Photochemical effects and hypericin photosensitized processes in collagen.

@article{Yova2001PhotochemicalEA,
  title={Photochemical effects and hypericin photosensitized processes in collagen.},
  author={Dido Yova and Vladimir A. Hovhannisyan and Theodossis A. Theodossiou},
  journal={Journal of biomedical optics},
  year={2001},
  volume={6 1},
  pages={
          52-7
        }
}
Emission and excitation spectra of collagen were recorded in the ultraviolet and visible regions. The existence of several types of chromophores absorbing and emitting throughout these spectral regions was observed. It was shown that laser irradiation at 355 and 532 nm caused collagen fluorescence photobleaching by 30%, when the delivered light doses were 9 and 18 J/cm2, respectively. This process of collagen fluorophores photodestruction was found to be a one-photon effect. The effect of… 
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An innovative photochemical crosslinking process was able to produce collagen scaffolds with fine microstructures; to strengthen, stiffen, and stabilize collagen membranes; and to modify their swelling ratio, which may broaden the use of collagen-based scaffolds in tissue engineering, particularly for weight-bearing tissues.
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