title: In vitro short-term platelet adhesion on various metals.
abstract: The in vitro short-term platelet adhesion on various metals, as accelerated by the addition of Ca(2+), was evaluated in this study. Metals used for medical devices [an austenitic stainless steel, a cobalt (Co)-chromium (Cr)-molybdenum (Mo) alloy, a titanium (Ti)-6 aluminum (Al)-4 vanadium (V) alloy, a Ti-6Al-7 niobium (Nb) alloy, a Tinickel (Ni) alloy, and commercially pure Ti] were immersed into a platelet-rich plasma solution for 5 or 20 min, and platelet adhesion and aggregation on the surfaces were observed using a scanning electron microscope. The platelet adhesion level on each metal after 5 min of immersion in a platelet-rich plasma solution was the smallest in this order: stainless steel <or= Co-Cr-Mo alloy < Ti-6Al-4V alloy < Ti-6Al-7Nb alloy < Ti-Ni alloy = Ti. The levels after 5 min of immersion were almost the same as those after 20 min of immersion. Platelet adhesion was minimal on stainless steel and Co-Cr-Mo alloy, which have a Cr(2)O(3)-containing passive surface oxide film, but was accelerated on Ti and Ti alloys having a TiO(2)-containing film. A Cr(2)O(3)-containing oxide film has a lower relative permittivity than a TiO(2)-containing film; it thus supports a larger electrostatic force than the latter, adsorbs more albumins, which work as inhibitory proteins, and inhibits platelet aggregation. Therefore, platelet adhesion and aggregation are controlled by the composition of the surface oxide film on a metal due to the relative permittivity of the metal, which influences the amount of adsorbed proteins.
authors.affiliation: Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Chiyoda-ku, Tokyo, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Kazuya
authors.initials: K
authors.lastname: Kurashima
authors.forename: Haruka
authors.initials: H
authors.lastname: Saito
authors.forename: Akiko
authors.initials: A
authors.lastname: Nagai
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Tsutsumi
authors.forename: Hisashi
authors.initials: H
authors.lastname: Doi
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Nomura
authors.forename: Takao
authors.initials: T
authors.lastname: Hanawa
mesh_terms: D001672:Biocompatible Materials; D001792:Blood Platelets; D008422:Materials Testing; D008670:Metals; D008855:Microscopy, Electron, Scanning; D010973:Platelet Adhesiveness; D010974:Platelet Aggregation; D053657:Platelet-Rich Plasma
chemical_list: D001672:Biocompatible Materials; D008670:Metals