Blood platelet adhesion to protein studied by on-line acoustic wave sensor

Abstract

The attachment of blood platelets to the surface of bare and protein-coated thickness-shear mode acoustic wave devices operating in a flow-through configuration has been studied. Platelets in washed from bind to the gold electrodes of such sensors, but the resulting frequency shifts are far less than predicted by the conventional mass-based model of device operation. Adherence to albumin and various types of collagen can be produced by on-line introduction of protein or by a pre-coating strategy. Differences in attachment of platelets to collagen types I and IV and the Horm variety can be detected. Platelets attached to collagen yield an interesting delayed, but reversible signal on exposure to a flowing medium of low pH. Scanning electron microscopy of sensor surfaces at various time points in this experiment reveals that originally intact platelets are eventually destroyed by the high acidity of the medium. The reversible frequency is attributed to the presence of removable platelet granular components at the sensor-liquid interface.

Platelet aggregation monitoring with a newly developed quartz crystal microbalance system as an alternative to optical platelet aggregometry

“…28 Admittedly, biological cells like platelets do not comply with these simplifying assumptions, as internal dissipative effects and trapped water in the adherent cell layers can interfere with the calculated mass determination. Previous publications concerning platelet adhesion on acoustic wave sensors 29 have found similar outcomes. In addition to that the penetration depth of acoustic wave into the bulk medium has a maximum of about 179 nm, 16 which is shorter than the diameter of a biological cell.…”

Real-time monitoring of adhesion and aggregation of platelets using thickness shear mode (TSM) sensor

“…TSM sensors operating at 5 or 9 MHz, and coated with collagen, were shown to be sensitive to platelet adhesion using whole blood, platelet-rich plasma, or platelet/blood/cell suspensions. However, developing a sensor that is specific for platelet adhesion/aggregation using whole blood will not be simple, because plasma flowing over the sensor contributes to rapid changes of the sensor signal due to protein adsorption, the magnitude of which is similar to adherent platelets (Cavic et al, 2001). It is also unclear how these sensors can differentiate between inhibited platelet adhesion, activation, and aggregation.…”

A survey of the 2001 to 2005 quartz crystal microbalance biosensor literature: applications of acoustic physics to the analysis of biomolecular interactions

“…For example Andersson et al (2003) found that epithelial cells did not adhere to a supported phospholipid bilayer, but did adhere and proliferate on SiO 2 , tissue culture glass and TiO 2 . Adhesion of platelets to bare and protein pre-coated surfaces was studied both by QCM and by scanning electron microscopy, which showed that positive frequency shifts observed during adhesion were due to the loss of platelet granular components in the low pH media used in the study (Cavic et al, 2001).…”