title: PDMS content affects in vitro hemocompatibility of synthetic vascular grafts.
abstract: An unsolved problem when employing small-diameter vascular grafts for aorto-coronary by-pass and peripheral reconstruction is the early thrombotic occlusion. The PEtU-PDMS is a new elastomeric material, composed of poly(ether)urethane and polydimethylsiloxane, synthesized to realize grafts with improved hemocompatibility characteristics. In order to investigate the effect of PDMS content on hemocompatibility, three different percentages of PDMS containing grafts (10, 25 and 40) were evaluated. Grafts realized with Estane 5714-F1 and silicone medical grade tubes were used as references. The hemocompatibility was investigated by an in vitro circuit in which human anticoagulated blood was circulated into grafts by a peristaltic pump modified to obtain a passive flow. For each experiment, 40 cm length graft was closed into a circular loop and put in rotation for 2 h at 37 degrees C. At the end of the experiments different parameters regarding platelet adhesion and activation were evaluated: circulating platelets count, beta-thromboglobulin release, platelet CD62P expression and amount of monocyte-platelet conjugates. PEtU-PDMS grafts with 25 and 40% of PDMS induced the lowest platelet adhesion, plasma level of beta-TG and amount of monocyte-platelet conjugates. No significative variations were observed in CD62P expression. In conclusion, PDMS content significatively affects blood-graft surface interaction, in fact higher PDMS percentage containing grafts showed the best in vitro hemocompatibility.
authors.affiliation: Laboratory for Biomaterials and Graft Technology, Institute of Clinical Physiology CNR, Via Aurelia Sud - Loc. Montepepe, 54100 Massa, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Spiller
authors.forename: Paola
authors.initials: P
authors.lastname: Losi
authors.forename: Enrica
authors.initials: E
authors.lastname: Briganti
authors.forename: Silverio
authors.initials: S
authors.lastname: Sbrana
authors.forename: Silvia
authors.initials: S
authors.lastname: Kull
authors.forename: Ilaria
authors.initials: I
authors.lastname: Martinelli
authors.forename: Giorgio
authors.initials: G
authors.lastname: Soldani
mesh_terms: D000328:Adult; D001672:Biocompatible Materials / Q000737:chemistry*; D001792:Blood Platelets / Q000187:drug effects; D001807:Blood Vessel Prosthesis; D004129:Dimethylpolysiloxanes / Q000737:chemistry* / Q000494:pharmacology*; D006461:Hemolysis; D006801:Humans; D008422:Materials Testing / Q000379:methods; D009000:Monocytes / Q000502:physiology; D009757:Nylons / Q000737:chemistry* / Q000494:pharmacology*; D019007:P-Selectin / Q000378:metabolism; D010973:Platelet Adhesiveness / Q000187:drug effects; D001620:beta-Thromboglobulin / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; D009757:Nylons; D019007:P-Selectin; D001620:beta-Thromboglobulin; C085707:poly(dimethylsiloxane)-polyamide copolymer