Platelet adhesion onto a polystyrene surface under static conditions: role of specific platelet receptors and effect of divalent cations

Abstract

An experimental model was used to elucidate the basic mechanisms involved in the interaction of platelets with an artificial surface. The role of divalent cations and the involvement of specific platelet membrane receptors were evaluated. Isolated platelets were allowed to interact with a polystyrene surface for 20 min in the presence of divalent cations (Ca2+, Mg2+ or Zn2+), a chelating agent (ethylenediaminetetraacetic, EDTA), and specific antibodies to the main platelet receptors, glycoproteins (GP) Ib and IIb-IIIa. The degree of platelet interaction was evaluated using light and electron microscopy. Morphometric analysis was performed to follow up the progression of platelet shape changes after surface activation. Neither Ca2+ nor Mg2+ influenced the number of adherent platelets or the degree of spreading on the polymer. Only Zn2+ induced a statistically significant increase in the rate of platelet adhesion (P<0.01) with higher proportion of fully spread platelets (P<0.01). Chelation of internal pools of divalent cations did not modify the rates of platelet adhesion but prevented platelet spreading. Presence of monoclonal antibodies to GPIb and GP IIb-IIIa did not result in significant differences in the studied parameters. These results suggest that platelet adhesion onto artificial surfaces, in the absence of flow and plasma proteins, is more dependent on cellular motility, where Zn2+ could play an important role, and less dependent on major receptorial mechanisms.

Antibody binding, platelet adhesion, and protein adsorption on various polymer surfaces

“…In comparison to albumin-coated micoplates, contact of platelets directly with artificial surface induced significant increase in the rate of ADP-induced platelet adhesion. This observation, which is consistent with the previous report on platelet adhesion to Thermanox (a polyester that is highly resistant to most chemicals) [10], indicates that platelets are able to undergo substantial response on non-coated plastic surfaces. According to Grunkemeier et al [11], platelet adhesion directly to artificial surfaces, such as glass or polystyrene materials leads to induction of the procoagulant state in platelets and may depend on the surface (for instance, platelet adhesion to glass was about four times higher than to oxygen-treated polystyrene).…”

“…The polymer surfaces used for the aforementioned purposes are the materials synthesized de novo [4] or commercially available surfaces [10], which can be then chemically modified [12]. There are many commercially available polymer surfaces for in vitro applications, manufactured by leading companies or produced by smaller companies.…”

“…According to the particular research question, the observations were made following exposure of proteins (human plasma, serum, mixtures of proteins and purified proteins) [2,8,9] or blood platelets onto artificial surfaces under different conditions [10,11]. Among proteins, fibrinogen appears to be very extensively studied, as it has been recognized as an essential cofactor in platelet adhesion and aggregation [6,9].…”

Effects of single-walled carbon nanotubes on the functions of plasma proteins and potentials in vascular prostheses

“…Platelet activation induces a conformational change in GPIIb/IIIa that exposes a ligand binding site to fibrinogen and other proteins in plasma [13,14]. It is well established that the binding of fibrinogen to the GPIIb/IIIa complex appears to be the final common pathway for platelet aggregation and thrombosis formation.…”

Evaluation of ion release, cytotoxicity, and platelet adhesion of electrochemical anodized 316 L stainless steel cardiovascular stents

“…Perfusions were carried out in flat chambers according to the method already described. 31,32 Treated and untreated alloy metal coverslips were placed in a flat perfusion chamber as a thrombogenic surface. Blood was recirculated through the chamber for 20 min at a shear rate equivalent to 800 s 21 using a peristaltic pump.…”