[Interaction of platelets with an artificial polystyrene surface under flow conditions: comparative study versus collagen].

PURPOSE

Platelets are known to interact with artificial surfaces, which leads to thrombosis that in turn may hamper repairing surgery. In order to evaluate such interaction, platelet adhesiveness on a polystyrene surface (Thermanox) was studied in an in vitro perfusion model.

MATERIAL AND METHODS

Anticoagulated human blood was recirculated through a plain perfusion chamber containing fragments of the material under study, uncovered and covered with collagen. The studies were performed at a shearing coefficiente of 800 s-1 and with different timing. Additional blood samples were incubated with an anti- GPIIb-IIIa antibody. Platelet deposition on the perfused material was morphometrically evaluated with a computerized system of image analysis.

RESULTS

The values attained, expressed as percent surface covered by platelets over the uncovered polystyrene surface, at 2, 5, 10 and 20 minutes, were, respectively, as follows: 10.4% +/- 1.83%, 27.04% +/- 2.32%, 36.04% +/- 3.09% and 61.48% +/- 8.86%; for the collagen-covered material these figures were: 35.2% +/- 1.3%, 47.8% +/- 4.2%, 71.7% +/- 2.4% and 73% +/- 3.2%, for similar timing (n = 7 for each group).

CONCLUSIONS

The perfusion method proved useful for evaluating the interaction of platelets with artificial surfaces. These data show their polystyrene surfaces have high reactivity toward platelets and confirm that GPIIb-IIIa plays an important role in this reactivity.