Editing Porphyrin (section)

===Photodynamic therapy===
Porphyrins have been evaluated in the context of [[photodynamic therapy]] (PDT) since they strongly absorb light, which is then converted to heat in the illuminated areas.<ref>{{cite encyclopedia|title=Porphyrin conjugates for cancer therapy| vauthors = Giuntini F, Boyle R, Sibrian-Vazquez M, Vicente MG | veditors = Kadish KM, Smith KM, Guilard R |encyclopedia=Handbook of Porphyrin Science|year=2014|volume=27|pages=303–416}}</ref> This technique has been applied in [[macular degeneration]] using [[verteporfin]].<ref name="pmid17636693">{{cite journal | vauthors = Wormald R, Evans J, Smeeth L, Henshaw K | title = Photodynamic therapy for neovascular age-related macular degeneration | journal = The Cochrane Database of Systematic Reviews | issue = 3 | pages = CD002030 | date = July 2007 | pmid = 17636693 | doi = 10.1002/14651858.CD002030.pub3 | url = https://researchonline.lshtm.ac.uk/id/eprint/6367/1/Wormald_et_al-2007-The_Cochrane_library.pdf }}</ref>

PDT is considered a noninvasive cancer treatment, involving the interaction between light of a determined frequency, a photo-sensitizer, and oxygen. This interaction produces the formation of a highly reactive oxygen species (ROS), usually singlet oxygen, as well as superoxide anion, free hydroxyl radical, or hydrogen peroxide.<ref>{{cite journal | vauthors = Price M, Terlecky SR, Kessel D | title = A role for hydrogen peroxide in the pro-apoptotic effects of photodynamic therapy | journal = Photochemistry and Photobiology | volume = 85 | issue = 6 | pages = 1491–1496 | year = 2009 | pmid = 19659920 | pmc = 2783742 | doi = 10.1111/j.1751-1097.2009.00589.x }}</ref> These high reactive oxygen species react with susceptible cellular organic biomolecules such as; lipids, aromatic amino acids, and nucleic acid heterocyclic bases, to produce oxidative radicals that damage the cell, possibly inducing apoptosis or even necrosis.<ref>{{cite journal | vauthors = Singh S, Aggarwal A, Bhupathiraju NV, Arianna G, Tiwari K, Drain CM | title = Glycosylated Porphyrins, Phthalocyanines, and Other Porphyrinoids for Diagnostics and Therapeutics | journal = Chemical Reviews | volume = 115 | issue = 18 | pages = 10261–10306 | date = September 2015 | pmid = 26317756 | pmc = 6011754 | doi = 10.1021/acs.chemrev.5b00244 }}</ref>