CONE-AND-PLATE DEVICE FOR THE INVESTIGATION OF PLATELET BIOMATERIAL INTERACTIONS

A device based on the cone-and-plate flow geometry commonly employed f or viscometry was developed for the investigation of cell-surface inte ractions. The cone-and-plate geometry is capable of generating uniform , constant shear-rate flow fields, and control of cone rotational spee d allows for easy variation of fluid shear rate. The current design is adapted for use with any material that is available in the form of a flat plate (film or coating). It also allows for replicate samples (th e same or different surfaces) to be evaluated simultaneously The devic e was tested under varying flow conditions for its ability to measure platelet adhesion from suspensions of washed platelets containing red cells. Collagen- and albumin-coated polymer materials were used as ''s tandard'' surfaces of known platelet reactivity (high and low, respect ively). Adhesion to the collagen-coated surface was measured over a ra nge of shear rate from 0 to 300 s(-1) and times up to 15 min. Platelet adhesion was observed to increase with increasing shear rate and time . Adhesion was significantly higher in the presence of red cells as ha s been observed by others. Effective platelet diffusion coefficients, calculated from the data on adhesion to the collagen surface, increase d with increasing shear rate. Very little platelet adhesion to the alb umin-coated surface, known to be unreactive to platelets, was observed when measured over a 15 min time period at 300 s(-1) shear rate, indi cating that the device itself does not stimulate the platelets in the flow field. The data generated provide validation for this device as a simple means of measuring cell adhesion under controlled flow conditi ons to any smooth surface available in flat plate form. (C) 1997 John Wiley & Sons, Inc.