Photochemical effects and hypericin photosensitized processes in collagen

Yova, D; Hovhannisyan, V; Theodossiou, T

dc.contributor.author	Yova, D	en
dc.contributor.author	Hovhannisyan, V	en
dc.contributor.author	Theodossiou, T	en
dc.date.accessioned	2014-03-01T01:16:56Z
dc.date.available	2014-03-01T01:16:56Z
dc.date.issued	2001	en
dc.identifier.issn	1083-3668	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/14282
dc.subject	collagen	en
dc.subject	gelatin	en
dc.subject	hypericin	en
dc.subject	chlorin e(6)	en
dc.subject	laser photobleaching	en
dc.subject.classification	Biochemical Research Methods	en
dc.subject.classification	Optics	en
dc.subject.classification	Radiology, Nuclear Medicine & Medical Imaging	en
dc.subject.other	Bleaching	en
dc.subject.other	Collagen	en
dc.subject.other	Diagnosis	en
dc.subject.other	Emission spectroscopy	en
dc.subject.other	Fluorescence	en
dc.subject.other	Irradiation	en
dc.subject.other	Laser applications	en
dc.subject.other	Organic polymers	en
dc.subject.other	Ultraviolet spectroscopy	en
dc.subject.other	Hypericin	en
dc.subject.other	Laser photobleaching	en
dc.subject.other	Photosensitized process	en
dc.subject.other	Polycyclic quinone	en
dc.subject.other	Photochemical reactions	en
dc.subject.other	collagen	en
dc.subject.other	drug derivative	en
dc.subject.other	gelatin	en
dc.subject.other	hypericin	en
dc.subject.other	perylene	en
dc.subject.other	radiosensitizing agent	en
dc.subject.other	animal	en
dc.subject.other	article	en
dc.subject.other	cattle	en
dc.subject.other	chemistry	en
dc.subject.other	drug effect	en
dc.subject.other	fluorescence	en
dc.subject.other	laser	en
dc.subject.other	methodology	en
dc.subject.other	photochemistry	en
dc.subject.other	radiation exposure	en
dc.subject.other	solution and solubility	en
dc.subject.other	Animals	en
dc.subject.other	Cattle	en
dc.subject.other	Collagen	en
dc.subject.other	Fluorescence	en
dc.subject.other	Gelatin	en
dc.subject.other	Lasers	en
dc.subject.other	Perylene	en
dc.subject.other	Photochemistry	en
dc.subject.other	Radiation-Sensitizing Agents	en
dc.subject.other	Solutions	en
dc.title	Photochemical effects and hypericin photosensitized processes in collagen	en
heal.type	journalArticle	en
heal.identifier.primary	10.1117/1.1331559	en
heal.identifier.secondary	http://dx.doi.org/10.1117/1.1331559	en
heal.language	English	en
heal.publicationDate	2001	en
heal.abstract	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/cm(2), respectively. This process of collagen fluorophores photodestruction was found to be a one-photon effect. The effect of hypericin (HYP), a polycyclic quinone, photosensitization on collagen was also studied. Addition of HYP aqueous solution to collagen produced quenching, redshift of the maximum, and broadening of the spectral form of its fluorescence. These effects became more prominent with increasing HYP concentration. The fluorescence of HYP sensitized collagen decreased in a spectrally nonproportional manner during laser irradiation at both 355 and 532 nm. (C) 2001 Society of Photo-Optical Instrumentation Engineers.	en
heal.publisher	Society of Photo-Optical Instrumentation Engineers, Bellingham, WA, United States	en
heal.journalName	Journal of Biomedical Optics	en
dc.identifier.doi	10.1117/1.1331559	en
dc.identifier.isi	ISI:000166802700006	en
dc.identifier.volume	6	en
dc.identifier.issue	1	en
dc.identifier.spage	52	en
dc.identifier.epage	57	en