Thrombogenicity studies on micro/nano topographic surfaces.

Abstract

Platelet adhesion and activation resulting from the interaction between the flowing blood and the surface of foreign material of a medical device or implant are adverse events that lead to the formation of thrombus. The modulation of platelet-surface interactions to increase the thromboresistance of foreign surfaces is therefore a vital aspect in the design of blood-compatible surfaces. In this thesis, the effects of fibrinogen adsorption and subsequent platelet interaction on a variety of surfaces with chemical and topographical structures are investigated.

Carbon nanotubes are initially evaluated due to their promising applications in a variety of biological systems. They are employed as means of topographical features to investigate on the influence topographical effect on platelet interaction with surfaces. Additionally, the influence of surface chemistry was also investigated. Specifically, two different types CNT orientations, namely tip-wise and diameter-wise, are incorporated separately within the polymer matrix and compared to that of a pristine graphite surface with similar surface chemistry. The effect of surface chemistry was evaluated by comparing the results from two material surfaces; graphite and a biodegradable polymer. The results highlight that in addition to chemistry, appropriate topographical surface modifications can be a powerful approach to elicit a low level of platelet response.