title: Hemodynamic aspects of reduced platelet adhesion on bioinspired microstructured surfaces.
abstract: Occlusion by thrombosis due to the absence of the endothelial cell layer is one of the most frequent causes of failure of artificial vascular grafts. Bioinspired surface structures may have a potential to reduce the adhesion of platelets contributing to hemostasis. The aim of this study was to investigate the hemodynamic aspects of platelet adhesion, the main cause of thrombosis, on bioinspired microstructured surfaces mimicking the endothelial cell morphology. We tested the hypothesis that platelet adhesion is statistically significantly reduced on bioinspired microstructured surfaces compared to unstructured surfaces. Platelet adhesion as a function of the microstructure dimensions was investigated under flow conditions on polydimethylsiloxane (PDMS) surfaces by a combined experimental and theoretical approach. Platelet adhesion was statistically significantly reduced (by up to 78%; p≤0.05) on the microstructured PDMS surfaces compared to that on the unstructured control surface. Finite element method (FEM) simulations of blood flow dynamic revealed a micro shear gradient on the microstructure surfaces which plays a pivotal role in reducing platelet adhesion. On the surfaces with the highest differences of the shear stress between the top of the microstructures and the ground areas, platelet adhesion was reduced most. In addition, the microstructures help to reduce the interaction strength between fluid and surfaces, resulting in a larger water contact angle but no higher resistance to flow compared to the unstructured surface. These findings provide new insight into the fundamental mechanisms of reducing platelet adhesion on microstructured bioinspired surfaces and may lay the basis for the development of innovative next generation artificial vascular grafts with reduced risk of thrombosis.
authors.affiliation: Chair of Materials Science, Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University Jena, Löbdergraben 32, D-07743 Jena, Germany.
authors.forename: Tam Thanh
authors.initials: TT
authors.lastname: Pham
authors.affiliation: Institute for Bioprocessing and Analytical Measurement Techniques, Rosenhof 1, D-37308 Heilbad Heiligenstadt, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Wiedemeier
authors.affiliation: Chair of Materials Science, Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University Jena, Löbdergraben 32, D-07743 Jena, Germany; Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Neugasse 23, D-07743 Jena, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Maenz
authors.affiliation: Institute for Bioprocessing and Analytical Measurement Techniques, Rosenhof 1, D-37308 Heilbad Heiligenstadt, Germany.
authors.forename: Gunter
authors.initials: G
authors.lastname: Gastrock
authors.affiliation: Department of General, Visceral and Vascular Surgery, Jena University Hospital, Erlanger Allee 101, D-07747 Jena, Germany.
authors.forename: Utz
authors.initials: U
authors.lastname: Settmacher
authors.affiliation: Chair of Materials Science, Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University Jena, Löbdergraben 32, D-07743 Jena, Germany; Jena Center for Soft Matter, Friedrich Schiller University Jena, Humboldstr. 10, D-07743 Jena, Germany; Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Neugasse 23, D-07743 Jena, Germany. Electronic address: k.jandt@uni-jena.de.
authors.forename: Klaus D
authors.initials: KD
authors.lastname: Jandt
authors.affiliation: Department of General, Visceral and Vascular Surgery, Jena University Hospital, Erlanger Allee 101, D-07747 Jena, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Zanow
authors.affiliation: Chair of Materials Science, Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University Jena, Löbdergraben 32, D-07743 Jena, Germany; Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Neugasse 23, D-07743 Jena, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Lüdecke
authors.affiliation: Chair of Materials Science, Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University Jena, Löbdergraben 32, D-07743 Jena, Germany; Jena School for Microbial Communication (JSMC), Friedrich Schiller University Jena, Neugasse 23, D-07743 Jena, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Bossert
mesh_terms: D001792:Blood Platelets / Q000502:physiology*; D020342:Finite Element Analysis; D006439:Hemodynamics; D010973:Platelet Adhesiveness / Q000502:physiology*; D013927:Thrombosis
keywords: Artificial vascular grafts; FEM simulation; Flow cell; Platelet adhesion; Thrombosis; Wall shear stress