Ambient-light patch speeds wound healing in animals

Under ordinary room light, a soft patch developed by researchers at POSTECH and Konkuk University begins emitting red light without a battery, cable or external power source. In tests, the device helped wounds close while also supporting the growth of new tissue.

The key is a material called RSLP, short for room-light- and sunlight-activatable luminescent particles. Embedded in stretchable Ecoflex silicone, calcium-strontium sulfide/sulfate particles doped with europium and thulium absorb a broad range of ambient light and emit red light at approximately 640 nm. Their brief afterglow continues even when the surrounding light is interrupted. An adhesive hydrogel keeps the patch attached as skin moves, while its light emission remains functional when the patch is stretched or folded.

The emitted light activates chlorin e6, or Ce6, a photosensitizer that triggers collagen crosslinking at the wound interface. That is photochemical tissue bonding, or PTB: a way to seal an incision without conventional sutures or tissue adhesives. The same light also drives photobiomodulation, or PBM, by promoting fibroblast proliferation and cell migration, alleviating inflammation and supporting new tissue formation.

The results so far are early. In animal-model experiments, wounds treated with the patch for 12 hours closed faster and showed significantly enhanced tissue regeneration; circular wounds also healed more rapidly. A preliminary human evaluation involved the normal facial skin of healthy adults, not postoperative or traumatic wounds, and found improved skin elasticity recovery and reduced visible redness after nine hours.

So what does it change in practice? If further development confirms these results, postoperative care or skin-regeneration treatment could move beyond hospital equipment: a patient might wear a conformal patch while exposed to everyday room light or sunlight. For now, the evidence supports a research prototype, and the published work does not establish routine clinical use.