title: Platelet adhesion to photodynamic therapy-treated extracellular matrix proteins.
abstract: Photodynamic therapy (PDT) produces reactive species that alter vascular wall biology and vessel wall proteins. In this study, we examined platelet adhesion to PDT-treated (photosensitizer = Photofrin; fluence 100 J/cm2; lambda = 630 nm) extracellular matrix (ECM), fibrinogen, von Willebrand factor (vWF) and collagen Types I and III, under flow conditions in a recirculating perfusion chamber. Platelet adhesion was quantified by image analysis. The effect of PDT on vWF was assessed by measuring the binding of domain-specific antibodies to treated vWF. PDT significantly decreased platelet adhesion to the ECM, fibrinogen and vWF. However, PDT of collagen resulted in significantly increased platelet adhesion, with large aggregate formation. PDT affected mostly the A1 (glycoprotein [GP]-Ib-binding site), A2 and A3 (collagen-binding site) domains of vWF but not the D'-D3 (factor VIII-binding site) and B-C1 (GP-IIb/IIIa-binding site) domains. In conclusion, PDT can alter the ECM, resulting in decreased platelet adhesion. However, vessels with high collagen content, such as veins and small arteries, may become increasingly prone to thrombosis. The results of this study may thus play a role in understanding the thrombogenic properties and mechanisms of vascular PDT.
authors: Department of Vascular Surgery, University Hospital Utrecht, The Netherlands. pfungaloi@hotmail.com
authors: Patrick
authors: P
authors: Fungaloi
authors: Randolph
authors: R
authors: Statius van Eps
authors: Ya-Ping
authors: YP
authors: Wu
authors: Jan
authors: J
authors: Blankensteijn
authors: Phillip
authors: P
authors: de Groot
authors: Hero
authors: H
authors: van Urk
authors: Richard
authors: R
authors: van Hillegersberg
authors: Glenn
authors: G
authors: LaMuraglia
mesh_terms: D001792:Blood Platelets / Q000166:cytology*; D002448:Cell Adhesion; D002478:Cells, Cultured; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D010778:Photochemotherapy; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D014841:von Willebrand Factor; D005340:Fibrinogen