Adhesion of macrophages on collagen irradiated with ultraviolet light

Properties of collagen irradiated with ultraviolet (UV) light were examined using the techniques of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, spectroscopic measurements, and cell adhesion assay. Both photopolymerization and photodegradation of the collagen appeared to occur with UV irradiation because the aggregation of collagen and disintegration of the triple-helical structure were observed. The formation of the cross-links between the tyrosine residues in collagen by photoreaction was presumed. The adhesion of macrophages (Mphis) on a polystyrene plate was suppressed by coating the plate surface with collagen. Anti-adhesive activity of collagen on Mphi cells decreased with UV irradiation. However, appreciable anti-adhesive activity remained in the modified collagen even when collagen was irradiated with UV light for 24 h.