Ultraviolet Radiation in Wound Care: Sterilization and Stimulation

Significance: Wound care is an important area of medicine considering the increasing age of the population who may have diverse comorbidities. Lightbased technology comprises a varied set of modalities of increasing relevance to wound care. While low-level laser (or light) therapy and photodynamic therapy both have wide applications in wound care, this review will concentrate on the use of ultraviolet (UV) radiation. Recent Advances: UVC (200-280 nm) is highly antimicrobial and can be directly applied to acute wound infections to kill pathogens without unacceptable damage to host tissue. UVC is already widely applied for sterilization of inanimate objects. UVB (280-315 nm) has been directly applied to the wounded tissue to stimulate wound healing, and has been widely used as extracorporeal UV irradiation of blood to stimulate the immune system. UVA (315-400 nm) has distinct effects on cell signaling, but has not yet been widely applied to wound care. Critical Issues: Penetration of UV light into tissue is limited and optical technology may be employed to extend this limit. UVC and UVB can damage DNA in host cells and this risk must be balanced against beneficial effects. Chronic exposure to UV can be carcinogenic and this must be considered in planning treatments. Future Directions: New high-technology UV sources, such as light-emitting diodes, lasers, and microwave-generated UV plasma are becoming available for biomedical applications. Further study of cellular signaling that occurs after UV exposure of tissue will allow the benefits in wound healing to be better defined.