Active wrinkles to drive self-cleaning: A strategy for anti-thrombotic surfaces

The inner surfaces of arteries and veins are naturally anti-thrombogenic, whereas synthetic materials placed in blood contact commonly experience thrombotic deposition that can lead to device failure or clinical complications. Presented here is a bioinspired strategy for self-cleaning anti-thrombotic surfaces using actuating surface topography. For the specific application of prosthetic vascular grafts, the potential of using pulse pressure, i.e. the continual variation of blood pressure between systole and diastole, to drive topographic actuation was investigated. Soft cylindrical tubes with a luminal surface that transitioned between smooth and wrinkled states were constructed. Upon exposure to blood under continual pressure pulsation, these cylindrical tubes also showed reduced platelet deposition versus control samples under the same fluctuating pressure conditions. We speculate that the observed thrombo-resistance behavior is attributable to a biofilm delamination process in which the bending energy within the biofilm overcomes interfacial adhesion. This novel physical strategy to reduce thrombotic deposition may be applicable to several types of medical devices placed into the circulatory system, particularly vascular grafts.