Photoinduced effect of hypericin on collagen and tissues with high collagen content

Yova, D; Theodossiou, T; Hovhannisyan, V

dc.contributor.author	Yova, D	en
dc.contributor.author	Theodossiou, T	en
dc.contributor.author	Hovhannisyan, V	en
dc.date.accessioned	2014-03-01T01:48:42Z
dc.date.available	2014-03-01T01:48:42Z
dc.date.issued	1999	en
dc.identifier.issn	0277786X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/25566
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-0032631382&partnerID=40&md5=f29a1616f63209b2084489a37ab3927d	en
dc.subject.other	Collagen	en
dc.subject.other	Fluorescence	en
dc.subject.other	Second harmonic generation	en
dc.subject.other	Solid state lasers	en
dc.subject.other	Tissue	en
dc.subject.other	Hypericin	en
dc.subject.other	Polycyclic quinone	en
dc.subject.other	Laser tissue interaction	en
dc.title	Photoinduced effect of hypericin on collagen and tissues with high collagen content	en
heal.type	journalArticle	en
heal.publicationDate	1999	en
heal.abstract	The photoinduced effect of hypericin, a polycyclic quinone, on collagen has been investigated. It was found that after laser irradiation at both 532 nm and 337 nm, the spectral form of triple helix structure collagen fluorescence, changed to a spectral profile bearing resemblance to that of its polypeptide single chain counterpart, gelatin, or heated collagen. The effect of Chlorin e6 on collagen was also investigated and proved to be dissimilar to that of hypericin and not indicative of profound structural alterations. Second Harmonic Generation (SHG) of 1064 nm-nanosecond laser radiation in collagen was studied. While it was very efficient for pure collagen, the signal intensity was found to diminish by at least an order of magnitude after hypericin photosensitization or heating. The above noted fluorescence spectral form alteration was also observed in a smaller scale in collagen rich chicken tissue (tendon). Non sensitized chicken tendon tissue exhibited very efficient SHG, unlike skin and artery samples.	en
heal.publisher	Society of Photo-Optical Instrumentation Engineers, Bellingham, WA, United States	en
heal.journalName	Proceedings of SPIE - The International Society for Optical Engineering	en
dc.identifier.volume	3565	en
dc.identifier.spage	174	en
dc.identifier.epage	180	en