Hypericin-Mediated Selective Photomodification Of Connective Tissues

Controllable modification of biological molecules and supramolecular components of connective tissue are important for biophysical and biomedical applications. Through the use of second harmonic generation imaging, two-photon fluorescence microscopy, and spectrofluorimetry, we found that hypericin, a natural pigment, induces photosensitized destruction of collagen fibers but does not affect elastic fibers and lipids in chicken tendon, skin, and blood vessels. We demonstrated the dynamics and efficiency of collagen photomodification and investigated mechanisms of this processes. Our results suggest that hypericin-mediated photoprocesses in biological tissues may be useful in biomedical applications that require selective modification of connective tissues. (C) 2014 AIP Publishing LLC.