Direct Assessment of Platelet Adhesion to Glass: A Study of the Forces of Interaction and the Effects of Plasma and Serum Factors, Platelet Function, and Modification of the Glass Surface

Platelet adhesion to glass has beendirectly determined with a cover slipchamber. These studies have separated the functions of platelet adhesionto a foreign surface from platelet cohesion (aggregation). The forces ofthe platelet-glass interaction have beenstudied, and the qualitative variablesaffecting this interaction have beendefined. Fibrinogen and calcium ormagnesium are required for adhesionof either unwashed or washed platelets in plasma. Platelet adhesion infresh serum requires thrombin andprobably the fibrinogen of the plateletsurface, since washed platelets arenot adherent in fresh serum. Plateletsincubated at 37°C for 48 hr can neitherspread nor adhere to glass, a defectthat may reflect decreased plateletsurface area and membrane deformability. Platelets are equally asadherent to siliconized glass as to untreated glass surfaces. However, platelets cannot adhere to glass treatedwith the hydrogen-bonding polymer,poly(ethylene oxide). In contrast tosilicone, poly(ethylene oxide)-treatedglass surfaces do not impede bloodcoagulation. These surface propertiesfurther distinguish the two major factors involved in thrombogenesis: platelet adhesion and plasma coagulation.

Submitted on May 29, 1972 Revised on July 7, 1972 Accepted on July 10, 1972