UVA-photoactivated riboflavin effect on isolated vaginal tissues derived from pelvic organ prolapse cases

Purpose: 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.

Conclusion: 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.