title: Photo-induced processes in collagen-hypericin system revealed by fluorescence spectroscopy and multiphoton microscopy.
abstract: Collagen is the main structural protein and the key determinant of mechanical and functional properties of tissues and organs. Proper balance between synthesis and degradation of collagen molecules is critical for maintaining normal physiological functions. In addition, collagen influences tumor development and drug delivery, which makes it a potential cancer therapy target. Using second harmonic generation, two-photon excited fluorescence microscopy, and spectrofluorimetry, we show that the natural pigment hypericin induces photosensitized destruction of collagen-based tissues. We demonstrate that hypericin-mediated processes in collagen fibers are irreversible and may be used for the treatment of cancer and collagen-related disorders.
authors.affiliation: Department of Physics, National Taiwan University, Taipei106, Taiwan.
authors.forename: V
authors.initials: V
authors.lastname: Hovhannisyan
authors.affiliation: Department of Physics, National Taiwan University, Taipei106, Taiwan.
authors.forename: H W
authors.initials: HW
authors.lastname: Guo
authors.affiliation: Multimedia &Programming, European Regional Education Academy, Yerevan, Armenia.
authors.forename: A
authors.initials: A
authors.lastname: Hovhannisyan
authors.affiliation: Neuroscience Center, University of North Carolina at Chapel Hill, NC USA.
authors.forename: V
authors.initials: V
authors.lastname: Ghukasyan
authors.affiliation: Department of Physics, National Taiwan University, Taipei106, Taiwan.
authors.forename: T
authors.initials: T
authors.lastname: Buryakina
authors.affiliation: Department of Physics, National Taiwan University, Taipei106, Taiwan ; yfchen@phys.ntu.edu.tw.
authors.forename: Y F
authors.initials: YF
authors.lastname: Chen
authors.affiliation: Department of Physics, National Taiwan University, Taipei106, Taiwan ; Center for Quantum Science and Engineering, National Taiwan University, Taipei 106, Taiwan.
authors.forename: C Y
authors.initials: CY
authors.lastname: Dong
keywords: (170.3880) Medical and biological imaging; (180.4315) Nonlinear microscopy; (190.1900) Diagnostic applications of nonlinear optics