Ultraviolet-A Light and Negative Pressure Wound Therapy to Accelerate Wound Healing and Reduce Bacterial Proliferation

Background: Ultraviolet-A therapy is a simple, inexpensive, and effective modality for wound healing with tremendous potential to improve healing and reduce clinical infections in several clinical settings. To date, application of UV-A relies on bulky and hard to dose lamps that provide inconsistent therapy, thus making it difficult to apply therapy that is appropriate for the patient. Methods: This study was designed to test the effectiveness of a novel wound therapy device that combines UV-A with traditional negative pressure wound therapy to promote wound healing. Further, we tested the ability of fiber optic UV-A delivery to inhibit bacterial proliferation. Finally, we assayed the level of DNA damage that results from UV-A as compared to established UV-C therapies. Wound healing studies were performed in a porcine model using an articulated therapy arm that allows for continued therapy administration over an extended time course. Negative pressure wound therapy was administered alone or with ultraviolet-A fiber optic therapy for 2 weeks. Dressings were changed twice a week at which time wound area was assessed. Results: Data demonstrate that UV-A with NPWT treatment of wounds results in greater healing than NPWT alone. Using the same therapy device, we demonstrate that exposure of Staphylococcus aureus and Pseudomonas aeruginosa to fiber optic UV-A results in decreased colony area and number of both bacterial strains. Finally, we show that UV-A induces minimal DNA damage in human fibroblasts and no more DNA damage in wound tissue as compare to intact skin. Conclusions: These data demonstrate that UV-A can decrease bacterial proliferation and promote wound healing when coupled with NPWT.

Corresponding Author; email: kathryn.davis@utsouthwestern.edu