Mimicking arterial thrombosis in a 3D-printed microfluidic in vitro vascular model based on computed tomography angiography data

Abstract

Arterial thrombosis is the main instigating factor of heart attacks and strokes, which result in over 14 million deaths worldwide every year. The mechanism of thrombosis involves factors from the blood and the vessel wall, and it also relies strongly on 3D vessel geometry and local blood flow patterns. Microfluidic chipbased vascular models allow controlled in vitro studies of the interaction between vessel wall and blood in thrombosis, but until now, they could not fully recapitulate the 3D geometry and blood flow patterns of real-life healthy or diseased arteries. Here we present a method for fabricating microfluidic chips containing miniaturized vascular structures that closely mimic architectures found in both healthy and stenotic blood vessels. By applying stereolithography (SLA) 3D printing of computed tomography angiography (CTA) data, 3D vessel constructs were produced with diameters of 400 μm, and resolution as low as 25 μm. The 3D-printed templates in turn were used as moulds for polydimethylsiloxane (PDMS)-based soft lithography to create microfluidic chips containing miniaturized replicates of in vivo vessel geometries. By applying computational fluid dynamics (CFD) modeling a correlation in terms of flow fields and local wall shear rate was found between the original and miniaturized artery. The walls of the microfluidic chips were coated with human umbilical vein endothelial cells (HUVECs) which formed a confluent monolayer as confirmed by confocal fluorescence microscopy. The endothelialised microfluidic devices, with healthy and stenotic geometries, were perfused with human whole blood with fluorescently labeled platelets at physiologically relevant shear rates. After 15 minutes of perfusion the healthy geometries showed no sign of thrombosis, while the stenotic geometries did induce thrombosis at and downstream of the stenotic area. Overall, the novel methodology reported here, overcomes important design limitations found in typical 2Dwafer-based soft lithography microfabrication techniques and shows great potential for controlled studies of the role of 3D vessel geometries and blood flow patterns in arterial thrombosis.

MineLoC: A Rapid Production of Lab-on-a-Chip Biosensors Using 3D Printer and the Sandbox Game, Minecraft

“…Kitson et al and Symes et al [ 4 , 5 ] proposed a 3D printed device for a chemical reactor. Costa et al [ 6 ] and Lind et al [ 7 ] successfully recreated 3D architecture of vascular and muscular tissue, respectively. Other 3D-printed designs also succeeded in lowering the cost of particle/cell detection [ 8 , 9 ], developing micro-scale culture devices [ 10 , 11 ], and achieving minimally invasive biopsy via bio-inspired conformal microfluidic device directly interfacing with the whole organ [ 12 ].…”

Biofabrication Strategies and Engineered In Vitro Systems for Vascular Mechanobiology

“…Adapted with permission. [ 335 ] Copyright 2017, The Royal Society of Chemistry. Abbreviations—tPA, tissue plasminogen activator, vWF, von Willebrand factor.…”

“…[ 334,336 ] Several microfluidic systems have been developed to model stenosis‐induced thrombosis and thrombolysis and have shed light on underlying hemodynamic forces and signaling mechanisms driving these events (Figure 8). [ 333,335,337,338 ] For example, a sudden increase in sheer magnitude at a stenotic site activates platelets in response to endothelial vWF secretion and integrin‐mediated adhesion and aggregation along the decreasing shear gradient via restructuring of filamentous platelet tethers. [ 334,336 ] This principle can also be applied in designing microfluidic devices with stenosed flow geometries that can be used for real‐time evaluation of clotting function with small blood volumes.…”

Recreating Physiological Environments In Vitro: Design Rules for Microfluidic‐Based Vascularized Tissue Constructs

“…By printing structural support negatives for growing cells that can later be broken down or left incorporated into the construct, this method can be useful for developing millimeter‐range diameter vessels. By using stereolithography, Costa et al developed a 3D model of an arteriole vessel which was used as a sacrificial mold for casting PDMS . After PDMS curing, the arteriole was developed simply by breaking the 3D printed mold and removing its vessel parts using forceps, leaving an open channel inside the PDMS with the majority of the channel diameter being 400 µm.…”