EFFECTS OF ULTRAVIOLET-LIGHT ON FIBROBLAST FIBRONECTIN PRODUCTION ANDLATTICE CONTRACTION

Chronic wounds present a tremendous challenge to healthcare providers. New modalities have been developed to treat these wounds, including u ltraviolet light C (UVC). The effects of UVC on naive dermal fibroblas ts were determined, focusing on released and cell-bound fibronectin (F N) and contraction of fibroblast-populated collagen lattices. Fibrobla st cultures (n=15) were established from dermal explants and half of t he third passage cells were irradiated by 187.5 mJoules/cm(2) of 254 n m UV light. The amount of FN released into the medium and the amount b ound to the cell surface was determined. Irradiated fibroblasts exhibi ted less cell-surface bound FN for 14 of the 15 subjects (mean decreas e of 14% +/- 8%), while irradiated cells released more FN into the med ium for all 15 subjects (mean increase of 42% +/- 33%). Lattices const ructed with irradiated cells contracted significantly faster for 12 of the 15 samples (mean change 15% +/- 9%). The increase of FN productio n with UV light exposure and increased rate of lattice contraction may be a potential mechanism by which UVC-irradiated chronic wounds heal.