Just as the Na’vi in the film Avatar heal wounds with light beneath the Tree of Souls, ambient light may now be harnessed to help treat skin wounds in humans. A research team led by Professor Sei Kwang Hahn, a master’s student Kyungjoo Jo, and Dr. Seong-Jong Kim in the Department of Materials Science and Engineering and the GraduateSchool of Convergence Science and Technology at POSTECH, has developed, in collaboration with Professor Hyemin Kim’s research team at Konkuk University, a wearable patch that simultaneously promotes wound closure and tissue regeneration using room light or sunlight, without batteries or an external electrical power source. This work has been published online in Advanced Materials , an international journal in materials science.
Various technologies for treating wounds with light have been developed recently. When a wound is exposed to light at a specific wavelength, collagen molecules at the wound interface can be crosslinked, allowing the wound to be closed without conventional sutures or tissue adhesives. This technique is known as photochemical tissue bonding, or PTB. Light can also regulate cellular metabolism and inflammatory responses, thereby promoting rapid tissue repair through a process known as photobiomodulation, or PBM. These approaches are attractive because they may reduce scarring and reduce the need for invasive procedures. The challenge, however, is how to deliver the therapeutic light. Conventional phototherapeutic systems generally rely on externally powered devices such as LEDs, lasers, optical fibers, and batteries. Wearing bulky or tethered equipment for extended periods is particularly difficult on highly visible areas such as the face.
To overcome this limitation, the research team explored a way to use the room light and sunlight that people routinely encounter in everyday life. At the heart of the technology are room light- and sunlight-activatable luminescent particles, or RSLPs, which convert ambient light into the red light required for phototherapy. The researchers developed calcium–strontium sulfide/sulfate-based particles doped with europium (Eu) and thulium (Tm). By engineering defects and heterostructures within the particles, they enabled the particles to absorb light across a broad wavelength range. The resulting particles emit red light at approximately 640 nm, a wavelength suitable for wound treatment. Even when the surrounding light is briefly interrupted, the particles continue to emit an afterglow, much like glow-in-the-dark stars. The red light emitted by the particles activates the photosensitizer chlorin e6, or Ce6, inducing collagen crosslinking at the wound interface and helping seal incisional wounds. At the same time, the red light promotes fibroblast proliferation and cell migration, alleviates inflammation, and supports new tissue formation. In other words, a single light-emitting platform performs two therapeutic functions simultaneously: wound closure and tissue regeneration.
The researchers uniformly embedded the particles within Ecoflex, a highly stretchable silicone elastomer, to create a soft patch that conforms closely to the skin. An adhesive hydrogel layer allows the patch to remain securely attached even as the skin moves, while its light-emitting performance is maintained when the patch is stretched or folded. Simply being exposed to room light or sunlight can therefore provide therapeutic red light without the need for LEDs or batteries.
Animal-model experiments demonstrated clear therapeutic effects. When the patch was applied to incisional wounds for 12 hours, wound closure was accelerated and tissue regeneration was significantly enhanced. Circular wounds also healed more rapidly. In addition, a preliminary human evaluation involving the normal facial skin of healthy adults showed that wearing the patch for only 9 hours improved skin elasticity recovery and reduced visible redness.
This technology points toward a future in which patients can continue postoperative wound care or skin-regeneration treatments as part of their everyday life, rather than remaining dependent on hospital-based equipment. “This study demonstrates that light readily available in the everyday environment can be used to promote wound closure and tissue regeneration simultaneously, without requiring an external electrical power source,” said Professor Sei Kwang Hahn. “With further development, this technology could become a next-generation wearable photomedicine platform that allows patients to conveniently continue wound care outside the hospital.”
This research was supported by the BRIDGE Research Program, the KOBRA Project, the Basic Science Research Program, the Korea Medical Device Development Fund, the B-IRC Program, the Sejong Science Fellowship, and the National Research Facilities and Equipment Center Program of the Korea Basic Science Institute, funded by the Ministry of Science and ICT through the National Research Foundation of Korea.
Advanced Materials
Ambient Light-Activatable Luminescent Particle-Embedded Conformal Patch for Photochemical Tissue Bonding and Photobiomodulated Healing
4-Jul-2026