The effect of incoherent ultraviolet light on the renal capsule tissue using dynamic mechanical analysis and FTIR spectroscopy

Nowadays, mechanical properties of collagenous tissues are improved by physical crosslinking methods like ultraviolet radiation. Collagen as the major structural protein of tissues absorbs far ultraviolet light. There is a tight competition between the two mechanisms of crosslinking and photodegradation during UV irradiation. The occurrence of each depends on the irradiation dose.

In this study, in order to estimate the effect of ultraviolet radiation at 254 nm on collagenous tissue of the renal capsule, mechanical tests including dynamic tensile tests associated with chemical tests i.e. FTIR spectroscopy have been performed.

Samples reach their maximum stiffness until 30 minutes (13.86 J/cm2) irradiation. It means that crosslinking procedure predominates. Increasing the irradiation dose results in photodegradation of the whole tissue. FTIR spectroscopy shows shifting of amide bonds I and II which illustrates the peptide bond destruction in the period of high irradiation.