodulation and Wound Healing: What Happens Beneath the Surface?
When we watch a cut or injury heal, the most obvious change is that the wound gradually becomes smaller. But underneath the surface, something much more complex is happening.
Skin cells have to migrate into the injured area, rebuild the protective outer layer, regulate inflammation, produce and reorganize collagen, and gradually remodel the damaged tissue.
A recent preclinical study explored how photobiomodulation supports wound healing across several of these processes. The findings suggest that light may do more than help a wound close. It may influence how the tissue organizes the repair itself.¹
Photobiomodulation Accelerated Early Wound Closure
Researchers created paired full-thickness skin wounds in mice. One wound received daily photobiomodulation treatment, while the other remained untreated. From Day 5 through Day 11, the treated wounds consistently showed greater closure. At Day 7:
- 75.84% of the photobiomodulation-treated wound had closed
- 64.88% of the untreated wound had closed¹
That is a difference of nearly 11 percentage points. By Day 15, both groups were approaching complete closure, suggesting that photobiomodulation had its most noticeable effect during the earlier stages of wound repair.
Helping Skin Cells Move Into the Wound
A key part of wound healing is re-epithelialization, the process of rebuilding the skin barrier over the damaged area. Keratinocytes, the main cells in the outer layer of our skin, play a central role. After an injury, they have to activate and migrate from the edges of the wound toward the centre.
In laboratory experiments using human keratinocyte cells, photobiomodulation significantly accelerated this migration at 48 and 72 hours. Importantly, the treatment did not appear to damage the cells or interfere with their ability to grow.¹ When researchers examined the mouse wounds, they saw similar signs of increased activity. Treated wounds showed stronger markers of keratinocyte proliferation and earlier rebuilding of the epidermis.
Healing Continues Beneath the Surface
Closing the skin is only part of wound repair. The tissue underneath also has to rebuild its structure, and collagen plays a major role in that process. Compared with untreated wounds, the photobiomodulation-treated tissue showed:
- Earlier collagen maturation
- Better-organized collagen fibres
- Improved dermal structure
- Reduced inflammatory activity
- Changes in genes involved in tissue growth and remodelling¹
The researchers also found lower expression of an inflammatory signal called interleukin-6 during the early healing period. Inflammation itself is not a bad thing. It is an essential part of wound healing. The problem arises when the inflammatory phase continues for too long and interferes with rebuilding.
The findings therefore suggest photobiomodulation helps support the transition from inflammation into regeneration, rather than simply suppressing inflammation altogether.
Healing Is About Timing
One of the more interesting findings came later in the study. By Day 15, some markers of keratinocyte activation were lower in the photobiomodulation-treated wounds than in untreated wounds.
The researchers suggest this may be because the treated wounds were already further along in the repair process. The cells had become active earlier, helped rebuild the skin, and were beginning to settle again.
It is a useful reminder that healing is not simply about stimulating more activity. It is about coordination, something that photobiomodulation helps influence¹:
Cell migration → re-epithelialization → inflammation regulation → collagen organization → tissue remodelling
This research is promising, and the study gives us is a deeper understanding of how photobiomodulation may interact with the body’s natural repair processes, from the movement of individual skin cells to the organization of the collagen beneath them.
🌿
We’ll continue following the research as scientists learn more about photobiomodulation, tissue repair, and wound healing. If you’re recovering from an injury or curious about whether light therapy could complement your current care, connect with the RegenClinic team. We’re always happy to answer your questions.
Call or text us at 250-208-4218
Email: hello@regenclinic.ca