title: Riboflavin-sensitized photo-crosslinking of collagen using a dental curing light.
abstract: BACKGROUND
  Photo-crosslinking of biomolecules such as collagen and fibrinogen is an emerging area of research interest. The use of a small dental curing light with a non-toxic photosensitizer represents a novel, practical approach to periodontal wound treatment.
  
  
  OBJECTIVE
  This study evaluated the effects of riboflavin-sensitized photo-oxidation using a dental curing light on two collagenous biomaterials, as a preliminary step towards developing a medical technology for wound closure/healing.
  
  
  METHODS
  A collagenous biomaterial (DBP) and type I collagen gels were treated by this photo-oxidative technique and characterized by hydrothermal isometric tension (HIT) analysis, amino acid analysis, SDS-PAGE, and rheology.
  
  
  RESULTS
  HIT analysis suggested that dental curing light exposure for 300 s with riboflavin produced heavily crosslinked DBP. Dental curing light exposure for 300 s with riboflavin also showed a reduction in lysine concentration of DBP. SDS-PAGE showed that dental curing light exposure for 30 or 300 s with riboflavin resulted in crosslinked collagen gels. Dental curing light exposure for 30 s with riboflavin yielded a collagen gel with the strongest rheological characteristics.
  
  
  CONCLUSIONS
  This novel approach to wound treatment has potential for wide adoption and clinical use, particularly because dental curing lights, riboflavin, and collagen biomaterials are all used clinically, but not yet combined together as one technology for broad application.
authors.affiliation: School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada.
authors.forename: Ellen P
authors.initials: EP
authors.lastname: Brennan-Pierce
authors.affiliation: Department of Dental Clinical Sciences, Faculty of Dentistry, Dalhousie University, Halifax, NS, Canada.
authors.forename: Ian
authors.initials: I
authors.lastname: MacAskill
authors.affiliation: Department of Dental Clinical Sciences, Faculty of Dentistry, Dalhousie University, Halifax, NS, Canada.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Price
authors.affiliation: School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Lee
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002417:Cattle; D024042:Collagen Type I / Q000737:chemistry*; D055117:Curing Lights, Dental; D004591:Electrophoresis, Polyacrylamide Gel; D010084:Oxidation-Reduction; D010496:Pericardium / Q000737:chemistry*; D055668:Photochemical Processes; D017319:Photosensitizing Agents / Q000737:chemistry*; D051381:Rats; D012212:Rheology; D012256:Riboflavin / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D001672:Biocompatible Materials; D024042:Collagen Type I; D017319:Photosensitizing Agents; D012256:Riboflavin
keywords: Collagen; crosslink; dental curing light; photo-oxidation; riboflavin