title: UVA-photoactivated riboflavin effect on isolated vaginal tissues derived from pelvic organ prolapse cases.
abstract: OBJECTIVE
  To determine the optimal riboflavin exposure time before UVA irradiation and to study the effects of exogenous collagen on the mechano-tensile stiffness of isolated vaginal tissue strips after riboflavin UVA photoactivation.
  
  
  METHODS
  Vaginal tissue strips from pelvic organ prolapse (POP) cases were soaked in 0.1% riboflavin (0, 10, 20, 30 min), exposed to UVA photoactivation, and tensile stiffness was measured with a tensiometer. Collagen solution was injected (0.2 mL) into each strip, exposed to riboflavin with or without UVA photoactivation, and tensile stiffness was measured (n=6).
  
  
  RESULTS
  Vaginal tissues treated with riboflavin for 10, 20 or 30 min followed by UVA irradiation displayed 21.2, 32.4 and 33.9% stronger tensile stiffness, respectively. Exogenous collagen administered before riboflavin UVA photoactivation resulted in 20% improvement in tensile stiffness. The tensile stiffness of vaginal tissues injected with collagen without the riboflavin UVA treatment was similar to control tissues.
  
  
  CONCLUSIONS
  The results demonstrated increased tensile stiffness in isolated POP-derived vaginal tissues after riboflavin UVA photoactivation suggesting improved mechanical properties from collagen cross-linking. Administering exogenous collagen before riboflavin UVA treatment also improved tensile stiffness. More studies are needed to corroborate the present minimally invasive approach for strengthening vaginal tissues.
authors.affiliation: Department of Gynecology and Obstetrics, Loma Linda University School of Medicine, 11370 Anderson Street, Suite 3950, Loma Linda, CA, 92354, USA.
authors.forename: Kimberly S
authors.initials: KS
authors.lastname: McMillan
authors.forename: Sam
authors.initials: S
authors.lastname: Siddighi
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Hardesty
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Yune
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Chan
mesh_terms: D000328:Adult; D003094:Collagen / Q000737:chemistry / Q000494:pharmacology*; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D004548:Elasticity / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D056887:Pelvic Organ Prolapse / Q000503:physiopathology / Q000628:therapy; D012256:Riboflavin / Q000494:pharmacology*; D013718:Tensile Strength / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects; D013997:Time Factors; D014466:Ultraviolet Rays; D014621:Vagina / Q000187:drug effects* / Q000503:physiopathology / Q000528:radiation effects
chemical_list: D003432:Cross-Linking Reagents; D003094:Collagen; D012256:Riboflavin