A micro-fluidic study of whole blood behaviour on PMMA topographical nanostructures

Abstract

BackgroundPolymers are attractive materials for both biomedical engineering and cardiovascular applications. Although nano-topography has been found to influence cell behaviour, no established method exists to understand and evaluate the effects of nano-topography on polymer-blood interaction.ResultsWe optimized a micro-fluidic set-up to study the interaction of whole blood with nano-structured polymer surfaces under flow conditions. Micro-fluidic chips were coated with polymethylmethacrylate films and structured by polymer demixing. Surface feature size varied from 40 nm to 400 nm and feature height from 5 nm to 50 nm. Whole blood flow rate through the micro-fluidic channels, platelet adhesion and von Willebrand factor and fibrinogen adsorption onto the structured polymer films were investigated. Whole blood flow rate through the micro-fluidic channels was found to decrease with increasing average surface feature size. Adhesion and spreading of platelets from whole blood and von Willebrand factor adsorption from platelet poor plasma were enhanced on the structured surfaces with larger feature, while fibrinogen adsorption followed the opposite trend.ConclusionWe investigated whole blood behaviour and plasma protein adsorption on nano-structured polymer materials under flow conditions using a micro-fluidic set-up. We speculate that surface nano-topography of polymer films influences primarily plasma protein adsorption, which results in the control of platelet adhesion and thrombus formation.

Influence of the fiber diameter and surface roughness of electrospun vascular grafts on blood activation

“…Our findings with electrospun fibers thus agree with conclusion derived from utilizing other types of surface topographies: it has been widely observed that platelet adhesion and blood reaction both depend on surface roughness [48][49][50][51][52], and that platelet adhesion and blood activation are also affected by other defined surface topographies, i.e. pillars [53], lenses [54] and struts [55].…”

Glue masquerading as a catheter: Retrieval of embolized vertebroplasty cement

“…[2] The rationale for anticoagulation is to prevent thrombus formation on the foreign body until the it endothelizes. [8] The optimal duration of treatment has not been defined. One case report presented evidence of thrombus attached to bone cement retrieved from the right atrium nearly five years post vertebroplasty.…”

Well plate microfluidic system for investigation of dynamic platelet behavior under variable shear loads

“…It is the latter three points that have been lacking in previous microfluidic vascular platforms. Most works have focused on a single channel or small (up to 6) arrays that require manual tubing-to-chip connections (Gutierrez et al, 2008;Ku et al, 2008;Maloney et al, 2010;Minelli et al, 2008;Okorie and Diamond, 2006;Sarvepalli et al, 2009). Additionally, because the working lifespan of a fresh blood draw is often short (minutes to hours depending on the type of anti-coagulant treatment used), any optimized device would allow for a large number of samples to be queried quickly and preferably simultaneously with minimal device preparation (Dong, 2009).…”

“…Several microfluidic designs systems have been used to investigate various conditions of matrix deposition, shear flow, and online agonist addition (Gutierrez et al, 2008;Ku et al, 2008;Lincoln et al, 2010;Maloney et al, 2010;Minelli et al, 2008;Okorie and Diamond, 2006;Sarvepalli et al, 2009). Advantages of microfluidic systems for vascular studies include low reagent consumption (especially important for murine and pediatric samples, where sample volumes are limited), physiologically relevant channel dimensions, the promise of quick sample-to-result, accurate flow control, easy fluidics interfacing, and the opportunity for highly parallel studies.…”